Personal development of participants in special Olympics unified sports teams

June 13, 2017 | Autor: Sandra Dowling | Categoria: Human Movement
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University School of Physical Education in Wrocław University School of Physical Education in Poznań University School of Physical Education in Kraków

vol. 13, number 3 (September), 2012

University School of Physical Education in Wrocław (Akademia Wychowania Fizycznego we Wrocławiu) University School of Physical Education in Poznań (Akademia Wychowania Fizycznego im. Eugeniusza Piaseckiego w Poznaniu) University School of Physical Education in Kraków (Akademia Wychowania Fizycznego im. Bronisława Czecha w Krakowie) Human Movement quarterly vol. 13, number 3 (September), 2012, pp. 195 – 292 Editor-in-Chief Alicja Rutkowska-Kucharska University School of Physical Education, Wrocław, Poland Associate Editor

Wiesław Osiński University School of Physical Education, Poznań, Poland Andrzej Klimek University School of Physical Education, Kraków, Poland

Editorial Board Tadeusz Bober Jan Celichowski Lechosław B. Dworak Ewa Kałamacka Tadeusz Koszczyc Stanisław Kowalik Juliusz Migasiewicz Edward Mleczko Łucja Pilaczyńska-Szcześniak Zbigniew Szyguła Aleksander Tyka Marek Zatoń

University School of Physical Education, Wrocław, Poland University School of Physical Education, Poznań, Poland University School of Physical Education, Poznań, Poland University School of Physical Education, Kraków, Poland University School of Physical Education, Wrocław, Poland University School of Physical Education, Poznań, Poland University School of Physical Education, Wrocław, Poland University School of Physical Education, Kraków, Poland University School of Physical Education, Poznań, Poland University School of Physical Education, Kraków, Poland University School of Physical Education, Kraków, Poland University School of Physical Education, Wrocław, Poland

Advisory Board Wojtek J. Chodzko-Zajko Gudrun Doll-Tepper Józef Drabik Kenneth Hardman Andrew Hills Zofia Ignasiak Slobodan Jaric Toivo Jurimae Han C.G. Kemper Wojciech Lipoński Gabriel Łasiński Robert M. Malina Melinda M. Manore Philip E. Martin Joachim Mester Toshio Moritani Andrzej Pawłucki John S. Raglin Roland Renson Tadeusz Rychlewski James F. Sallis James S. Skinner Jerry R. Thomas Karl Weber Peter Weinberg Marek Woźniewski Guang Yue Wladimir M. Zatsiorsky Jerzy Żołądź

University of Illinois, Urbana, Illinois, USA Free University, Berlin, Germany University School of Physical Education and Sport, Gdańsk, Poland University of Worcester, Worcester, United Kingdom Queensland University of Technology, Queensland, Australia University School of Physical Education, Wrocław, Poland University of Delaware, Newark, Delaware, USA University of Tartu, Tartu, Estonia Vrije University, Amsterdam, The Netherlands University School of Physical Education, Poznań, Poland University School of Physical Education, Wrocław, Poland University of Texas, Austin, Texas, USA Oregon State University, Corvallis, Oregon, USA Iowa State University, Ames, Iowa, USA German Sport University, Cologne, Germany Kyoto University, Kyoto, Japan University School of Physical Education, Wrocław, Poland Indiana University, Bloomington, Indiana, USA Catholic University, Leuven, Belgium University School of Physical Education, Poznań, Poland San Diego State University, San Diego, California, USA Indiana University, Bloomington, Indiana, USA University of North Texas, Denton, Texas, USA German Sport University, Cologne, Germany Hamburg University, Hamburg, Germany University School of Physical Education, Wrocław, Poland Cleveland Clinic Foundation, Cleveland, Ohio, USA Pennsylvania State University, State College, Pennsylvania, USA University School of Physical Education, Kraków, Poland

Translation: Michael Antkowiak, Tomasz Skirecki Design: Agnieszka Nyklasz Copy editor: Beata Irzykowska Proofreading: Michael Antkowiak, Anna Miecznikowska Indexed in: SPORTDiscus, Index Copernicus, Altis, Sponet, Scopus 8 pkt wg rankingu Ministerstwa Nauki i Szkolnictwa Wyższego © Copyright 2012 by Wydawnictwo AWF we Wrocławiu ISSN 1732-3991 http://156.17.111.99/hum_mov Editorial Office Secretary: Dominika Niedźwiedź 51-612 Wrocław, al. Ignacego Jana Paderewskiego 35, Poland, tel. 48 71 347 30 51, [email protected] Certyfikat jakości na zgodność z PN-EN ISO 9001:2009 Circulation: 200

HUMAN MOVEMENT 2012, vol. 13 (3)

contents

Stephen Slaughter, Patrick Butler, Heather Capozzella, Amanda Nguyen, Lonn Hutcheson The comparative gait effects of select walking surfaces using kinetic and EMG analyses .............................198 Soraia Cristina Tonon da Luz, Aluisio Otavio Vargas Ávila, Mario César de Andrade, Beatriz Conceição Silva Alves Rodrigues Treadmill gait analysis of rehabilitated and independent lower-limb amputees ............................................ 204 Ihor Zanevskyy, Yuliya Korostylova, Volodymyr Mykhaylov Aiming point trajectory as an assessment parameter of shooting performance..............................................211 Thomas Heinen, Konstantinos Velentzas, Pia M. Vinken Functional relationships between gaze behavior and movement kinematics when performing high bar dismounts – an exploratory study..........................................................................218 Krystyna Zatoń, Stefan Szczepan, Robert Kazimirów, Marek Rejman Advisability on the shift from standard front crawl swimming technique to the “kayaking” and “loping” variants........................................................................................................... 225 Jacek Polechoński, Dorota Olex-Zarychta The influence of tactile feedback on hand movement accuracy....................................................................... 236 Andreia Pelegrini, Maria Fátima Glaner, Edio Luiz Petroski Association between anthropometric indicators and serum lipid profile in adolescents............................... 242 Ireneusz Cichy, Andrzej Rokita The use of the “eduball” educational ball in rural and urban primary schools and the physical fitness levels of children...........................................................................................................247 Bruno Barth Pinto Tucunduva Assessing body culture level and its association with the level of physical activity in university students...........................................................................................................................................258 Hanna Kołoło, Monika Guszkowska, Joanna Mazur, Anna Dzielska Self-efficacy, self-esteem and body image as psychological determinants of 15-year-old adolescents’ physical activity levels............................................................................................ 264 Maciej Wilski, Anna Nadolska, Sandra Dowling, Roy Mcconkey, David Hassan Personal development of participants in Special Olympics unified sports teams............................................271 Renata Osborne Physical education in the decade of education for sustainable development: a study with Brazilian physical education teachers and educators.................................................................. 280 Publishing guidelines – Regulamin publikowania prac....................................................................................... 288

197

HUMAN MOVEMENT 2012, vol. 13 (3), 198– 203

THE COMPARATIVE GAIT EFFECTS OF SELECT WALKING SURFACES USING KINETIC AND EMG ANALYSES doi: 10.2478/v10038-012-0022-5

STEPHEN SLAUGHTER *, PATRICK BUTLER, HEATHER CAPOZZELLA, AMANDA NGUYEN, LONN HUTCHESON Department of Biology, University of Dallas, Dallas, USA

Abstract

Purpose. This study investigated the EMG characteristics of muscles crossing the knee and the kinetics of the lower extremity during side-slope walking and other activities of daily living. We studied the difference in EMG data of the medial gastrocnemius and vastus lateralis muscles bilaterally and the relative rotation of the thigh to leg. Methods. Eleven outdoor workers (47.3 ± 13.9 years old) were recruited for this study. Participants walked on a 0° flat surface, 5° and 10° side-sloped surfaces, 10° inclined treadmill and ascended stairs. The EMG activity and rotation about a vertical axis during stance phase were analyzed. Results. Except for minor variations, ANOVA showed no significant difference in EMG activity between the walking surfaces, furthermore, the relative rotation of thigh-to-leg showed little or no differences between the variables. Multivariate ANOVA showed p-values between 0.1602 and 0.9943 when comparing the EMG data of all side-sloped surfaces. The relative rotation of the thigh to the leg showed p-values of 0.7837 and 0.9813 when comparing the left 0° to 10° and right 0° to 10°, respectively. Conclusions. The results of this study indirectly indicate that when considering rotation about a vertical axis and EMG activity, there is little difference in knee joint loading.

Key words: gait, kinetics, EMG, side-sloped walking surface

Introduction This study was undertaken to determine the electrical activity of the lower extremity skeletal muscles associated with the tibio-femoral joint and the rotational differences between the leg and thigh during gait over different walking surfaces. There is a large amount of research on gait and knee joint effects over level surfaces [1], ascending or descending stairs [2, 3] and on ramps [4, 5]. Knee joint power as a product of joint moments and angular velocity was also shown to have significant increases with extreme (39%) upslope walking. Ground reaction forces and select gait parameters on cross-sloped walking surfaces have also been previously studied. While many activities of daily living (ADL) typically occur on flat surfaces, walking surfaces in physical training, rehabilitation and industrial settings could include slopes of various directions (side, incline and decline) and surfaces of different textures (smooth, gravel, concrete, rocky, etc.). In the lower extremities, research has shown that the quadriceps and gastrocnemius muscles are major contributors to knee joint loading especially during stance phases [6]. In the quadriceps muscle group, the vastus lateralis is the largest component and is inserted on the lateral border of the patella, which then blends with the quadriceps tendon. The gastrocnemius muscle originates near both condyles of the femur and both com-

* Corresponding author. 198

ponents of the muscle course distally to insert on the posterior aspect of the calcaneus bone of the foot [7]. Data have shown axial joint force peak magnitudes during stance phases at 810 N and 860 N for the vastii and gastrocnemius muscles, respectively [8]. The previous study also showed knee joint force during the swing phase to be negligible compared to stance values. It was also reported that the vastus lateralis (VL) and the medial gastrocnemius (GM) produce more force in individuals who experience patellofemoral pain [9]. Wireless inertial measurement units (IMUs) can be used to monitor movement and gait in test subjects. These IMU devices provide data that include acceleration, rotation and magnetic field parameters that go beyond the current wearable units that monitor only acceleration [10]. The quantification of motions of everyday living by using accelerometers can provide useful classification data and include sitting, standing, walking, stair climbing and cycling [11]. The combination of accelerometer and gyroscope data utilizing bodymounted sensors has been demonstrated by measuring knee movement during gait [12]. The accurate and realtime measurement of the posture parameters of human body segments with magnetometers, gyroscopes and accelerometers has been previously demonstrated [13]. Published research concerning the relationship between knee problems and tasks performed at work have shown mixed results. Male farm workers, forestry workers and postal workers have not demonstrated an increased risk of knee osteoarthritis [14]. Previous studies have shown a correlation between the physical

HUMAN MOVEMENT S. Slaughter et al., The comparative gait effects

demands of knee bending/squatting and the development of osteoarthritis [15]. It is possible that there are intervening factors unrelated to the knee that could impact the development of knee problems. A study by Murley et al. [16] looked at foot arch height differences and EMG activity during gait. The research showed only small differences in EMG readings in the GM and did not include the VL muscles. Investigation into the kinetics and muscle activity related to the knees in subjects who walk on a variety of surfaces could help illuminate the resultant effects as well as the potential for these surfaces to lead to knee dysfunction. It was hypothesized for this study that there would be no or little significant difference between the EMG activity of the muscles under investigation when walking on flat, side-sloped, inclined surfaces or when ascending stairs. Furthermore, it was hypothesized that the electrical activity generated by the motor units close to the electrodes would be similar. Since the GM and VL muscles that were tested in each lower extremity of the subjects in this study cross the knee joint and have been shown to contribute significantly to knee joint forces, then walking on these test surfaces may not bring about significant contributions of the four muscles to increased knee joint loading. It was further anticipated that the IMU data may show differences in rotation of the leg relative to the thigh during the stance phase when walking on side-sloped surfaces. Material and methods Gait analysis on varying types of surfaces was performed on 11 healthy adults, eight males and three females (47.3 ± 13.9 years). Participants walked on a plywood platform of 12 meters (length) by 1.2 meters (width) at 0° (flat) and at 5° and 10° of side-slope (sideslope angle measured perpendicular to forward movement). The participants also ascended stairs and walked on a treadmill at a 10° incline. Institutional Review Board approval was obtained prior to the investigations and the informed consent of the participants was obtained. All work conformed to the Declaration of Helsinki principles. The anthropometric data recorded included mean height (166.75 cm ± 8.6) and average weight (84.27 kg ± 19.6). The lower extremities were measured for leg length discrepancy (LLD) and it was determined that two participants had a shorter left lower extremity and two participants had a shorter right lower extremity. A LLD 0.6 cm was classified as significant [17]. Foot arch heights were measured utilizing the navicular bone as a reference and it was determined that only one participant was at the high normal range [18]. For testing, each subject wore a pair of standard leather work boots (Red Wing Shoes, USA, 6-inch, laceup boot). Participants practiced walking on each surface before data collection. Wireless EMG devices (Shimmer

Research, Ireland ) were attached via 15 mm Ag/AgCl surface electrodes spaced 25 mm apart using 200 mm leads. Before attachment, the selected area of skin was swabbed with 70% isopropyl alcohol and allowed to dry. The raw EMG data were collected (1000 Hz) and bandpass filtered (10–500 Hz) to remove motion artifacts. For each subject, the vastus lateralis (VL) and medial head of the gastrocnemius (GM) were palpated bilate­ rally. Electrodes were applied bilaterally to the VL muscle at a midpoint between the greater trochanter and the lateral epicondyle of the femur. For the GM, electrodes were applied bilaterally to the GM at a midpoint between the medial epicondyle of the femur and the medial malleolus. After practice, the isometric maximum voluntary contraction (MVC) of each muscle was recorded for the participant and used as the upper limit in for later calculations. The MVC of the vastus lateralis was tested while the participant was in a seated position and attempted to extend their lower leg against an immovable object. The MVC of the gastrocnemius was recorded simultaneously for both legs with the participant standing on their toes and contracting their muscles. EMG data were synchronized with 300 Hz video recordings to determine gait cycle phases. Wireless IMU devices (MEMSense, USA) were attached to the subject’s lower extremities bilaterally. An IMU device was placed on each thigh of the participant at a midpoint between the greater trochanter and the epicondyle of the femur. Each leg of the participant had an IMU device attached at the midpoint of the condyle and the malleolus of the tibia. The IMU devices have a bandwidth of 150 Hz and provide three axes each with acceleration, rotation, and magnetic field data. Magnetometer data were used to identify the time when the foot was in contact with the ground (Fig. 1) during all side slope and treadmill walking. The gyroscope’s y-coordinate data were used to identify the stance phase during stair walking. The angular velocity rotation in the x-direction was analyzed by normalizing the times between the thigh and leg, calculating the means and then finding the thigh-to-leg ratio. Before data recording, the participants practiced their gait on each of the test surfaces. On the flat and side-sloped surfaces, subjects were asked to walk at a normal, self-selected speed on the 1.2 m wide by 12 m long platform, turn around, and return to the starting position. This provided data when the right or left thigh/leg was on the high side (LH) and when the right or left thigh/leg was on the low side (LL). The side slope of the heavily braced walking platform was adjustable from 0° to 5° to 10°. For each angle, the participants performed this cycle three times in one continuous sequence. The angle of the platform was changed after each run and the angle order was randomized for each participant. For the 10° inclined treadmill surface, participants were then asked to walk at normal gait speed. The ascending stair surface was comprised 199

HUMAN MOVEMENT S. Slaughter et al., The comparative gait effects

Heel Strike

Toe Off 1 20 39 58 77 96 115 134 153 172 191 210 229 248 267 286 305 324 343 362 381 400 419 438

Magnetic Field (G)

0.3 0.2 0.1 0 –0.1 –0.2 –0.3 –0.4 –0.5 –0.6 –0.7 –0.8

Time (1/150 s)

Figure 1. (left) Orientation of axes as the devices were worn by participants. (middle) Typical magnetometer data used to determine corresponding rotation data for analysis. (right) Participant wearing IMUs and EMGs

of 11 steps (rise = 19.05 cm and run = 29.21 cm) and participants were asked to engage at a cadence that was normal for them. The collected 12-bit digital data were then converted to voltage, full-wave rectified and imported into the Delsys EMGworks (Delsys, USA) program for analysis. Each file was examined to determine the best representative stance phase peak for each test. The root mean square (RMS) was then calculated, exported to Excel (Microsoft, USA) and further analyzed to find the area under the curve using the trapezoid rule, with the results then summed. The data were normalized using the recorded MVC data for useful comparisons. Statistical analysis was performed with XLStat-Pro (Addinsoft, USA). Multi­ variate ANOVA, 2-way ANOVA with repeated measures, one-way ANOVA, and Pearson’s product-moment correlation were used to make appropriate comparisons. The significance level was fixed at 0.05. Results Overall, multivariate ANOVA found there was no significant effect of angle on EMG data from the left lower extremity (Wilks’ Lambda = 0.861, F (8,54) = 0.525, p = 0.832). The right lower extremity also showed there

was no significant effect of angle on EMG data (Wilks’ Lambda = 0.0.836, F (8.54) = 0.633, p = 0.746 (Tab. 1). The Pearson product-moment correlation of the EMG data shows close correlations between the 0°, 5°, 10° side-slope angles. There were nine of the r values that ranged between 0.401 and 0.520, out of 400. The ave­ rage r value was 0.8187 ± 0.1083. Similar comparisons between the 10° side-slope, 10° inclined treadmill and ascending stairs data showed an average r value of 0.7748 ± 0.1346. Although the left and right GM had slightly higher average treadmill values, the EMG data comparing 10° side-slope, 10° inclined treadmill (Tm) and ascending stairs data showed a mean of 37.01 ± 2.72 (Fig. 2). The increased GM Tm values might be expected in the 10° incline due to the forward alignment with the axis of progression and the increase in the force of plantar flexion. When combining the RMS data from both the right and left lower extremities in each of the 11 participants in all three side-slope angles (Fig. 3), subjects #4 and #10 had noticeably lower values. Participant #10 was the oldest in the test group (age 65) and the associated aging and atrophy could account for the decreased

Table 1. Multivariate ANOVA of the Medial Gastrocnemius (GM), and Vastus Lateralis (VL) – Left Leg High (Left LH), Left Leg Low (Left LL), Right Leg High (Right LH), Right Leg Low (Right LL) at all angles and for all participants Source GM Left LH GM Right LL GM Right LH GM Right LL VL Left LH VL Left LL VL Right LH VL Right LL 200

MS 0.1383 31.6658 80.0885 20.3792 17.2757 8.0098 12.6425 16.2632

F

p-value

0.0057 0.8048 1.9481 0.7224 0.5363 0.1976 0.2007 0.4883

0.9943 0.4566 0.1602 0.4939 0.5904 0.8217 0.8192 0.6185

Figure 2. Averaged % MVC data for all 11 subjects at 10° side-slope, 10° incline on treadmill (Tm) and ascending stairs (St). The vertical axis represents 0% – 50% MVC

HUMAN MOVEMENT S. Slaughter et al., The comparative gait effects

Table 2. Rotation in the x-axis (standing vertical axis of the subject): ANOVA values

0.0035 0.003

0.002 0.0015 0.001 0.0005 10

11

Figure 3. Averaged RMS data including the right and left lower extremities at 0°, 5°, 10°

300

200

200

0

0

14,7

15,0

14,9

14,9

14,8 14,8

–300

14,6 14,7 14,7

–300

14,6

–200 14,5

–200

14,5

–100

14,5

–100

100

14,4 14,4

0

14,3 14,4

100

14,5

18,6

200

14,4 14,5

18,5

200

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300

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14,9

Times (s)

300

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18,5

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18,1

18,2

18,1

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18,0 18,0

–200 –300

18,4

–100

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–100

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0.0764 0.7837

0.0006 0.9813

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14,9

0

F

left (LL/LH) and right (LL/LH) lower extremities for angles 0° and 10°. The ratio of the leg-to-thigh rotation was considered (Tab. 2). The high p-values indicate that we cannot rule out the null hypothesis and indicates that there is little or no rotational difference between the left LH/LL 0° and 10° angles and the right LH/LL 0° and 10° angles. An example of an x-axis gyroscope recording is given in Figure 4. It shows the characteristic higher rotation values seen in the thigh. This is expected given the rotation and flexion of the thigh that occurs by several muscle groups during gait. This participant had normal foot arch heights and no LLD. It was noted that the participants with left short/ right long LLD showed an increased std(X) of 0.4645 (LL) and 0.0376 (LH) when comparing the 0° to 10° surfaces. However there were only four participants in this LLD category. The treadmill at a 10° incline, the stairs data, and 0° flat and 10° side-sloped surfaces were compared to examine rotation in x. Two-factor with replication ANOVA showed left F (3,79) = 0.1629, p = 0.9214 and right F (3,79) = 0.3992, p = 0.7540 at a sig- nificance level of 0.05.

18,3 18,4

100

17,9 17,9

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300

17,9 18,0

Velocity (0/s)

electrical activity. Participant #4 was a diabetic with known neuropathies. The LH/LL RMS values for the 5° and 10° side-slope surfaces indicates no significant difference between the LH and LL conditions at the 5° and 10° side-sloped angles. ANOVA shows p = 0.9869, p = 0.5131, p = 0.7230 and p = 0.9336 for the left GM 10°, left GM 5°, right GM 10° and right GM 5°, respectively. The VL data shows p = 0.9603, p = 0.7004, p = 0.9755, p = 0.9030 for the left VL 10°, left VL 5°, right VL 10° and right VL 5°, respectively. The Pearson Product Moment Correlation (r) values for the left GM 10° (r = 0.93), left GM 5° (r = 0.88), right GM 10° (r = 0.88), right GM 5° (r = 0.42), left VL 10° (r = 0.85), left VL 5° (r = 0.76), right VL 10° (r = 0.63) and right VL 5° (r = 0.86) show generally close correlations. The right GM 5° (r = 0.42) was the weakest. The four participants fitting the criteria of LLD using ANOVA showed F(19,79) = 0.2311, p = 0.9996 when compared among themselves at 0°, and at 5° and 10° side-slope angles for GM and VL (LL/LH) data. A two-factor with replication ANOVA was conducted on the IMU data to compare the effects of angle on the

14,8 14,8

9

0.2471 0.2564 0.2878 0.2734 0.2090 0.5316 0.2571 0.2150

18,3

8

0.1353 0.1457 0.1836 0.1656 0.0967 0.6261 0.1465 0.1025

18,2

5 6 7 Participant

1.1540 1.2397 1.2650 1.1943 0.9695 1.0502 0.9936 1.0331

14,6 14,7

4

Left LL 0° Left LH 0° Left LL 10° Left LH 10° Right LL 0° Right LH 0° Right LL 10° Right LH 10°

18,1

3

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var(X)

14,6

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0.0025

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Figure 4. (top left) x-axis thigh rotation, velocity average of absolute values = 65.3, (top right) equi­ valent x-axis leg rotation, velocity average of abso­ lute values = 50.4. Both graphs of the 0 0 flat sur­ face and include LL data. (bottom left) x-axis thigh rotation, velocity average of absolute values = 66.1, (bottom right) equivalent x-axis leg rotation, velo­ city average of absolute values = 62.9, both graphs of the 10 0 side-slope sur­ face and include LL data 201

HUMAN MOVEMENT S. Slaughter et al., The comparative gait effects

Discussion This study presented EMG and IMU data for the GM and VL bilaterally on several different walking surfaces. These muscles have been shown in literature to be the top contributors to knee forces during gait. We could not rule out our null hypothesis that there would be little or no difference in EMG activity in the tested muscles when walking on the various surfaces. The correlation between all surfaces was similar. The Pearson values showed a strong degree of linear correlation between the normalized EMG variables. So while there appears to be little significant difference between the three side-slope surfaces, the r values indicate similarities. Previous studies have shown little or no increase in EMG activity of the GM and VL muscles when flat surface walking, ramp walking and ascending stairs [19]. Our data support this assessment. We have demonstrated that there are little or no differences in EMG activity between flat surface and side-slope walking with the GM and VL muscles. Knee net forces have been shown to be similar during flat-surface walking and stair ascent [20]. Furthermore, the profiles for those activities were similar in all three force directions. There was a slight increase in EMG activity of the GM on the 10° inclined treadmill surface. While it was expected that the IMU data would show increased rotation between the leg and the thigh in stance phase, this was not the case. These data showed a similar lack of significance between the 0° flat, 10° side-slope, 10° inclined treadmill and stair surfaces. The right lower extremity stair data did show higher var(X) values. Normal rotation at the knee during walking has been cited as ~20° between 20° and 40° of flexion [21]. We have shown this to be true when considering the relative rotations of the thigh to the leg on flat surfaces as well as the other surfaces in this study. Although the IMU std(X) values were comparatively higher, LLD and foot arch parameters did not appear to have a statistically significant effect on the data. There were two subjects in this study that had LLD with shorter left extremity and two subjects that had LLD with a shorter right extremity. The foot arches were within normal limits, where only one subject in this study had high normal arch height. The right LL/LH rotation in x showed lower average values than the left side which may be due to late­ rality and the high percentage of right dominant individuals [22]. This study showed that symmetry in gait is not a valid assumption. This is further supported when looking at subjects expressing dorsi-flexor and plantar-flexor weaknesses [23]. Some the limitations of this study in relation to IMU data acquisition are similar to those found in markerbased video-motion analysis, which includes the motion of the bone relative to skin artifacts [24]. In addition, 202

EMG signals are obtained and recorded from a wide area muscle and are also susceptible to motion artifacts [25]. Another limitation is that the types of surfaces and forms of ADL were limited to five in this study. Future research could include an examination of additional ADLs and walking surfaces. The N = 11 study size could be increased and additional anthropometric measurements could include limb, waist, and chest circumferences along with an estimation of % body fat. Conclusion This research showed no significant differences in GM/VL EMG data on a flat surface, 5° and 10° side-slope surfaces, a 10° inclined treadmill surface and when ascending stairs. The thigh-to-leg relative rotation ratios also showed no significant differences when subjects were in stance phase. The data presented would indirectly indicate similar knee joint loading within the confines of our experimental parameters. This study has provided useful data on the effects of side-slope walking surfaces in four significant knee related muscles and the vertical axis rotation of the thigh relative to the leg during stance phase. The information in this study could provide useful information to clinicians who evaluate the potential contributors or causes of knee-related injuries. Acknowledgements The authors acknowledge the O’Hara Chemical Science In­sti­ tute, BIOMEC Services LLC and the Marcus Chair in Science/ Mathematics for partial support as well as David Andrews for his statistical insight and to Jason Bassett for foot arch determinations.

References 1. Perry J., Gait Analysis: Normal and Pathological Function. Slack Incorporated. Professional Book Division. Thorofare, NJ, USA, 1992. 2. Samuel D., Rowe P., Hood V. Nicol A., The biomechanical functional demand placed on knee and hip muscles of older adults during stair ascent and descent. Gait Posture, 2011, 34 (2), 239–244, doi: 10.1016/j.gaitpost.2011.05.005. 3. Brechter J.H., Powers C.M., Patellofemoral joint stress during stair ascent and descent in persons with and without patellofemoral pain. Gait Posture, 2002, 16 (2), 115–123, doi: 10.1016/S0966-6362(02)00090-5. 4. Lay A.N., Hass C.J., Nichols R., Gregor R.J., The effects of sloped surfaces on locomotion: an electromyographic analysis. J Biomech, 2007, 40 (6), 1276–1285, doi: 10.1016/ j.jbiomech.2006.05.023. 5. McIntosh A.S., Beatty K.T., Dwan L.N., Vickers D.R., Gait dynamics on an inclined walkway. J Biomech, 2006, 39 (13), 2491–2502, doi: 10.1016/j.jbiomech.2005.07.025. 6. Kim H.J., Fernandez J.W., Akbarshahi M., Walter J.P., Fregly B.J., Pandy M.G., Evaluation of predicted kneejoint muscle forces during gait using an instrumented knee implant. J Orthop Res, 2009, 27 (10), 1326–1331, doi: 10.1002/jor.20876. 7. Gray H., Goss C., Gray’s Anatomy. 29th ed. Lea & Febiger, Philadelphia 1975.

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8. Sasaki K., Neptune R., Individual muscle contributions to the axial knee joint contact force during normal walking. J Biomech, 2010, 43 (14), 2780–2784, doi: 10. 1016/j. jbiomech.2010.06.011. 9. Besier T., Fredericson M., Gold G., Beaupré G., Delp S., Knee muscle forces during walking and running in patello­ femoral pain patients and pain-free controls. J Biomech, 2009, 42 (7), 898–905, doi: 10.1016/j.jbiomech. 2009.01.032. 10. Zheng H., Black N.D., Harris N.D., Position-sensing technologies for movement analysis in stroke rehabilitation. Med Biol Eng Comput, 2005, 43 (4), 413–420, doi: 10.1007/ BF02344720. 11. Bussmann H.B.J., Reuvekamp P.J., Veltink P.H., Martens W.L.J., Stam H.J., Validity and reliability of measurements obtained with an “activity monitor” in people with and without a transtibial amputation. Phys Ther, 1998, 78 (9), 989–998. 12. Heyn A., Mayagoitia R.E., Nene A.V., Veltink P.H., The kinematics of the swing phase obtained from accelerometer and gyroscope measurements. In: Proceedings of the 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society: Bridging Disciplines for Biomedicine. 31 Oct–3 Nov 1996, Amsterdam, Netherlands. IEEE, 1996, 2, 463–464. 13. Bachmann E.R., McGhee R.B., Yun X., Zyda M.J., Inertial and magnetic posture tracking for inserting humans into networked virtual environments. In: Proceedings of the ACM symposium on virtual reality software and techno­ logy, November 2001, Baniff, Alberta, Canada, 9–16. 14. Holmberg S., Thelin A., Thelin N., Is there an increased risk of knee osteoarthritis among farmers? A populationbased case-control study. Int Arch Occup Environ Health, 2004, 77 (5), 345–350, doi: 10.1007/s00420-004-0518-1. 15. Vingård E., Osteoarthrosis of the knee and physical load from occupation. Annal Rheumatic Diseases, 1996, 55 (9), 677–684. doi:10.1136/ard.55.9.677. 16. Murley G., Menz H., Landorf K., Foot posture influences then electromyographic activity of selected lower limb muscles during gait. J Foot Ankle Res, 2009, 2 (35), doi: 10.1186/1757-1146-2-35. 17. Nichols P., Bailey N., The accuracy of measuring leglength differences. Br Med J, 1955, 2 (4950), 1247–1248, doi: 10.1136/bmj.2.4950.1247.

18. Williams D.S., McClay I.S., Measurements used to characterize the foot and the medial longitudinal arch: reliability and validity. Phys Ther, 2000, 80 (9), 864–871. 19. Ciccotti M., Kerlan R., Perry J., Pink M., An electromyographic analysis of the knee during functional activities. I. The normal profile. Am J Sports Med, 1994, 22 (5), 645–650, doi: 10.1177/036354659402200512. 20. Costigan P., Deluzio K., Wyss U., Knee and hip kinetics during normal stair climbing. Gait Posture, 2002, 16 (1), 31–37, doi: 10.1016/S0966-6362(01)00201-6. 21. Wheeless C., Wheeless’ Textbook of Orthopaedics. Available from: URL: http://www.wheelessonline.com/ [accessed September 01, 2011]. 22. Õunpuu S., Winter D.A., Bilateral electromyographical analysis of the lower limbs during walking in normal adults. Electroenceph Clin Neurophysiol, 1989, 72 (5), 429–438, doi: 10.1016/0013-4694(89)90048-5. 23. Jeleń P., Wit A., Dudziński K., Nolan L., Expressing gaitline symmetry in able-bodied gait. Dyn Med, 2008, 7, 17, doi: 10.1186/1476-5918-7-17. 24. Benoit D.L., Ramsey D.K., Lamontagne M., Xu L., Wre­ tenberg P., Renström P., Effect of skin movement artifact on knee kinematics during gait and cutting motions measured in vivo. Gait Posture, 2006, 24 (2), 152–164, doi: 10.1016/j.gaitpost.2005.04.012. 25. Pullman S.L., Goodin D.S., Marquinez A.I., Tabbal S., Rubin M., Clinical utility of surface EMG: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology, 2000, 55 (2), 171–177, doi: 10.1212/WNL.55.2.171.

Paper received by the Editors: October 21, 2011 Paper accepted for publication: April 19, 2012 Correspondence address Stephen Slaughter Department of Biology University of Dallas 1845 East Northgate Dr. Irving, TX 75062, USA e-mail: [email protected]

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HUMAN MOVEMENT 2012, vol. 13 (3), 204– 210

TREADMILL GAIT ANALYSIS OF REHABILITATED AND INDEPENDENT LOWER-LIMB AMPUTEES doi: 10.2478/v10038-012-0023-4

SORAIA CRISTINA TONON DA LUZ *, ALUISIO OTAVIO VARGAS ÁVILA, MARIO CÉSAR DE ANDRADE, BEATRIZ CONCEIÇÃO SILVA ALVES RODRIGUES State University of Santa Catarina, Santa Catarina, Brazil

Abstract

Purpose. A description of gait analysis during overground locmotion has been the subject of various studies, in relation to de­scribing both the kinetic and spatial-temporal characteristics of walking. Measuring the gait of amputees using treadmills is a useful test to quantify locomotive ability, and a tool that helps to control gait parameters during rehabilitation. The aim of this study is to describe the kinetic and spatial-temporal characteristics of gait of rehabilitated amputees, measured with an instrumented treadmill. Methods. Twenty-four participants aged between 20 and 40 years were chosen, who had all suffered unilateral traumatic amputation either above or below the knee, and were classified as well-rehabilitated. Following a paperbased assessment form, the participants were subjected to gait analysis on an instrumented treadmill fitted with two force platforms. Results. The first peak vertical force of intact and amputated limbs presented higher values and was significantly (p 0.05) larger than the second peak vertical force for the amputated limb, indicating less propulsion during walking. A significant difference was observed in the load rate in intact and amputated limbs, indicating more overload in the intact limb. The spatial-temporal variables, cadence, step and stride length were significantly greater (p 0.05) in the below-knee than in the above-knee amputees. Conclusions. The kinetic and spatial-temporal characteristics of gait, measured with an instrumented treadmill, which were observed in all lower limb amputees involved in this study, were similar to the ones commonly reported in numerous studies on overground walking. Thus, treadmill gait training and control of the progress of rehabilitation with amputees is recommended.

Key words: amputation, gait, treadmill

Introduction Amputation of the lower limb not only affects the ability to walk, but also has an impact on the ability of the individual to participate in various activities [1], on body image perception [2], and on quality of life in general [3]. Furthermore, a reduction in the capacity for walking with a prosthesis is associated with a decrease in carrying out activities of daily living [4]. The walking abilities of amputees requires great effort and has a heterogeneous and multifactorial origin, encompassing the general health of the individual who has undergone amputation and the influence of various contextual factors including age, sex, co-morbidity, social support and physiological factors [5]. Riley et al. [6] commented that a treadmill is a tool that helps to control walking speed, allowing for a more meaningful comparison of the kinetic parameters between sessions. The most basic instrumented treadmills measure only one component of the ground reaction force, typically the vertical force [1–3]. Few studies report that treadmill walking is equivalent to overground walking in healthy subjects [7, 8].

* Corresponding author. 204

Some authors [6, 9–11] expressed the opinion that there are no clear differences between treadmill and overground gait and concluded that the mechanics are very similar. In contrast, several other authors [12, 13] pointed out several differences [14], particularly that walking on a treadmill increases cadence and decreases the support period, the variability of the steps and several kinematic components. Gait analysis on the treadmill and overground is used both in scientific approaches for investigating the neuronal organization and ontogenetic development of locomotion, and in a variety of clinical applications [12];

however, the description of the gait parameters of amputees walking on an instrumented treadmill have not been reported. Measuring walking speed of amputees with different levels of amputation is a useful test to quantify locomotor abilities during the progression of rehabilitation [15–18]. Most studies with amputees on a treadmill report the energetic expenditure required for walking and compare this expenditure in different levels of amputation [8, 19] or in different outdoor walking conditions [7]. Gait analysis performed on instrumented treadmills with well-rehabilitated and independent lower limb amputees provides kinetic and spatial-temporal information relevant for the development of metho­do­

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logies which could help multidisciplinary rehabilitation teams. This contribution refers to the increase of ability, independence and safety during gait training, with the goal of achieving the fullest locomotor potential according to the level of amputation, age and activity level. The purpose of this study was to describe the kinetic and spatial-temporal characteristics of the gait of rehabilitated and independent amputees, measured with an instrumented treadmill. The hypothesis of this study is based on this question: Are the gait parameters of amputees with different levels of amputation similar to those commonly reported in numerous studies on overground walking? Material and methods This study examined twenty-four participants with unilateral amputation (14 below-knee and 10 aboveknee). The inclusion criteria for the present study were as follows: participants should have no associated health problems known to affect gait and/or balance, should not present decompensated hypertension or orthopaedic problems including arthritis or ligament problems in the intact knee, should be aged between 20 and 40 years, should present below-knee or aboveknee amputation or knee disarticulation due to trauma. The following inclusion criteria classified the subjects as well-rehabilitated: the absence of problems with the amputation stump, such as wounds, pain and hypertrophic scars; no problems with the prosthetic socket, such as excessive pressure, looseness or noises during walking; participants should carry out daily activities independently; should use a prosthesis for more than five years, should be with the same prosthesis for at least one year; and have no self-reported problems with alignment; nor should they have changed any of the components of the prosthesis in the month prior to testing. The unilateral amputees used the same prosthetic components: Above-knee amputation: CAT-CAM-type socket, 3R46 polycentric hydraulic knee, dynamic response feet (1D10) Below-knee amputation: KBM-type socket with silicone and distal attachment, dynamic response feet (1D10). The present study was approved by the ethics committee of the State University of Santa Catarina and conformed to the Helsinki Declaration of the World Medical Association. All of the subjects signed a Term of Free and Informed Consent. Data acquisition was performed at the Biomechanics Laboratory of CEFIDUDESC in Florianópolis-SC, Brazil. An assessment form was employed to obtain personal details, the time since amputation, the time of adaptation to the prosthesis, and to check for fulfillment of the inclusion criteria of the study.

Figure 1. Treadmill Gait

The Kistler Gaitway Instrumented Treadmill System™ (Fig. 1) was used for treadmill gait assessment. It is a piezoelectric ground reaction force measurement system which is able to measure vertical ground reaction forces for complete, consecutive, multiple foot strikes during walking and running. It has been designed using a tandem force plate design (one plate in front of the other) and includes an algorithm which distinguishes left from right strikes. The system consists of the Gaitway software system data acquisition board, a dual force plate instrumented treadmill with an eight-channel charge amplifier, six user defined inputs, a foot discriminator circuit and a belt speed sensor. This equipment allows the participants to easily set the walking speed. It also reports real time data through the Gaitway software, which enables the experimenter to inform the participants of the results of their evaluation immediately after the test. After an adjustment period of walking on the treadmill (about 10 minutes), the participants self-selected a comfortable speed. Data were collected with an acquisition frequency of 100 Hz, ten repetitions in a one-minute walk for each acquisition. The number of repetitions was chosen based on the regularity of the dynamic and temporal standard of gait, the recording of the graphs of vertical force, and also the smallest standard deviation possible among the data collected. The variables were described taking into consideration the prosthetic limb (PL) and the intact limb (IL) and the choice of them was based on those most commonly used in studies of gait vertical force. The kinetic variables (Fig. 2) refer to the behavior of the vertical ground reaction force: first force peak (FFP) corresponds to the period just after the heel touches the force plate and the center of gravity is traveling down toward the ground resulting in an increased reaction force from the ground in the vertical direction, while second force peak (SFP) corresponds to the toe pushing off the force plate applying a force onto the ground which is matched by an increase in the ground reaction force, while the 205

HUMAN MOVEMENT S.C. Tonon da Luz  et al., Treadmill Gait analysis of amputees

Figure 2. Graph of vertical ground reaction force representing the Load Rate, First Force Peak and Second Force Peak

weight acceptance rate or Load rate (LR) represents the rate of change of ground force (from heel strike to FFP). The spatial-temporal variables were measurements of temporal and length relationships: cadence (CAD), step time (Tstep), step length (Lstep), stride time (Tstride), stride length (Lstride). Statistical analysis included analysis of variance (ANOVA) with two factors, the level of amputation and prosthesis, for the variables FFP, SFP, LR, CAD, Lstep, Tstep, Lstride and Tstride. Walking speed was subjected to analysis of variance (ANOVA) with a single factor: the level of amputation. Pearson’s linear correlation coefficient was calculated for the variables LR and CAD for the pairs (prosthetic limb and intact limb). Significance level was fixed at 0.05 (p 0.05). There are two limitations that need to be acknowledged regarding the present study. The first limitation concerns the difficulty of obtaining participants who meet the group inclusion criteria, since the subjects should be classified as well-rehabilitated. The second

limitation was the impossibility of performing overground gait analysis to compare the data. Results Table 1 presents the participants’ characteristics including age, body mass, height, gender, time since amputation and duration of using the prosthesis. No significant differences were observed between the two groups (below-knee and above-knee) on age, height, body mass, time since amputation and duration of using of prosthesis. For the 24 individuals with unilateral amputation it was possible to obtain the highest peak force, and in which limb it occurred, by calculating the difference between the first and second peak (Tab. 2), in the limb with the prosthesis and in the intact limb as follows: FFP (PL) – SFP (PL ), FFP (IL) – SFP (IL). We observed statistically significant higher values for the FFP in the

Table 1. Characteristics of amputee participants – Mean (SD) Amputation Level/ Subjects (N)

Age (years)

Height (cm)

Body Mass (kg)

n/Gender

Time since amputation (years)

Duration of prosthesis use (years)

BK (n = 14)

29.35 (6.0)

169 (0.05)

70.86 (8.9)

3F 11 M

10.6 (1.2)

9.4 (0.65)

AK (n = 10)

34.2 (4.6)

170 (0.04)

71.67 (9.2)

2F 8M

13.4 (0.7)

11.7 (1.2)

BK – Below-Knee; AK – Above-Knee; M – masculine; F – feminine Table 2. Mean (SD) kinetic data for peak vertical ground reaction force (N/kg) and weight acceptance rate (N/Kg/s) on treadmill gait Amputees Participants

SFP – FFP

One-Way ANOVA F and p values

Load Rate

One-Way ANOVA F and p values

Prosth

Intact

(Prosth/Intact)

Prosth

Intact

(Prosth/Intact)

BK (n = 14)

0.10 (0.10)

0.03 (0.06)

(BK/AK)

7.35 (0.7)

10.80 (1.6)

(BK/AK)

AK (n = 10)

0.21 (0.15)

0.03 (0.13)

F = 2.94 p = 0.09

7.90 (1.6)

15.69 (3.2)

F = 1.94 p = 0.16

SFP – Second Vertical Force Peak; FFP – First Vertical Force Peak; BK – Below-Knee; AB – Above-Knee significant difference at p 0.05 206

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160

45 40 35 30 25 20

Spearman’s rho = 0.84882

140

Spearman’s rho = 0.7418

p = 0.00

120

p = 0.00

CAD (IL)

Load Rate (N/kg/s) – Intact Limb

S.C. Tonon da Luz  et al., Treadmill Gait analysis of amputees

100 80 60

15 10 5 0

40 20 0 0

5

10

15

20

0

25

20

40

60

80

100

120

140

CAD (WP)

Load Rate (N/kg/s) – Prosthetic Limb

Figure 3. Graph of dispersion for Load Rate in Intact Limb and Prosthetic Limb on treadmill gait

Figure 4. Graph of dispersion for cadence (CAD). WP – with prosthesis; IL – intact limb on treadmill gait

Table 3. Mean (SD) walking speed and temporal-spatial treadmill gait parameters Amputee participants

BK n = 14

AK n = 10

p value (BK/AK)

Walking speed (m/s)

1.07 (0.06)

1.01 (0.1)

0.13

Prosth

Intact

Prosth

Intact

One-Way ANOVA F and p values (AK/BK)

(Prosth/Intact)

Cadence (steps/min)

101.6 (5.3)

110.3 (6.0)

84.2 (7.1)

98.1 (7.0)

F = 5.42 p = 0.024

F = 3.17 p = 0.08

Step length (m)

0.66 (0.02)

0.71 (0.02)

0.60 (0.02)

0.64 (0.02)

F = 6.01 p = 0.0001

F = 3.63 p = 0.06

Step time (s)

0.90 (0.25)

0.98 (0.27)

0.86 (0.36)

1.0 (0.35)

F = 0.01 p = 0.91

F = 1.65 p = 0.20

Stride length (m)

1.26 (0.02)

1.29 (0.02)

1.19 (0.01)

1.18 (0.02)

F = 13.55 p = 0.0001

F = 0.08 p = 0.77

Stride time (s)

1.09 (0.02)

1.06 (0.02)

1.12 (0.01)

1.07 (0.03)

F = 7.37 p = 0.009

F = 28.68 p = 0.0001

BK – Below-Knee; AB – Above-Knee; significant difference (p

limb with the prosthesis, indicating little impact absorption in this limb. There was a strong linear correlation for load rate among the 24 unilateral amputees (Fig. 3), while the mean values in the intact limb and prosthetic limb were significantly different, indicating that the intact limb presented a higher load rate and, consequently, more overload. The treadmill spatial-temporal parameters for all participants with two levels of amputation are presented in Table 3. There was no significant difference between the walking speed of the below-knee group and that of the above-knee group. The linear correlation of cadence in the intact limb and prosthetic limb was found to be strong (Fig. 4), with a significant difference between the below-knee and above-knee levels, indicating lower cadence in transfemoral amputees group. The mean values for step length, stride length and stride time are presented in Table 2 and Figure 5, which

0.05)

show significant differences between below-knee and above-knee levels. Comparing the intact limb and prosthetic limb, the step and stride length variables were not significantly different. The variable stride time, the mean values for step length, stride length and the mean of stride time, were significantly different between below-knee and above-knee levels and the intact limb and prosthetic limb indicating greater stride time in the transfemoral amputees and the prosthetic limb. Discussion During walking on the treadmill it was observed that there was no significant difference between the speed of the below-knee and above-knee amputation groups, even though several studies on overground gait analysis demonstrated higher speeds in the case of below-knee amputations [20–23]. Numerous studies with overground walking [17, 18, 207

HUMAN MOVEMENT S.C. Tonon da Luz  et al., Treadmill Gait analysis of amputees

1.4 1.3

Step length Stride length Stride time

1.2

Ratios

1.1 1.0 0.9 0.8 0.7 0.6 0.5

Below-Knee Above-Knee

Below-Knee Above-Knee

Prostheses

Intact Limb

20, 24, 25] have reported that in below-knee and aboveknee amputees the vertical ground reaction force is smaller in the prosthesis limb when compared to the intact limb, indicating less propulsion during walking. Here, the difference between force peaks (FFP – SFP), which was significantly greater for the prosthetic limb, indicated the same characteristics: little toe-off in this active phase of gait. A series of reports in overground walking has shown that the heel strike and the toe-off of the prosthetic foot were inadequate and generated a compensatory response in the intact limb in both periods of double support [17, 18, 26–28], and associated this with many factors: muscle weakness in the residual limb, altered sensitivity in the amputation stump, difficulty in controlling the prosthetic knee, and inefficiency of the components of the prosthetic foot. Other authors such as Silverman et al. [18] state that increasing hip extensor strength and output in the residual leg may be a useful mechanism to reduce vertical ground reaction force loading asymmetry between the intact and residual legs. Amputees have an increased risk of deve­ loping joint disorders in the intact leg due to an increased dependence on this limb [29, 30]. The importance of preventing these diseases must be noted, as it has been suggested that the age at the time of amputation has an adverse effect on walking potential. The analysis of this study identified that the loading rate during treadmill walking in individuals with unilate­ ral amputation was higher in the intact limb with low propulsion of the prosthetic limb. We associate this fact to the lack of stability or equilibrium of the prosthetic limb, which causes a greater burden on the intact limb when its heel starts to hit the treadmill. It has been reported, in studies of overground gait, that unila­ teral amputees prefer to use the intact limb for weight discharge with a consequent decrease in speed of move208

Figure 5. Graph of step length, stride length and stride time, for two levels of amputation: below-knee and aboveknee, with and without prosthesis on treadmill gait

ment [20, 23, 31]. The findings suggest that reducing the speed of movement is important to protect the healthy limb against stress and repeated trauma, especially in patients whose etiology of amputation is vascular. Some authors, such as Fey et al. [32] state that exceeding the loading rate on the intact limb and the low level of propulsion with the prosthetic limb are due to muscle imbalance. They studied changes in muscle activity in below-knee amputees in response to increased walking speed and found that the differences occurred in the biceps femoris – the long head of the residual limb, the vastus lateralis and the rectus femoris. They commented that these adaptations are consistent with the need for additional support in order to propel the body forward in the absence of plantar flexors. We observed that the spatial-temporal variables, cadence, step and stride length were significantly greater (p 0.05) in below-knee than in above-knee amputees. Some studies [21, 22], associated with gait kinetic ana­ly­ sis of overground walking, clarify that the asymme­tries in spatial-temporal parameters in below-knee subjects, compared to above-knee subjects, may be explained by maintaining the functional integrity of the knee joint, controlling the swing phase and activating a strong lever to achieve hip extension with this level of amputation. In this study, the participants were classified as wellrehabilitated according to the inclusion criteria and all individuals were independent in terms of carrying out daily activities and leisure using proper prosthetic components. However, the asymmetries found in kinetic and spatial-temporal variables in two levels of amputation, investigated here on an instrumented treadmill, have been reported in the literature for overground walking. We thereby emphasize, in particular, that the maintenance of these characteristics in the long term may

HUMAN MOVEMENT S.C. Tonon da Luz  et al., Treadmill Gait analysis of amputees

be highly damaging to the intact joints and suggest that intervention in the rehabilitation process of the amputee should focus on protecting the intact limb from weight overload. Gait training of amputees on instrumented treadmills can facilitate the rehabilitation of walking with a prosthesis by means of increasing control over the asymmetries in the studied parameters as well as preventing injury, especially of the intact limb. Conclusion The present data strongly suggest that the kinetic and spatio-temporal characteristics of gait, measured with an instrumented treadmill, observed in rehabilitated and independent amputees with different levels of amputation, were similar to the results commonly reported in numerous studies of overground gait. Thus, treadmill gait training and control of the progress of rehabilitation with amputees is recommended. References 1. Tonon S.C., Avila A.O.V.A., Gait analysis in amputees with different level of amputation. Rev Bras Biomec, 2000, 1, 27–31. 2. Gallagher P., Horgan O., Franchignoni F., Giordano A., MacLachlan M., Body image in people with lower-limb amputation: a Rasch analysis of the Amputee Body Image Scale. Am J Phys Med Rehabil, 2007, 86 (3), 205–215, doi: 10.1097/PHM.0b013e3180321439. 3. Pell J.P., Donnan P.T., Fowkes F.G., Ruckley C.V., Quality of life following lower limb amputation for peripheral arterial disease. Eur J Vasc Surg, 1993, 7 (4), 448–451. 4. Collin C., Wade D.T., Cochrane G.M., Functional outcome of lower limb amputees with peripheral vascular disease. Clin Rehabil, 1992, 6 (1), 13–21, doi: 10.1177/026921559 200600103. 5. Sansam K., Neumann V., O’Connor R., Bhakta B., Predicting walking ability following lower limb amputation: a systematic review of the literature. J Rehabil Med, 2009, 41 (8), 593–603, doi: 10.2340/16501977-0393. 6. Riley P.O., Paolini G., Della Croce U., Paylo K.W., Kerrigan D.C., A kinematic and kinetic comparison of overground and treadmill walking in healthy subjects. Gait Posture, 2007, 26 (1), 17–24, doi: 10.1016/j.gaitpost. 2006.07.003. 7. Starholm I.M., Gjovaag T., Mengshoel A.M., Energy expenditure of transfemoral amputees walking on a horizontal and tilted treadmill simulating different outdoor walking conditions. Prosthet Orthot Int, 2010, 34 (2), 184–194, doi: 10.3109/03093640903585016. 8. Waters R., Perry J., Antonelli D., Hislop H., Energy cost of walking of amputees: the influence of level amputation. J Bone Joint Surg Am, 1976, 58 (1), 42–46. 9. Murray M.P., Spurr G.B., Sepic S.B., Gardner G.M., Mol­ linger L.A., Treadmill versus floor walking: kinematics, electromyogram, and heart rate. J Appl Physiol, 1985, 59 (1), 87–91. 10. Barbeau H., Locomotor training in neurorehabilitation: emerging rehabilitation concepts. Neurorehabil Neural Repair,2003,17(1),3–11,doi:10.1177/0888439002250442.

11. Owings T.M., Grabiner M.D., Step width variability, but not step length variability or step time variability, discrimi­ nates gait of healthy young and older adults during treadmill locomotion. J Biomech, 2004, 37 (6), 935–938, doi: 10.1016/j.jbiomech.2003.11.012. 12. Stolze H., Kuhtz-Buschbeck J.P., Mondwurf C., BoczekFuncke A., Jöhnk K., Deuschl G., Illert M., Gait analysis during treadmill and overground locomotion in children and adults. EEG Clin Neurophysiol, 1997, 105 (6), 490–497. 13. Alton F., Baldey L., Caplan S., Morrissey M.C., A kinematic comparison of overground and treadmill walking. Clin Biomech, 1998, 13 (6), 434–440, doi: 10.1016/ S0268-0033(98)00012-6. 14. Dingwell J.B., Cusumano J.P., Cavanagh P.R., Sternad D., Local dynamic stability versus kinematic variability of continuous overground and treadmill walking. J Biomech Eng, 2001, 123 (1), 27–32. 15. Jaergers S.M., Arendzen J.H., Jongh H.J., Changes in hip muscles after above-knee amputation. Clin Orthop Relat Res, 1995, 319, 276–284. 16. Courtemanche R., Teasdale N., Boucher P., Fleury M., Lajoie Y., Bard C., Gait problems in diabetic neuropathic patients. Arch Phys Med Rehabil, 1996, 77 (9), 849–855, doi: 10.1016/S0003-9993(96)90269-5. 17. Vanicek N., Strike S., McNaughton L., Polman R., Gait patterns in transtibial amputee fallers vs. non-fallers: Biomechanical differences during level walking. Gait Posture, 2009, 29 (3), 415–420, doi: 10.1016/j.gaitpost. 2008.10.062. 18. Silverman A.K., Fey N.P., Portillo A., Walden J.G., Bos­ ker G., Neptune R.R., Compensatory mechanisms in below-knee amputee gait in response to increasing steadystate walking speeds. Gait Posture, 2008, 28 (4), 602–609, doi: 10.1016/j.gaitpost.2008.04.005. 19. Perry J., Gait analysis: Normal and pathological function. Slack Inc., Thorofare, NJ, USA, 1992, 192–195. 20. Vrieling A.H., Keeken H.G., Schoppen V., Otten E., Hal­ bertsma J.P.K., Hof A.L., Postema K., Obstacle crossing in lower limb amputees. Gait Posture, 2007, 26 (4), 587–594, doi: 10.1016/j.gaitpost.2006.12.007. 21. Oberg K., Lanshammar H., An investigation of kinematic and kinetic variables for the description of prosthetic gait using the ENOCH system. Prosthet Orthot Int, 1982, 6 (1), 43–47, doi: 10.3109/03093648209167740. 22. Skinner H., Effeney D., Gait analysis in amputees: special review. Am J Phys Med Rehabil, 1985, 64 (2), 82–89. 23. Rossi S.A., Doyle W., Skinner H.B., Gait initiation of persons with below-knee amputation: the characterization and comparison of force profiles. J Rehabil Res Dev, 1995, 32 (2), 120–127. 24. Torburn L., Perry J., Ayyappa E., Shanfield S.L., Belowknee amputee gait with dynamic elastic response prosthetic feet: a pilot study. J Rehabil Res Dev, 1990, 27 (4), 369–384. 25. Zuniga E.M., Leavitt L.A., Calvert J.C., Canzoneri J., Peterson C.R., Gait patterns in above-knee amputees. Arch Phys Med Rehabil, 1972, 53 (8), 373–382. 26. Isakov E., Mizrahi J., Bilateral simultaneous measurements of standing ground reaction forces in hemiparetics, below-knee amputees, and healthy adults. Basic Appl Myol, 1997, 7 (2), 97–101. 209

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27. Isakov E., Burger H., Krajnik J., Gregoric M., Marincek C., Double-limb support and step-length asymmetry in belowknee amputees. Scand J Rehab Med, 1997, 29 (2), 75–79. 28. Menard M.R., McBride M.E., Sanderson D.J., Murray D.D., Comparative biomechanical analysis of energy-storing prosthetic feet. Arch Phys Med Rehabil, 1992, 73 (5), 451–458. 29. Burke M.J., Roman V., Wright V., Bone and joint changes in lower limb amputees. Ann Rheum Dis, 1978, 37 (3), 252–254, doi:10.1136/ard.37.3.252. 30. Melzer I., Yekutiel M., Sukenik S., Comparative study of osteoarthritis of the contralateral knee joint of male amputees who do and do not play volleyball. J Rheumatol, 2001, 28 (1), 169–172. 31. Winter D.A., Sienko S.E., Biomechanics of below-knee amputee gait. J Biomech, 1988, 21 (5), 361–367, doi: 10.1016/0021-9290(88)90142-X. 32. Fey N.P., Silverman A.K., Neptune R.R., The influence of increasing steady-state walking speed on muscle activity in below-knee amputees. J Electromyogr Kinesiol, 2010, 20 (1), 155–161, doi: 10.1016/j.jelekin.2009.02.004.

Paper received by the Editors: June 29, 2011 Paper accepted for publication: July 4, 2012 Correspondence address Soraia Cristina Tonon da Luz Biomechanics Laboratory Science Center for Health and Sport State University of Santa Catarina Paschoal Simone, 358 Florianópolis, Santa Catarina, Brazil CEP: 88080-350 e-mail: [email protected]

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HUMAN MOVEMENT 2012, vol. 13 (3), 211– 217

AIMING POINT TRAJECTORY AS AN ASSESSMENT PARAMETER OF SHOOTING PERFORMANCE doi: 10.2478/v10038-012-0024-3

IHOR ZANEVSKYY 1 *, YULIYA KOROSTYLOVA 2 , VOLODYMYR MYKHAYLOV 3 1

Casimir Pulaski Technical University, Department of Physical and Health Education, Radom, Poland Lviv State University of Physical Culture, Department of Kinesiology, Lviv, Ukraine 3 Lviv State University of Physical Culture, Department of Shooting Sports, Lviv, Ukraine 2

Abstract

Purpose. The purpose of this study was to elaborate on the scientific methodology for providing an assessment of air-pistol shooters’ aiming stability by (i) substantiating the parameters of aiming stability, (ii) specifying the quantitative evaluation methods in using an optoelectronic target, (iii) evaluating the reliability of tests determining aiming stability, and (iv) developing a methodology for creating individual and group parameters of aiming stability. Methods. The aiming trajectories of 95 airpistol shooters, each of whom fired 60 shots using a SCATT optoelectronic simulator, were calculated to develop individual and group aiming stability parameters. Research methods included an optoelectronic registration of movement, research on top air-pistol shooters’ sports results, mathematical modelling, variation statistics, cluster analysis, two-way ANOVA with data correlation and reliability theory tests. Results. It was found that an average aiming point trajectory on the SCATT optoelectronic target measured one second before a shot could be accepted as an assessment parameter of aiming stability, as it is one of the basic parameters of technical preparation and its position is not influenced by the ballistic characteristics of the pistol and pellets (ŋ = 0.944). Conclusions. The parameters of aiming stability in air-pistol shooting were developed using a modification of the clustering method. This allows for the identification of weak points in the structure and organization of shooters’ training and for adjustment of the training process.

Key words: air-pistol shooting, aiming stability, optoelectronic training system

Introduction Contemporary air-pistol shooting technique consists of three elements: aiming, weapon retention and firing (pulling the trigger). Weapon retention is synonymous with stability, where controlling hand vibrations is an important factor when aiming and when the trigger is pulled [1]. The quantitative technical parameters of shot performance can be obtained by using optoelectronic shooting simulators such as the SCATT Professional Training Systems [2], Home Trainer [3] and the Sport Shooter Training System [4]. It has been found that if aiming stability is disturbed 0.1–0.2 s before firing (simple reaction time), the aiming point trajectory moves rapidly away from the point of aim. It occurs due to the difficulty in simultaneously controlling all the three processes (aiming, weapon retention and firing) and by muscle non-coordination. It is evident that an attempt to counteract this instability by firing earlier (during simple reaction time) would be an incorrect approach as this cannot eliminate the effects of muscle non-coordination [5]. Individual and group competitive techniques are developed to optimize shooters’ training. Training programmes should consider long-term planning in order * Corresponding author.

to avoid physical overstrain. A number of parameters of shooting technique should be cultivated to help shooters break bad habits and achieve better sport results [6]. For the effective management of the training process, especially when planning a training schedule, one should not only consider the individual features of shooting technique, but also study the informative characteristics of top competitors. This allows for the identification of weak points in both the structure and organization of training and to appropriately adjust the training process [7]. This is particularly true in competitive shooting technique. That is why the further development of aiming stability parameters is one of the key elements in improving shooting technique and is the main theoretical and practical task of shooters’ training in a shooting sport. Theoretical and practical training with optoelectronic simulators is gaining more importance as they are more widely used. Many practical recommendations are provided by the developers of these simulators [2–4] on aiming, weapon retention and firing in order to improve shooting technique [8–10]. In spite of this, little research has been conducted to analyse the algorithms and models of these simulators that can help compare virtual shots with real ones. Our previous research has revealed statistically significant differences between the SCATT simulator’s virtual shots (as the location of the “holes” marked at the moment when the trigger is pulled) and real shots, which were 211

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found to begin from a zero value of the simulator’s ballistics coefficient, i.e., without any artificial dispersion. This difference increases as the simulator’s ballistics coefficient grows. This indicates a large discrepancy between the SCATT model and the real lateral component of bullet (pellet) movement. As a result, a digitization method of the aiming point trajectory coordinates on SCATT interface graphs, based on accessible Microsoft Office programmes, was developed. It is a simple, accurate and acceptable way to quantitatively estimate the optoelectronic peculiarities in an air-pistol shooters’ training [5]. As far as the problem of assessing aiming stability is concerned, the only study that analysed this issue was one on the aiming technique of an 11-year-old air-pistol shooter; no other publications were found on this subject [11]. Therefore, the aim of this study was to elaborate on the scientific methodology for providing an assessment of air-pistol aiming stability by analysing the following issues: (i) substantiating the parameters of aiming stability, (ii) specifying a quantitative evaluation method by use of an optoelectronic target, (iii) evaluating the reliability of the test for determining aiming stability, and (iv) developing a methodology for creating indivi­dual and group parameters that determine aiming stability. Material and methods The study analysed top air-pistol shooters’ results that were recorded on a SCATT optoelectronic simula-

tor [2] as well as data available on the internet on their results [12]. The aiming trajectories of 95 air-pistol shooters, each of whom took 60 shots in accordance to International Official Statutes, Rules and Regulations [13], were calculated to develop individual and group parameters of aiming stability. An average aim point trajectory (on the SCATT optoelectronic target) taking place one second before a shot was considered as a parameter of the weapon retention process (see Fig. 1). This parameter of technical preparedness does not depend on the ballistic characteristics of a pistol and pellets [14]. For this study, the data from the SCATT target coordinate system of all 60 trajectory centres (aiming points) was averaged in order to eliminate systematic aiming error. The coordinates of the aiming trajectories were recalculated into this coordinate system. The distances from the average of these 60 aiming trajectories to the average of each aiming trajectory were then calculated. The horizontal (x) and vertical (y) coordinates of the average aiming points were extracted into a spread sheet file showing all shot data. Parametric statistical methods were used to analyse the results as the number of experimental samples was quite large (60 shots in each series). Variation statistics (arithmetic mean and standard deviation), Student’s t-test, Snedecor’s F-test [15], and cluster analysis [16] were used to substantiate the parameters of aiming stability and to further quantitatively evaluate the research method. Two-way ANOVA with data correlation and reliability theory tests [17] were used to evalu­ate the test reliability of the selected parameters of aiming stability. Significance level was fixed

Figure 1. A sample target showing the aiming parameters: t = –1 s is the beginning of the aiming tra­jec­ tory 1 s before pulling the trigger; t = 0 is the moment when the shot is taken; Ok is the trajectory centre of one shot; O is the total average point of all aiming trajectories (60 shots) 212

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at 0.05. An inter-group correlation coefficient was used to calculate a test reliability coefficient: ŋ=

MSt – MSe , (1) MSt

where MSt is the inter-group variance that estimates the difference between the shooters’ results; MSe is the variance of errors that estimates the sum of the dispersion of the shot results in the series as well as among them. Variation statistics and a clusterization method were used to develop the group parameters of aiming stability. The basic idea of this approach was based on the fundamentals of cluster analysis, which is used to divide the object sample into clusters that do not overlap one another. Each cluster consists of similar objects, but the objects of different clusters are very dissimilar. Each object was characterized by a number of object factors. A matrix of distances was developed using these factors, and each object was described in relation to its distance from other objects in the system. The quantitative parameter of the cluster process is mathematical criterion. The limits between the cluster groups of the objects were defined with the help of this criterion. The system of parameters measuring aiming stabi­ lity consisted of samples of the average distance away from the total average of the aiming point trajectories (60) to the average point of each aiming trajectory one second before the shot. Each sample characterizes the shooter by the average distance and its variation: N

M=

lk

k=1

N

experimental samples (4) were obtained using Snedecor’s F-distribution:

N

; SE =

(lk – M)2

k=1

N (N – 1)

H0 : MSi = MSj .

(4)

These levels were taken into consideration when the Student’s t-test formula was defined. The shooters’ groups were clustered by three confidence levels (0.95, 0.99 and 0.999) using the results of statistical hypothesis testing on arithmetic means. The clusters’ borders were defined using the following algorithm: the results of the first shooter were compared to the other 94 shooters at the confidence level of 0.999. In the second clusterization attempt, the comparison process started from the last (nth) shooter, and in the third clusterization attempt, from the middle n + 1 2

th

shooter. The borders between the clusters

at 0.99 and 0.95 confidence levels were defined by the three attempts mentioned above. A critical value of the confidence level was chosen according to the optimal interval number, which was defined by Sturges’ formula [18]: K = 3.32lg(n). (5) The interval range (h) was defined by the following equation: h=

Mmax – Mmin , (6) K

where Mmax and Mmin are the extreme arithmetic means. ,

(2)

where M is the arithmetic mean, lk is the average distance taken from the total average aiming point (from 60 trajectories) to the average point of each aiming trajectory one second before the k-shot, N is the number of shots, i.e. 60, and SE is the standard error of arithmetic mean. The confidence level, on which the null hypothesis could be rejected based on the samples of two shooters from one parent population, was used as a mathe­ matical criterion to define the borders between the clusters. As such, a distance matrix between the average results of the shooters was developed from the estimated value of the confidence level on which the null hypothesis (3) could be rejected: H0 : Mi = Mj , (3) where i, j = 1.2…n. Student’s t-test, independent of the variables, was used to test this hypothesis. Corresponding confidence levels for the null hypothesis on the dispersion of the

Fisher’s chi-square distribution for attributive cha­rac­ ters was used to develop a methodology for creating individual and group models of aiming stability as well as to test them. The influence of the grouping method (the interval or the cluster) on shooters’ distribution results in the qualification groups was examined with: 2

=

(O – E)2 , (7) E

where O is the number of intervals and clusters and E is the average number of corresponding pairs of intervals and clusters. The calculations were performed using Microsoft Excel and Statistica (StatSoft, USA). Results and discussion The results of two-way ANOVA with data correlation, which was used to evaluate the reliability of the weapon retention test, are presented in Table 1. No statistically significant differences were found between the shot results in series (p = 0.107). Therefore, the test reliability coefficient was estimated as an inter-group correlation coefficient (1): ŋ = 0.944; test reliability was sufficient as ŋ > 0.900. Consequently, if a shooter is 213

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Table 1. Two-way ANOVA results of the average aiming point distance of 95 shooters in a 60-shot series: SS is a sum of squared deviation; df is the number of degrees of freedom; MS is variance; F is Snedecor’s criteria; p value; Q is a part of the total dispersion Cause of dispersion

SS

Series Shooters Interaction Errors Total

df

MS

F

p

Q, %

835 59 14.15 1.236* 0.107 1.0 19177 94 204.01 17.818† 0.000 23.0 63500 5546 11.45 76.0 64335 5605 11.48 77.0 83512 5699 14.65 100

Figure 2. Parameters of shooters’ aiming stability (M + SE)

* F0.05; 59; 5546 = 1.323; † F0.05; 94; 5546 = 1.254

plying that these results belong to the first cluster (see Tab. 3). Other shooters (9÷95) belong to the other clusters due to their confidence level values being smaller than the critical value of 0.999. The right border of the second cluster was defined starting with the 9th row of Table 2. Thus, the 95 competitors were divided into five clusters as model “a” (see Tab. 3). For the second clusterization attempt, the comparison began from the last (95th) shooter (model “b”). For the third clusterization attempt, the comparison started from the middle (48th) shooter (model “c”). The same algorithm was used to define the locations of the clusters’ borders at the confidence levels of 0.99 and 0.95 (models “d” ÷ “i”, respectively). The number of clusters in each clusterization attempt varied between four and eight. The optimal number of intervals defined by Sturges’ formula (5) was seven. In such cases, some specialists recommend to choose a value of seven or eight intervals [18]. That is why the clusterization results are not used if the number of clusters equalsed four÷six (models “a” ÷ “f”). The number of clusters that equalled eight were found when the clustering process began from the objects located at the extreme ends (i.e. the results of the

well-qualified, the value of this parameter would be small (the highest level was found to be 2.5 mm; the lowest level, 11.4 mm) and vice versa. As no statistically significant differences were found between the locations of the aiming trajectory centres, the dispersion of the distances of these points was used as an individual model characteristic of aiming performance. The stability of the parameters of individual aiming technique was evaluated with a rather small part (Q = 1.0%) of total dispersion (see Tab. 1). The individual characteristics of aiming stability were developed using the parameters of the aiming trajectory coordinates (see Fig. 2). The confidence levels of the first 10 shooters (from a total of n = 95), on which the null hypotheses (3) and (4) from the sample origin of one parent population could be rejected, are presented in Table 2. The average of the shooters’ results, starting with the smallest (the best) results, are shown in Figure 2. When comparing the results of the first shooter with the remaining 94 at a confidence level of 0.999, one can see that the values of the confidence levels starting with the 2nd and up to 8th columns of the first row in the right upper part of Table 2 (0.0945÷0.0029) are more than the critical value of 0.001, thereby im-

Table 2. The value of a significance level (the first 10 out of n = 95 shooters), which the null hypotheses on the sample origin from one parent population can be rejected: p(t) \ p(F) No

1

1

2

3

4

5

6

7

8

9

10

0.0945

0.0416

0.0425

0.0639

0.0416

0.0272

0.0029

0.0002

0.0006

0.7297

0.7130

0.7037

0.5900

0.5206

0.0995

0.0235

0.0321

0.9770

0.9355

0.8137

0.7442

0.1651

0.0465

0.0583

0.9564

0.8363

0.7686

0.1775

0.0528

0.0645

0.8916

0.8328

0.2326

0.0891

0.0978

0.9434

0.2780

0.1113

0.1201

0.2907

0.1127

0.1231

0.7069

0.6563

2

0.9982

3

0.8027

0.8010

4

0.9749

0.9767

0.7785

5

0.0888

0.0892

0.0514

0.0947

6

0.1476

0.1482

0.0900

0.1565

0.7975

7

0.4089

0.4102

0.2825

0.4269

0.3781

0.5317

8

0.0087

0.0088

0.0042

0.0095

0.3482

0.2327

0.0698

9

0.1796

0.1803

0.1119

0.1900

0.7162

0.9148

0.6041

0.1937

10

0.0078

0.0078

0.0037

0.0085

0.3283

0.2176

0.0640

0.9684

214

0.9155 0.1805

HUMAN MOVEMENT I. Zanevskyy, Y. Korostylova, V. Mykhaylov, Aiming point trajectory

first or last shooter), where the confidence level was 0.95. However, the borders of these clusters were located at random and labelled as models “h” and “i”. It is possible that the differences with these border locations are the result of the influence of extreme effects. In addition, the recommended number of qualifying groups in sport competition is seven: the highest, high, upperintermediate, intermediate, lower-intermediate, low and

the lowest [18]. This method of division is suitable for model “i”. So, the highest sports skill level was equated with the first cluster (the results of the record-holders). The other six clusters were equated with the six official rankings based on the Unified Sports Classification System used in the former USSR [19]: Master of Sports at the International Level (high level), Master of Sports (upper-intermediate level), Master of Sports Candidate

Table 3. The division variants of air-pistol shooters by clusters and intervals (n = 95) Clusters Ranks

a

b

c

d

e

Intervals f

g

h

i

95

48

The object from which the clusterization began 1

95

48

1

p = 0.001 1. 2. 3. 4. 5. 6. 7. 8.

1 ÷ 8 9 ÷ 48 49 ÷ 72 73 ÷ 91 92 ÷ 95 – – –

1 2 ÷ 9 10 ÷ 49 50 ÷ 73 74 ÷ 95 – – –

95

48

1

p = 0.01 1 ÷ 7 8 ÷ 72 73 ÷ 91 92 ÷ 95 – – – –

1 ÷ 7 8 ÷ 34 35 ÷ 63 64 ÷ 84 85 ÷ 92 93 ÷ 95 – –

1 ÷ 7 8 ÷ 31 32 ÷ 62 63 ÷ 83 84 ÷ 95 – – –

j

p = 0.05 1 2 ÷ 11 12 ÷ 64 65 ÷ 84 85 ÷ 92 93 ÷ 95 – –

1 ÷ 2 3 ÷ 8 9 ÷ 32 33 ÷ 58 59 ÷ 75 76 ÷ 90 91 ÷ 93 94 ÷ 95

1 2 ÷ 4 5 ÷ 13 14 ÷ 35 36 ÷ 58 59 ÷ 73 74 ÷ 90 91 ÷ 95

1 2 ÷ 7 8 ÷ 21 22 ÷ 63 64 ÷ 82 83 ÷ 91 92 ÷ 95 –

1 ÷ 13 14 ÷ 52 53 ÷ 67 68 ÷ 81 82 ÷ 91 92 93 ÷ 95 –

Table 4. The test results of the null hypothesis on the frequency similarities in the qualification groups based on intervals and clusters Parameter Oin Ocl Sum E 2(O-E)2/E

Number of intervals or clusters 1.

2.

3.

4.

5.

6.

7.

13 1 14 7 10.27

39 6 45 22.5 24.20

15 9 24 12 1.50

14 47 61 30.5 17.85

10 19 29 14.5 2.79

1 9 10 5 6.40

3 4 7 3.5 0.14

Sum 95 95 190 95 63.17

Table 5. The test results of the null hypothesis on the similarity of the results distribution in the qualification groups based on intervals and clusters Statistics Min SDin Mcl SDcl F-test vin vcl F(0.05;vin; vcl) p(F) t-test v t(0.05; v) p(t)

1.

2.

3.

4.

5.

6.

7.

3.33 1.86 2.52 1.50 1.529 779 59 1.406 0.021 3.287 838 1.963 0.001

4.47 2.70 3.09 1.64 2.718 2339 359 1.145 0.000 9.440 2698 1.961 0.000

5.73 3.39 3.76 2.05 2.734 899 539 1.137 0.000 12.173 1438 1.962 0.000

6.95 3.80 4.76 2.90 1.722 839 2819 1.094 0.000 17.786 3658 1.961 0.000

8.13 4.56 6.83 3.91 1.358 599 1139 1.123 0.000 6.188 1738 1.961 0.000

9.66 5.59 8.18 4.42 1.600 59 539 1.346 0.004 2.388 598 1.964 0.017

10.92 6.95 10.61 6.65 1.093 179 239 1.256 0.260 0.472 418 1.966 0.637 215

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(intermediate level), First-Class Shooter (low intermediate level), Second-Class Shooter (low level) and ThirdClass Shooter (the lowest level). That is why a modification of the clustering process proposed here for model ‘i’, starting from the middle object at a confidence level of 0.95, was taken as the basis for characterizing the entire group into corresponding qualification groups. The division of the variation series into intervals was considered as an elemental method for developing subgroups. The width of the intervals (h = 1.27) was defined by using equation (6) for all the 95 shooters, with the extreme arithmetic means of Mmax = 11.41 mm and Mmin = 2.52 mm. The initial borders of the intervals are as follows: 3.79, 5.06, 6.33, 7.60, 8.87 and 10.14 mm (see Fig. 2). The number of shooters in each variation series interval is shown in model “j” (see Tab. 3). The characteristics of the groups’ fullness, its ability to be divided and the interval and cluster similarities (or differences) in the variation parameters and in overall tendency were used to compare the characteristics of the variation series and the cluster analysis methods. A comparison revealed an influence of the grouping method on the distribution of the shooters’ results among the qualification groups. The calculated values by chi-square distribution (7) is higher ( 2 = 63.17) than its critical value ( 20.05; 6 = 12.59). Thus, the division into clusters is statistically significantly different (p = 0.05) from the division into intervals, i.e. the null hypothesis on similarity was rejected (see Tab. 4). The most informative indicator as a comparative characteristic of both of the methods mentioned above is the interval and cluster similarities of the variation parameters and of central tendency (see Tab. 5). The test results of the null hypotheses on the similarity of the results distributed into qualifying groups, based on the variation series intervals and on the clusters, indicate a similarity of dispersions (p = 0.260) and arithmetic means (p = 0.637) only in the seventh pair of intervals and clusters. In 12 out of 14 possible comparative analysis options, a statistically significant difference of scattering was detected (p = 0.05). Therefore, the location of the interval borders differs from the location of the cluster borders. This is probably because of the difference in the grouping principles of both methods. The proposed variant of the clustering method is based on Student’s parametric test, which takes into account the central tendency and the variation of the samples when the null statistical hypothesis is tested. The variation series method of grouping is based on the location of extreme objects (the amplitude is the least informative characteristic of variation). Thus, it is believed that such a proposed modification of the clustering method should be used in an assessment of an air-pistol shooter’s aiming stability. The results of the variation series method can be used for defining the clusters number by the number of variation series intervals (see Fig. 3). 216

Figure 3. The quantitative parameters of the shooters’ aiming stability developed with intervals (i) and clusters (c)

Conclusions 1. An average aiming point trajectory taken one second before taking a shot on the SCATT optoelectronic target should be accepted as an assessment parameter of aiming stability, as it is one of the basic parameters of technical preparedness and does not depend on the ballistic characteristics of a pistol and pellets. This test has shown high reliability in the assessment of sports technique (ŋ = 0.944). If a shooter is well-qualified, the value of this parameter is small, and vice versa (the highest level – 2.5 mm; the lowest level – 11.4 mm). Nonetheless, statistically significant differences between the locations of the aiming trajectory centres (p = 0.107) in a competition series provided us an opportunity to take the parameters of the scattering of these points as a quantitative characteristic of the individual manner of aiming stability. 2. The outlined clustering method could be useful and suitable for defining the limits between shooters’ qualification groups (as a parameter of aiming stability). A confidence level (where the null hypothesis could be rejected, based on the samples of two shooters’ results from the same general population) can be used as a quantitative criterion to define the borders between the clusters of aiming stability. Clustering the group results of about 95 shooters has to be performed at a significance level of 0.05 in order to create an optimal number of qualifying groups. 3. The clustering process should start with a comparative analysis of the central objects in the matrix, i.e. shooters ranked in the middle of the series. If the clustering process starts with the first or last shooter, it will change the position of the limits between clusters due to the influence of extreme effects. The limits formed by variation series intervals differ significantly from the cluster limits because of the difference in the principles of grouping in these two methods. The proposed variant of the clustering method is based on the Student’s parametric test, which takes into account the central

HUMAN MOVEMENT I. Zanevskyy, Y. Korostylova, V. Mykhaylov, Aiming point trajectory

tendency and variation of the samples when the null statistical hypothesis is tested. 4. Variation series and cluster methods have a high level of separating power of the grouping processes (p < 0.0001). The test results of the null hypothesis on the frequency similarity of the qualifying groups, based on the clusters and variation series intervals, show a total dissimilarity of the corresponding pairs of intervals and clusters (p = 0.05). 5. The proposed modification of the clustering method should be used in an assessment of an air-pistol shooter’s aiming stability. The results of the variation series method can be used for defining the cluster numbers based on the number of variation series intervals. 6. Parameters of aiming stability in air-pistol shooting were developed using the proposed modification of the clustering method. This allows for the identification of weak points in the structure and organization of shooters’ training and allows for adjustment of the training process. Acknowledgements The research was partly supported by the Ministry of Edu­cation and Science of Ukraine, Research Grant No. 0106U012607. The authors would like to express their gratitude to Anonymous Referees for their valuable comments.

References 1. Pyatkov-Melnik V.T., Shooting Sport Science in Ukraine 2001–2005 [in Ukrainian]. Sportyvna Nauka Ukrainy, 2006, 6, 10–30. 2. SCATT, Professional training systems. ZAO NPP SCATT. Available online from: URL: http://www.scatt.com [accessed 6 May 2011]. 3. RIKA, RIKA Home Trainer. Available online from: URL: http://www.rika1.com/default.asp?Language=E [accessed 6 May 2011]. 4. NOPTEL, Sport Shooter Training System from Noptel. Available online from: URL: http://www.noptel.fi/eng/ sport [accessed 6 May 2011]. 5. Zanevskyy I., Korostylova Y., Mykhaylov V., Specificity of shooting training with the optoelectronic target. Acta of Bioengineering and Biomechanics, 2009, 11 (4), 63–70. 6. Verhoshansky Yu.V., Theory and methodology of sports training: block system of training of elite shooters [in Russian]. Teoria i Practika Fizicheskoy Cultury, 2005, 4, 2–13. 7. Kashuba V.A., Habinets T.O., How to increase the effectiveness of shooters training using the cumulative effect of biomechanics ergogenic methods. In: Vynohradsky B.A. (ed.), Striletska pidgotovka v Olympiyskyh dys-

cyplinach [in Ukrainian]. Ukrainian Technologies, Lviv 2004, 10–14. 8. Ball K.A., Best R.J., Wrigley T.V., Body sway, aim point fluctuation and performance in rifle shooters: interand intra-individual analysis. J Sports Sci, 2003, 21 (7), 559–566, doi: 10.1080/0264041031000101881. 9. Edelmann-Nusser J., Heller M., Hofmann M., Ganter N., On-target trajectories and the final pull in archery. Eur J Sport Sci, 2006, 6 (4), 213–222, doi: 10.1080/17461 390601012579. 10. Mononen K., Viitasalo J.T., Era P., Konttinen N., Optoelectronic measures in the analysis of running target shooting. Scand J Med Sci Sports, 2003, 13 (3), 200–207, doi: 10.1034/j.1600-0838.2003.00130.x. 11. Zanevskyy I., Korostylova Y., The aiming technique mo­ del of a young air-pistol shooter [in Ukrainian]. Fizychne Vyhovannya, Sport i Kultura Zdorovya u Suchasnomu Suspilstvi, 2009, 3, 97–102. 12. Ukrainian Shooting Federation, On-Line Shooting Contest of the Ukrainian Shooting Federation. Available online from: URL: http://www.shooting-ua.com/control_ On-Line.htm [accessed 6 May 2011]. 13. International Shooting Sport Federation, Official Statu­ tes Rules and Regulations. International Shooting Sport Federation, Munich 2009. 14. Korostylova Y., Zanevskyy I., Accuracy of shooting results imitation with an optoelectronic training system. Book of Abstracts of the 14th Annual Congress of the European College of Sport Science in Olso, Norway from 24–27 June 2009, p. 603. Edited by Loland, S., Bø, K., Fas­ ting, K., Hallèn, J., Ommundsen, Y., Roberts, G., Tsolakidis, E. 15. Vincent W.J., Statistics in Kinesiology. Human Kinetics, Champaign 2005. 16. Hastie T., Tibshirani R., Friedman J., The Elements of Statistical Learning. Springer,  Heidelberg 2003. 17. Morrow J., Jackson A., Disch J., Mood D., Measurement and Evaluation in Human Performance. Human Kinetics, Champaign 2002. 18. Zatsiorsky V.M., Sport metrology [in Russian]. Fiziches­ kaja Kultura i Sport, Moscow 1982. 19. Great Soviet Encyclopedia. 3rd ed. (trans). Macmillan, New York 1973–1983.

Paper received by the Editors: May 17, 2011 Paper accepted for publication: March 1, 2012 Correspondence address Ihor Zanevskyy PR KWFiZ ul. Malczewskiego 22 26-600 Radom, Poland e-mail: [email protected]

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HUMAN MOVEMENT 2012, vol. 13 (3), 218– 224

FUNCTIONAL RELATIONSHIPS BETWEEN GAZE BEHAVIOR AND MOVEMENT KINEMATICS WHEN PERFORMING HIGH BAR DISMOUNTS – AN EXPLORATORY STUDY doi: 10.2478/v10038-012-0025-2

THOMAS HEINEN 1 *, KONSTANTINOS VELENTZAS 2 , PIA M. VINKEN 3 1

University of Hildesheim, Germany Bielefeld University, Germany 3 Leibniz University, Hanover, Germany 2

Abstract

Purpose. The aims of this study were, first, to investigate visual spotting and, second, to explore the functional relationships between movement structure and gaze behavior in gymnasts as they perform preparatory giant swings (traditional and scooped technique) and dismounts (single straight and double tucked salto) with increasing difficulty on the high bar. It was predicted that visual spotting would occur in all experimental tasks. Methods. Relationships between gaze behavior and movement kinematics were explored to provide a clearer picture of how gaze is interconnected with the kinematics of dismounts on the high bar. For this purpose, kinematic parameters were measured with an optical movement-analysis system while gaze behavior was measured by using a portable and wireless eye-tracking system. Results. The measurement of gaze behavior revealed that gymnasts use visual spotting in all three tasks showing fixations throughout the whole movement. Each task was furthermore characterized by a sequence of visual fixations that was thought to serve specific movement goals. In particular, fixations during the downswing phase of the preparatory giant swings were significantly correlated with the movement phases when beginning the hip extension and flexion in the “kick through” as well as with the athlete’s distance of flight during the dismounts. Conclusions. The findings suggest that gymnasts can use visual spotting during preparatory giant swings and dismounts on the high bar and that there are functional relationships between different fixations and specific movement goals.

Key words: gymnastics, giant swings, eye-tracking

Introduction Intentionally directing one’s gaze to objects or locations in a surrounding environment such as gymnastic apparatus, distant walls, the floor or the ceiling is conceptually referred to as visual spotting [1]. Visual spotting is thought to play a critical role for optimizing the movement execution of certain skills in sport [2]. It usually accompanies a series of fixations in which the visual system can extract information needed for skill performance [1, 3]. However, little is known about visual spotting and the relationship between visual spotting and movement kinematics in more complex skills that are similar in movement structure but differ in movement dynamics. Therefore, the aim of this study was to investigate visual spotting as well as to explore functional relationships between gaze behavior and movement kinematics in preparatory giant swings and dismounts with increasing difficulty on the high bar. It has been suggested that the information extracted from visual spotting is primarily used to provide the athlete with information to control the landing of aerial skills [4, 5]. Davlin et al. [4] observed for instance that the landing stability of a back tuck salto was significantly affected by any loss of vision: with no vision

* Corresponding author. 218

yielding worse performance than reduced vision. Luis and Tremblay [6] had experienced acrobats perform back tuck saltos under four different visual conditions: (1) full vision, (2) vision at angular head velocities below 350° s –1, (3) vision at angular head velocities above 350° s –1, and (4) no vision. The angular velocity of the head was calculated in real time, triggering liquid crystal goggles to manipulate visual information pickup. It was shown that all vision conditions resulted in better landing performance than the no-vision condition, supporting the assumption that visual information pickup is an important factor which affects gymnasts’ performance in aerial skills. One could, however, argue that manipulating visual information pickup could force gymnasts to rely more strongly on visual spotting and/or to focus their visual attention more intensively [7]. One may additionally assume that the visual information that was manipulated in the previously mentioned studies was either not needed in the performance of the experimental tasks or was related to landing stability only. It could just be the case that when manipulating other visual information, such as the reduction of binocular vision, other parameters may be impacted outside of only landing stability, especially when performing a complex aerial skill. This may at least in part explain why for instance Davlin et al. [4] found no effect on movement kinematics when manipulating visual information pickup.

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It is furthermore argued that during high angular velocities of the head (e.g., during a salto), gaze is not likely to be fixated during a skill, as high angular velocities are thought to exceed the functional range of the vestibulo-ocular reflex in stabilizing the retinal picture [8]. There is, however, additional evidence that athletes’ visual systems seem to adapt to training complex skills that incorporate fast whole-body rotations [9]. This may lead to the assumption that rotation trained athletes can extract visual information and/or use adaptive gaze behavior during the performance of skills incorporating fast whole-body rotations. When exhibiting an adaptive gaze behavior, gymnasts would still be able to extract the visual information needed in the performance of the task at hand. As a consequence they would still be able to produce an accurate and precise movement pattern that does not differ from their movement pattern under full vision [9, 10]. Recent work on natural tasks has furthermore demonstrated that the observer’s cognitive goals play a criti­ cal role in the direction of gaze during a wide range of natural behaviors [3, 11]. It was revealed that subjects usually use eye movements in a proactive manner [12]. Grasso et al. [13] measured the head and horizontal eye movements of individuals walking around corners. It could be shown that when turning, individuals made anticipatory eye and head movements to align with their intended walking trajectory. Hollands et al. [14] had participants walk along a 9-m pathway and measured their gaze behavior and their head and body movements. Participants maintained a straight walking trajectory or changed their walking direction by 30° or 60° at the midpoint of the pathway. The authors found that prior to changing the walking direction, participants aligned their gaze with the end-point of the required travel path. Head and body reorientation accompanied this realignment. These results lead to the assumption that eye movements also during complex skills may be aligned with movement goals. However, empirical evidence concerning this aspect in complex skills, incorporating whole-body rotations, is still lacking. In summary, performing complex skills with rotations on one or more body axes places specific demands on athletes’ spatial orientation [1]. Vision has been proposed to play a critical role in providing athletes with the necessary cues for spatial orientation through visual spotting [4, 6]. However, empirical support on visual spotting and the relationships between gaze behavior and movement kinematics in complex aerial skills is still limited with gaps existing in literature on the subject. Therefore, the goal of the current study was to investigate visual spotting by expert athletes as they perform dismounts with increasing difficulty and the dynamics after preparatory giant swings on the high bar. The athle­tes’ gaze and movement behavior were analyzed in a natural setting in order to determine how their gaze is related to performance [2, 10]. It was predicted that visual spotting

would occur in all set tasks, given that athlete’s visual system may adapt to training skills incorporating fast whole-body rotations [9]. An additional point of interest was to explore for relationships between gaze behavior and movement kinematics from an exploratory viewpoint, with hopes at providing a clearer picture of how gaze is interconnected with the kinematics of dismounts on the high bar. In contrast to existing research on gaze behavior [15], how distinct fixations may serve specific functions during skill exe­cution were also investigated. It was argued that functional relationships do exist, given that research has demonstrated that participants often use anticipatory eye movements that align with their future (movement) goals [3]. Material and methods A sample of N = 12 gymnasts was recruited to participate in this study. The gymnasts were able to perform dismounts from the high bar with increasing difficulty, such as single and double saltos in tucked, piked or layout body positions with and without twists. The gymnasts were active gymnasts competing in the German 2nd federal league with at least ten years of training and competition experience (age: 23 ± 2 years). It was decided to recruit expert gymnasts and study their movement and gaze behavior in a natural setting in order to determine how athletes’ gaze contributes to performance [2]. All participants were informed about the purpose and the procedures of the study and provided their written consent prior to the study. All had normal or corrected-to-normal vision. The study was carried out according to the ethical guidelines and with the approval of the university’s local ethical committee. The experimental tasks were two different backward dismounts on the high bar performed from preparatory giant swings with two different techniques. The general aim of the preparatory giant swings is to achieve sufficient angular momentum together with a sufficient take-off velocity in order to perform the intended dismount. Two distinct techniques for preparatory giant swings have evolved in gymnastics, the traditional technique and the scooped technique [16]. Both techniques differ with regard to the intensity and timing of extension and flexion of the hip joint and the shoulder joint. In the traditional technique the gymnast maintains a straight body configuration from the handstand position. There is then a slight flexion of the body prior to the bottom of the giant swing, followed by an extension of the body as the gymnast passes under the bar (see Fig. 1). During the upswing phase the gymnast maintains a shallow pike body configuration and extends his body into the handstand [16]. The scooped technique is characterized by a flexed body position as the gymnast passes through the horizontal in the downswing phase followed by a hyper-extension of the 219

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Figure 1. Prototypical stick-figure sequence of the layout salto (right) with a preparatory giant swing (traditional technique) on the high bar (left). The numbers indicate the time structure of the skill. The dotted lines represent the fixations and fixation direction during the skill. The thickness of the dotted lines indicates fixation duration. F1 to F15 indicate the sequence of fixations. A1 to A3 indicate each of the fixation’s area of interest that was directly related to movement kinematics

Figure 2. Prototypical stick-figure sequence of the double salto (right) with a preparatory giant swing (traditional technique) on the high bar (left). The numbers indicate the time structure of the skill. The dotted lines represent the fixations and fixation direction during the skill. The thickness of the dotted lines indicates fixation duration. F1 to F14 indicate the sequence of fixations. A1 to A3 indicate each of the fixation’s area of interest that was directly related to movement kinematics

hip [17]. The “kick through” is delayed compared to the traditional technique, and appears as an accentuated piking action late in the upswing, which conti­ nues over the top of the bar (Fig. 2). Both techniques are appropriate to produce large amounts of angular momentum [18]. However, the scooped technique may be more functional during the gymnast-bar system energy exchange, especially when the aim is to maximize angular momentum and to optimize flight time during the dismount [19]. The scooped technique may also be advantageous by providing a wider release win220

dow and, therefore, provide a greater margin of error than the traditional technique [17]. It was decided to use both the traditional technique and the scooped technique in two different dismounts (single backward salto in a layout body configuration vs. double backward salto in a tucked body configuration) in order to answer the question of how gaze behavior is related to performance depending on the dynamics of both the preparatory giant swings and dismounts. This resulted into the three experimental conditions: (1) single salto in a layout body configuration (tradi-

HUMAN MOVEMENT T. Heinen, K. Velentzas, P.M. Vinken, Visual spotting in gymnastics

Figure 3. Prototypical stick-figure sequence of the double salto (right) with a preparatory giant swing (scooped technique) on the high bar (left). The numbers indicate the time structure of the skill. The dotted lines represent the fixations and fixation direction during the skill. The thickness of the dotted lines indicates fixation duration. F1 to F14 indicate the sequence of fixations. A1 to A4 indicate each of the fixation’s area of interest that was directly related to movement kinematics

tional giant swing technique, Fig. 1), (2) double salto in a tucked body configuration (scooped giant swing technique, Fig. 2) and (3) double salto in a tucked body configuration (traditional giant swing technique, Fig. 3). The gymnasts were videotaped in order to allow for further kinematic analysis. The horizontal and vertical coordinates of nine points (body landmarks) were recorded in each frame using movement analysis software (WinAnalyze 3D, Mikromak, Germany) [20]. The nine body landmarks were used to define a 7-segment model of the human body. As the three chosen tasks only contain regulatory low frequency movements, a frame rate of 50 Hz was deemed sufficient for kinematic analysis of the high bar performances by an independent biomechanist. A digital filter (cutoff frequency of 6 Hz) was applied for data smoothing. A mean temporal error of ± 0.02 s and a mean spatial error of ± 0.007 m were calculated from the present data. The body-segment parameters were calculated on the basis of the individual anthropometric properties of each participant. The swing motions prior to release in the traditional and scooped technique are characterized by a particular coordination of the hip and shoulder joints [18]. In order to describe the timing of the giant swings and the dismounts, the relative phase durations were analyzed. Changes in body configuration during the movement phases were expressed by the values of the shoulder angle and the hip angle [21]. Finally, the landing was expressed by calculating the distance of the feet to the high bar during touch-down. A recently developed recording system was used to record eye movements [10]. The system consists of

a modified bicycle helmet with an attached wireless infrared miniature camera (approximate weight 250 g). The miniature camera records images of the eyeball at a sampling rate of 50 Hz, and can be synchronized with the WinAnalyze 3D movement-analysis system. The eyeball is illuminated by two infrared diodes that create two reflection points on the cornea. The X- and Y-coordinates of both corneal reflection points, the centroid of the pupil, and another reference point (inner side of nasal bone) were digitized in a semi-automatic manner. From the coordinates of the reference points, camera movements that occur during complex movements were then mathematically corrected. The rotation of the eyeball was calculated from the corneal reflection points and the centroid of the pupil. Angular data of the eyeball was then integrated into the kinematic data from the movement analysis system and the current gaze direction was superimposed on the digital video sequences of the saltos. Eye movement measurement error was given as 0.5° between –15° and +15° of the visual field in the horizontal and the vertical directions and 1.0° between +15° to +30° and –15° to –30° of the visual field in the horizontal and the vertical directions. In this study, two gaze behavior variables were analyzed: the direction and duration of the visual fixations. A fixation was defined as any state in which the gaze remains stationary on one reference point in the environment for five video frames or longer (100 ms) [22]. During a giant swing or salto this may occur especially when the eyes rotate to compensate for rotations of the head in order to hold the gaze fixated on one reference point. Two independent and trained re221

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search assistants coded the visual fixations and eye blinking frame by frame. Inter-rater reliability was calculated at r = 0.91 (p 0.05). In order to analyze how gaze behavior was connected with movement behavior, the gymnast’s gaze behavior and movement kinematics were averaged over all trials for each of the three dismounts. From this average, prototypical stick-figure sequences were generated, indicating the distinct fixations to the same areas of interest that occurred in more than 68% of the trials [23]. As a last step, productmoment correlations were calculated between kinematic parameters and gymnasts gaze behavior. The high bar used in the experiment was arranged as it would be in an international competition with safety mats in the front, below and behind the high bar. Each participant took part in two familiarization trials without the use of the eye-tracking helmet and another three trials with it in order to get used to the equipment. There was no time pressure in this study and each participant was allowed to take breaks as needed. After the familiarization trials, the participants were asked to perform the experimental tasks in a random order. The participants were instructed to perform a landing as per gymnastic rules at the end of the dismount and then stabilize their landing for at least three seconds. Each participant was asked to perform four dismounts of each of the studied saltos for a total of twelve dismounts. Results As this study attempted to explore the relationships between gaze behavior and movement kinematics, the results of both were averaged over all the trials performed by all participants for each of the three dismounts. Figures 1, 2 and 3 present the prototypical movement sequences together with visual fixations on specific areas of interest in the layout salto, the double salto (traditional technique) and the double salto (sco­ oped technique), respectively. A prototypical layout salto with the preparatory giant swing was characterized by a sequence of 15 fixations, starting during the handstand position of the preparatory giant swing and ending during the landing. The first, sixth, seventh and eleventh fixation were directed toward the high bar. The second, third, eighth, ninth, and twelfth fixations were directed toward the rear mat. The fourth, tenth and thirteenth fixations were directed towards the front mat. The fifth fixation was directed towards the distant wall in front of the gymnast, and the fourteenth and fifteenth fixations were also directed towards the front mat. Three significant correlations were found that seemed to be of high functional relevance. First, the direction of the second and eight fixations were significantly correlated (r = 0.85, p 0.05) with the moment of when the hip extension began during the preparatory giant swing and 222

during the downswing prior to the dismount, which indicates the starting point of the kick through. A correlation of r = 0.87 (p 0.05) was found between the direction of the third, ninth and twelve fixations and the moment when the hip joint started to be flexed in order to perform the kick through. Finally, the fixation direction of the fourth, tenth and thirteenth fixations was significantly correlated with the athlete’s distance of flight (r = 0.91, p 0.05). A prototypical double salto performed with the traditional giant swing technique was characterized by a sequence of 14 fixations. The first, fifth, sixth and tenth fixations were directed towards the high bar. The second, third, seventh, eighth and eleventh fixations were directed towards the rear mat. The fourth, ninth, twelfth, thirteenth and fourteenth fixations were directed towards the front mat. In line with the results reported for the layout salto, again, significant correlations were found that seem to be of high functional relevance. First, the direction of the second and seventh fixations were, on average, significantly correlated (r = 0.87, p 0.05) with the moment of when the hip extension began during the preparatory giant swing and during the downswing prior to the dismount, indicating the starting point of the kick through. An average correlation of r = 0.86 (p 0.05) was found between the direction of the third, eighth and eleventh fixations and the moment when the hip joint started to be flexed in order to perform the kick through. Finally, the fixation direction of the fourth, ninth and twelfth fixations was significantly correlated with the athlete’s flight distance (r = 0.90, p 0.05). A prototypical double salto performed with the scooped giant swing technique was characterized by a sequence of 10 fixations. The first, fourth and seventh fixations were directed towards the high bar. The second fixation was directed toward the rear mat. The third, fifth, sixth and eighth fixations were directed towards the front mat. Similar to the results of the layout salto, again, three significant correlations were found that seemed to be of high functional relevance. First, the direction of the second fixation was significantly correlated (r = 0.87, p 0.05) with the moment when the hip extension began during the preparatory giant swing. The moment when straight body posture was achieved prior to the flexion of the hip during the upswing of the dismount was significantly correlated with the direction of the fifth fixation (r = 0.75, p 0.05). Finally, the fixation direction of the third, sixth and eighth fixations were, on average, significantly correlated with the athlete’s flight distance during the dismount (r = 0.89, p 0.05). Discussion The goals of the current study were to investigate visual spotting in gymnasts as they perform complex

HUMAN MOVEMENT T. Heinen, K. Velentzas, P.M. Vinken, Visual spotting in gymnastics

rotational movements with increasing difficulty and to explore the functional relationships between movement kinematics and gaze behavior. Gymnasts’ gaze behavior and movement kinematics were measured while they performed three different dismounts on the high bar. It was predicted that visual spotting would occur in all experimental tasks. Additionally, relationships between gaze behavior and movement kinematics were explored to provide a clearer picture of how gaze is interconnected with the kinematics of dismounts performed on the high bar. The measurement of gaze behavior revealed that gymnasts use visual spotting in all three tasks because they show fixations throughout the entire movement. Visual fixations on informational aspects that are rele­ vant for movement control when specific constraints are met could be part of a perceptual strategy to control preparatory giant swings and dismounts on the high bar [10]. Gymnast experts may optimize their visual information pickup in different movement phases because they know better “where” to look and “what” to look for [24, 25]. An optimized visual information pickup system could in turn lead to optimized movement planning and regulation [26]. Land and Furneaux [3] concluded from eye movement research in a wide variety of tasks that both motor skills and eye movements are specific to particular set tasks, and it seems sensible to think of eye movements as an integral part of each skill. The authors, furthermore, state, “The eye must be told where to look, what to expect there, and what further observations or measurements to make” [3, p. 1238]. This may explain why correlations between gaze direction and the spatial parameters of significant movement events were found in the present study. One main result of our study was that fixations during the downswing phase of the preparatory giant swings were significantly correlated with the moment at the beginning of hip extension and flexion in the “kick through”, as well as with the athlete’s flight distance during the dismounts. There were additional significant correlations between the athletes’ flight distance and fixation direction during the last phase of the dismounts. For instance, a correlation between fixation direction and landing position during the preparatory giant swing could indicate that gymnasts try to pick up visual information related to the (intended) landing position already during the preparatory giant swings and integrate this information with their current movement state in order to prepare for the dismount. The same argument could hold true for controlling hip extension and hip flexion during the preparatory giant swing. Vision is the only human sensory modality capable of providing information about distant environmental features [27]. Such a characteristic may account for visual information being used in a feed-forward manner to modulate movement patterns, thereby allowing gymnasts to reach their specific goals in a spe-

cific environment, such as the defined extension-flexion movement of the hip in a given time window during the giant swing prior to the dismount. This may also explain the fixations made on a landing position during the flight phase of the dismounts. Most likely they serve as a function that prepares the gymnast for the landing phase. The differences in gaze behavior between the different tasks may, however, reflect the ability of experienced athletes to guide eye movements proactively, in anticipation of events that are likely to occur [12]. Since the experimental tasks differed in their dynamic structure (e.g., traditional vs. scooped technique), it can be assumed that the participants had to rapidly adapt their motor behavior to make optimal use of whatever sources of information available in their movement environment in order to solve the experimental task [28]. However, in regards to the complex skills in gymnastics, it has been argued that skilled participants do not rely on whatever sources of information that are available, but rather use information in the movement environment that is more closely related to movement execution in terms of temporal and/or spatial parameters [1]. There are a number of critical issues present in the experiment that need to be taken into account, with three specific aspects that need to be emphasized. First, visual information pickup was not manipulated, where only athletes’ gaze behavior was analyzed in a natural environment as to better understand how gaze behavior contributes to complex movement execution. Manipu­ lating visual information pickup, while concurrently measuring gaze behavior, could reveal if it leads to adaptive gaze behavior that masks the effect of visual manipulation. Second, a sample of N = 12 participants was recruited. It must be acknowledged that this is a potential limitation with regards to the present results. However, a power analysis on the results revealed that the average power for all significant results was above .80, which can be assumed as sufficient given the design of the present study [29]. Third, it must be acknowledged that the correlative relationships found between movement kinematics and gaze direction may not be interpreted in a causative manner [30]. Nevertheless, these correlations may serve in creating new hypotheses when assessing the interaction of gaze and movement behavior in gymnasts. As a final note, assuming that athletes can extract information on orientation by anchoring their gaze on objects or areas within their environment, coaches should encourage athletes to intentionally use visual spotting when practicing giant swings and dismounts. Acknowledgements We wish to thank Christoph Haase for his support in data acquisition and data analysis and Sonja Parlow for her help in preparing the first draft of this manuscript.

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References 1. Davlin C.D., Sands W.A., Shultz B.B., Do gymnasts “spot” during a back tuck somersault? Int Sport J, 2004, 8 (2), 72–79. 2. Vickers J.N., Perception, cognition and decision training: The quiet eye in action. Human Kinetics, Champaign 2007. 3. Land M.F., Furneaux S., The knowledge base of the oculomotor system. Phil Trans R Soc B, 1997, 352, 1231–1239. 4. Davlin C.D., Sands W.A., Shultz B.B., The role of vision in control of orientation in a back tuck somersault. Motor Control, 2001, 5 (4), 337–346. 5. Hondzinski J.M., Darling W.G., Aerial somersault performance under three visual conditions. Motor Control, 2001, 5 (3), 281–300. 6. Luis M., Tremblay L., Visual feedback use during a back tuck somersault: Evidence for optimal visual feedback utilization. Motor Control, 2008, 12 (3), 210–218. 7. Wulf G., Attention and motor skill learning. Human Kinetics, Champaign 2007. 8. Roy F.D., Tomlinson R.D., Characterization of the vestibulo-ocular reflex evoked by high velocity movements. Laryngoscope, 2004, 114 (7), 1190–1193, doi: 10.1097/ 00005537-200407000-00011. 9. von Laßberg C., Mühlbauer T., Krug J., Spatial orientation during fast body rotations in horizontal plane. In: Schöllhorn W.L., Bohn C., Jäger J.M., Schaper H., Alich­ mann M. (eds.), European workshop on movement scien­ce. Mechanics – physiology – psychology. Sport und Buch Strauß, Cologne 2003, 96. 10. Raab M., de Oliveira R.F., Heinen T., How do people perceive and generate options? In: Raab M., Hekeren H., Johnson J.G. (eds.), Progress in Brain Research. Vol. 174. Mind and motion: The bidirectional link between thought and action, Elsevier, Amsterdam 2009, 49–59, doi: 10.1016/ S0079-6123(09)01305-3. 11. Hayhoe M., Ballard D., Eye movements in natural behavior. Trends Cogn Sci, 2005, 9 (4), 188–194, doi: 10.1016/ j.tics.2005.02.009. 12. Jovancevic-Misic J., Hayhoe M., Adaptive gaze control in natural environments. J Neurosci, 2009, 29 (19), 6234– 6238, doi: 10.1523/JNEUROSCI.5570-08.2009. 13. Grasso R., Prévost P., Ivanenko Y.P., Berthoz A., Eye-head coordination for the steering of locomotion in humans: an anticipatory synergy. Neurosci Lett, 1998, 253 (2), 115–118, doi: 10.1016/s0304-3940(98)00625-9. 14. Hollands M.A., Patla A.E., Vickers J.N., “Look where you’re going!”: gaze behaviour associated with maintaining and changing the direction of locomotion. Exp Brain Res, 2002, 143 (2), 221–230, doi: 10.1007/s00221001-0983-7. 15. Williams A.M., Davids K., Williams J.G.P., Visual perception and action in Sport. E. & F.N. Spon, London 1999. 16. Kerwin D., Swinging in gymnastics. In: Prassas S., San­ ders R. (eds.), Proceedings of the XVII international symposium on biomechanics in sports: Acrobatics. Edith Cowan University, Perth 1999, 49–59.

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17. Hiley M.J., Yeadon M.R., The margin for error when releasing the high bar for dismounts. J Biomech, 2003, 36 (3), 313–319, doi: 10.1016/S0021-9290(02)00431-1. 18. Hiley M.J., Yeadon M.R., Optimization of backward giant circle technique on the asymmetric bars. J Appl Biomech, 2007, 23 (4), 300–308. 19. Arampatzis A., Brüggemann G.-P., Mechanical energetic processes during the giant swing exercise before dismounts and flight elements on the high bar and the uneven parallel bars. J Biomech, 1999, 32 (8), 811–820, doi: 10.1016/S0021-9290(99)00065-2. 20. Mikromak, WINanalyze 3D (ver. 2.1.1). Berlin, Germany, 2008. 21. Busquets A., Marina M., Irurtia A., Ranz D., Angulo-Barroso R.M., High bar swing performance in novice adults: Effects of practice and talent. Res Q Exerc Sport, 2011, 82 (1), 9–20. 22. Abernethy B., Russell D.G., The relationship between expertise and visual search strategy in a racquet sport. Hum Mov Sci, 1987, 6 (4), 283–319, doi: 10.1016/01679457(87)90001-7. 23. Bates B.T., James R., Dufek J.S., Single-subject analysis. In: Stergiou N. (ed.), Innovative analyses of human movement. Human Kinetics, Champaign 2004, 3–28. 24. Land M.F., Mennie N., Rusted J., The roles of vision and eye movements in the control of activities of daily living. Perception, 1999, 28 (11), 1311–1328, doi: 10.1068/ p2935. 25. Williams A.M., Ericsson K.A., Perceptual-cognitive expertise in sport: Some considerations when applying the expert performance approach. Hum Mov Sci, 2005, 24 (3), 283–307, doi: 10.1016/j.humov.2005.06.002. 26. Pelz J.B., Canosa R., Oculomotor behavior and perceptual strategies in complex tasks. Vision Res, 2001, 41, 3587– 3596, doi: 10.1016/S0042-6989(01)00254-0. 27. Foley H.J., Matlin M.W., Sensation and perception. Pearson Education, Boston 2010. 28. Elliott D., Lyons J., Optimizing the use of vision during motor skill acquisition. In: Piek J. (ed.), Motor behavior and human skill: a multidisciplinary approach. Human Kinetics, Champaign 1998, 57–72. 29. Cohen J., Statistical power analysis for the behavioral sciences, 2nd ed., Lawrence Erlbaum, New York 1988. 30. Kenny D.A., Correlation and causality, John Wiley & Sons, New York 1979.

Paper received by the Editors: February 15, 2012 Paper accepted for publication: May 10, 2012 Correspondence address Thomas Heinen Institute of Sport Sciences, University of Hildesheim Marienburger Platz 22, 31141 Hildesheim, Germany e-mail: [email protected]

HUMAN MOVEMENT 2012, vol. 13 (3), 225– 235

ADVISABILITY ON THE SHIFT FROM STANDARD FRONT CRAWL SWIMMING TECHNiQUE TO THE “KAYAKING” AND “LOPING” VARIANTS doi: 10.2478/v10038-012-0026-1

KRYSTYNA ZATOŃ, STEFAN SZCZEPAN *, ROBERT KAzIMIRÓW, MAREK REJMAN University School of Physical Education, Wrocław, Poland

Abstract

Purpose. The aim of this study was to analyze selected kinematics parameters of standard front crawl swimming technique and its variants, the “kayaking” and “loping”, in order to estimate the differences that can determine swimming effectiveness and efficiency Methods. Eighteen swimmers, divided equally into three groups, took part in the research. The first group was composed of individuals who favored the standard technique, the second group used the “kayaking” variant and the third one swam in the “loping” variant. All swimmers were instructed to swim the 50 m freestyle with their technique of choice at maximum velocity. Analysis of kinematic parameters (time, average swimming velocity), swimming cycle parameters (stroke length, stroke rate), and the swimming efficiency coefficient (stroke index) was calculated using SIMI’s 2D Reality Motion Systems software. Results. The Kruskal-Wallis test and Mann-Whitney U test found statistically significant differences in the studied parameters between the standard technique (S) and the “kayaking” (K) and “loping” (L) variants in the time to swim 25 m ( S = 15.472 s, K = 13.540 s, L = 14.108 s), and between (S) and (K) in the 15 m swim time ( St = 9.598 s, Kt = 8.593 s) and average swimming velocity ( Sv = 1.562 m/s, Kv = 1.757 m/s). Conclusions. Analysis of the differences in the kinematic parame­ters that define front crawl swimming technique finds justification in the need to modify the standard technique of the propulsive movement used in swimming towards those that employ the “kayaking” and “loping” variants as they are more effective in affecting swimming velocity.

Key words: front crawl, “kayaking”, “loping”, stroke length, stroke rate, stroke index

Introduction

In the “kayaking” variation, the alternately-sided movements of the arms are also performed in uninterrupted coordination, in which the movement of one arm mirrors (in a general sense) the movement of the other arm. The distinguishing feature of “kayaking” in comparison to standard technique is the different arm movement structure in the propulsive phase. This limits elbow flexion in the stroke phase and reduces the adduction of the straightened arm when pointing to the torso during the push back phase, with the hand moving in the sagittal plane and resembling the shape of the letter “I” (Fig. 1b). When observed in its entirety, the shape of the movement is analogous to someone paddling in a kayak. The effectiveness of the “kayaking” variant has been confirmed in research studies by, among others, Kjendlie et al. [4, 5], while competitors such as Popov, Bernard and Cielo have applied the “kayaking” variant in international competition. The “loping” variant of front crawl swimming technique does not feature equal time intervals of the arms during the propulsion and recovery phases, as is found

This study was rooted in the issues surrounding the use of more modern developed swimming techniques that attempt to optimize the front crawl. The aim of this study was to analyze front crawl swimming technique and the “kayaking” and “loping” variants as shown in Figure 1 [1–3]. The movement pattern of standard front crawl swimming technique was used as a reference point in order to identify the movement structure propulsive phase of the arm as well as its coordination with the “kayaking” and “loping” variants. All of the above-mentioned techniques are used in the freestyle sprint as well as a finishing sprint in medium and long distances. In the standard technique, arm movements occur alternately and maintain equal time intervals during the propulsive and recovery phases. The trajectory of the hand in the propulsion phase, in the frontal plane, resembles the shape of the letter “S” (where the hand moves in the direction of the long axis of the body, then it is straightened out towards the back and reaches towards the hip, Fig. 1a).

a) * Corresponding author.

b)

c)

Figure 1. Illustration of the differences in upper extremity coordination in standard front crawl technique (a) and the “kayaking” (b) and “loping” (c) variants 225

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in the standard technique and “kayaking” variant (Fig. 1c). Mutual alignment of the arms is asymmetric during the different phases of the stroke cycle. Specifically, the arm’s movement at the end of the preparatory phase, when straightened out at the elbow, is held in place for a slightly extended period of time, creating an impression of one arm “catching-up” to the other. While using “loping” variant, the arm movement structure as well as hand trajectory does not differ from the standard technique. However, there is a lack of research literature on the evolution of this stroke variant, but “loping” has been popularized by such swimmers as Bondi, van den Hoogenband, Lochte and Phelps. It is well known that improving one’s results in sport is based on the development of motor skills, movement techniques, and mental readiness to take part in competition [6]. Biomechanics study an athlete’s movement processes in both time and space, creating a scientific basis to monitor the quality of movement structure (as a sign of improving technique) and monitor its coordination (as a manifestation of motor skills) [7]. Within the context of swimming technique, both of the abovementioned elements can be construed as the effective and efficient human propulsion in water [8]. It is assumed that movement coordination is the organized movement activity that results from a mutual alignment of all the elements that compose human movement when interacting with an environment [9]. These structural elements can be defined by using movement sequences, i.e., the division of movement as a biomechanical chain composed of the smallest elements of spatial displacement [10]. In sport activities composed of cyclic propulsive phases (such as swimming), the time (and velocity) used to cover a certain distance is a measure of the effectiveness and efficiency of an individual’s technique; it pro­v ides an impartial criterion for evaluation [6]. The relationship between technique and race results is far more pronounced in swimming than in other sports due to the aquatic environment. The lack of physical support makes any attempt at stabilizing cyclic propulsive phases (with the exception of swimmers at the highest levels [11]) imperfect in nature. The power ge­ nerated by a swimmer will vary from each motor sequence to the next and in each cycle phase and, therefore, due to water’s active resistance, lead to intra-cycle changes in velocity [12]. These inrta-cycle changes in velocity are detrimental as the goal of competitive swimming is to obtain maximum velocity [12]. In addition, variable velocity results in rising energy expenditure. Thus, an increase in cycle velocity while minimizing inner-cyclical velocity fluctuations appears to be the basic criterion for effective [13] and efficient [14] swimming. Stabilizing inner-cyclical velocity variations is an especially important aspect of swimming technique in the front crawl as this is the fastest and, therefore, the most stabilized 226

(due to velocity) swimming style. One of the ways in minimizing iinrta-cycle velocity changes in the front crawl is by having a high level of coordination abilities that allow one to perfectly perform propulsive arm movements [15]. Therefore it seems reasonable that the search for newer, more effective and efficient variations of the front crawl should focus on modifying the structure of the propulsive phase as well as overall movement coordination. Research on the effectiveness and efficiency of various front crawl techniques has so far analyzed a variety of determinants that can cause an increase in swimming velocity and the ability to maintain it across various distances. These studies have defined and developed alternative coordination models (“opposition, “catch-up” and “superposition”) [2, 3] and created a Coordination Index (IdC) to quantify the delays of various forms of arm motor coordination [3]. Other studies branched out to evaluate the energy costs of using various types of coordination structures in the front crawl [2, 16]. Based on the above premise, the aim of this study was to identify the factors that influence front crawl velocity variations by analyzing swimmers who have trained in competitive swimming at the highest levels. However, an original aspect of this study was the attempt to interpret the results in a practical context by objectively assessing the effectiveness and efficiency of swimmers who are high skilled in the swimming techniques here under analysis, and then determining the direction and size of these changes on swimmers just beginning to master various swimming styles and techniques. In this context, it is felt that an objective quantification of the differences in standard front crawl swimming technique and the “kayaking” and “loping” variants in experienced swimmers can justify the advisability of modifying the currently used standard movement algorithm in order to optimize technique and result in an increase in swimming velocity. Therefore, the hypothesis of this study was to analyze recorded kinematic parameters of the standard front crawl technique and its “kayaking” and “loping” variants in order to determine their effectiveness and efficiency. With this in mind, the following research questions were examined: (1) Are the differences in time (and velocity) to swim a specific distance and the differences in the parameters that define cyclic propulsive movement (stroke length, stroke rate and the swimming efficiency coefficient) significant enough to objectively estimate the effectiveness and efficiency of standard front crawl technique and the “kayaking” and “loping” variants? (2) Does analysis of the differences in the kine­ matic parameters of the three analyzed swimming techniques by experienced swimmers create an objective basis on the advisability of using these modified techniques in the early stages of swimmers’ training?

HUMAN MOVEMENT K. Zatoń et al., Modified freestyle swimming technique

Material and methods A total of 18 male swimmers voluntarily participated in the study. The subjects were divided into three groups, where the first group (NS = 6) consisted of swimmers who preferred to swim the standard front crawl, the second group (NK = 6) were swimmers who preferred to swim the “kayaking” technique, while the third group (NL = 6) were those who swam the “loping” variant. Data on the participants’ characteristics (Tab. 1) reflected the selection criteria that were originally selected in order to fulfill the study objectives. The subjects were randomly chosen according with the following criteria: (1) participants’ age and career length were treated as a differentiating factor, (2) while a factor assessing their similarity was their skill level (i.e., each of the subjects had mastered their swimming technique at a similar level), which was determined by their fastest personal record in the 50 m freestyle. (3) Similarities of the swimmers’ somatic parameters were used as an objective basis to compare their potential in terms of efficient and effective swimming (quantified by the kine­

matic parameters that characterize cyclical movement propulsion – stroke stride and stroke rate) [17]. It was decided that an objective assessment of the test groups’ homogeneity would be assessed with a stan­ dard deviation of the mean values no larger than 10%. This was based on Bartlett’s test, which is used to verify the equality (homogeneity) of variance in all subgroups of a population [18]. This test is based on asymptotic chi-square distribution and can be used for very small samples. The Bartlett test uses the relationships between the means and standard deviations of the sample to reflect the homogeneity of the results obtained from one individual (statistical significance at = 0.05) with the results from the other swimmers. Bartlett’s statistical formula was used only with decimal logarithms [18]. The results of the test found that the samples were homogeneous and met the assumptions that the selected group, in terms of skill level and the other selected parameters, should be characterized by a standard deviation of no more than 10% of arithmetic mean. Swimming trials were conducted in a 25 m pool under the same conditions for all subjects. The task was to

Table 1. Characteristics of the swimmers participating in the study, in each research group Group

Standard

Subjects X1 X2 X3 X4 X5 X6 s

Kayaking

Y1 Y2 Y3 Y4 Y5 Y6 s

Loping

Total

Z1 Z2 Z3 Z4 Z5 Z6

Swimming career (years) 7 9 5 10 8 11

50 m freestyle personal best (s)

Age (years)

Body height Body mass (m) (kg)

29.50 29.61 26.32 28.34 29.80 29.70

17 19 20 22 21 23

1.68 1.92 1.89 1.65 1.83 1.73

66.0 84.0 78.0 65.0 74.0 71.5

28.878 1.3624

20.3 2.16

1.783 0.1127

73.08 7.242

8 10 8 20 7 13

27.12 24.96 22.30 22.31 28.20 24.27

18 23 18 27 17 23

1.73 1.84 1.91 1.94 1.66 1.77

74.5 81.0 86.0 88.0 66.5 78.5

11.0 4.90

24.860 2.4363

21.0 3.95

1.808 0.1080

79.08 7.883

8 10 11 12 5 9

24.01 25.25 26.80 22.52 26.36 24.90

18 19 21 25 29 21

1.68 1.76 1.94 1.90 1.82 1.84

66.5 75.5 90.0 82.0 81.0 79.5

8.3 2.16

s

9.2 2.48

24.973 1.5677

22.2 4.12

1.823 0.0942

79.08 7.781

s

9.5 3.40

26.237 2.5903

21.2 3.40

1.805 0.1003

77.08 7.745

(t2/1) (%) –1.12 –1.07 1.39 –2.21 –3.45 2.70

3.50 –0.60 –2.83 –0.24 0.39 –0.39

1.06 –2.45 –1.49 0.31 –0.35 3.44

(t2/1) – percent difference in the time to swim a distance in the first and second attempt, assuming that the swimmers’ results do not differentiate more than 10% from their personal record 227

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swim 50 m in the front crawl at maximum velocity in two trails, with the time measured in order to verify if they performed at maximum capacity. It was assumed that the swimmers’ times should differ –10% to 10% between first and second trails (equation #1) and that the results should not differ more than 10% than their personal best time (Tab. 1). t2/1 = 100 –

t2 × 100. t1

(#1)

The need to swim at maximum velocity was dictated by the existing relationships between swimming velocity and the swimming cycle parameters (stroke length and stroke rate) [19]. Each trial was conducted after a 15 min warm-up, followed by a 5 min rest to stabilize heart rate. The swimmers then swam in their preferred swimming technique (standard front crawl or the “kayaking” or “loping variants). All of the athletes completed the trials in the prescribed manner mentioned above. A solid basis for discussing the advisability of modi­ fying the standard movement algorithm of the front crawl towards more optimal swimming technique needs to be based on the objective and normative selection of athletes as well as reliable and valid diagnostic tasks. This can stem from simulating starting conditions that accompany the swimmers during competition. At the same time, motivating the swimmers to achieve their maximum velocity (measured by a 10% tolerance of their personal best) can provide comparable results, determined at least in terms of their current fitness level. Data on swimming technique were recorded during the first trial in the first 25-metre half of the 50 m distance the swimmers had to swim (by water start). The swimmers were timed with the Colorado Time system, an automated system that is composed of a tensometric starting platform, a touch plate and a stopwatch with a sampling frequency of 0.001 s. The remaining kinematic parameters were recorded for a distance of 15 m (excluding a 5-meter buffer at the end of the pool for flip turns) (Fig. 2). The athletes were registered by two cameras filming at a frequency of 50 Hz. The first camera (DCR-TRV 22E, Sony, Japan) was placed under water at a depth of 1 m in the middle of the pool. The axis of the camera lens was

perpendicular to the swimming direction in order to film the swimmer at the property angle possible, as this would allow for the filming of at least one full movement cycle. The measurement track was calibrated with a 2 × 2 m measurement frame that was placed vertically in such a way as to not adversely affect the swimmer. The swimmers wore markers in contrasting colors on the head and on the radial-axis of both limbs [20]. Video samples of the registered cycles were then randomly selected for direct measurement of swimmers’ stroke length as well as to describe and verify the quality of the propulsive movement structure of the arms in each of the examined swimming techniques (Fig. 3). Another camera of the same make and model was also placed in the middle of the pool but on top of the water. Video from this camera was used to record the swimmers’ time in covering the 50 m distance (measured to nearest 0.001 s) and to calculate their average stroke rate and swimming efficiency ratio. The filmed data was then directly analyzed by 2D Motion Software System software (SIMI, Germany) according to the producer’s guidelines and recommendations. Stroke rate was measured by the distance a swimmer covered in one movement cycle. This parameter was determined (Fig. 4) by the horizontal displacement of the marker placed on the swimmer’s head from the time when the hand began “catching” the water (A) up to the moment when the hand completed the propulsion and preparatory phase and returned to the entry position (B) [11]. The mean stroke length was then calculated by using the equation [21]: d(m , (#2) c where: d – distance, c – number of movement cycles. l(m/cycle) =

Stroke rate, as the average number of full movement cycles per time unit, was calculated by the formula [21]: f(cycle/s) =

c , t(s)

where: c – number of movement cycles, t – time to swim the distance. An additional equation (#4) was used to calculate average swimming velocity. This parameter (whose diagnostic value is identical to the time spent in swim-

Figure 2. Schema of the measurement track 228

(#3)

recovery

entry and catch

pull

push

pull push recovery

entry and catch

recovery

entry and catch

pull

push

push

entry and catch

entry and catch

push

start of recovery

push

pull

phase of arm movements entry and catch

standard technique kayaking variant loping variant

standard technique kayaking variant loping variant

*movement trajectory during the propulsive phase of the movement shaped as the letter “I”

recovery

pull

recovery (to the transverse axis)

pull

entry and catch

recovery

recovery (to the transverse axis)

push

*movement trajectory during the propulsive phase of the movement shaped as the letter “I”

entry and catch

push

*movement trajectory during the propulsive phase of the movement shaped as the letter “S”

push

entry and catch

right

entry and catch

recovery

push

left

arm movement phases

HUMAN MOVEMENT

K. Zatoń et al., Modified freestyle swimming technique

Figure 3. Illustration and explanation of the differences in the structure of the upper limb movements and their coordination phases of the standard, “kayaking” and “loping” front crawl techniques

229

HUMAN MOVEMENT K. Zatoń et al., Modified freestyle swimming technique

Table 3. Results of the Mann-Whitney U test assessing the statistical significance of the parameters’ differences between two swimming techniques Parameter A B A B Figure 4. Illustration showing measurement of the stroke rate from the first sequence (phase A) to the last sequence (phase B) [11]

A

B

25 m time (t25)

ming the total distance) was introduced only for hypo­thetical purposes: s(m) v(m/s) = , t(s)

(#4) where: s – swim distance, t – time to swim the distance.

15 m time (t15)

The swimming efficiency coefficient (stroke index) describes the ability to generate maximum swimming velocity using the minimum number of movement cycles (a longer stroke rate) and is expressed by [22]:

15 m swimming velocity (v)

SI = l(m) × v(m/s), SI = (1/s), (#5) where: SI – stroke index, v – velocity, l – length of stroke rate.

Comparison of the front crawl swimming techniques standard

kayaking loping

0.004 0.038

kayaking

standard loping

0.004 0.503

loping

standard kayaking

0.038 0.503

standard

kayaking loping

0.012 0.058

kayaking

standard loping

0.012 0.702

loping

standard kayaking

0.058 0.702

standard

kayaking loping

0.014 0.087

kayaking

standard loping

0.014 0.623

loping

standard kayaking

0.087 0.623

= 0.05

Statistically significant differences at are marked in bold

Statistical analysis was performed with Statistica 9.0 (Statsoft, USA) software at a statistical significance level of = 0.05. The Kruskal-Wallis and Mann-Whitney U test were used to test for statistically significant differences between the groups among all the measured parameters. They were used for the small sized groups under the assumption that the selected parameters do not show normal distribution [23]. In addition, ISO 9001:2009 standards were used for to standardize the recordings and to analise kinematic parameter of swimming cycle.

Significance level

have a diagnostic value when comparing the three swimming techniques and, because of this, they were then subjected to the Mann-Whitney U test (Tab. 3). The Mann-Whitney U test (Tab. 3) indicated statistically significant differences in the time needed to swim 25 m in each of the front crawl swimming techniques. Significant differences were also found between the standard technique and the “kayaking” variant in the 15 m swim time (as well as the average velocity to swim this distance). The 25 m distance was swum the fastest by swimmers who specialize in the “kayaking” variant of the front crawl ( = 13.5396 s), while those who used standard front crawl technique took the longest to cover the same distance ( = 15.4722 s) (Fig. 5). The average time of swimmers using the “loping” variant was = 14.1080 s. Similar to the results in the 25 m distance, the shortest

Results Statistical analysis by the Kruskal-Wallis test found statistically significant differences in three of the analyzed parameters: the 25 m time, the 15 m time and the 15 m average swimming velocity (Tab. 2). These results point to the fact that only these specified parameters

Table 2. Results of the Kruskal-Wallis test evaluating the statistical significance of the differences across all measured parameters for each swimming technique variation Parameter Chi-square Degrees of freedom Asymptotic significance

t25

t15

v

l (Hay)

l (Simi)

6.587 1 0.010

5.769 1 0.016

5.789 1 0.016

0.026 1 0.871

0 1 1.00

f

SI

3.718 1 0.054

1.641 1 0.200

t25 – 25 m time, t15 –15 m time, v – 15 m average swimming velocity, l (Hay) – stroke length, l (Simi) – stroke length, f – stroke rate, SI – swimming efficiency coefficient (stroke index) Statistically significant differences at = 0.05 are marked in bold 230

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Swimming velocity (15 m) (m/s)

15 m time (s)

25 m time (s)

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A

B

C

stroke length (Hay) (m)

stroke length (Simi) (m)

Figure 5. Mean values of the parameters differentiating the front crawl swimming techniques: A – 25 m time, B – 15 m time, C – 15 m swimming velocity

B

stroke index SI

stroke rate (stroke/s)

A

C

D

Figure 6. Mean values of the movement cycle parameters in the front crawl swimming techniques: A – stroke length (Hay), B – stroke length (SIMI), C – efficiency coefficient (stroke index), D – stroke rate

time to swim the 15 m distance was by swimmers using the “kayaking” variant ( = 8.5927 s); the standard technique swimmers were the slowest ( = 9.5977 s) while those using the “loping” variant in the 15 m swim were in the middle ( = 8.8379 s). Similar results were also found in the average swimming velocity, although this was calculated only for hypothetical purposes. The fastest velocity in the 15 m distance was attained by the “kayaking” swimmers ( = 1.7568 m/s), while the slowest swimmers were those who used the standard technique ( =

1.5616 m/s). Swimmers who used the “loping” variant achieved an average velocity of 1.7000 m/s in the 25 m. Time (and velocity) was treated as the key parameter in assessing the various swimming techniques due to it being singled out as a statistical diagnostic measurement. The remaining parameters of cyclic propulsive movements (Fig. 6), lacking a diagnostic character, were classified as additional forms of measurement in the assessment of swimming technique [22]. The results in Figure 6 illustrate that the values of the parameters 231

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that characterize the “loping” variant are significantly different from those values calculated for the standard and “kayaking” techniques. The “loping” variant is distinguished in terms of having the longest stroke length and smallest stroke rate. Consequently, the “loping” variant featured the highest swimming efficiency coefficient (stroke index) (Fig. 6). Discussion The objective of this study was to identify the differences in the kinematic parameters when swimming the standard front crawl technique and its two variations, “kayaking” and “loping” styles. The statistically demonstrated differences created a basis for analyzing the impact of modifying the standard front crawl technique in terms of time (and velocity). In addition, the deliberate selection of the groups of swimmers who specialize in each of the swimming techniques, aimed at forming a homogenous sample population in terms of skill and their ability to generate efficient and effectiveness propulsion, also provided an objective basis for this study. Analysis of the parameters which determine the efficiency and effectiveness (stroke length, stroke rate and swimming efficiency) of the various swimming techniques did not confirm the supremacy of the standard technique over the other variations and if time (and average velocity) are taken under consideration, then the gap separating the standard technique is even smaller. Therefore, there is evidence to support the advisability of modifying the use of the standard movement algorithm in the direction of more optimized swimming techniques by focusing it on swimming velocity. A puzzling difference was revealed in the times (and swimming velocities) between the two swimming techniques that maintain equal time intervals during the recovery and propulsive phases of both arms (standard technique and “kayaking” variant) and the technique, which due to an extended pull phase, features time intervals that are irregular and can lead to asymmetric arm positions during the phases of the cycle (“loping”). As was shown, the “loping” variant was characterized by the highest rate of swimming efficiency, probably stemming from holding out the hand after finishing the recovery stroke phase (an extended pull). Feature of this coordination pattern can be of importance in terms of economizing the propulsion movements in distances longer than the one in this study (50 m). This aspect has been confirmed by swimmers using this variant in the 100 and 200 m freestyle [24]. However, in shorter distances, the results point to “kayaking” as the most effective front crawl technique. “Kayaking” is also the most preferred style by top swimmers competing in shorter sprints such as the 50 and 100 m freestyle [24]. These results gained additional significance when coupled with the fact that these studies used fair 232

and standarized tests on swimmers of different skill levels who also regularly competed against one ano­ther in international competitions. As such, this raises the need for recognizing the need of modifying the techniques of swimmers who are just beginning to choose their swimming specialization. The search for efficient and effective swimming should go beyond the use of standard techniques; it should consider viable alternatives, as in this case (freestyle swimming), the use of the “kayaking” and “loping” variants. The differences in time (and velocity) by the swimmers using their preferred custom swimming techniques were found to be far smaller than the differences recorded for those that used the standard technique. These results, based on the different movement structure of the hands during the propulsion phases when using the “kayaking” and “loping” variants, suggest that the shape of the hand trajectory (as the path that gene­ rates propulsion) is not the only determining factor in effective and efficient swimming when measured by time or velocity. In such a context, the advisability of modifying standard front crawl swimming technique appears to stem more from overall motor coordination of the arms than their structure. Such quality control techniques can assist coaches and athletes in identifying which coordination variation pattern is best suited to their strength level and the distance they have to swim. The use of such a strategy can optimize swimmers’ performance in a race by taking into consideration their swimming pace distribution over a distance as well as being able to individually select what strategy would work best in a given situation [15]. As was previously mentioned, stroke length and stroke rate were the most objective measurements that determine the best-suited swimming technique [17]. Their distinct relationship with swimming velocity allow for the interpretation of the results in categories that can describe the effectiveness of swimming by using arm coordination algorithms (reflected by the relationship between stroke length and stroke rate). Based on the assumption that swimming velocity is directly proportional to stroke length (l) and stroke rate (f) (equation #6), it is possible to predict changes in swimming velocity over a certain distance depending on the swimming strategy and the distribution of its parameters [25]: v = l × f. (#6) Assuming that the relationship between the movement stroke parameters (stroke length and stroke rate) are compensatory (an increase in one parameter lowers the value of the second, equation #7), swimming velocity can only be increased if only one of the parameters change while the second remains unchanged (equation #8), or when one of the parameters increases while the second decreases, but the increase is so large that it offsets the reduction of the second parameter (equation #9):

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(l –  l) × (f +  f ), (#7) v +  v = (f +  f ) × l, (#8) where (l ~const) v +  v = (l –  l) × (f +  f ); [(l –  l) × (f +  f ) > l × f ]. (#9) The situation described in equation #9 illustrates the results attained when swimming the “kayaking” variant, which features a short stroke length (l) and high stroke rate (f ) (Fig. 6) with a tendency to shorten the stroke length with an increase in stroke rate. In the case of the “loping” variant, a long stroke length (l) and low stroke rate (f ) is observed with a tendency to increase stroke length while remaining at a constant stroke rate (equation #10): v +  v = (l +  l) × f, (10) where (f~const). These dependencies illustrate the fact that high swimming velocity can be the effect of using different stra­ tegies in terms of coordination (by using strategies of different stroke length and stroke rate), but, regardless of the used strategy, the basic criterions of maximum swimming speed is to minimize intra-cyclic veliocity fluctuations – as an objective measure of efficiency and effectiveness. It is well known that fulfilling this criterion is only possible with a high level of coordination ability combined with a perfect propulsion movement structure [15]. High frequency arm movements (stroke rate) and a fixed time sequence during the propulsion phase of the “kayaking” variant suggests that it generates less intra-cyclic velocity variation than the “loping” technique. However, the “loping” technique was found to have the highest stroke index (swimming efficiency coefficient) both in this study as well as in the work of other authors [22]. On this basis, it can be assumed that the “loping” variants longer stroke length combined with a relatively low stroke rate compensates for intra-cyclic velocity fluctuations generated during the propulsion phase. In accordance to the results, an adequate explanation can be that the propulsion phases, interspersed with the period of an extended pull, do not result in an increase of water resistance [16] and therefore do not undercut the validity of the “loping” technique as an alternative to the standard technique. The results of this study do not allow us to accurately judge which of the analyzed front crawl techniques is the most effective and efficient. Such a generalization is still being discussed by other authors. Costilla et al. [16] indicated that the superposition model (a variation of the “loping” variant) is the most economical in terms of energy expenditure. However, Chatard et al. [2] emphasize the relatively low energy costs of the “kayaking” variant. Nonetheless, in light of such a context, a rational basis on the modification of the standard tech-

nique in order to use other swimming variations lays more in the predisposed individual abilities of swimmers in terms of their coordination and physical abilities and their ability to adapt to new motor skills. It is not the intention of this study’s authors to rele­ gate the use of the standard technique as a method at achieving success in sprint freestyle competition. Although it may seem inconsequential to be uncritical of the standard technique in the early stages of a swimmers’ specialization, the role it plays once perfectly mastered in the preliminary stage of swimmers’ technical training is undisputed. The acquisition of skills by novice swimmers that are consistent with the universally accepted standard technique, which was formed on the basis of swimmers’ practical experience and existing knowledge, is both natural and necessary. However, improvement in technique, understood as expanding one’s motor experience, should adjust towards the use of the standard technique in terms of the individual prefere­ nces of a swimmer (such as their somatic characteristics, style preferences, physical fitness level, etc.) in such a way as the allow a swimmer to take advantage of their full (unrestricted by standard principles) potential. The implicational and cohesive character of this study goes along with the evolution of swimming technique as one that takes into consideration the “feel of the water”, which is the specific sensitivity of a swimmer as an adaptive process built on gained experience. It is based on controlling and differentiating the “sensitivity” one feels from various receptors to sense motion in water [26]. In the generally standard technique, the “feel of the water” helps construct an image of movement, which itself determines the creation of a movement pattern program and whether it is correct when swimming in real-time conditions [8]. With individual techniques, as motor adaption developed by repeated stimuli, a swimmer becomes sensitive to motion and therefore increases his/her multi-sensory experience. This allows a swimmer to improve their motor skills in very complicated coordination sequences [27]. The collection of these types of experiences allow an individual to develop more precise movement control and, consequently, improve athletic progression [28], as well as in swimming [29, 30]. Inter-individual variability in one’s kinesthetic differentiation levels and the speed at which one learns motor skills has been found to depend on individual predisposition [29, 30]. Therefore, the individualized technical training of young swimmers seems to be crucial in order to fulfill the idea of evolving one’s technique, which is emphasized in this study. Hence, the need to accept the postulate of initiating a search for optimal variations of front crawl technique is the awareness that only through shaping a swimmer’s standard technique based on stabilization of “kinesthetic differention level” [30], can justify the decision of using more advanced variant by towards modifying the structure and coordination of propulsive movements. 233

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The original nature of the issues taken under consideration in this study do point to the fact that the results and their interpretations are not entirely exhaustive in terms of the complexity of the issues analyzed herein. However, it is hoped that the reliability of the scientific interpretation used in this study can contribute for further discussion and deeper exploration of this subject. Conclusion An objective interpretation of the differences between the kinematic parameters of front crawl swimming indicate that the standard technique was less effective and efficient than its “kayaking” and “loping” variants. At the same time, it was recognized that using the “kayaking” variant is an optimal technique in increasing effectiveness and may contribute to an increase in swimming velocity. However, the highly efficient nature of the “loping” variant makes it the optimal technique if energy-economical swimming is concerned. Thus, the advisability of modifying the standard move­ment technique used in front crawl swimming towards its more optimal, in terms of efficiency and effectiveness, variants is applicable. The results that support such a statement were obtained in trials by swimmers who specialize in the techniques taken under consideration. The groups were all homogenous in nature in terms of their the body composition and their ability to gene­rate similar levels of effective and efficient propulsion, with the swimmers differing only in terms of age and the length of their career as a swimmer. Taking these facts into consideration when interpreting the results of this study, there is credence to the use of the front crawl “kayaking” and “loping” variations in the technical training of swimmers who are at the beginning of choosing their swimming specialization, as long as any changes in a swimmer’s propulsive movement structure and coordination take place after fully mastering the standard technique. Modifications to a swimmer’s standard technique seem to be even more reasonable when their arm coordination pattern in taken under consideration than as a change to their movement structure. The results do not offer a clear decision on which front crawl swimming techniques are more effective and efficient, but the study does point to the need for individualized technique training in order to fully exploit a swimmer’s coordination and fitness abilities. References 1. Pawłowicz K., What does kayaking have to do with front crawl? Presentation about natural differences in front crawl swimming styles [in Polish]. 2006, 1–3. Available from: URL: http://masters.waw.pl/plywanie/co_ma_kayaking/ [accessed: February 2011]. 2. Chatard J.C., Collomp C., Maglischo E., Maglischo C., Swimming skill and stroking characteristics of front crawl 234

swimmers. Int J Sports Med, 1990, 11 (2), 156–161, doi: 10.1055/s-2007-1024782. 3. Chollet D., Chalies S., Chatard J.C., A New Index of Coordination for the Crawl: Description and Usefulness. Int J Sports Med, 2000, 21 (1), 54–59, doi: 10.1055/s-20008855. 4. Kjendlie P.L., Haljand R., Fjørtoft O., Stallman R.K., Stroke frequency strategies of international and national swimmers in 100 m races. In: Vilas-Boas J.P., Alves F., Marques A. (eds.), Biomechanics and Medicine in Swimming X. Portuguese Journal of Sport Sciences, 2006, 6 (supl. 2), 52–54. 5. Kjendlie P.L., Haljand R., Fjørtoft O., Stallman R.K., The temporal distribution of race elements in elite swimmers. In: Vilas-Boas J.P., Alves F., Marques A. (eds.), Biomechanics and Medicine in Swimming X. Portuguese Journal of Sport Sciences, 2006, 6 (supl. 2), 54–56. 6. Bober T., Biomechanics – methods of measurement, analysis and evaluation techniques for sport [in Polish]. RCMSKFiS, Warszawa 1988. 7. Hirtz P., The component coordinator [in German]. Korpererziehung, 1995, 45, 102–106. 8. Czabański B., Selected aspects of teaching and learning sport technique [in Polish]. AWF, Wrocław 1991. 9. Meinel K., Schnabel K., Kinesiology – motor sports (9 heavily revised edition) [in German]. Sportverlag, Berlin 1998. 10. Ungerer D., On the theory of sensorimotor learning. 3rd ed. [in German]. Hoffman, Schorndorf 1971. 11. Chollet D., Pelayo P., Delaplace C., Tourny C., Sidney M., Stroking characteristic variations in the 100-m freestyle for male swimmers of differing skill. Percept Mot Skills, 1997, 85 (1), 167–177. 12. Schnitzler C., Seifert L., Alberty M., Chollet D., Hip velocity and arm coordination in front crawl swimming. Int J Sports Med, 2010, 31 (12), 875–881, doi: 10.1055/s0030-1265149. 13. Schnitzler C., Seifert L., Ernwein V., Chollet D., Arm coordination adaptations assessment in swimming. Int J Sports Med, 2008, 29 (6), 480–486, doi: 10.1055/s-2007989235. 14. Kolmogorov S., Duplischeva O., Active drag, useful mechanical power output and hydrodynamic force coefficient in different swimming strokes at maximal velocity. J Biomech, 1992, 25 (3), 311–318, doi: 10.1016/00219290(92)90028-Y. 15. Seifert L., Chollet D., Bardy B., Effect of swimming velocity on arm coordination in front crawl: a dynamical analysis. J Sports Biomech, 2004, 3, 15–27. 16. Costill D.L., Maglischo E.W., Richardson A.B., Swimming. Blackwell Scientific Publications, Oxford 1992. 17. Alberty M., Sidney M., Pelayo P., Toussaint H.M., Stroking characteristics during time to exhaustion tests. Med Sci Sports Exerc, 2009, 41 (3), 637–644, doi: 10.1249/ MSS.0b013e31818acfba. 18. Greń J., Mathematical statistics task and models [in Polish]. PWN, Warszawa 1976. 19. Craig A., Pendergast D., Relationships of stroke rate, distance per stroke, and velocity in competitive swimming. Med Sci Sports, 1979, 11 (3), 278–283. 20. Plagenhoef S., Patterns of Human Motion – a Cinematographic Analysis. Prentice-Hall, Englewood Cliffs 1971. 21. Hay J.G., Guimaraes A.C.S., Grimston S.K.A., Quantitive look at swimming biomechanics. In: Hay J.G. (ed.),

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Starting, Stroking & Turning. A Compilation of Research on the Biomechanics of Swimming. University of Iowa, Iowa 1983–1986, 1–4. 22. Costill D.L., Kovaleski J., Porter D., Kirwan J., Fielding R., King D., Energy expenditure during front crawl swimming: predicting success in middle-distance events. Int J Sports Med, 1985, 6 (5), 266–270, doi: 10.1055/s-20081025849. 23. Corder G.W., Foreman D.I., Nonparametric statistics for non-statisticians: a step-by-step approach. Wiley, Hoboken 2009. 24. www.swim.ee - website of Rein Hailand. Available from: URL: http:// www.swim.ee [accessed: May, 2011]. 25. Ballreich R., Model for estimating the influence of stride length and stride frequency on the time in sprinting events. In: Komi P.V. (ed.), Biomechanics V-B. University Park, Baltimore 1976, 208–212. 26. Bajdziński M., Starosta W., Kinaesthetic differentiation and its conditioning [in Polish]. MSMS, Warszawa–Go­ rzów Wlkp. 2002. 27. Wolpert D., Miall C., Kawato M., Internal models in the cerebellum. Trends Cogn Sci, 1998, 2 (9), 338–347, doi: 10.1016/S1364-6613(98)01221-2. 28. Starosta W., Conditionings of lateral kinaesthetic differentiation in advanced competitors in different disciplines of sport [in Polish]. Medycyna Sportowa, 2001, 4, 152–160. 29. Albiński P., Zatoń K., Changes in the level of kinesthetic differentiation in the training process among swimmers between 14 and 18 years of age. Polish Journal of Environmental Studies, 2006, 15, 646–650. 30. Zatoń K., Klarowicz A., Speech as a factor favouring kinaesthetic awareness in the process of learning swimming skills [in Polish]. Hum Mov, 2003, 2 (8), 45–53.

Paper received by the Editors: November 15, 2011 Paper accepted for publication: March 21, 2012 Correspondence address Stefan Szczepan Zakład Pływania Akademia Wychowania Fizycznego Kryta Pływalnia al. I.J. Paderewskiego 35 51-612 Wrocław, Poland e-mail: [email protected]

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THE INFLUENCE OF TACTILE FEEDBACK ON HAND MOVEMENT ACCURACY doi: 10.2478/v10038-012-0027-0

JACEK POLECHOŃSKI *, DOROTA OLEX-ZARYCHTA The Jerzy Kukuczka Academy of Physical Education, Katowice, Poland

Abstract

Purpose. This study aimed at measuring the reaction of the hand when tactile feedback was impaired in upper extremity motor performance in order to empirically evaluate how precision was affected during visually controlled hand and arm movement. Methods. 26 right-handed young male adults were tested with the use of a line tracking task by means of Schuhfried’s Vienna Test System. Tactile feedback during line tracking task was impaired by the use of different gloves: a chirurgical latex glove, a rubber glove and a thick work glove made of soft animal leather. Results. The results found a strong relationship between hand movement accuracy and the degree of tactile impairment; no significant relationship was found between tactile impairment and movement speed. Limiting tactile feedback was found to influence motor task accuracy during local wrist movements (using only the carpal and palm joints), while tasks that allowed global movement (both wrist and forearm) were found to have accuracy influenced only when tactile feedback was highly impaired (line tracking with the thick leather glove). Conclusions. The results have indicated that the role of tactile feedback on accuracy during visually-guided precision movement is far greater than previously reported.

Key words: tactile feedback, movement precision, motor control

Introduction Precision is the ability to make highly controlled movement adjustments to improve a preconceived aim, particularly in tasks that demand a high degree of coordination [1, 2]. Movement accuracy, speed and variability are important aspects of motor coordination and influence the quality of controlled movement. The different cause/effect relationships of these parameters determine the speed and precision level of a given motor action [3]. Movement accuracy has been reported to be crucial in accomplishing tasks by the majority of vo­ luntary motor actions [1]. Whether a movement can be precisely controlled is decided by the accuracy of the control mechanisms that are involved in a corrective feedback loop: sensory input, central processing capacity, timing and motor output [2, 4]. The entire process of integrating information from multiple inputs is responsible for both anticipatory and on-line motor control, and this integration process is assumed to be the basis of movement adaptability [5]. Sensory information from cutaneous, proprioceptive and visual afferents is essential for skilled movements of the upper extremities (grasping, reaching for an object, etc.). Visual feedback of the hand contributes to the on-line control of reaching throughout the full extent of movement, even during relatively fast upper extremity actions [6]. Previous findings found evidences that vision and proprioception contribute differently to kinematic planning * Corresponding author. 236

and solving inverse dynamics [7]. Visual feedback control might steer the hand to maintain a predetermined visual path, making corrective adjustments, while sensory feedback seems to indicate the position of the hand and its deviations from a desired trajectory [8]. Previous studies on adaptation assume that the motor system does attempt to maintain preferred kinematic trajectories, such as straight-line paths [9, 10]. Although information on the position of the hand is available from both visual and non-visual sources, the role of vision has been also considerably emphasized in some studies [1, 11]. It has been suggested that sensory feedback from vision influences both motion and position in the initial as well as final phase of hand movement [8]. The role of other sensory information on the speed and accuracy of visually constrained movements is still not well documented, as well as the relationships between different sensory inputs during precise hand movement. Although the tactile feedback mechanisms involved in the on-line control of hand movements are still not clear, some experiments indicated their important role in the successful transmission of precise information on velocity [12]. Tactile information has been shown to play an essential role in the regulation of grasping force [13]. Experiments on the influence of cutaneous feedback on hand grip have shown intact sensory feedback to be crucial for predictive grip force regulation [14]. A complete elimination of tactile feedback by local digital anesthesia produced severe deficiencies in the control of the grip force in object manipulation tasks [15, 16]. However, there is still no clear information on the relationship of sensory-motor coordination and a partial lack of the

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tactile information from fingers during manipulative actions requiring speed and accuracy. An interesting study by Romano et al. has shown a prolonged reaction time in the absence of sufficient tactile feedback [17], and another study has pointed to unnecessarily high grip force of an object’s surface due to low levels of tactile input [18]. In the present study we measured the response of the hand to tactile feedback impairment during upper extremity motor performance in order to evaluate the contributions of tactile feedback during the on-line control of visually controlled hand movements. Once common example when tactile information is limited is when using gloves; therefore, in this experiment we used three different kinds of gloves to analyze what tactile effect they have on movement speed and accuracy. The results are expected to highlight the role of sensory input from tactile receptors on hand movements requiring precision. Material and methods A group of 26 right-handed young male adults aged 22.4 ± 2.7 years took part in the experiment in accor­ dance to the guidelines from the Bioethical Board of the Academy of Physical Education in Katowice, Poland. All participants provided informed consent but were kept unaware of the true purpose of the experiment. The level of psychomotor performance was evaluated by the use of selected tests from a computer-aided psychological diagnosis system, the Vienna Test System (VST, Schuhfried, Austria). A motor-performance test battery (the Motorische Leistungsserie, MLS) from VTS was used to measure the speed and accuracy of hand and arm movement. The MLS is a battery of tests providing a detailed examination of fine motor abilities (Fig. 1). The apparatus consists of a 300 × 300 × 15 mm work panel covered with holes, grooves and contact surfaces. A special pen is attached to each (left and right) edge

Figure 1. The MLS device from VTS

Figure 2. The shape of the VTS full length tracking task – hand/arm performance from the left to the right side

Figure 3. The shape of the VTS short tracking task – hand performance from the left to the right side

of the work panel. In this experiment, hand and arm movement precision was analyzed by the use of a unilateral line tracking task with the right pen (for the right, dominant hand). The task was to track an outlined groove with the pen as quickly and accurately as possible – without any contact with the groove’s outer walls. Contact with the wall was recorded as a performance error. The speed and the accuracy of hand/arm performance were measured by the following variables: the time to complete the task, the time of the errors and the number of errors. Only the dominant (right) hand of each participant was tested. The experimental design included two variants of the outlined task. In the first variant, each participant was seated comfortably at the work panel. The tested arm was free to move in any direction (no elbow support was provided) in order to complete the line tracking task. The entire length of the tracking groove was used in this tracking task (Fig. 2). In the second variant, each participant was also seated comfortably at the work panel, but arm movement was restricted by stabilizing the elbow and forearm on the table. In such conditions only radial movements – by the carpal and palm joints – were allowed to be used to complete the tracking task. The length of the tracking groove was shortened to adjust for the use of the restraints (Fig. 3) as well as to allow for a comparison of both line tracking variants (a short track and a long track) by differentiating the influence of tactile feedback on movement speed and precision during local and more global upper extremity movements. Both variants of the test were performed by the participants four times, each time with different situations 237

HUMAN MOVEMENT J. Polechoński, D. Olex-Zarychta, Tactile feedback and movement accuracy

Figure 5. The influence of tactile feedback impairment on the number of errors in the full length tracking task (error bars show standard error) Figure 4. Gloves used in the experiment: a) chirurgical latex glove, b) rubber glove, c) thick work glove made of soft animal leather

of tactile perception: using their bare hand or wearing a chirurgical latex glove, a rubber glove or a thicker work glove made of soft animal leather (Fig. 4). To eliminate the impact of learned strategies (motor learning) on subsequent tests, the participants were randomly divided into two groups of 13 individuals; the first subject in the first group started the tests with his bare hand while the other group started testing with a glove. The full length tracking task was performed first by all participants. The trials were performed with two-minute pauses in order to eliminate the effects of fatigue. The total amount of errors (how many times the participant touched the walls of the groove with the pen) during the line-tracking tasks as well as the total time of error (the length of time being outside of the groove) were recorded as indicators of movement precision. The obtained data were analyzed with standard descriptive statistics methods. Chosen procedures enabled to describe the normality of the distribution of data obtained in the experiment. One-way analysis of variance (ANOVA) for repeated measures was used to determine the influence of tactile feedback on hand/arm movement accuracy. The chosen level of significance was fixed at p 0.05. Fisher’s Least Significance Difference (LSD) method during post-hoc testing was also used for a more detailed analysis of the differences among the movement parameters. All statistics were calculated with Statistica ver. 9.1 software by Statsoft (USA). Results When subjected to variance analysis (p 0.05), the results indicated that limited tactile perception influenced accuracy when performing the full length tracking task. Significant differences in accuracy, measured by the number of errors, were found among the various tactile impairment trials. The largest amount of errors were made when the subject was burdened with the largest degree of tactile impairment (the thick work glove, see Fig. 5). A significant relationship was also found 238

Figure 6. The influence of tactile feedback impairment on the time of error in the full length tracking task (error bars show standard error)

Figure 7. The influence of tactile feedback impairment on the time of the test in full length tracking task (error bars show standard error)

between tactile impairment and the time of error. In the full length tracking task, the total time of error was more prolonged when participants wore the thick work glove (Fig. 6). No significant differences were found in the time it took to complete the task in relation to the degree of tactile impairment (Fig. 7). When the short line tracking task was performed (with a stabilized arm and elbow), the results also indicated an evident influence of tactile perception impairment on the quality of motor performance (p < 0.001). Similar to the full length tracking task, no differences in the time of task completion were found among the various degrees of tactile impairment (p > 0.05). In the short tracking task, significant differences in movement accuracy were recorded by the number of errors

HUMAN MOVEMENT J. Polechoński, D. Olex-Zarychta, Tactile feedback and movement accuracy

Figure 8. The influence of tactile feedback impairment on the number of errors in the short tracking task (error bars show standard error)

Figure 9. The influence of tactile feedback impairment on the time of errors in the short tracking task (error bars show standard error)

Figure 10. The influence of tactile feedback impairment on the time of the test in the short tracking task (error bars show standard error)

and the time of error not only when using the work glove, the bare hand or chirurgical glove, but also between the bare hand and rubber glove, and between the rubber glove and the thick work glove (Figs. 8–10). Discussion The results of this study only partially corroborated previous findings on the relationship of tactile feedback and motor coordination. It was previously suggested that during precise movement when information from many different sensory sources is involved, the role of visual feedback is of particular importance [4, 11, 19]. It was also stated that minimum variance integration is an important component of sensorimotor processing

[20]. Our results have indicated that limiting tactile information negatively influences movement quality, where a decline in accuracy is coupled to a rise in the degree of tactile impairment, even despite full visual control of the movement. The relationship between tactile feedback and performance accuracy was clearly visible during localized hand movements, even when the fingers are minorly impaired. In the short tracking task, the differences among the results of different tactile conditions were much greater than in the full length tracking version – movements that engage longer kine­ matic chains (hand/forearm/arm movements). The relationship between tactile feedback and final accuracy were significant only when the hand had a high degree of tactile impairment. These results seem to indicate a more pronounced role of tactile information during localized hand performance (fine movements) in comparison to more global arm movements, which incorporate more muscles and joints. In some previous studies, tactile feedback improved movement accuracy and control during tactile precision-grip tasks [21]. These results seems to highlight the special importance of tactile receptors in the on-line control of fine movement. It is possible that in gross motor tasks the lack of feedback from tactile receptors may be compensated by other sensory inputs (vision, proprioception of the joints and muscles, etc.) to process the corrective mechanisms involved in the closed-loop control [4]. Taking into consideration that visual information takes longer to process in the voluntary feedback loop than in the kinesthetic loop [22], it seems quite logical that individuals would use non-visual sources of information on movement accuracy in the short tracking line task. It was previously proven that in time-restricted movements there is a trade-off between the time allotted to gather visual information, action planning and motor execution [23]. Our results support these findings and suggest tactile information plays a special role in the motor accuracy of hand movement. Previous studies have indicated that tactile perception is crucial for optimal speed and movement accuracy when a visual cue of movement is not available. In such conditions, a host of tactile receptor information can allow an individual to maintain an optimal movement speed without losing a high level of accuracy [24]. In visually controlled tasks, the role of vision was previously suggested as critical in both movement speed and accuracy. Feedback information from the visual sensory system was assumed to dominate over information from the other senses during the process of sensory integration. Vision was assumed to be crucial in the reduction of movement error [3, 4]. Our results have suggested on-line, afferent feedback from tactile receptors in the control of movement accuracy plays an important role despite full visual control of hand movement. However, we found no such effect on movement speed. Saunders and Knill [8] reported that visual 239

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cues of both hand movement trajectory and hand position influence all phases of movement only in specific conditions, such as when there is a lack of other sensory inputs and when vision is the only sensory contributor for precision performance (this experiment was conducted in virtual reality). Experiments on total visual impairment and full vision found that an activation of the visual cortex could occur in situations of no visual control not only in blind but also sighted participants when learning a fine motor task [6, 19, 25]. These and other results confirm that in human motor control, many sources of sensory information may be simultaneously involved while control processes can dynamically adapt to task conditions. Position estimates, used in movement vector planning, were suggested to rely mostly on visual input, whereas estimates used to compute joint-based motor command relied more on proprioceptive signals [7]. This suggests that when estimating the arm’s position, the brain selects different combinations of sensory inputs. However, our results on the length of the test contradict the results of Kinoshita [18], who reported differences in the time of the task in relation to the material of the gloves that were used. The main limitations of this study were the laterality of the limbs when performing the task as well as an asymmetry of the results, caused by the fact that the tasks were performed only with the dominant hand. Another aspect to consider would be the type of glove and material used, the weight of the glove or the degree in how it adheres to the hand. Another interesting research issue related to the relationship of tactile feedback and movement precision is what problems they pose in terms of motor learning. Another research aspect not analyzed in this study were individual differentiations – this issue aspect requires research on different sample population, such as athletes from different sports. It seems, therefore, that the research question analyzed in this study warrants further research. Conclusion In conclusion, our results have indicated that the role of tactile feedback in the accuracy of hand movement may be far greater than previously believed and is worth further research in variable tasks conditions. Limitations of tactile feedback seem to influence movement accuracy while no effect was found on movement speed. This suggests that the time control of movement execution probably relies on sensory inputs other than tactile ones and/or on the sensory integration process. However, our experiment proved that in visually controlled tasks the role of tactile information is important in performing accurate, aimed hand movements. Acknowledgement This study was supported by a research grant from the Aca­ demy of Physical Education in Katowice.

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References 1. Rothwell J., Control of human voluntary movement. 2nd ed. Chapman and Hall, London 1996. 2. Shephard R., Physical activity and growth. Year Book Medica Publishers, Chicago–London 1982. 3. Plamondon R., Alimi A., Speed/accuracy trade-offs in target-directed movements. Behav Brain Sci, 1997, 20 (2), 279–349. 4. Schmidt R.A., Wrisberg C.A., Motor learning and performance. 4th ed. Human Kinetics, Champaign 2008. 5. Witney A., Wing A., Thonnard J.L., Smith A.M., The cutaneous contribution to adaptive precision grip. Trends Neurosc, 2004, 27 (10), 637–643, doi: 10.1016/j.tins.2004. 08.006. 6. Sathian K., Visual cortical activity during tactile perception in the sighted and the visually deprived. Dev Psychobiol, 2005, 46 (3), 279–283, doi: 10.1002/dev.20056. 7. Sober J.S., Sabes P.N., Multisensory integration during motor planning. J Neurosci, 2003, 23 (18), 6982–6992. 8. Saunders J.A., Knill D.C., Visual Feedback Control of Hand Movements. J Neurosci, 2004, 24 (13), 3223–3234, doi: 10.1523/​J NEUROSCI.4319-03.2004. 9. Shadmehr R., Mussa-Ivaldi F.A., Adaptive representation of dynamics during learning of a motor task. J Neurosci, 1994, 14, 3208–3224. 10. Wolpert D.M., Ghahramani Z., Jordan M.I., Are arm trajectories planned in kinematic or dynamic coordinates? An adaptation study. Exp Brain Res, 1995, 103 (3), 460– 470, doi: 10.1007/BF00241505. 11. Saunders J.A., Knill D.C., Humans use continuous visual feedback from the hand to control fast reaching movements. Exp Brain Res, 2003, 152, 341–352, doi: 10.1007/ s00221-003-1525-2. 12. Kotani K., Yu T., Asao T., Horii K., Representation of velocity information by using tactile apparent motion. Lect Notes Comput Sci, 2009, 5611, 470–478, doi: 10.1007/9783-642-02577-8_51. 13. Smith A.M., Some shear facts and pure friction related to roughness discrimination and the cutaneous control of grasping. Can J Physiol Pharmacol, 1994, 72 (5), 583– 590, doi: 10.1139/y94-083. 14. Nowak D., Glasauer S., Hermsdörfer J., How predictive is grip force control in the complete absence of somato­ sensory feedback? Brain, 2004, 127, 182–192, doi: 10.1093/ brain/awh016. 15. Augurelle A.S., Smith A.M., Lejeune T., Thonnard J.L., Importance of cutaneous feedback in maintaining a secure grip during manipulation of hand-held objects. J Neurophysiol, 2003, 89 (2), 665–671, doi: 10.1152/jn. 00249.2002. 16. Monzée J., Lamarre Y., Smith A.M., The effects of digital anaesthesia on force control using a precision grip. J Neurophysiol, 2003, 89 (2), 672–683, doi: 10.1152/jn. 00434.2001. 17. Romano, J.M., Gray, S.R., Jacobs N.T., Kuchenbecker, K.J., Toward Tactilely Transparent Gloves: Collocated Slip Sensing and Vibrotactile Actuation. World Haptics 2009 – Third Joint EuroHaptics conference and Symposium on Haptic Interfaces for Virtual Environment and Tele­ operator Systems, Salt Lake City, UT, USA, March 18–20, 2009, 279-284.

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18. Kinoshita H., Effect of gloves on prehensile forces during lifting and holding tasks. Ergonomics, 1999, 42 (10), 1372–1385, doi: 10.1080/001401399185018. 19. Tipper S.P., Lloyd D., Shorland B., Dancer C., Howard L.A., McGlone F., Vision influences tactile perception without proprioceptive orienting. Neuroreport, 1998, 9 (8), 1741– 1744, doi: 10.1097/00001756-199806010-00013. 20. Block H., Bastian A., Sensory reweighting in targeted reaching: effects of conscious effort, error history and target salience. J Neurophysiol, 2010, 103 (1), 206–217, doi: 10.1152/jn.90961.2008. 21. Rabin E., Muratori L.K., Svokos K., Gordon A., Tactile/ proprioceptive integration during arm localization is intact in individuals with Parkinson’s disease. Neurosci Lett, 2010, 470 (1), 38–42, doi: 10.1016/j.neulet.2009. 12.051. 22. Wulf G., Attention and motor skill learning. Human Kinetics, Champaign 2007. 23. Battaglia P.W., Schrater P.R., Humans trade off viewing time and movement duration to improve visuomotor accuracy in a fast reaching task. J Neurosci, 2007, 27 (26), 6984–6994, doi: 10.1523/JNEUROSCI.1309-07.2007. 24. Sribunruangrit N., Marque C.K., Lenay C., Hanneton S., Gapenne O., Vanhoutte C., Speed-accuracy tradeoff during performance of a tracking task without visual feedback. IEEE Trans Neural Syst Rehabil Eng, 2004, 12 (1), 131– 139, doi: 10.1109/TNSRE.2004.824222. 25. Weisser V., Stilla R., Peltier S., Hu X., Sathian K., Shortterm visual impairment alters neural processing of tactile form. Exp Brain Res, 2005, 166 (3–4), 572–582, doi: 10.1007/s00221-005-2397-4.

Paper received by the Editors: November 14, 2011 Paper accepted for publication: March 21, 2012 Correspondence address Jacek Polechoński Katedra Teorii i Metodyki WF Akademia Wychowania Fizycznego ul. Mikołowska 72a 40-058 Katowice, Poland e-mail: [email protected]

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HUMAN MOVEMENT 2012, vol. 13 (3), 242– 246

ASSOCIATION BETWEEN ANTHROPOMETRIC INDICATORS AND SERUM LIPID PROFILE IN ADOLESCENTS doi: 10.2478/v10038-012-0028-z

ANDREIA PELEGRINI 1 *, MARIA FÁTIMA GLANER 2 , EDIO LUIZ PETROSKI 3 1

State University of Santa Catarina, Florianopolis, Santa Catarina, Brazil State University of Londrina, Londrina, Paraná, Brazil 3 Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil 2

Abstract

Purpose. The aim of this study was to verify and analyze the association between anthropometric indicators and serum lipid profiles in adolescents. Methods. The study included 250 adolescents aged 11–17 years from both sexes. The anthropometric variables measured were body weight, height and waist circumference. Body mass index and waist circumference were used to calculate a nutritional status rating (whether normal weight or overweight) and abdominal obesity, respectively. Total cholesterol, high-density lipoproteins, low-density lipoprotein and triglyceride levels were determined by an enzymatic colorimetric method using automatic spectrophotometry and were categorized according to cutoff points established by the III Brazilian Guidelines on Dyslipidemia and Atherosclerosis Prevention from the Brazilian Society of Cardiology. Results. The overweight and abdominal obesity prevalence was found to be 23.6% and 40.0%, respectively. Undesirable total cholesterol, high-density lipoprotein, low-density lipoprotein and triglyceride levels were found in 40.8%, 8.4%, 36.0% and 13.6% of the studied adolescents, respectively. Overweight adolescents were 2.29 (CI 95%, 1.07-4.91) times more likely to have high triglyceride levels, and those with abdominal obesity were 2.47 (CI 95%, 1.14-5.37) times more likely to show high triglyceride levels. Conclusions. A high prevalence of overweight and abdominally obese adolescents, with high levels of serum lipid profiles, were observed. Moreover, overweight and abdominally obese adolescents were more likely to have high triglyceride levels.

Key words: dyslipidemia, risk factors, body mass index, abdominal obesity, adolescents

Introduction Obesity has been considered a worldwide public health problem [1]. In Brazil, a rise in overweight and obesity levels from 4% to 13% was observed among children and adolescents (6-18 years of age) from the 1970s to the 1990s [2]. This excess is associated with a number of metabolic and cardiovascular complications [3], even among children. One complication which stands out in particular is dyslipidemia, which is characterized by increased plasma total cholesterol and/or triglyceride levels or decreased high-density lipoprotein (HDL-C) [4]. Although clinical manifestations of cardiovascular disease occur only in adulthood, a number of risk factors can be present already in childhood and adolescence [5], which can lead to an increased risk of morbidity and mortality in adulthood [6]. To this effect, determining the prevalence of these risk factors in children should be considered a priority as early diagnosis favors the adoption of health promotion strategies and a healthy lifestyle that may persist into adulthood [7]. A number of anthropometric indicators have been recommended for the identification of cardiovascular risk factors in a pediatric population [8, 9]. Body mass

* Corresponding author. 242

index (BMI) is considered an indicator of overall adiposity, while waist circumference (WC) is an indicator of central fat tissue distribution [10]. In addition, most studies linking obesity and cardiovascular risk factors in adolescents have been conducted in intermediateand large-sized cities. Only one survey was conducted among adolescents in a small city in southern Brazil [11]. Thus, this study aimed to determine and analyze the association between anthropometric indicators and the serum lipid profile of adolescents residing in both urban and rural areas, and of European descent, in a city in southern Brazil. Material and methods This study, on the association of anthropometric indicators and serum lipid profile in adolescents, was developed as a part of a cross-sectional study entitled “Interaction Between Variables That May Influence Body Fat Accumulation and Lipid Profile of Parents and Children” and was approved by the Ethics Research Committee of the Catholic University of Brasilia (Process No. 026/2009). This study was conducted on a re­ presentative sample of adolescents from the municipality of Saudades, located in the extreme western part of the state of Santa Catarina (SC) in southern Brazil. This town is predominantly composed of individuals who are of German descent and consists of only 8,880

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inhabitants. Saudades-SC is classified as having a high human development index with a Human Development Index of 0.82 [12]. The entire study population consisted of 1381 adolescents aged 11 to 17 years enrolled in public schools; there are no private schools in the city. Students attending their 5th year of elementary school education up to those finishing their 3rd year of secondary school were selected from the only school found in an urban area, with a group of elementary school students (from the 1st to 9th years) from another school located in a rural area also added. As this analysis was part of a broader study, several sample sizes were calculated for different health outcomes. For this analysis, a known prevalence level of 28% was adopted for high total cholesterol and used to calculate a representative sample size [13]. In addition, an acceptable error of seven percentage points was assigned with a confidence level of 95% and a design effect of 1.4, increased by 10% for eventual losses and refusals. Thus, an assessment of 219 adolescents would be required for statistical analysis. Due to the characteristics of the sampling process, which involved all of the individuals belonging to various city areas, 250 adolescents participated in the sample. For anthropometric measurement, the height and weight measurements of each child were collected. Subsequently, the body mass index was calculated [BMI = body mass (kg)/height2 (m2)]. For BMI classification, cutoff points recommended by the International Obesity Task Force were used [14], which vary according to gender and age. Adolescents were grouped into cate­gories of normal weight and excess weight (which included those who are overweight and obese). The waist circumference was measured 2.5 cm above the umbilicus [15] using a tape measure. Abdominal obesity was classified according to cutoff points established by Katzmarzyk et al. [16], which vary according to gender and age. For analysis of serum lipid levels, 5 mL of blood were collected from each of the subjects to measure blood concentrations of total cholesterol, HDL-C, LDL-C and triglyceride levels. Blood samples were collected by venipuncture after a fasting period from 12 to 14 hours. The blood samples were stored in flasks containing a coagulation accelerator. Total cholesterol, HDL-C and triglyceride (TG) levels were determined by an enzymatic colorimetric method (using reagents from Lab­ test, Brazil) by automatic spectrophotometry (Cobas Mira Plus, Roche, Switzerland) according to the standardized procedures established by the reagent’s maker and by the manufacturer of the equipment. LDL-C was calculated using a formula proposed by Friedewald et al. [17], where the triglyceride concentration is below 400 mg/dL. The cutoff points used were those proposed by the III Brazilian Guidelines on Dyslipidemia and Atherosclerosis Prevention from the Brazilian Society of Cardiology [18], with desirable values for TC

< 170 mg/dL, LDL-C < 110 mg/dL, HDL-C 35 mg/dL and TG 130 mg/dL. A descriptive analysis of the variables, mean values, standard deviations and frequency distribution were used for statistical analysis. The association between outcome/dependent variable (serum lipid profile) and independent variables (anthropometric indicators) was analyzed by logistic regression, estimating the odds ratios and their confidence intervals at 95%. Two models were tested, one simple and another adjusted (including all independent variables). In all tests, the significance level adopted was 5%. Results Mean (± SD) results of the study participants were: age (years): 14.1 (± 1.9), BMI (kg/m²): 20.3 (± 3.3), WC (cm): 71.8 (± 8.6). The serum lipid profile is exhibited in Table 1. The prevalence of overweight and obesity among the subjects was 23.6% and 40.0%, respectively. Of the adolescents surveyed, 40.8% had high total cholesterol levels, 36.0% had increased LDL-C, 13.6% had high triglyceride levels and 8.4% had low HDL-C (Tab. 2). Of the previously mentioned risk factors (total cholesterol, triglyceride, HDL-C and LDL-C levels), it was found that 14.4% of adolescents had one risk factor, 33.2% had two risk factors, 5.2% had three risk factors and 0.4% had all four risk factors (data not shown). Table 1. Mean and standard deviation of serum lipid profiles in adolescents according to gender (N = 250) Total (dp) Total Cholesterol (md/dL) HDL-C (md/dL) LDL-C (md/dL) Triglycerides (md/dL)

Boys (dp)

Girls (dp)

167.16 (30.45) 160.35 (28.95) 172.08 (30.65) 47.84 (10.40) 103.88 (26.04) 76.58 (45.41)

47.16 (11.37)

48.32 (9.64)

98.70 (24.78) 107.63 (26.38) 71.93 (42.71)

79.95 (47.13)

HDL-C – HDL lipoproteins, LDL-C – LDL lipoproteins Table 2. Proportion of adolescents with desirable and undesirable anthropometric indicators and serum lipid profile values (N = 250) Desirable

BMI WC Total Cholesterol HDL-C LDL-C Triglycerides

N

%

191 150 148 229 160 216

76.4 60.0 59.2 91.6 64.0 86.4

Undesirable N 59 100 102 21 90 34

% 23.6 40.0 40.8 8.4 36.0 13.6

BMI – body mass index, WC – waist circumference, HDL-C – HDL lipoproteins, LDL-C – LDL lipoproteins 243

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Table 3. Odds ratios between BMI, WC and serum lipid profile among the studied adolescents (N = 250) BMI OR (CI95%) Total Cholesterol HDL-C LDL-C Triglycerides

0.75 (0.41–1.38) 2.69 (1.07–6.73)† 0.98 (0.53–1.80) 2.29 (1.07–4.91)†

WC OR* (CI95%) 0.43 (0.15–1.22) 2.08 (0.79–5.43) 1.92 (0.68–5.37) 2.52 (1.11–5.72)†

OR (CI95%) 0.88 (0.53–1.48) 2.14 (0.87–5.28) 0.93 (0.55–1.58) 2.43 (1.16–5.07)†

OR* (CI95%) 0.71 (0.30–1.68) 1.79 (0.70–4.58) 1.23 (0.52–2.92) 2.47 (1.14–5.37)†

BMI – body mass index, WC – waist circumference HDL-C – lipoprotein HDL, LDL-C – lipoprotein LDL OR – odds ratio, CI – confidence interval, * OR adjusted for all lipid profile variables, † p < 0.05

Table 3 shows the crude and adjusted odds-ratio values and the confidence intervals between the anthropometric indicators and serum lipid profile of the adolescents. Crude analysis found an association between HDL-C and triglyceride levels with BMI. When the analysis was adjusted for all independent variables, it was observed that only triglycerides remained associated with BMI. These results show that obese adolescents were 2.29 (CI 95% = 1.07-4.91) times more likely to show high triglyceride levels compared to eutrophic individuals. Similarly, it was observed that abdominally obese adolescents, verified by WC, were 2.47 (CI 95% = 1.14-5.37) times more likely to have high triglyceride levels. Discussion The findings in this study found that 23.6% of studied adolescents are considered overweight. Overweight pre­ valence among adolescents may be explained by changes in eating patterns (increased consumption of simple sugars, processed foods and an inadequate intake of fruits and vegetables) and by a progressive reduction of physical activity combined with more time dedicated to low-intensity activities (watching television, computer usage and playing video games) [19]. Sedentary behavior may cause an increase in body weight and thus contribute to the increased prevalence overweight and obese adolescents [20]. It was observed that 40% of adolescents in this study were abdominally obese. Beck et al. [11] investigated adolescents aged 14–19 years in the city of Três de Maio, in state of Rio Grande do Sul, by using the same cutoff points as in this study and found that 32.6% of adolescents had abdominal obesity. These data show the need for public policies aimed at reducing body fat in the central region of the body in children and adolescents, especially when considering its relationship with the occurrence of cardiovascular diseases in adulthood [21]. Among the additional findings of this study, the high prevalence of total cholesterol (40.8%) among adolescents attracted attention. Lower prevalence levels have been found among adolescents in another Brazilian 244

city [22]. This difference in total cholesterol levels in childhood and adolescence is a predictor of cholesterol levels in adulthood. In addition, the onset of atherosclerosis in childhood could be increased in later life by obesity and by a number of other factors such as family history, physical inactivity and hypertension [23]. The proportion of adolescents with increased LDL-C levels was found to be 36.0%. Lower prevalence levels have been found in other Brazilian studies [22]. Epidemiological and laboratory evidence support the hypo­ thesis that the increased concentration of both total cholesterol and LDL-C levels leads to coronary artery disease [24]. Furthermore, high LDL-C concentrations in children and young adults are associated with an increased risk of atherosclerotic disease [25] due to oxidation and the deposition of LDL-C in the artery walls [26]. The 13.6% of adolescents with increased serum triglyceride levels found in this study was similar to what was found in other Brazilian cities [27]. As for HDL-C, a low prevalence of adolescents with levels below the re­ commended value for this variable was observed (8.4%). Low levels of this lipoprotein are alarming given its importance as a protective factor against chronic diseases, particularly atherosclerosis [28]. This is partly due the function of HDL-C, which acts in reverse cholesterol transport, i.e., it helps remove cholesterol from artery walls to the liver where it is re-used or converted into bile acids or discarded [29]. Adolescents who are overweight, as determined by BMI, are twice as likely to show increased triglyceride levels when compared to adolescents with normal weight. Similar results were found by Cobayashi et al. [30], who analyzed two groups of adolescents (obese and normal) and found that obese adolescents are more likely to have elevated serum triglycerides and low HDL-C levels compared to eutrophic adolescents. Although the clinical symptoms caused by cardiovascular disease occur in adulthood, atherosclerosis can begin in childhood, with being overweight a major determinant factor [31]. As for abdominal obesity, it was found that adolescents with high central adiposity are more likely to have elevated triglyceride levels. Weight and body fat are the main modulators of plasma lipid levels. Triglyce­

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ride, total cholesterol and LDL-C levels above the recommended values, combined with decreased HDL-C, increase the likelihood of developing cardiovascular diseases [32]. The main limitations of this study were the use of a cross-sectional design that does not allow for establishing a cause/effect relationship between the outcome and independent variables, which may point to a reverse causality between such associations. It should be stressed that this study, with the objective of searching for associations between anthropometric indicators and serum lipid profiles, was the first to be conducted on adolescents of European ancestry, who are different from the mixed Brazilian population and who reside in rural and urban areas. The results shown in this study allow for the conclusion that a large proportion of adolescents have high serum lipid profile levels. Moreover, those with overweight and abdominal obesity are more likely to have elevated triglyceride levels. Acknowledgments This study was sponsored by the National Council for Scientific and Technological Development, Process No 481859/2007-1.

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indices for identifying dyslipidemia in school children. Clin Biochem, 2011, 44 (8–9), 659–664, doi: 10.1016/j. clinbiochem.2011.02.004. 9. Kelishadi R., Gheiratmand R., Ardalan G., Adeli K., Mehdi Gouya M., Mohammad Razaghi E. et al., Association of anthropometric indices with cardiovascular disease risk factors among children and adolescents: CASPIAN study. Int J Cardiol, 2007, 117 (3), 340–348, doi: 10.1016/j.ijcard.2006.06.012. 10. Rexrode K.M., Buring J.E., Manson J.E., Abdominal and total adiposity and risk of coronary heart disease in men. Int J Obes Relat Metab Disord, 2001, 25 (7), 1047–1056. 11. Beck C.C., Lopes A.S., Giuliano I.C.B., Borgatto A.F., Cardiovascular risk factors in adolescents from a town in the Brazilian South: prevalence and association with sociodemographic variables [in Portuguese]. Rev Bras Epidemiol, 2011, 14 (1), 36–49, doi: 10.1590/S1415790X2011000100004. 12. United Nations, Human Development Index, Municipal 1991 and 2000. All cities in Brazil. Available from: URL: http://www.pnud.org.br/atlas/tabelas/index.php [accessed February 02, 2011]. 13. Giuliano I.C., Coutinho M.S., Freitas S.F., Pires M.M., Zunino J.N., Ribeiro R.Q., Serum lipids in school kids and adolescents from Florianópolis, SC, Brazil – Healthy Floripa 2040 Study [in Portuguese]. Arq Bras Cardiol, 2005, 85 (2), 85–91, doi: 10.1590/S0066782X2005001500003. 14. Cole T.J., Bellizzi M.C., Flegal K.M., Dietz W.H., Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ, 2000, 320, 1240–1243, doi: 10.1136/bmj.320.7244.1240. 15. Callaway C.W., Chumlea W.C., Bouchard C., Himes J.H., Lohman T.G., Martin A.D. et al., Circumferences. In: Lohman T.G., Roche A.F., Martorell R.N. (eds.), Anthropometric standartization reference manual. Human Kinetics Books, Champaign 1991. p. 39-54. 16. Katzmarzyk P.T., Srinivasan S.R., Chen W., Malina R.M., Bouchard C., Berenson G.S., Body mass index, waist circumference, and clustering of cardiovascular disease risk factors in a biracial sample of children and adolescents. Pediatrics, 2004, 114 (2), 198–205. 17. Friedewald W.T., Levy R.I., Fredrickson D.S., Estimation of the concentration of low-density lipoprotein cholesterol in plasma without use of the preparative ultracentrifuge. Clin Chem, 1972, 18 (6), 499–502. 18. Department of the Brazilian Society of Cardiology: III Brazilian Guidelines on dyslipidemia and guideline of atherosclerosis prevention from atherosclerosis [in Portuguese]. Arq Bras Cardiol, 2001, 77 (suppl. 3), 1–48, doi: 10.1590/S0066-782X2001001500001. 19. Enes C., Slater B., Obesity in adolescence and its main determinants [in Portuguese]. Rev Bras Epidemiol, 2010, 13 (1), 163–171, doi: 10.1590/S1415-790X2010000100015. 20. Maffeis C., Aetiology of overweight and obesity in children and adolescents. Eur J Pediatr, 2000, 159 (suppl. 1), S35–S44. 21. Park J., Hilmers D.C., Mendoza J.A., Stuff J.E., Liu Y., Nicklas T.A., Prevalence of metabolic syndrome and obesity in adolescents aged 12 to 19 years: comparison between the United States and Korea. J Korean Med Sci, 2010, 25 (1), 75–82, doi: 10.3346/jkms.2010.25.1.75. 245

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22. Ribas A.S., Silva L.C.S., Dyslipidemia in schoolchildren from private schools in Belém [in Portuguese]. Arq Bras Cardiol, 2009, 92 (6), 446–451, doi: 10.1590/S0066782X2009000600006. 23. Pereira A., Guedes A.D., Verreschi I.T.N., Santos R.D., Martinez T.L.R., Obesity and its association with other cardiovascular risk factors in school children in Itapetininga, Brazil [in Portuguese]. Arq Bras Cardiol, 2009, 93 (3), 253–260, doi: 10.1590/S0066-782X2009000900009. 24. Gordon T., Castelli W.P., Hjortland M.C., Kannel W.B., Dawber T.R., High density lipoprotein as a protective factor against coronary heart disease. The Framingham study. Am J Med, 1977, 62, 707–714. 25. Bao W., Srinivasan S.R., Valdez R., Greenlund K.J., Wattigney W.A., Berenson G.S., Longitudinal changes in cardiovascular risk from childhood to young adulthood in offspring of parents with coronary artery disease. The Bogalusa Heart Study. JAMA, 1997, 278 (21), 1749– 1754, doi: 10.1001/jama.1997.03550210047037. 26. Shepherd J., Cobbe S.M., Ford I., Isles C.G., Lorimer A.R., MacFarlane P.W. et al., Prevention of coronary heart disease with pravastatin in men with hypercholesterolemia. West of Scotland Coronary Prevention Study Group. N Engl J Med, 1995, 333 (20), 1301–1307. 27. Franca E., Alves J.G.B., Dyslipidemia among adolescents and children from Pernambuco – Brazil [in Portuguese]. Arq Bras Cardiol, 2006, 87 (6), 722–727, doi: 10.1590/ S0066-782X2006001900007. 28. Dwyer T., Iwane H., Dean K., Odagiri Y., Shimomitsu T., Blizzard L. et al., Differences in HDL cholesterol concentrations in Japanese, American and Australian children. Circulation, 1997, 96 (9), 2830–2836, doi: 10.1161/01. CIR.96.9.2830.

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29. Navab M., Hama S.Y., Anantharamaiah G.M., Hassan K., Hough G.P., Watson A.D., Normal high-density lipoprotein inhibits three steps in the formation of mildly oxidized low density lipoprotein: steps 2 and 3. J Lipid Res, 2000, 41 (9), 1495–1508. 30. Cobayashi F., Oliveira F.L.C., Escrivão M.A.M.S., Silveira, D., Taddei, J.A.A.C., Obesity and cardiovascular risk factors in adolescents attending public schools [in Portuguese]. Arq Bras Cardiol, 2010, 95 (2), 200–206, doi: 10.1590/S0066-782X2010005000087. 31. McMahan C.A., Gidding S.S., Malcom G.T., Tracy R.E., Strong J.P., McGill H.C. Jr et al., Pathobiological determinants of atherosclerosis in youth risk scores are associated with early and advanced atherosclerosis. Pediatrics, 2006, 118 (4), 1447–1455, doi: 10.1542/peds.2006-0970. 32. Srinivasan S.R., Bao W., Berenson G.S., Coexistence of increased levels of adiposity, insulin, and blood pressure in a young adult cohort with elevated very-low-density lipoprotein cholesterol: the Bogalusa Heart Study. Metabolism, 1993, 42 (2), 170–176.

Paper received by the Editors: July 7, 2011 Paper accepted for publication: December 23, 2011 Correspondence address Andreia Pelegrini Universidade do Estado de Santa Catarina Centro de Ciências da Saúde e do Esporte Rua Pascoal Simone, 358, Coqueiros CEP: 88080-350 - Florianópolis, SC, Brazil e-mail: [email protected]

HUMAN MOVEMENT 2012, vol. 13 (3), 247– 257

THE USE OF THE “EDUBALL” EDUCATIONAL BALL IN RURAL AND URBAN PRIMARY SCHOOLS AND THE PHYSICAL FITNESS LEVELS OF CHILDREN doi: 10.2478/v10038-012-0029-y

IRENEUSZ CICHY *, ANDRZEJ ROKITA University School of Physical Education, Wrocław, Poland

Abstract

Purpose. Our study aimed at assessing the effects of introducing a modified physical educational program that uses “eduball” educational balls during exercise, play-time and games on the physical fitness of first-grade primary school students. In addition, the study also took under consideration whether any noted changes depended on where the students lived, i.e., in an urban or rural environment. Methods. A total of 127 first-grade students were selected to participate in the pedagogical experiment, with 48 students from a primary school in an urban environment and 79 students from two primary schools located in rural villages. The physical fitness levels of the children were assessed by using selected batteries from the International Physical Fitness Test before and after implementing the “eduball” physical education program. Results. The results found that physical fitness levels were not affected by the use of the “eduball” educational ball, regardless of the environment. However, the physical fitness results of both the boys and girls in the rural experimental group may confirm that the activities that used the educational balls, which emphasize running, can have an impact on the motor development of children’s speed and agility skills. Conclusions. The boys from the urban experimental and urban control groups in both tests achieved better results than their peers from rural areas. However, this may be more strongly related to the overall higher physical fitness levels of the boys from an urban environment (as was found in the first test), rather than their place of residence or their schools’ sports facilities, which were found to be comparable. In the groups of girls, a somewhat different trend was observed, with girls from the urban environment performing better than girls from rural areas among the analyzed fitness variables in the first test, but with the differences leveling out by the second test.

Key words: movement, educational balls, physical fitness

Introduction A child’s initial foray into the school educational system determines in a large part their relationship to education as well as their overall development. Of particular interest and importance is the motor development of children, which has been a subject of research for many years. Many studies have been conducted on children’s motor development [1–7], but knowledge on this subject is still limited and requires constant revision and updating. At the same time it should be noted with regret that many educators do not possess the appropriate competence in the field of physical education; few pay due attention to a child’s psychomotor development and unknowingly work to the detriment of children’s motor development. Among the many changes that children undergo at this stage of development when beginning school (around seven years of age), the proper development of physical fitness is of extreme importance. Physical fitness is not only associated with the function of the musculoskeletal system, but in a large part with the overall biological functioning of the entire body. Its impact is not only relegated to mastering movement exercises, but it is also essential in the efficient * Corresponding author.

functioning of all organs and bodily system, the capabilities of many motor abilities (strength, speed, endurance and coordination) and even some aspects of maintaining an active lifestyle [8]. When speaking about the significance of motor skill development in school-aged youth, with a focus on physical activity, it is essential to remember that the basic form of physical activity for children at this stage is fun; its goal is to create innumerable opportunities of pleasure, to create a sense of group membership as well as to strengthen their self-esteem [9]. Therefore, it is possible to encourage children to participate in school activities as long as they see an aspect of fun within the exercise. When taking these issues into consideration, it should also be remembered that the most dynamic subject within a school is the child, who at this stage of individual development is very active. Children naturally expect that a new environment will provide them with a wide gamut of active opportunities. Every teacher and parent knows that fun and games for children are a na­ tural way for them to get rid of excess energy and address their needs for coexisting with their peers. With teachers, well thought-out children’s games frequently teach children new and important skills or experience. In order to encourage children to participate in phy­ sical activities, it is important to reach out to unconven247

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tional strategies and equipment to make these activates more fun. In addition, in this regard it should also encourage children to independently seek their own inte­ resting solutions for fun. In such a way can the process of developing motor skills be conducted with the children’s awareness and acceptance [8]. In this context, the idea of using additional teaching aids that can be seen as both activating and being attractive for children at this early stage of development seems entirely reasonable. The aim of this study was to research the use of the “eduball” educational ball as an alternative form of physical activity as its emphasizes running, and can better support a child’s motor and mental development [10]. It was hoped to determine what impact can such a modified physical education curriculum using the “eduball” have on the physical fitness levels of first-grade students. Therefore, the following research questions were selected: 1. Are there changes in the physical fitness levels of children after participating in physical activities that use the “eduball”? 2. Do the changes in the physical fitness of children depend on where they live (in an urban or rural environment)? Material and methods A total of 127 pupils from primary schools located in Czarny Bor, Sułów, and Wrocław (Poland) participated in the study. The villages of Czarny Bor and Sułów comprised the rural aspect of this study, from which 79 first-grade students attending local primary schools during the 2004/2005 school year were selected. This part of the study was conducted under a grant provided by the Ministry of Science and Higher Education (No. 2PO5D058), whose principal researcher was the coauthor of this study, Andrzej Rokita. Due to the high comparability of both rural schools, the students were divided into an experimental (18 girls and 19 boys) and control (22 girls and 20 boys) group [7]. The children from an urban environment were 48 first-grade students from School No. 11 in the city of Wroclaw. This part of the study was conducted by Ireneusz Cichy during the 2006/2007 school year. Similarly, the students were divided into an experimental group consisting of 14 boys and 15 girls and a control group of 11 boys and 8 girls. The study was conducted with a parallel group technique, obtained from a previous pedagogical study by Rokita and Cichy [11]. Prior to the experiment, approval was obtained from the Senate Committee on Ethics at the University of Physical Education in Wroclaw and from the children’s parents. The study was conducted under the moniker of “Happy School”, which was used in the selected firstgrade classes at the primary schools in Czarny Bor, Sułów and Wroclaw. In the experimental groups, students participated in physical activity with the educational balls as part of their normal daily class routine, which was 248

guided by their class teacher. The exercises and games they were to play were a number pre-prepared scenarios, designed with the consultation of the class’ teacher. The exercise content was guided by strengthening or improving tasks that were either too difficult for the students to learn or those that were considered important enough to warrant additional focus. The principal structure of all the scenarios was to provide a form of fun. The time spent playing with the educational balls accounted for approximately 60% of the total duration of physical activity. The remaining time was devoted to other forms of physical activity that were part of the physical education curriculum. In the control groups, which continued to conduct the physical education component of their class in a standard manner, classes were also led by (as in the experimental groups) by their class teacher. In order to assess the differences in using the “edu­ ball” on children’s physical activity levels, this study employed the standard International Physical Fitness Test [12]. Only seven of the eight test batteries were employed, as the test of endurance (running a distance of 600 m) was not accepted by all of the children’s’ parents. In addition, the primary school in Wroclaw (located in the city center) did not have an area where this test could be performed. Research on both the rural/urban groups was conducted before the start of the experiment and after it concluded, i.e., at the beginning of the school year in September and at the end of the school year in late May/early June, respectively. The results were calculated with basic statistical measures such as arithmetic mean and standard deviation. The data concerning the two group was referred to the results (not to the data) Rokita [7], therefore, it was possible to compare the village and town gropu with the use of planned comparisons. Thus, the presented analysis is a compilations of variance analyses and t-Student test for dependent and independent gropus. The significance of the observed differences was determined at p 0.05. The results obtained from the physical fitness tests at the beginning and end of the school year were then subjected to multivariate analysis. Due to the size of the sample, the two research groups and their places of residence, those children from the city of Wroclaw were labeled as urban experimental (UE) or urban control (UC), while those from the rural schools in Czarny Bor and Sułów were labeled as either rural experimental (RE) or rural control (RC). Results A summary of the mean values obtained by the girls from the urban experimental (UE) and rural experimental (RE) groups are presented in Table 1. It can be seen in the 50 m race and palm dynamometry (handgrip strength) in the first test and the flexed arm hang in both the first and second test that the girls from

HUMAN MOVEMENT I. Cichy, A. Rokita, Use of the “eduball” educational ball

Table 1. Comparison of the average physical fitness values obtained by girls in the urban experimental (UE) and rural experimental (RE) groups Variable 50 run_1 (s) Jump_1 (m) Dynam._1 (kg) Hang_1 (s) 4 × 10 run_1 (s) Sit-ups_1 (num.) Toe touch_1 (cm) 50 run_2 (s) Jump_2 (m) Dynam._2 (kg) Hang_2 (s) 4 × 10 run_2 (s) Sit-ups_2 (num.) Toe touch_2 (cm)

UE

RE

N

x

S

N

x

S

15 15 15 15 15 15 15 15 15 15 15 15 15 15

10.51 1.09 12.60 10.51 15.58 13.87 2.67 10.12 1.17 12.73 11.79 15.12 15.67 3.13

0.65 0.14 1.28 6.03 1.35 3.85 5.03 0.76 0.15 1.59 6.75 1.00 2.76 6.49

16 16 16 16 16 16 16 16 16 16 16 16 16 16

11.91 1.05 0.83 2.76 15.14 13.75 –5.25 10.52 1.15 14.44 3.87 14.16 17 –1.94

0.83 0.24 0.2 4.26 1.03 4.39 7.35 1.22 0.17 2.45 4.42 0.79 4.97 9.62

p

Difference

0.0000* 0.5556 0.0000* 0.0003* 0.3155 0.9380 0.0016* 0.2894 0.7764 0.0298* 0.0005* 0.0057* 0.3680 0.0981

1.40 0.04 11.77 7.75 0.44 0.12 7.92 0.40 0.02 1.71 7.92 0.96 1.33 5.07

Legend for Tables 1–16 50 run – running a distance of 50 m 4 × 10 run – 4 × 10 m shuttle run with wooden blocks Jump – standing long jump Sit-ups – sit-ups from a lying position Dynam. – palm dynamometry (handgrip strength) Toe touch – forward bend from a standing position on a bench Hang – flexed arm hang N – number of participants, x – arithmetic mean, SD – standard deviation The designation _1 and _2 tells if the data was collected in the 1st or 2nd test * the significance of the observed differences at p 0.05 Table 2. Comparison of the average physical fitness values obtained by boys in the urban experimental (UE) and rural experimental (RE) groups Variable 50 run_1 (s) Jump_1 (m) Dynam._1 (kg) Hang_1 (s) 4 × 10 run_1 (s) Sit-ups_1 (num.) Toe touch_1 (cm) 50 run_2 (s) Jump_2 (m) Dynam._2 (kg) Hang_2 (s) 4 × 10 run_2 (s) Sit-ups_2 (num.) Toe touch_2 (cm)

UE

RE

N

x

S

N

x

S

14 14 14 14 14 14 14 14 14 14 14 14 14 14

10.34 1.15 14.93 10.58 15.28 16.79 –1.86 9.72 1.25 15.21 11.34 15.01 17.00 –2.50

1.26 0.19 3.11 9.03 1.66 3.70 4.54 1.21 0.21 3.34 9.51 1.65 3.90 4.12

18 18 18 18 18 18 18 18 18 18 18 18 18 18

11.53 1.05 2 1.78 14.93 14 –4.72 10.5 1.08 15 4.96 13.97 14 –3.54

0.74 0.15 1.34 1.9 0.8 3.71 7.31 0.88 0.12 3.43 8.06 0.8 3.71 9.58

the school in Wroclaw (urban setting) obtained better results, with the differences being statistically significant. It is worth noting that the girls in the rural experimental group in the second test performed better in the palm dynamometry (handgrip strength) test and in the 4 × 10 m run (Tab. 1). Based on adopted statistical indicators, significant differences were found in the first test between the urban

p

Difference

0.0023* 0.1017 0.0000* 0.0003* 0.4444 0.0434* 0.2093 0.0425 0.0061* 0.8605 0.0488* 0.0253* 0.0341* 0.7075

1.19 0.10 12.93 8.80 0.35 2.79 2.86 0.78 0.17 0.21 6.38 1.04 3.00 1.04

experimental (UE) and rural experimental (RE) groups of boys in the 50 m run, palm dynamometry (handgrip strength), flexed arm hang and sit-ups (Tab. 2). In each of these trials, the boys in the urban experimental group achieved significantly better results. In the second test, at the end of the school year, the boys in the urban experimental group again achieved better results that were statistically significant in the standing long jump, flexed 249

HUMAN MOVEMENT I. Cichy, A. Rokita, Use of the “eduball” educational ball

Table 3. Comparison of the average physical fitness values obtained by girls in the urban control (UC) and rural control (RC) groups UC

Variable 50 run_1 (s) Jump_1 (m) Dynam._1 (kg) Hang_1 (s) 4×10 run_1 (s) Sit-ups_1 (num.) Toe touch_1 (cm) 50 run_2 (s) Jump_2 (m) Dynam._2 (kg) Hang_2 (s) 4×10 run_2 (s) Sit-ups_2 (num.) Toe touch_2 (cm)

RC

N

x

S

N

x

S

8 8 8 8 8 8 8 8 8 8 8 8 8 8

11.09 1.20 13.13 6.45 16.54 13.00 4.00 9.38 1.19 13.13 7.86 14.91 13.50 0.75

1.43 0.02 2.90 3.43 1.74 2.73 9.84 0.59 0.10 3.40 4.33 1.14 2.45 5.75

20 20 20 20 20 20 20 21 21 21 21 21 21 21

11.68 0.95 0.9 3.93 15.06 13.4 0.25 11.06 1.06 16.05 14.45 14.45 15.29 0.48

1.69 0.2 0.99 2.61 2.1 5.59 4.43 1.77 0.23 3.12 1.56 1.56 4.15 7.85

p

Difference

0.3931 0.0017* 0.0000* 0.0445* 0.0910 0.8493 0.1704 0.0146* 0.1438 0.0363* 0.0000* 0.4544 0.2648 0.9303

0.59 0.25 12.23 2.52 1.48 0.40 3.75 1.68 0.13 2.93 6.59 0.46 1.79 0.27

Table 4. Comparison of the average physical fitness values obtained by boys in the urban control (UC) and rural control (RC) groups Variable 50 run_1 (s) Jump_1 (m) Dynam._1 (kg) Hang_1 (s) 4 × 10 run_1 (s) Sit-ups_1 (num.) Toe touch_1 (cm) 50 run_2 (s) Jump_2 (m) Dynam._2 (kg) Hang_2 (s) 4×10 run_2 (s) Sit-ups_2 (num.) Toe touch_2 (cm)

UC

RC

N

x

S

N

x

S

11 11 11 11 11 11 11 11 11 11 11 11 11 11

10.54 1.21 15.18 10.23 15.63 14.91 6.73 9.68 1.29 15.82 10.33 15.00 16.00 3.09

1.51 0.03 1.33 4.02 2.25 2.51 8.40 1.36 0.15 2.27 4.05 1.86 2.28 7.91

18 18 18 18 18 18 18 17 17 17 17 17 17 17

10.75 1 0.85 1.92 16.67 12.11 –2.5 10.35 1.11 14.18 2.58 14.97 13.18 –1.24

1.73 0.22 0.19 2.38 2.22 5.16 7.06 1.54 0.19 3.3 2.55 2.28 4.32 4.93

arm hang and sit-ups. The boys in the rural experimental group achieved better results that were statistically significant only in the 4 × 10 m shuttle run. It was therefore concluded that the students in the urban experimental group surpassed their rural peers in terms of hand and upper limb functional strength both before and after the “eduball” physical education program. Based on the results obtained from the pupils in the urban control (UC) and rural control (RC) groups (Tab. 3), it was found that the girls from Wroclaw (UC) in the first test achieved statistically significant better results in the standing long jump, palm dynamometry (handgrip strength) and flexed arm hang. When taking into account the second test, the girls in the urban con250

p

Difference

0.7392 0.0044* 0.0000* 0.0000* 0.2326 0.1057 0.0037* 0.2473 0.0151* 0.1628 0.0000* 0.9721 0.0578 0.0847

0.21 0.21 14.33 8.31 1.04 2.80 9.23 0.67 0.18 1.64 7.75 0.03 2.82 4.33

trol group were better than their peers in the 50 m run, palm dynamometry and bent arm hang, with significance differences noted among these results. When comparing the results obtained by the boys in the urban control (UC) and rural control groups (RC), a statistically significant difference in favor of the firstgraders from Wroclaw was found in the standing long jump, palm dynamometry (handgrip strength), bent arm hang and toe touch in the first test (Tab. 4). Comparative analysis of the results obtained by the same groups of students in the second test confirmed the advantage of the students from Wroclaw (UC) in nearly all samples, with the differences in the standing long jump and bent arm hang found to be statistically significant. The results

HUMAN MOVEMENT I. Cichy, A. Rokita, Use of the “eduball” educational ball

Table 5. Comparison of the average physical fitness values obtained by girls in the urban experimental (UE) and rural control (RC) groups Variable 50 run_1 (s) Jump_1 (m) Dynam._1 (kg) Hang_1 (s) 4 × 10 run_1 (s) Sit-ups_1 (num.) Toe touch_1 (cm) 50 run_2 (s) Jump_2 (m) Dynam._2 (kg) Hang_2 (s) 4 × 10 run_2 (s) Sit-ups_2 (num.) Toe touch_2 (cm)

UE

RC

N

x

S

N

x

S

15 15 15 15 15 15 15 15 15 15 15 15 15 15

10.51 1.09 12.60 10.51 15.58 13.87 2.67 10.12 1.17 12.73 11.79 15.12 15.67 3.13

0.65 0.14 1.28 6.03 1.35 3.85 5.03 0.76 0.15 1.59 6.75 1.00 2.76 6.49

20 20 20 20 20 20 20 21 21 21 21 21 21 21

11.68 0.95 0.9 3.93 15.06 13.4 0.25 11.06 1.06 16.05 14.45 14.45 15.29 0.48

1.69 0.2 0.99 2.61 2.1 5.59 4.43 1.77 0.23 3.12 1.56 1.56 4.15 7.85

p

Difference

0.0158* 0.0252* 0.0000* 0.0001* 0.4104 0.7832 0.1412 0.0630 0.1271 0.0006* 0.0884 0.1509 0.7616 0.2912

1.17 0.14 11.70 6.58 0.52 0.47 2.42 0.94 0.11 3.32 2.66 0.67 0.38 2.65

Table 6. Comparison of the average physical fitness values obtained by boys in the urban experimental (UE) and rural control (RC) group Variable 50 run_1 (s) Jump_1 (m) Dynam._1 (kg) Hang_1 (s) 4 × 10 run_1 (s) Sit-ups_1 (num.) Toe touch_1 (cm) 50 run_2 (s) Jump_2 (m) Dynam._2 (kg) Hang_2 (s) 4×10 run_2 (s) Sit-ups_2 (num.) Toe touch_2 (cm)

UE

RC

N

x

S

N

x

S

14 14 14 14 14 14 14 14 14 14 14 14 14 14

10.34 1.15 14.93 10.58 15.28 16.79 –1.86 9.72 1.25 15.21 11.34 15.01 17.00 –2.50

1.26 0.19 3.11 9.03 1.66 3.70 4.54 1.21 0.21 3.34 9.51 1.65 3.90 4.12

18 18 18 18 18 18 18 17 17 17 17 17 17 17

10.75 1 0.85 1.92 16.67 12.11 –2.5 10.35 1.11 14.18 2.58 14.97 13.18 –1.24

1.73 0.22 0.19 2.38 2.22 5.16 7.06 1.54 0.19 3.3 2.55 2.28 4.32 4.93

indicate a much faster rate of physical development in boys who live in urban areas, which may be associated with better personal development. Comparison of the results obtained by the girls in the urban experimental (EU) and rural control (RC) groups found that in the first test, before the experiment was conducted, the girls from the urban control group presented better results in running speed, explosive strength, static strength in the hands and upper extremities, with the results being statistically significant (Tab. 5). After a year of being subjected to the experimental conditions, these differences were not as pronounced, with grip strength of the girls from Czarny Bor and Sułów (RC) found to be clearly better. Based

p

Difference

0.4623 0.0496 0.0000* 0.0005* 0.0594 0.0076* 0.7693 0.2211 0.0553 0.3950 0.0010* 0.9551 0.0160* 0.4525

0.41 0.15 14.08 8.66 1.39 4.68 0.64 0.63 0.14 1.03 8.76 0.04 3.82 1.26

on the obtained results, it can be assumed that the implementation of the “eduball” educational ball in a primary school setting does not have an effect on the development on static strength of the hands. The differences in the results between the urban experimental (EU) and rural control (RC) groups of boys (Tab. 6) were similar to what was found in the group of girls (Tab. 5), finding that the physical fitness levels of urban students were better than their peers living in a village both in the first and second physical fitness test. The boys from Wroclaw obtained better results in most of the test variables, with the differences being statistically significant in palm dynamometry (handgrip strength) in the first test, and the bent arm hang 251

HUMAN MOVEMENT I. Cichy, A. Rokita, Use of the “eduball” educational ball

Table 7. Comparison of the average physical fitness values obtained by girls in the urban control (UC) and rural experimental (RE) groups UC

Variable 50 run_1 (s) Jump_1 (m) Dynam._1 (kg) Hang_1 (s) 4 × 10 run_1 (s) Sit-ups_1 (num.) Toe touch_1 (cm) 50 run_2 (s) Jump_2 (m) Dynam._2 (kg) Hang_2 (s) 4×10 run_2 (s) Sit-ups_2 (num.) Toe touch_2 (cm)

RE

N

x

S

N

x

S

8 8 8 8 8 8 8 8 8 8 8 8 8 8

11.09 1.20 13.13 6.45 16.54 13.00 4.00 9.38 1.19 13.13 7.86 14.91 13.50 0.75

1.43 0.02 2.90 3.43 1.74 2.73 9.84 0.59 0.10 3.40 4.33 1.14 2.45 5.75

16 16 16 16 16 16 16 16 16 16 16 16 16 16

11.91 1.05 0.83 2.76 15.14 13.75 –5.25 10.52 1.15 14.44 3.87 14.16 17 –1.94

0.83 0.24 0.2 4.26 1.03 4.39 7.35 1.22 0.17 2.45 4.42 0.79 4.97 9.62

p

Difference

0.0874 0.0949 0.0000* 0.0452* 0.0212* 0.6643 0.0164* 0.0208* 0.5704 0.2877 0.0476* 0.0713 0.0753 0.4767

0.82 0.15 12.30 3.69 1.40 0.75 9.25 1.14 0.04 1.32 3.99 0.75 3.50 2.69

Table 8. Comparison of the average physical fitness values obtained by boys in the urban control (UC) and rural experimental (RE) groups Variable 50 run_1 (s) Jump_1 (m) Dynam._1 (kg) Hang_1 (s) 4 × 10 run_1 (s) Sit-ups_1 (num.) Toe touch_1 (cm) 50 run_2 (s) Jump_2 (m) Dynam._2 (kg) Hang_2 (s) 4×10 run_2 (s) Sit-ups_2 (num.) Toe touch_2 (cm)

UC

RE

N

x

S

N

x

S

11 11 11 11 11 11 11 11 11 11 11 11 11 11

10.54 1.21 15.18 10.23 15.63 14.91 6.73 9.68 1.29 15.82 10.33 15.00 16.00 3.09

1.51 0.03 1.33 4.02 2.25 2.51 8.40 1.36 0.15 2.27 4.05 1.86 2.28 7.91

18 18 18 18 18 18 18 18 18 18 18 18 18 18

11.53 1.05 2 1.78 14.93 14 –4.72 10.5 1.08 15 4.96 13.97 14 –3.54

0.74 0.15 1.34 1.9 0.8 3.71 7.31 0.88 0.12 3.43 8.06 0.8 3.71 9.58

and sit-ups in both the first and second test. Therefore, it can be concluded that the boys in the urban experimental group that participated in activities with the “eduball” not only improved their physical fitness, but performed much better than their peers from Czarny Bor and Sułów. Based on the results obtained by the girls in the urban control (UC) and rural experimental (RE) groups, it was found that during the initial test the first-graders from Wroclaw had a definite advantage in physical fitness levels (Tab. 7). Statistically significant differences were found in the test variables of: palm dynamometry (handgrip strength), bent arm hang, 4 × 10 m shuttle run and toe touch. The second test found the results 252

p

Difference

0.0247* 0.0018* 0.0000* 0.0000* 0.2392 0.4799 0.0006* 0.0567 0.0003* 0.4897 0.0504 0.0482* 0.1200 0.0647

0.99 0.16 13.18 8.45 0.70 0.91 11.45 0.82 0.21 0.82 5.37 1.03 2.00 6.63

evened out in most of the variables, other than the 50 m run and bent arm hang. Comparison of the results obtained by the boys in the urban control (UC) and rural experimental (RE) groups found a pattern similar to what was with the girls, i.e., a higher physical fitness levels of the boys from Wroclaw (Tab. 8). The resulting differences were found to be statistically significant in the 50 m run, standing long jump, palm dynamometry (handgrip strength) and bent arm hang. However, no significant differences were found in the second test. The boys from Czarny Bor and Sułów did improve their performance, which provided a confirmation that the use of the “eduball” educational balls does not adversely affect physical fitness levels [7, 8, 10].

HUMAN MOVEMENT I. Cichy, A. Rokita, Use of the “eduball” educational ball

Table 9. Comparison of the average physical fitness values obtained by girls in the urban experimental (UE) group in tests 1 and 2 Test 1 (T1)

Variable

N

50 run (s) Jump (m) Dynam. (kg) Hang (s) 4 × 10 run (s) Sit-ups (num.) Toe touch (cm)

15 15 15 15 15 15 15

x 10.51 1.09 12.60 10.51 15.58 13.87 2.67

Test 2 (T2) S

N

x

S

0.650 0.143 1.281 6.029 1.346 3.846 5.030

15 15 15 15 15 15 15

10.12 1.17 12.73 11.79 15.12 15.67 3.13

0.76 0.15 1.59 6.75 1.00 2.76 6.49

T1–T2

p

1.49 1.37 0.25 0.55 1.05 1.47 0.22

0.1485 0.1823 0.8019 0.5897 0.3043 0.1520 0.8273

Table 10. Comparison of the average physical fitness values obtained by boys in the urban experimental (UE) group in tests 1 and 2 Test 1 (T1)

Variable 50 run (s) Jump (m) Dynam. (kg) Hang (s) 4 × 10 run (s) Sit-ups (num.) Toe touch (cm)

Test 2 (T2)

N

x

S

N

x

S

14 14 14 14 14 14 14

10.34 1.15 14.93 10.58 15.28 16.79 –1.86

1.26 0.19 3.11 9.03 1.66 3.70 4.54

14 14 14 14 14 14 14

9.72 1.25 15.21 11.34 15.01 17.00 –2.50

1.21 0.21 3.34 9.51 1.65 3.90 4.12

T1–T2

p

1.33 1.38 0.23 0.22 0.42 0.15 0.39

0.1944 0.1784 0.8166 0.8298 0.6771 0.8826 0.6979

Table 11. Comparison of the average physical fitness values obtained by girls in the urban control (UC) group in tests 1 and 2 Variable 50 run (s) Jump (m) Dynam. (kg) Hang (s) 4 × 10 run (s) Sit-ups (num.) Toe touch (cm)

Test 1 (T1)

Test 2 (T2)

N

x

S

N

x

S

8 8 8 8 8 8 8

11.09 1.20 13.13 6.45 16.54 13.00 4.00

1.43 0.02 2.90 3.43 1.74 2.73 9.84

8 8 8 8 8 8 8

9.38 1.19 13.13 7.86 14.91 13.50 0.75

0.59 0.10 3.40 4.33 1.14 2.45 5.75

T1–T2

p

3.13 0.36 0.00 0.72 2.21 0.39 0.81

0.0073* 0.7224 1.0000 0.4828 0.0442* 0.7054 0.4335

Table 12. Comparison of the average physical fitness values obtained by boys in the rural control (RC) group in tests 1 and 2 Variable 50 run (s) Jump (m) Dynam. (kg) Hang (s) 4 × 10 run (s) Sit-ups (num.) Toe touch (cm)

Test 1 (T1)

Test 2 (T2)

N

x

S

N

x

S

11 11 11 11 11 11 11

10.54 1.21 15.18 10.23 15.63 14.91 6.73

1.51 0.03 1.33 4.02 2.25 2.51 8.40

11 11 11 11 11 11 11

9.68 1.29 15.82 10.33 15.00 16.00 3.09

1.36 0.15 2.27 4.05 1.86 2.28 7.91

T1–T2

p

1.41 1.69 0.80 0.06 0.71 1.07 1.05

0.1747 0.1061 0.4320 0.9554 0.4851 0.2985 0.3083 253

HUMAN MOVEMENT I. Cichy, A. Rokita, Use of the “eduball” educational ball

Table 13. Comparison of the average physical fitness values obtained by girls in the rural experimental (RE) group in tests 1 and 2 Variable 50 run (s) Jump (m) Dynam. (kg) Hang (s) 4 × 10 run (s) Sit-ups (num.) Toe touch (cm)

Test 1 (T1)

Test 2 (T2)

N

x

S

N

x

S

16 16 16 16 16 16 16

11.91 1.05 0.83 2.76 15.14 13.75 –5.25

0.83 0.24 0.2 4.26 1.03 4.39 7.35

16 16 16 16 16 16 16

10.52 1.15 14.44 3.87 14.16 17 –1.94

1.22 0.17 2.45 4.42 0.79 4.97 9.62

T1–T2

p

3.81 1.39 22.15 0.74 3.09 1.99 1.11

0.0006* 0.1744 0.0000* 0.4679 0.0043* 0.0558 0.2770

Table 14. Comparison of the average physical fitness values obtained by boys in the rural experimental (RE) group in tests 1 and 2 Variable 50 run (s) Jump (m) Dynam. (kg) Hang (s) 4 × 10 run (s) Sit-ups (num.) Toe touch (cm)

Test 1 (T1)

Test 2 (T2)

N

x

S

N

x

S

18 18 18 18 18 18 18

11.53 1.05 2.00 1.78 14.93 14.00 –4.72

0.74 0.15 1.34 1.90 0.80 3.71 7.31

18 18 18 18 18 18 18

10.50 1.08 15.00 4.96 13.97 14.00 –3.54

0.88 0.12 3.43 8.06 0.80 3.71 9.58

T1–T2 4.00 0.72 15.22 1.64 3.83 0.00 0.43

p 0.0003* 0.4789 0.0000* 0.1103 0.0005* 1.0000 0.6665

Table 15. Comparison of the average physical fitness values obtained by girls in the rural control (RC) group in tests 1 and 2 Variable 50 run (s) Jump (m) Dynam. (kg) Hang (s) 4 × 10 run (s) Sit-ups (num.) Toe touch (cm)

Test 1 (T1)

Test 2 (T2)

N

x

S

N

x

S

20 20 20 20 20 20 20

11.68 0.95 0.90 3.93 15.06 13.40 0.25

1.69 0.2 0.99 2.61 2.1 5.59 4.43

21 21 21 21 21 21 21

11.06 1.06 16.05 14.45 14.45 15.29 0.48

1.77 0.23 3.12 1.56 1.56 4.15 7.85

T1–T2 1.36 1.89 21.32 21.16 1.35 1.58 0.12

p 0.1833 0.0662 0.0000* 0.0000* 0.1837 0.1231 0.9020

Table 16. Comparison of the average physical fitness values obtained by boys in the rural control (RC) group in tests 1 and 2 Variable 50 run (s) Jump (m) Dynam. (kg) Hang (s) 4 × 10 run (s) Sit-ups (num.) Toe touch (cm) 254

Test 1 (T1)

Test 2 (T2)

N

x

S

N

x

S

18 18 18 18 18 18 18

10.75 1.00 0.85 1.92 16.67 12.11 –2.50

1.73 0.22 0.19 2.38 2.22 5.16 7.06

17 17 17 17 17 17 17

10.35 1.11 14.18 2.58 14.97 13.18 –1.24

1.54 0.19 3.30 2.55 2.28 4.32 4.93

T1–T2

p

0.835 1.837 17.121 0.893 2.535 0.775 0.730

0.4096 0.0750 0.0000* 0.3782 0.0160* 0.4438 0.4704

HUMAN MOVEMENT I. Cichy, A. Rokita, Use of the “eduball” educational ball

Comparison of the results obtained by both girls and boys from the Wroclaw primary school in both the first and second test showed no statistically significant differences in the experimental groups (Tab. 9 and 10). The girls in the control group (Tab. 11) featured statistically significant differences in the 50 m run and 4 × 10 m shuttle run. Most of the obtained results point to the natural physical development of children, which itself is not dependent on any specific form of physical activity. In the control group of boys from Wroclaw, as in the case of the girls and boys in the experimental group from Wroclaw, there were no statistically significant differences between the first and second tests (Tab. 12). When taking into account the results obtained from the first and second test in the experimental group of girls (Tab. 13) and boys (Tab. 14) from Czarny Bor and Sułów (RE), significantly better results were obtained in the second test in all the test variables, with the results being statistically significant in the 50 m run, the 4 × 10 m shuttle run and palm dynamometry (handgrip strength). These results can confirm that the type of educational games played with the “eduball” (which emphasize running) were a determinant of the changes in both the speed and agility of children. The control groups of girls (Tab. 15) and boys (Tab. 16) from Czarny Bor and Sulow (RC) featured positive changes in all of the physical fitness variables taken under consideration. Statistically significant differences were noted in palm dynamometry (handgrip strength) and the bent arm hang in the group of girls and the palm dynamometry (handgrip strength) and the 4 × 10 m run in the group of boys. It should be noted that two parallel studies were conducted along with the experiment found here that yielded interesting results. In Czarny Bor and Sułów additional research was conducted on the search for a relationship between the use of the “eduball” physical education programs and reading and writing skills, while in Wroclaw the use of the “eduball” was studied with the acquisition of additional learning abilities. The studies found that physical activity conducted with the “eduball” in the group of rural children had an impact on their rate of acquiring reading skills [7], while the urban schoolchildren from Wroclaw achieved better results on a number of educational aptitude tests [8]. Discussion The aim of early childhood education is to support a child’s intellectual, emotional, social ethical, physical and aesthetic development [13]. It is recommended that a child should start their formal education after reaching the age of school maturity [14], which is a concept that not only takes into consideration the level of mental development that would allow a child to study, but also the degree of their socio-moral behavior, which would allow to them work and play with their peers.

A very important part of school maturity is also gross and fine motor development, which, unfortunately, has been often overlooked in pedagogical studies, even though it determines a number of changes in the overall development of early school-aged children (including reading and writing). Nonetheless, a number of publications in recent years have focused on the motor development of children and educational growth. In Poland, the importance of physical fitness on a child’s ability to work and play in a school environment has been analyzed by Szuman, Dzierżanka, Gniewkowska and Wilgocka-Okoń [in: 14]. These authors found that motor skill development was tied to children’s social development, such as if a child performs well in games and activities (including those with balls) it becomes easier for them to facilitate their “entry” within a group of their peers [in: 15]. In addition, recent studies have also been conducted on demonstrating the effectiveness of selected teaching methods, forms and materials on improving children’s educational achievements. These include studies conducted by researchers associated with the University of Physical Education in Wroclaw on the use of the “eduball” educational ball. Literature that dealt specifically with the use of “edu­ balls” can be traced back to pilot studies conducted in 2002 [16, 17] as well as more recent [7, 8, 10, 15, 18] studies on both pre-school and primary school education. These studies pointed to a number of interesting results on the effects of using the “eduball” on physical fitness as well as learning selected skills. Among others, Cichy and Rzepa analyzed the relationship between the use of the “eduball” and physical fitness development in grades one through three in primary schools [17]. Once concluding a year-long parallel-group peda­go­ gical experiment, the authors noted that a curriculum that includes the use of educational balls can effect children’s motor development in the same way as a traditional curriculum. Pawłucki [19] and Wojcik-Grzyb [20] also reported interesting results, with their belief that motor development, more specifically the development of coordination, is closely related to children’s speed in learning reading and writing skills. Rokita [10], implementing a study in a rural environment, and Rzepa and Wójcik [21], working on children in an urban environment, both stated that the setting where the “eduball” is used is insignificant, and that children’s fitness levels are dependent more on individual development than the introduction of an experimental factor such as the “eduball” [7]. Taking into regard the results attained by the aforementioned authors, it can be stated that the use of such educational balls during physical activity does not cause any adverse effects on overall physical fitness and body coordination [18] and may in fact contribute to more effective development of children’s learning skills at this age. 255

HUMAN MOVEMENT I. Cichy, A. Rokita, Use of the “eduball” educational ball

The authors of this study would like to highlight the need to include participants’ somatic parameters in future pedagogical studies of this sort, as they often play a large role in the development of selected physical fitness variables, as was evidenced by, among others, Pangrazi et al., Burdukiewicz, Fisher et al. and Malina et al. [6, 22–24]. Such information could specify whether the differences recorded in physical fitness levels are determined more by somatic build or gender dimorphism at this early stage of development (at an age of around seven years), as was indicated by Malina et al. [25, 26]. Conclusion 1. The overall majority of the obtained results on physical fitness levels were found not to result from using the “eduball” educational ball. However, both the girls and boys in the rural experimental groups provided results that could confirm this study’s assumptions due to the amount of running involved in the phy­sical activities that use the “eduball”, which can positively affect the speed and agility of the children. 2. Changes in the physical fitness levels of pupils participating in physical activities with the “eduball” depend whether they live in an urban or rural environment. The boys in the urban experimental and control groups performed better than their peers residing in rural areas. However, this may be more strongly related to the overall higher physical fitness levels of the boys from an urban environment (as was found in the first test), rather than their place of residence or their schools’ sports facilities, which were found to be comparable. In the groups of girls a somewhat different trend was observed, with girls from the urban environment performing better than girls from rural areas among the analyzed fitness variables in the first test, but with the differences leveling out by the second test. In addition, the girls from the rural environment showed higher strength levels in the second test. References 1. Baranowski T., Thompson W., DuRant R., Baranowski J., Puhl J., Observations on physical activity in physical locations: age, gender, ethnicity and month effects. Res Q Exerc Sport, 1993, 64 (2), 127–133. 2. Riddoch C.J., Boreham C.A.G., The health-related phy­si­ cal activity of children. Sports Med, 1995, 19 (2), 86–102. 3. Ignasiak Z., Conditions in development of morphological and motor skills of children at younger school age with respect to biological age [in Polish]. Studia i Monografie AWF we Wrocławiu, 1988, 19. 4. Żak S., Sterkowicz S., A relative evaluation of the develop­ ment of flexibility in boys aged between 8 and 15. Biol Sports, 2006, 23 (4), 401–412. 5. Migasiewicz J., Chosen manifestations of motor abilities of girls and boys aged 7 to 18 against the background 256

of their morphological development [in Polish]. 2 ed., AWF, Wrocław, 2006. 6. Pangrazi R.P., Corbin C.B., Welk G.J., Physical activity for children and youth. JOPERD, 1996, 67 (4), 38–43. 7. Rokita A., Physical classes with educational balls ‘Edu­ bal’ in the integrated education and physical fitness & reading and writing skills of students [in Polish]. Studia i Monografie AWF we Wrocławiu, 2008, 93. 8. Cichy I., Rokita A., Popowczak M., Naglak K., Psychomotor development of grade I primary school children who are educated by means of traditional and non-traditional program. Antropomotoryka, 2010, 49, 45–57. 9. Minkiewicz E.M., Play and its influence on psychomotor development of a child [in Polish]. Lider, 2002, 3, 6–8. 10. Rokita A., Reading and writing skills of children attending grades 0–III of primary school in the country. In: Koszczyc T. (ed.), Educational balls ‘Edu­bal’ in the integrated education. Research report [in Polish]. Studia i Mo­ nografie AWF we Wrocławiu, 2007, 88, 53–66. 11. Brzeziński J., Methodology of research in psychology [in Polish]. PWN, Warszawa 2007. 12. Drabik J., Testing physical fitness with school students [in Polish]. AWF, Gdańsk 1992. 13. General education program for the six-year enrolling program in primary schools and three-year gymnasiums [in Polish]. MEN, Warszawa 2008. 14. Wigocka-Okoń B., School readiness of six year old children [in Polish]. Wydawnictwo Akademickie Żak, Warszawa 2003. 15. Cichy I., Attempts at determining physical fitness with the use of educational balls in children at the end of grade I of the primary school [in Polish]. In: Sekułowicz M., Kruk-Lasocka J., Kulmatycki L. (eds.), Psychomotor studies: movement full of meaning. DSW, Wrocław, 2008, 221–229. 16. Rzepa T., Physical activity with the ball in achieving selected educational goals in the scope of Polish language classes of grade II of the primary school. In: Koszczyc T., Dembiński J. (eds.), Education and formation in the reformed school [in Polish]. WTN, Wrocław 2003, 57–61. 17. Cichy I., Rzepa T., Attempts at determining competences and the level of physical fitness in the integrated education with the use of educational balls. In: Bartoszewicz R., Koszczyc T., Nowak A. (eds.), Didactics of physical education in the light of modern educational needs [in Polish]. WTN, Wrocław 2005, 193–201. 18. Cichy I., Popowczak M., Psychomotor development of students at the end of grade I of the primary school educated by means of traditional and non-traditional program [in Polish]. Rozprawy Naukowe AWF we Wrocławiu, 2009, 27, 17–23. 19. Pawłucki A., School motor readiness of children who start their education [in Polish]. Roczniki Naukowe AWF w Warszawie, 1984, 28. 20. Wójcik-Grzyb A., Coordination skills as a condition of quick and precise learning to read and write. In: Bartoszewicz R., Koszczyc T., Nowak A. (eds.), Didactics of physical education in the light of modern educational needs [in Polish]. WTN, Wrocław, 2005, 335–340. 21. Rzepa T., Wójcik A., Reading and writing skills of children attending grades 0–III of primary school in the town. In: Koszczyc T. (eds.), Educational balls ‘Edubal’ in the integrated education. Research report [in Polish]. Studia i Monografie AWF we Wrocławiu, 2007, 88, 66–75.

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22. Burdukiewicz A., Diversity in body build of Wrocław children aged between 7 to 15 in longitudinal research [in Polish]. Studia i Monografie AWF we Wrocławiu, 1995, 46. 23. Fisher A., Reilly J.J., Kelly L.A., Montgomery C., Williamson A., Paton J.Y., Grant S., Fundamental movement skills and habitual physical activity in young children. Med Sci Sports Exerc, 2005, 37 (4), 684–688. 24. Malina R.M., Rożek K., Ignasiak Z., Sławińska T., Fugiel J., Kochan K. et al., Growth and functional characteristics of male athletes 11–15 years of age. Hum Mov, 2011, 12 (2), 180–187, doi: 10.2478/v10038-011-0017-7. 25. Malina R.M., Secular trends in growth, maturation and physical performance. A review. Anthropol Rev, 2004, 67, 3–31. 26. Malina R.M., Bouchard C., Bar-Or O., Growth, maturation, and physical activity. 2nd ed. Human Kinetics, Champaign 2004, 4–14.

Paper received by the Editors: January 15, 2012 Paper accepted for publication: May 15, 2012 Correspondence address Ireneusz Cichy Katedra Zespołowych Gier Sportowych Akademia Wychowania Fizycznego ul. Mickiewicza 58 51-684 Wrocław, Poland e-mail: [email protected]

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HUMAN MOVEMENT 2012, vol. 13 (3), 258– 263

ASSESSING BODY CULTURE LEVEL AND ITS ASSOCIATION WITH THE LEVEL OF PHYSICAL ACTIVITY IN UNIVERSITY STUDENTS doi: 10.2478/v10038-012-0030-5

BRUNO BARTH PINTO TUCUNDUVA Federal University of Paraná, Paraná, Brazil

Abstract

Purpose. Subjective values of physical activity are important for promoting active lifestyles. In theoretical research, body culture is the most appropriate term to analyze the complexity between exercise and human culture. The main goal of this study is to assess body culture level and to analyze its influence on physical activity levels. Methods. An online questionnaire containing the Exploratory Questionnaire of Body Culture Concepts, developed exclusively for this research, plus a short version of the International Physical Activity Questionnaire and a number of general identification questions were used to analyze body culture level. Results. 310 university students responded to the survey. A significant association between high body culture level and physical activity level was found. Conclusions. The assessment of body culture level helps to analyze the trends of physical activity. The role of cultural complexity of human movement should be considered as an important variable in the promotion of an active lifestyle.

Key words: physical education, body, culture, physical activity

Introduction Exercise is commonly recognized as a means of promoting health and well being [1]. However, levels of phy­ sical inactivity are very high amongst populations of various societies around the world [2]. In Brazil in particular, several studies have indicated the prevalence of sedentary activities during the leisure time of the popu­ lation [3]. These are two aspects of the same problem, which is the difficulty of promoting health through re­ gular exercise. Even though the positive effects of phy­ sical activity are widely recognized, people still pursue an inactive lifestyle. Hence, any analysis of physical activity still requires the identification of key factors that would effectively encourage an individual to regularly and independently participate in exercise programs. Through historical analysis, it has been shown that the first research into physical activity methods had a significant impact on the popular understanding of the organic benefits of exercise, creating a common acceptance of it as a tool for body development [4]. Although this is the (prime) popular concept of physical activity, it is still hegemonic in modern society. Current research shows that physical activity has a broad potential for cultural development and education [5]. Thus, it is believed that through widespread recognition of physical activity as a cultural element for human growth, complementing the traditional meaning of exercise, can it be possible to achieve a greater legitimacy for such practices in a daily routine, facilitating the promotion of an active lifestyle. Analyzing the cultural aspects of physical activity, the term body culture has been chosen as the most ap258

propriate concept to show how one perceive’s physical activity as an aspect of their own human experience. The term body culture analyzes body practices as a way for the subject to perceive act and relate with the external environment in a social, expressive or functional way [6]. Thus, this study attempts to assess the subject’s body culture level and analyze its level in relation to level of physical activity. Body culture can be described as a proportion of general culture. It involves the symbolic and material significance of the practices of human motricity in a society [6]. Body culture in its noun form embraces the meanings and expressions of the body and its practices in human culture. As an adjective, body culture is the level of development of an individual’s motricity in relation to their body consciousness, corporality and the recognition of the role of physical activity in the search for a healthy lifestyle [7]. The elements of body culture are described in games, sports, gymnastics, the practice of physical conditioning, rhythmic and expressive activities, dance and martial arts [7]. Its contents can be generalized as every human manifestation that links human spontaneous behavior to planned motor elements [6]. Hence, body culture contents extend from traditional sports to social activities, passing by other activities that involve a significant contingent of human motor function. Nevertheless, body culture is an element of general culture, which implies that a great deal of complexity needs to be understood, especially in relation to the dialectic relation of man with nature [8]. Although man is an integral part of nature and has to respect the rhythm of evolution, he has the reflective capacity of

HUMAN MOVEMENT B.B.P. Tucunduva, Body culture and physical activity

transforming himself and the environment, which allows his elevation beyond nature’s causality [9]. Culture is the connection of natural development with the intentional attribution of significant human meaning [9]. In terms of body culture, it is important to keep in mind that in physical activity there are natural elements, such as the physiological response of the body to the stimulus of exercise, as well as the perceived meaning of such activities for human growth. Another important aspect is that the term culture has a strong meaning of identity for the individual [10]. Culture represents all that is specific to a given society and includes the development of social identity within cultural growth. The word culture integrates the historical development of a society including a society’s traditions, beliefs, social and artistic developments and its technological and scientific advances. The single term encompasses the uniqueness of an individual in their society [10]. Similarly, body culture experiences are also an identity feature, since they bring a distinctive factor among individuals of a determined group, reflecting their development in the context of a society [11]. In light of such great complexity, a human’s actions are described as “biocultural”, where the organism is infiltrated by socio-cultural meanings [12]. Thus, body practices cannot be reduced to a physiological pheno­ menon, strictly as the displacement of the body in space and a set of muscular contractions, but must also be understood as an integrative activity of human expression in the wider world [13]. A diversity of intrinsic elements is developed by implementing a wide-ranging body culture [14]. Therefore, it is important that the subject comprehend that physi­ cal activity is an evolving element capable of an extensive cultural influence. This concept frames physical activity as something more than entertainment or a practice restricted to physical conditioning. Hence, the exploratory path of this research is directed to the assessment of the amplitude of perceived concepts linked to the term body culture in relation to the level of physical activity that individuals have in their daily routine. Material and methods The research took a quantitative approach with a transversal design, and was carried out by means of an online questionnaire with closed questions, broken down into three sections: the Exploratory Questionnaire of Body Culture Concepts (QBC) developed exclusively for this study; general identification; and the short version of the International Physical Activity Questionnaire (IPAQ) [15]. The first part of the questionnaire focused on the identification of each respondent’s anthropometric variables, which provided the Body Mass Index (BMI), gender, age and the Socioeconomic Status (SES), measured according to the Brazilian Economic Classification

Criterion [16]. These were considered to be variables that could influence the statistical correlation between the levels of body culture and physical activity. However, the statistical procedures revealed no influence of these variables, in neither body culture nor physical activity level, as is detailed in this document. The second part comprised of a short version of the International Physical Activity Questionnaire (IPAQ), which gave data on the amount of physical activity done in an individual’s daily routine [15]. The subjects answered eight questions about the number of times and the duration of their physical activity, indicating low, moderate, and high intensity exercise done during the previous week. The results were classified into categories of the individual’s physical activity level (A, B, or C), according to the criteria established by the American College of Sports Medicine (ACSM) and its general requirements of physical activity for health promotion [17]. Physical activity level C (PAL C) consisted of people who were below the recommendations for health promotion. Physical activity level B (PAL B) consisted of subjects who performed the basic recommendation of 150 minutes of moderate intensity activity or 75 minutes of vigorously intensive activity per week. Physical activity level A (PAL A) consisted of subjects who reached a complementary indication of at least 300 minutes of moderate intensity physical activity or 150 minutes of vigorous intensity physical activity per week to attain additional health benefits. The third part of the questionnaire was developed specifically for this study: the Exploratory Questionnaire of Body Culture Concepts (QBC). This instrument was based on the fundamentals of body culture, including areas such as human movement, body practices, and corporality. The QBC consisted of 31 questions divided into 9 thematic sections that were related to values and concepts of physical activity and body culture in the subject’s perspective. The answers fit into a Likert-type scale from 0 (null) to 4 (very high), which indicates the level of relevance given to the variable of each question [18]. The sections of the questionnaire were the following (See Appendix 1): – Section 1 – Personal – 11 questions: psychological aspects related to motivation and the influence of physical activity on subjective values; – Section 2 – Health – three questions: physical activity for the promotion of health; – Section 3 – Social – two questions: physical activity and socialization; – Section 4 – Body – three questions: emotions and sensations related to the practice of exercise; – Section 5 – Practice – three questions: the dynamics of the practice of physical activity; – Section 6 – Cultural – three questions: the level of participation in public events related to sports 259

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and other bodily practices. Access and interest in media related to physical activity; – Section 7 – History – one question/nine items: subjects’ experiences with physical activities categorized within the concept of body culture; – Section 8 – Spaces – one question/four items: utilization of different equipment and spaces for the practice of physical activity; – Section 9 – Physical Activity Programs – four questions: participation and relevance of public physical activity programs and other important characteristics of these activities. The QBC determined the body culture level (BCL) of the subjects by adding the responses in sections 1 to 9. The results were divided into tertiles according to the scores achieved by the subject, specifying three BCL levels. Such division is necessary due to the dispersion of the results across the scale. Low Body Culture Level ranges from 0 to 96 points and comprised 102 subjects. Medium Body Culture Level ranges from 97 to 119 points and comprised 105 subjects. High Body Culture Level ranges from 120 to 166 points and comprised 103 subjects. A pilot study to verify the reproducibility and relia­ bility of the QBC was conducted with fifty volunteers who did not participate in the final sample, but answered the questionnaire twice in a two week interval. The results of this stage were tested with an intraclass correlation and a paired t-test. All tests were performed with Statistical Package for Social Sciences, version 11 (IBM, USA). The result of the first measurement showed an average of 64.3 ± 6.8 points in the overall responses and a median of 64.5 points. The result of the second measurement showed an average of 64.4 ± 7.1 points in the overall responses and a median of 66

points. The significance level was fixed at 0.05 (p 0,05) and statistical analysis confirmed the reproducibility with an intra-class coefficient of 0.85 (95%CI (0.65 to 0.94) p 0.001) and a t-test result of –0.06 and p = 0.9543. In the final result of the questionnaire, the body culture level was proved to be reliable. This study was approved by the Research Ethics Committee of Universidade Federal do Paraná, under the report no 1032.157.10.10 and complied with resolution no 196/96 of the Brazilian National Health Council [19]. The participants consisted of 310 university students enrolled at the Universidade Tecnológica Federal do Paraná–Campus Curitiba (State Technical University of Paraná), aged between 18 and 28 years with an average of 21 ± 2.55 years. This campus has appro­ ximately 6,500 students in higher education, out of a pool of 21,000 students in all eleven campuses. To give a perspective of the number of students at the selected university, the University of São Paulo has approximately 88,000 students, the University of Rio de Janeiro has 46,000 students, the State University of Campinas (UNICAMP) has 37,000 students, and the State University of Rio Grande do Sul has 34,000 students. In Brazil, there are approximately six million higher education students, which accounts for 10% of all students of every educational level nationwide [20]. All of the following tests were performed in STATA 9.2 (StataCcorp, USA) adopting a significance level of 5% (p 0,05). The results showed a good distribution between men and women, 47.4% and 52.6% respectively, and a large concentration of subjects in the second class of socioeconomic status, at 64.5%. The body mass index (BMI) results were predominantly normal among the participants (82.1%), showing an average of 22.4 ± 3.6 kg/m2.

Table 1. Poisson regression model – bivariate and multivariate – for data equal or above Physical Activity Level B – basic recommendations for physical activity (n = 300) Variables

n

%

BCL Low Medium High

38 47 81

37.3 44.8 78.6

Bivariate Analysis

Multivariate Analysis

RP

IC95%

p

RP

IC95%

p

1 1,2 2,11

– (0,78–1,84) (1,44–3,10)

0.434 p = 0.011

1 1,18 1,91

– (0,76–1,82) (1,26–2,90)

0.467 p = 0.011

Table 2. Poisson regression model – bivariate and multivariate – for data equal or above Physical Activity Level A – complementary recommendations for physical activity (n = 310) Variables

n

%

BCL Low Medium High

56 80 98

54.9 76.2 95.1

260

Bivariate Analysis

Multivariate Analysis

RP

IC95%

p

RP

IC95%

p

1 1,39 1,73

– (0,99–1,95) (1,25–2,41)

0.061 p = 0.011

1 1,39 1,67

– (0,98–1,96) (1,17–2,39)

0.062 p = 0.011

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achieve a minimum threshold of relevance to the aspects of body culture to perceive the positive impact of physical activity on his life. After attaining this level of body consciousness, the subject is able to engage in an active lifestyle with more efficiency. Authors cite that physical activity can be the emanating center of relationships between different areas of life [21]. From this perspective, one can find out the natural role of motricity on human life, changing from a limited conception of an active lifestyle related to fitness and physical conditioning to an expansive meaning of physical activity. Thus, body practices become a path to constructing self-knowledge, where one can develop greater expression, perception, and action within a given society. The achievement of a high level of body culture has significant relevance to the nine areas addressed in the questionnaire, which demonstrates that physical exercise is important enough to be perceived as an indispensable part of one’s well-being. As physical activity has been shown to be associated to the subject’s body culture, it is possible to adapt the methods of physical education towards the development of this feature. The enrichment of the individual’s body culture should be considered as an important element for the promotion of an active lifestyle in society. However, there is a necessity to review the aims of current public policies for physical education under the current exclusive biophysical effectiveness of exercise. It should be determined whether or not they cater to the cultural complexity of human motricity.

A bivariate Poisson regression analysis was used to verify the association between the body culture level (BCL) and physical activity level (PAL). Also, a multivariated Poisson regression analysis was used to determine if the mentioned variables had any effect on the analysis between BCL and PAL. Excluding the high body culture level, the analyses did not find any significant results in the relations between BMI, gender, socioeconomic status (SES) and BCL when associated with PAL. A strong association was found between PAL and high BCL in both the bivariate and multivariate analy­ ses, as shown in Tables 1 and 2. Results It was demonstrated that 75.5% of the sample are physically active, 53.5% with the complementary recommendations of physical activity (PAL A) and only 24.5% of the population not sufficiently active for the promotion of health (PAL C) [17]. The statistical analysis has shown that there is an association only between a high BCL and PAL. Figure 1 shows the distribution of data among the classes of the BCL and the classes of PAL. It is possible to perceive that the PAL A group had the highest concentration of high BCL and lowest concentrations of low BCL, while the PAL C group had inverted results. Discussion

Conclusions

The main target of this study was achieved successfully. The research shows that 99% of people who have a high level of body culture also practice enough physical activity to promote health. As the association is only given at a high level, it seems that one must

This study shows that the common conception of physical activity can be complemented. Body culture is a key factor for the acknowledgement of physical activity as a kinesthetic experience of life. The research Figure 1. Percentage of subjects distributed by classes of the body culture level (BCL) by strata (high BCL, medium BCL and low BCL) divided by the classes of physical activity level (PAL) of the sample according to the categories established by ACSM (2010): PAL A – complementary recommendation, PAL B – minimum recommendation, PAL C – below the recommended minimum

PAL A

Low BCL Medium BCL

PAL B

High BCL

Low BCL Medium BCL

PAL C

High BCL

Low BCL Medium BCL High BCL

0%

10%

20%

30%

40%

50%

60%

70%

Percentage of subjects 261

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results can be taken as an instruction to health and physical education professionals, and may help to develop alternative and innovative strategies for the promotion of a better understanding of the complexity of cultural aspects of physical activity. Since an increased level of physically active people reflects better on public health, this study should highlight the legitimacy of body culture as content within fitness programs. Other important features of the study were the development of a method to measure body culture level, which can be expanded and improved. Appendix 1 Exploratory Questionnaire of Body Culture Concepts – English Version Section 1 – Personal 1 Do you like to practice physical activities? 2 What is the relevance of physical activity in your life? 3 What is the relevance of the emotions/sensations promoted by physical activity in your life? 4 What is the relevance of the practice of physical activity for your cultural development? 5 What is the relevance of the practice of physical activity for the development of your character/personal identity? 6 What is the relevance of the practice of physical activity for your self-esteem? 7 What is the relevance of the practice of physical activity for your expressiveness? 8 What is the relevance of the practice of physical activity for your way of life/personal beliefs/lifestyle? 9 What is the relevance of the practice of physical activity for your self-care/self-knowledge/inner focus? 10 What is the level of satisfaction/pleasure that the practice of physical activity promotes to you? 11 What is the relevance of overcoming challenges in the practice of physical activity? Section 2 – Health 12 What is the relevance of the practice of physical activity for your health? 13 What is the relevance of the practice of physical activity for your well-being? 14 What is the relevance of the practice of physical activity for your relaxation? Section 3 – Social 15 What is the relevance of the practice of physical activity for your socialization/social interaction? 16 What is the relevance of the practice of physical activity as a leisure choice? Section 4 – Body 17 What is the relevance of the practice of physical activity in your body appearance/esthetics? 18 What is the relevance of the practice of physical activity in your physical conditioning/physical capacity? 19 Which is the relevance of the practice of physical activity for your level of liveliness in daily routine? 262

Section 5 – Practice 20 What is the relevance of the development of body abilities/learning and expanding movement techniques in your practice of physical activity? 21 What is your level of self-effort/discipline on the practice of physical activity? 22 What is your level of interest in new experiences with physical activity? Section 6 – Cultural 23 What is your level of interest in sports and other phy­sical activities – inclusively dance – in general media? (Internet, TV, Radio, Journals and Magazines, etc.) 24 What is your level of interest in attending sports events and others physical activity presentations – including dance – such as championships, games, shows, etc.? 25 What is your level of interest in the consumption of pro­ ducts and services related to physical activity? Section 7 – History 26 What is the level of your lived experiences with the following activities that were relevant in your life? 26.1 Games and plays 26.2 Rhythmic and expressive activities 26.3 Dances 26.4 Fighting and martial arts 26.5 Team sports 26.6 Individual sports 26.7 Gymnastics and practices of physical conditioning 26.8 Physical activities in nature 26.9 Alternative physical activity Section 8 – Spaces 27 What is the relevance of the following areas and equipment for your practice of physical activity? 27.1 Parks and squares 27.2 Nature spaces (beaches, reserves, mountains, etc.) 27.3 Gyms and halls 27.4 Courts, fields and gymnasiums Section 9 – Physical activity programs 28 What is the relevance of the presence of a fitness instructor for your practice of physical activity? 29 What is your level of participation in public programs of physical activity? 30 What is your level of participation in public events of physical activity (competitions, meetings, events, etc.)? 31 What is your weekly level of use of public areas/physical activity equipment?

References 1. World Health Organization, The World Health Report 2008: Primary Health Care Now More Than Ever. World Health Report, 2008. World Health Organization. Geneva, Switzerland, available from: http://www.who.int/ whr/2008/en/ [accessed: February 2010]. 2. Steffen L.M., Arnett D.K., Blackburn H., Shah G., Armstrong C., Luepker R.V., Jacobs D.R.Jr, Population trends in leisure-time physical activity: Minnesota Heart Survey, 1980–2000. Med Sci Sports Exerc, 2006, 38 (10), 1716– 1723, doi: 10.1249/01.mss.0000227407.83851.ba. 3. Pitanga F.J.G., Lessa I., Prevalence and variables ass­o ­ ciated with leisure-time sedentary lifestyle in adults [in

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Portuguese]. Cadernos de Saúde Pública, 2005, 21 (3), 870–877, doi: 10.1590/S0102-311X2005000300021. 4. Carbinatto M., Moreira W.W., Body and health – reconnection of knowledge [in Portuguese]. Revista Brasileira de Ciências do Esporte, 2006, 27 (3), 185–200. 5. Fensterseifer P.E., Corporality and the development of health professionals [in Portuguese]. Revista Brasileira de Ciências do Esporte, 2006, 27 (3), 93–102. 6. Betti M., Physical Education and body culture: a pheno­ menological perspective and semiotics [in Portuguese]. Revista da Educação Física/UEM, 2007, 18 (2), 207–217. 7. Neira M.G., Identity valorization: popular body culture as a content of the curriculum of Physical Education [in Portuguese]. Revista Motriz, 2007, 13 (3), 174–180. 8. Hannerz U., Cultural complexity: studies in the social organization of meaning. Columbia University Press, New York 1992. 9. Eagleton T., The Idea of Culture [in Portuguese]. UNESP, São Paulo 2005. 10. Elias N., “The Germans”. Columbia University Press, New York 1992. 11. Silveira G.C.F., Pinto J.F., Physical education in the perspective of body culture: a pedagogical proposal [in Portuguese]. Revista Brasileira de Ciências e Esporte, 2001, 22 (3), 137–150. 12. Mendes M.I.B.S., Nobrega T.P., Culture movement: reflections on the relationship between body, nature and culture [in Portuguese]. Revista Pensar a Prática, 2009, 12 (2), available from: http://www.revistas.ufg.br/index. php/fef/article/view/6135/4981 [accessed: February 2010]. 13. Merleau-Ponty M., Phenomenology of perception [in Portuguese]. Martins Fontes, São Paulo 1994. 14. Tavares A.F., Costa V.L.M., Tubino M.J.G., Recreation sports and its bodily challenges in the German Complex [in Portuguese]. Revista Motriz, 2010, 16 (1), 258–268.

15. IPAQ – International Physical Activity Questionnaire, available from: [accessed July, 2010]. 16. Brazilian Association of Research Enterprises, Brazilian Economic Classification Criterion [in Portuguese]. Available from: [accessed: July 2010]. 17. American College Of Sports Medicine “2008 Physical Activity Guidelines for Americans” U.S. Department of Health and Human Services, July, 2010, Available from: . [accessed: February 2010]. 18. Likert R., A Technique for the Measurement of Attitudes. Archives of Psychology, 1932, 22 (140), 1–55. 19. Ministry of Health. Resolution 196/96 of the National Health Council – about the regulatory standards and guidelines on research involving humans [in Portuguese]. Diário Oficial da União, October, 1996. 20. Brazilian Institute Of Geography And Statistics. Demographic Census [in Portuguese], November, 2010. 21. Silva A.M., Damiani I.R., The contemporary body practices: assumptions of a field of research and social intervention [in Portuguese]. In: Silva A.M., Damiani I.R., Body Practices v. 3: physical education experiences for human formation [in Portuguese]. Naemblu Ciência e Arte, Florianópolis 2005, 12–39.

Paper received by the Editors: July 7, 2011 Paper accepted for publication: January 4, 2012 Correspondence address Bruno Barth Pinto Tucunduva Street: Lodovico Geronazzo. 249 Curitiba, Paraná, Brazil e-mail: [email protected]

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HUMAN MOVEMENT 2012, vol. 13 (3), 264– 270

SELF-EFFICACY, SELF-ESTEEM AND BODY IMAGE AS PSYCHOLOGICAL DETERMINANTS OF 15-YEAR-OLD ADOLESCENTS’ PHYSICAL ACTIVITY LEVELS doi: 10.2478/v10038-012-0031-4

HANNA KOŁOŁO 1 *, MONIKA GUSZKOWSKA 1, JOANNA MAZUR 2 , ANNA DZIELSKA 2 1 2

Józef Piłsudski University of Physical Education, Warsaw, Poland The Institute of Mother and Child, Warsaw, Poland

Abstract

Purpose. The aim of the study was to analyze which psychological factors can determine the physical activity levels of 15-yearold adolescents. The psychological factors examined were self-efficacy, physical self-esteem (body weight and body appearance) and body image. A multifactorial perspective based on a socioecological approach as well as Bandura’s social learning theory was used to clarify the relationships between the determinants and physical activity levels. Methods. The study participants were 2277 15-year-old adolescents (1086 boys and 1191 girls). Selected questions and scales from HBSC’s international standard questionnaire were used, including the Moderate to Vigorous Physical Activity index, the self perception of body weight and body appearance question, the General Self-Efficacy Scale and the Body Image Subscale. Results. It was found that over half of the Polish 15-year-old population featured an insufficient level of physical activity. Self-efficacy, body image and physical self-esteem of both body mass and body image were significant predictors of physical activity. The role of these predictors was found to be differentiated by gender. Conclusions. The physical activity levels of 15-year-old adolescents can be predicted by use of psychological variables.

Key words: physical activity, adolescence, self-efficacy, self-esteem, body image

Introduction Data available on the physical activity levels (PAL) of youth is alarming. Although programs aimed at increasing children’s and adolescents’ physical activity levels have existed for quite some time, few have yielded satisfactory results. Only those programs that were particularly steadfast were able to document a positive effect on physical activity (especially during childhood and adolescence), health, fitness and the quality of life in later adulthood and old age. Some of the more common, and simpler, methods of influencing adolescents’ physi­ cal activity levels were by investments in infrastructure: the modernization and construction of playgrounds, sports fields and other sports facilities as well as seeing that physical education classes’ had a well-suited curriculum. However, recent scientific studies have found that these types of solutions produce limited results [1]. The aim of this study was to therefore seek and analyze criterion outside of environmental factors that could increase adolescent physical activity levels with lasting and positive effects. There exist a number of ways of differentiating the factors that could be classified as determinants of physical activity. This study focuses largely on those which are psychological in nature. Among the determinants of physical activity that fall within this category are those which hold a special sig-

* Corresponding author. 264

nificance in Bandura’s social learning theory [2], which provided the theoretical basis of this study. To accomplish this, an approach deriving from both social learning and self-efficacy theory was used to accentuate the interaction of the numerous individual, environmental and behavioral factors that come into play. Such an approach would focus attention on, among others, the role of self-regulatory processes on a variety of behaviors, in this case physical activity, as one entity [2]. Emphasis on the importance of psychological factors such as self-efficacy and self-esteem can provide an alternative to those approaches in previous studies that focused solely on physical factors, as well as expose a gamut of previously unconsidered factors that can modify physical activity levels. As was mentioned, one of the most important determinants of behavioral change is self-efficacy, where “self-efficacy is the optimistic belief of one’s possibilities through actions that are in accordance with a chosen goal, regardless of the obstacles one faces in achieving this goal or the belief that one is able to perform actions that will create certain results. In addition, self-efficacy allows an individual to decide when to initiate action, decide how much effort should be exerted and if they will be able to continue in spite of additional obstacles and/or failures” [3, p. 66]. Self-efficacy affects how people feel and how they react. Individuals with low self-efficacy frequently have feelings of anxiety, helplessness, sadness and severe depression. High levels of self-efficacy allow for better decision-making, task implementation, information pro-

HUMAN MOVEMENT H. Kołoło et al., Psychological determinants of adolescents’ physical activity

cessing, goal formulation and, therefore, goal achievement. It also affects how much effort is put into countering the discrepancies between the results of our actions and our designated goals. It determines if people use their cognitive resources more efficiently by accurately assessing a given situation and examining for ways to effectively cope with the difficulties one meets when attempting to realize an aim. The source of such behavior in individuals convinced of their self-efficacy is holding a higher level of positive emotions and a lower level of negative emotions. Self-efficacy is also one of the factors that influences an increase in the belief that one can manage to solve problems, increasing the inner-motivation needed towards formulating goals as well as increasing our initiative in taking action. Individuals with high self-efficacy augment the amount of effort they put in achieving an objective when obstacles are encountered or when they are unhappy with a certain outcome. Des­pite the negative emotions one feels when dealing with failure, such individuals mobilize and renew their efforts. In contrast, individuals with a low sense of self-efficacy who encounter obstacles or failures frequently become apathetic, depressed and abandon their goals. Self-efficacy may therefore have both a direct and indirect impact on making healthy behavioral choices, which includes physical activity. Another factor that was pointed out in literature on adolescent physical activity levels was self-esteem. It is defined as the feeling individuals have of themselves, one that is encompassed by numerous psychological dimensions and influences the behavior of individuals [4]. Although self-esteem can be made up of these different individual dimensions (appearance, knowledge, intelligence, specific skills), not all are equally important for a given individual. Self-esteem can be assessed intentionally, from information gathered on one’s ability, such as by the implementation of a task at hand, or unintentionally, based on an evaluation (by assessing oneself or by being assessed by others) of the results of their own actions. Among the information derived from different sources about oneself, there is a number of interactions that make up global self-esteem; it is a collection of all the elements of self-esteem. Another differentiating factor of physical activity is body image, usually understood as the internal re­ presentation of one’s external appearance, i.e., the perception of one’s body [5]. It is closely connected to the emotional sphere (thoughts and feelings), and in some cases it can have an impact on an individual’s behavior. Depending whether an individual’s body image is positive or negative, it can lead to either positive emotions or depressive bouts, or even behavioral disorders resulting from too many negative emotions. One of the more modern definitions of body image define it as an image that we form in our own minds [6]. Body image is highly subjective, unstable and suscep-

tible to many environmental influences; it can change due to one’s mood, the context of one’s self-evaluation and by suggestions given from others. Body image is a systematic, cognitive, affective, conscious and at the same time unconscious image that a person has of his or her own body, an image that is cultivated during one’s development and by social relationships. It is a sensual image of sizes and shapes that is accompanied by feelings of the whole or certain parts of the body [7]. Body image and self-esteem are mutually dependent on each other. The results from Harter’s studies [8, 9] point to a strong correlation between self-esteem and body image. Body image is a key element of self-esteem, which makes it an important component of mental health throughout an entire lifetime. This study aimed at determining the importance of self-efficacy, self-esteem and body image as differen­ tiating factors of physical activity levels in a sample of 15-year-old adolescents, guided with the following research questions: 1. What is the relationship between the physical activity levels and 15-year-olds’ sense of self-efficacy? 2. What is the relationship between 15-year-olds’ physical activity levels and perceived body weight, body appearance and body image? 3. Do relationships between 15-year-olds’ physical activity levels and mentioned psychological factors differ in terms of gender? Material and methods To analyze the set-out research questions, the study employed a diagnostic poll, and as a research technique, a questionnaire survey was used. The measurement tool used was the standard, international HSBC questionnaire (Health Behavior in School-aged Children. A WHO Crossnational Collaborative Study) from 2006, which analyze health behaviors of school-aged youth. The study was conducted at the Department of Child and Adolescent Health at the Institute of Mothers and Child under a research grant from the Ministry of Science and Higher Education (No. 2PO5D04330) Protective factors against risk behaviors and their relationships on school-children’s health in Poland and other countries, led in 2006–2008 by Dr. Joanna Mazur, who is the Principal Investigator of the HSBC study in Poland. Physical activity level was determined by using an MVPA indicator (Moderate-to-Vigorous Physical Activity scale) – classified as physical activity of moderate to intense levels (increased heart rate with, at times, shortness of breath) and best determines overall physical activity. The physical activity question was preceded by an introduction in order to help the adolescents understand the concept of physical activity, stating: “[it] is any activity that increases your heart rate and makes you get out of breath some of the time. Physical activity can be done in sports, school activities, playing with friends, or walking to school. Some examples of physical activity are running, 265

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brisk walking, biking, dancing, skating, soccer. When answering the questions, please think about how much time you spend each day on physical activity.” The survey’s questions were aimed at calculating the physical activity level expressed in the number of days in the preceding week that an individual devoted to physical activity lasting at least 60 minutes. The questions were sourced from a screening test by Prochaska et al. [10], which was confirmed by the HSBC network in 2002 after a number of pilot and validations studies. The adolescents answered how many days they were active by use of a visual scale from 0 to 7. Due to the multidimensional analysis of this study, the physical activity level was then converted into a binary variable, where 0 meant a sufficient level of physical activity, and 1 as insufficient physical activity. Insufficient physical activity was determined as less than five days of physi­ cal activity, each lasting at least 60 minutes. In order to assess the level of self-efficacy, Schwarzer’s General Self-Efficacy Scale was used. It was translated by Juczyński [11] into Polish and had been previously used in studies on health behavior and its long-term effects, on the prevention of substance abuse and in diagnosing adaptability capabilities. The Scale’s total score, based on distribution analysis, was divided into three categories: a low sense of self-efficacy (0–15 points), an average sense of self-efficacy (16–20 points) and high sense of self-efficacy (21–30 points). In later analysis, the psychometric properties of the scale were found to be reliable: Cronbach’s alpha reliability coefficient was 0.850, while factor analysis found a common factor accounting for 44% of the scale’s variability. Self-esteem was defined by three dimensions: a selfassessment of one’s weight, an assessment of appearance and an assessment of body image (the perception of one’s own body). Questions were answered either with individual answers or by rating their feelings on a scale. A self-assessment of weight was analyzed with the question, “Do you think your body is…? :”, with responses being either, “much too thin, a bit too thin, about the right size, a bit too fat, much too fat”. A self-assessment of appearance was examined by asking, “Do you think you are…?, which could be answered with “good looking, quite good looking, about average, not very good looking, not at all good looking”. Body image was examined by the Body Image Subscale, which is one of many subscales that make up the Body Investment Scale, developed by Orbach and Miku­ lincer [12] to quantify one’s experiences with their body. The Body Image Subscale (BIS) was adapted and based on available information, this part of the 2006 HSBC survey was the first time this measurement tool was used in Poland. The BIS scale is composed of six partial assessments, with a total score ranging from 0–24 points that is subdivided into three scoring cate­gories (a low score of 0–14 points, indicating a negative perception 266

of the body, a score of 15–20 points indicating an average perception, and a score of 21–24 points indicating a posi­ tive image of the body). This scale also featured a high reliability of the studied psychometric properties, with Cronbach’s alpha reliability coefficient at 0.853, and one factor accounting for 58% of total variance. In total, the study examined 2287 female and male high schools attending their third year of high school. The students were randomly chosen from a list of schools from the Ministry of Education as well as a database of schools previously selected in a HSBC study conducted in 2002. The selection criterion was the grade. The number of students selected from each of Poland’s region was proportional to its share in the total population as well as proportional in terms of the urbanization level of each region. Due to incomplete data from some of the tested adolescents, the final sample size on which analysis was conducted was N = 2277, made up of 1086 boys and 1191 girls. The minimum accepted significance level was p = 0.05. Results Insufficient physical activity was found in nearly 65% of the studied Polish 15-year-olds, with a significant higher number of girls than boys (Tab. 1). In order to establish a relationship between physical activity and the selected psychological variables of selfefficacy and self-esteem of one’s body weight, appearance and body image, logistic regression models were constructed for each of the variables, followed by a model including all of the collective psychological factors. Both low and high levels of self-efficacy were found to be associated with the level of physical activity in adolescents. Those individuals who were less confident of their own effectiveness were more vulnerable of having a poor physical activity levels [OR = 1.42; CI(OR):1.06–1.89, OR – odds ratio, CI – confidence interval], while those more convinced of their effectives were significantly less likely of having a low physical activity level [OR = 0.46; CI(OR):0.48–0.85]. Gender-specific models found that those with high self-efficacy were found to have less risk in featuring insufficient physical activity in both males [OR = 0.62; CI(OR):0.47–0.80] and females [OR = 0.46; CI(OR): 0.48–0.85]. Table 1. Relationship of the level of physical activity and gender (% of 15-year-old adolescents) Gender Boys Girls Total

Physical activity level * sufficient

insufficient

45.4 26.6 35.6

54.6 73.4 64.4

* chi2 = 87.411; df = 1; p = 0.0000

HUMAN MOVEMENT H. Kołoło et al., Psychological determinants of adolescents’ physical activity

Similarly, gender was found to weaken the predictive abilities of low self-efficacy, which in this model was found to be insignificant and therefore points to the dominant role of gender. The relationships and the way the risks of low physical activity can be predicted for the rest of the parameters were found to be the same as in the individual models – the male gender and a high value of self-efficacy reduced the risk of having poor physical activity: [OR = 0.44; CI(OR):0.37–0.53] and [OR = 0.62; CI(OR):0.52–0.76]), respectively. Those adolescents who evaluated themselves as too fat were found to be at risk of having insufficient physical activity [OR = 1.71; CI(OR):1.39–1.25]. In the gender-specific models, analysis found that the relationship remained unchanged, i.e., the belief in being too fat increased the risk of having insufficient phy­ sical activity [OR = 1.93; CI(OR):1.27–2.71]. However, the model for the girls shows a significant relationship between the personal conviction of being too thin and insufficient physical activity, and therefore increases the risks one faces [OR = 1.59; CI(OR):1.04–2.42]. After switching to the gender-variable model, the goodness of fit was found to significantly worsen and be at the limit of admissibility (Naglekerk’s R 2 = 0.57). Therefore, in this model both gender (the male gender reduces the risk of insufficient physical activity) and the conviction of being too fat are the most important, at [OR = 0.47; CI(OR):0.39–0.56] and [OR = 1.36; CI(OR): 1.09–1.68], respectively. A negative perception of one’s appearance (not very good looking) reduces the likelihood of having insufficient physical activity in 15-year-old boys and girls [OR = 0.65; CI(OR):0.46–0.91]. Analysis independent of both sexes was found to have similar results: a nega­ tive self-assessment of appearance has a slightly stronger predictive value in the group of girls [OR = 0.61; CI(OR): 0.40–0.94] than in boys [OR = 0.52; CI(OR):0.28–0.94]. When analyzing the model that incorporates gender as a variable, it was found that gender was independently connected to insufficient physical activity, where the male gender significantly reduces this risk of this occurring [OR = 0.41; IC(OR):0.34–0.50]. In addition, a negative perception of appearance significantly reduces the risk of having insufficient physical activity [OR = 0.58; CI(OR):0.41–0.82]. A negative self-assessment of body image was found to be associated with an increased risk of insufficient physical activity [OR = 1.29; CI(OR):1.02–1.63], while a positive evaluation of the body reduced the risk of having insufficient physical activity [OR = 0.64; CI(OR): 0.52–0.79]. In analyzing the data in terms of gender, it can be stated that in the group of boys a negative self-assessment increased the risk of having insufficient physical activity [OR = 1.90; CI(OR):1.24–2.91], while a positive assessment had a protective effect by reducing the risk of having insufficient physical activity [OR = 0.74; CI(OR):0.57–0.97]. For the group of girls, the only pre-

dictor of being at risk of insufficient physical activity was a positive self-assessment of one’s body, which was found to correlate with a reduction in risk [OR = 0.65; CI(OR):0.46–0.91]. A gender-variable model found that the male gender and a positive self-assessment of body image reduced the risk of showing insufficient physical activity at [OR = 0.46; CI(OR):0.38–0.56] and [OR = 0.69; CI(OR):0.56–0.86], respectively. Based on the logistic regression analysis performed on all of the separately analyzed psychological factors, a 95% confidence interval was calculated for the odds ratios (OR) and plotted in Figure 1. Individual analysis found that the strongest buffers against featuring insufficient physical activity were having a high level of self-efficacy, followed by positive body image and a negative self-assessment of appearance. The most dominating factor against individuals featuring insufficient physical activity was the belief in being too fat. The strongest determinants of featuring low levels of physi­ cal activity in youth is low self-efficacy and negative body image (Fig. 1). The next step consisted of building a logistic regression model that incorporated all of the analyzed psychological factors. Figure 2 shows the odds ratio (OR) 2,5 2 1,71 1,5 1,29

1,42

1 0,5 0

high selfefficacy

0,65

0,64

0,61

positive body image

“look bad” appearance rating

negative body image

low selfefficacy

“too fat” weight rating

- lower limit of confidence interval odds ratio (OR) - upper limit of confidence interval

Figure 1. Risk of 15-year-olds having insufficient physical activity based on individual psychological factors 2,5 2 1,52

1,5 1 0,5 0

0,66

0,65

“look bad” appearance rating

high self-efficacy

0,75

positive body image

“too fat” weight rating

- lower limit of confidence interval odds ratio (OR) - upper limit of confidence interval

Figure 2. Risk of 15-year-olds having insufficient physical activity based on all of the psychological factors acting simultaneously 267

HUMAN MOVEMENT H. Kołoło et al., Psychological determinants of adolescents’ physical activity

2,5

2,5

2

2 1,68

1,5

1,57

1,5 1

1 0,52

0,5 0

“look bad” appearance rating

0,61 0,5 high self-efficacy

“too fat” weight rating

- lower limit of confidence interval odds ratio (OR) - upper limit of confidence interval

0

0,67

high self-efficacy

“too fat” weight rating

- lower limit of confidence interval odds ratio (OR) - upper limit of confidence interval

Figure 3. Risk of 15-year-old boys having insufficient physical activity based on all of the psychological factors acting simultaneously

Figure 4. Risk of 15-year-old girls having insufficient physical activity based on all of the psychological factors acting simultaneously

and confidence intervals (CI) of all the psychological factors acting simultaneously. As a result, four factors independently determining the level of physical activity were found. The strongest variable that works against having insufficient physical activity was a negative self-assessment of appearance, followed by a high belief of one’s self-efficacy and positive body image. The strongest determinant of being a risk of having insufficient physical activity was the belief in being too fat (Fig. 2). Since there existed a strong independent relationship between physical activity and gender, which was found to distort the other variables’ relationships, the final model for analysis did not include gender as a variable. Instead, two separate models were created for the analyzed boys and girls (Fig. 3 and 4). Analysis performed on the model for the boys pointed to the existence of three determinants of physical acti­ vity: a self-assessment of one’s appearance, weight, and self-efficacy. A negative assessment of appearance and a high sense of self-efficacy were found to reduce the risk of insufficient physical activity while the belief in being too fat increased the risk of insufficient physi­cal activity (Fig. 3). In the model tailored just for girls, there were only two factors that influenced physical activity: self-efficacy and a self-assessment of body weight, where a high opinion of self-efficacy reduced the risk of insufficient physical activity while the belief in being too thin increased it (Fig. 4).

of having a high sense of self-efficacy against insufficient physical activity levels was found in the general population of 15-year-olds as well as in the group of 15-year-old girls. In the case of boys, self-efficacy is an independent predictor of physical activity levels. A positive relationship between self-efficacy and physical activity was also confirmed by other authors [13–15]. Detailed studies conducted by Rodgers et al. [16, 17] have indicated a relationship between self-efficacy and physical activity. Chase [18] and George [19] compared adolescents with a better sense of self-efficacy to those with a weaker belief in their self-efficacy in terms of motor skills and found that those with a higher sense of self-efficacy showed higher physical activity levels, engaged in physical activity with more determination, were able to better cope in the face of setbacks and achieve overall better results. Based on the concepts of Bandura, the main source of self-efficacy comes from successful experience in adopting and maintaining physical activity. Therefore, it can be said that they key to combating insufficient levels of exercise in youth is by encouraging adolescents to not only engage in physical activity but to sustain their active involvement in exercise until their self-efficacy rises to a level that can ensure it being ingrained as a longterm behavior. Another effective method of forming self-efficacy is through behavior modeling, or in other words, the acquisition of behaviors by observation. One of the factors that can increase the chances of successful modeling is by there being similarities to the observer in terms of gender, age, physical fitness and body weight. A potentially successful program would need to therefore start by showing less active adolescents, those who are initially reluctant to exercise, not necessarily physically fit or featuring poor body build and show the process of how they begin to exercise every day, where they are able to chose the physical activity that best suits them and successfully continue exercising, all the while showing the benefits both in terms of physical health and mental health.

Discussion Based on the logistic regression models, the first research question on the relationship between physical activity and 15-year-olds’ sense of self-efficacy was answered by finding that self-efficacy can predict physical activity when considering an entire adolescent population as well as when taking into account only a res­ pondent’s gender. At the same time, the protective role 268

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In response to the second and third research questions that consider the relationships between 15-yearolds’ physical activity levels and a variety of psychological factors (a self-assessment of body weight, appearance and body image) and the crucial role of gender, it is clear that the results of this study reveal the existence of a curvilinear relationship between adolescent physical activity levels and self-esteem, in terms of appearance and body image. In regards to self-esteem connected with appearance, it was found that “average” body appearance was a determining factor of insufficient physical activity. In the case of body weight, it was found that body weight judged about the right size determined a proper level of physical activity. Positive body image was found to determine sufficient physical activity levels in 15-year-old boys and girls. It should be noted that Mulvihill et al.’s qualitative study [22] proved that body mass index (BMI) is a less important determinant of physical activity then the perception (self-assessment) of body weight, body appearance and body image. In addition, it was also shown that adolescents frequently assess their own body weight incorrectly when compared to their actual weight. Teenage girls had a higher tendency to overstate their weight than boys. Adolescent youth attach great importance to physi­ cal appearance and weight, and as was found, the perception (self-assessment) of one’s body was the second, after negative emotions and depression, strongest factor that influences mental health, both in feeling satisfaction and quality of life. According to the results, adolescents with negative body image and a negative self-assessment of body weight (I am too fat) are characterized by insufficient physi­cal activity. This relationship may stem from a reluctance to participate in recreational activities and sports due to a lack of self-acceptance and therefore create a vicious circle. On the one hand, the components of self-esteem (a negative perception of body weight and body image) are factors that prevent an adolescent from taking up physical activity. On the other hand, the most optimal way to control and maintain body weight is through physical activity combined with a proper diet. Adolescents who perform less physical activity while featuring excess body weight have a reduced chance at controlling their weight or bringing it to an acceptable level and may even lead to a continual increase in body weight, which in turn causes an further increased risk of featuring insufficient physical activity. Such a mechanism may be interrupted if an adolescent begins to exercise and remains physically active thanks to a positive feedback mechanism. Only syste­ matically implemented exercise can help reduce weight and increase self-esteem of one’s physical capabilities. Experiencing success through exercise can lead to increased self-efficacy and therefore increase the willingness to participate in more physical activity, thereby increasing the likelihood of further weight reduction and an increase of both self-esteem and self-efficacy.

Furthermore, the level of physical activity was found to be dependent on one’s assessment of their appearance. The largest amount of insufficient physical activity was found in adolescent’s who were satisfied with their appearance, where almost three-quarters of the females in this study that were satisfied with their appearance featured insufficient physical activity. This relationship may stem from a lack of incentive mechanisms to take part in physical activity, where only those adolescent girls who were dissatisfied with their appearance would have the desire to improve their physical looks. Despite the fact that the main motivating factor for girls to participate in physical activity appears to stem from a dissatisfaction with their appearance, this vari­ able should not be too strongly emphasized when trying to increase this group’s physical activity level. Being dissatisfied with one’s appearance can be a symptom of a more serious disorder that can cause a reduction in overall self-esteem, and can lead to alienation, depression, risky behavior and eating disorders. Instead, in this group, it would be better to activate and strengthen health-related and hedonistic themes, with emphasis on the pleasure of performing various kinds of exercise. This requires an adaptation of adolescent physical activities to meet individual needs, preferences and expectations. The results of this study indicate that adolescent physical activity is related to a number of psychological factors. However, in order to more accurately specify the nature of these relationships, additional studies should be conducted on the effectiveness of different types of intervention strategies aimed at increasing the physical activity level of adolescents. A theoretical basis for future studies should be developed on the basis of modern health psychology and behavioral change theory, especially in the form of hybrid models [23], which can take into account the various psychological factors that condition physical activity [1]. Conclusion A number of psychological factors were found to be important determinates of adolescents’ physical acti­ vity levels, however, one especially important criterion was gender – girls are more likely than boys to feature insufficient physical activity. In addition, gender was found to differentiate the importance of some of the studied psychological factors. A high level of self-efficacy was found to reduce the risk of featuring insufficient physical activity in both boys and girls. Insufficient physical activity was also found among those adolescents with negative body image or a negative perception of their body weight. Adolescents’ physical activity levels were found to also depend on the perception of one’s appearance, those who were satisfied with their appearance were more often characterized by insufficient physical activity. 269

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References 1. Biddle S.J.H., Mutrie N., Psychology of physical activity. Routledge, London–New York 2008. 2. Bandura A., Social learning theory [in Polish]. PWN, Warszawa 2007. 3. Łuszczyńska A., The change of health behaviors [in Polish]. GWP, Gdańsk 2004. 4. Kofta M., Doliński D., Cognitive approach to personality [in Polish]. In: Strelau J. (ed.), Psychology. Academic ma­ nual. GWP, Gdańsk 2000, 561–600. 5. Thompson K., Heinberg L., Antabe M., Tantleff-Dunn S., Exacting beauty. Theory, assessment, and treatment of body image disturbance. APA, Washington 1999. 6. Cash T., Pruzinski T. (eds.), Body image. A handbook of theory, research & clinical practice. Guilford Press, New York–London 2004. 7. Brytek-Matera A., Body image – self-image. The image of body in psychosocial approach [in Polish]. Difin, War­ sza­wa 2008. 8. Harter S., Jackson B., Young adolescents’ perceptions of the link between low self-worth and depressed affect. J Early Adolesc, 1993, 33 (4), 383–407, doi: 10.1177/0272 431693013004003. 9. Wichstrøm L., Harter’s self-perception profile for adolescents: reliability, validity, and evaluation of question format. J Pers Assess, 1995, 65 (1), 100–116, doi: 10.1207/ s15327752jpa6501_8. 10. Prochaska J., Sallis J., Long B., A physical activity screening measure for use with adolescents in primary care. Arch Pediatr Adolesc Med, 2001, 155 (5), 554–559, doi: 10.1001/archpedi.155.5.554. 11. Juczyński Z., The measurement instruments in health promotion and psychology [in Polish]. Pracownia Testów Psychologicznych PTP, Warszawa 2001. 12. Orbach I., Mikulincer M., Body Investment Scale. Construction and validation of a body experience scale. Psychol Assess, 1998, 10, 415–425. 13. Reynolds K.D., Killen J.D., Bryson S.W., Maron D.J., Tay­ lor C., Maccoby N. et al., Psychosocial predictors of phy­ si­cal activity in adolescents. Prev Med, 1990, 19 (5), 541– 551, doi: 10.1016/0091-7435(90)90052-L. 14. Trost S., Pate R., Saunders R., Ward D., Dowda M., Felton G., A prospective study of the determinants of phy­ sical activity in rural fifth-grade children. Prev Med, 1997, 26 (2), 257–263, doi: 10.1006/pmed.1996.0137.

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Paper received by the Editors: June 15, 2010 Paper accepted for publication: December 7, 2011 Correspondence address Hanna Kołoło Wydział Wychowania Fizycznego Akademia Wychowania Fizycznego Józefa Piłsudskiego ul. Marymoncka 34 00-968 Warszawa, Poland e-mail: [email protected]

HUMAN MOVEMENT 2012, vol. 13 (3), 271– 279

PERSONAL DEVELOPMENT OF PARTICIPANTS IN SPECIAL OLYMPICS UNIFIED SPORTS TEAMS doi: 10.2478/v10038-012-0032-3

MACIEJ WILSKI 1 *, ANNA NADOLSKA 1, SANDRA DOWLING 2 , ROY MCCONKEY 2 , DAVID HASSAN 2 1 2

University School of Physical Education, Poznań, Poland University of Ulster, Jordanstown, Northern Ireland

Abstract

Purpose. This study aims to identify the impact of the Special Olympics’ Unified Sports program on the personal development of its participants. Methods. A qualitative method was used, which included gathering data by interviewing individual athletes and unified teams, by collecting individual personal histories and by use of connection charts from five European countries that participate in the Unified Sports program. A total of 221 data samples were recorded. Results. Athletes reported improvements in their abilities on the field as well as increased fitness and technical ability. They emphasized the importance of team-work and trust between athletes. Improvements in confidence, self-esteem and communication skills were also reported by athletes. Partners also reported a positive change in attitude towards people with intellectual disabilities. Friendships were a central and vital aspect of taking part in the teams. Friendships developed between athletes and partners. Athletes reported increased access to community “places” such as sports facilities and social venues. Conclusions. Unified Sports is an exciting initiative that holds much promise in transforming the life experiences of young athletes with intellectual disabilities. The impact of the Unified Sports program on the personal development of participants applies to all areas of human functioning – physical, mental and social. Our evaluation suggests that its concepts and modes of operations transcend national boundaries and cultures at least within a European context.

Key words: unified sports, intellectual disability, personal development, empowerment

Introduction Among the key objectives often cited in the case of disabled individuals during their rehabilitation process is the need to create conditions for their personal deve­ lopment. This should be reflected in all forms of human functioning, such as physical, mental and social deve­ lopment. As this is not an easy task, especially in cases of individuals with serious disabilities, there is a search for other forms of interaction that can positively affect disabled individuals in the most comprehensive way possible. One very desirable feature is versatility, as it can provide an individual with a balanced form of personal development. One of these, as we can call them, integrative rehabilitation approaches is through sport and physical activity. It can be surmised that the main objectives of practicing sport are relegated to the development of motor skills and sensorimotor functions, improved movement patterns as well as learning healthy lifestyle habits [1]. Yet these are just a few of the advantages that physical activity can provide. According to Sherrill [2], one of the most important goals is rather to gain a sense of independence in order to allow for personal growth. However, this can only be achieved if an individual * Corresponding author.

activates their development potential in all areas of human functioning. As a result, this goes hand in hand with intellectual development, developing positive character traits, perseverance, ambition, mental strength, the understanding of appropriate social behaviors as well as taking advantage of opportunities and overall social integration. The benefits of physical activity for disabled individuals are well known. Patterson and Pegg [3] indicated that recreational activities and sports help the disabled improve their quality of life, allow their lives to be more tolerable, reduce hypertension, allow them to build and maintain relationships with family and friends as well as increase self-esteem and improve their physical fitness and health [4, 5]. Sport and physical activity can also be a great form of stimulating personal development and empowerment. Numerous studies conducted on persons with a disability suggested that participation in organized sports had a positive effect on mood and self-efficacy and contributed to the growth of individual empowerment [6, 7]. Sport also provides a number of opportunities for learning new skills, taking risks, reducing the risk of disease and helps build and maintain social relationships and networks [5, 8]. In examples where young people with intellectual disabilities took part in sports, the results pointed to overwhelming positive results. Taking the above into consideration, it is evident that there is a need for more 271

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organized sports activities for the disabled, which in a comprehensive and well-planned structure can provide ample opportunities for personal development. In order to meet this need, the Special Olympics introduced the Unified Sports program, whose aim was to integrate individuals with intellectual disabilities (athletes) with those without intellectual disabilities (partners) through common practice sessions and team games. The Unified Sports program in Europe/Eurasia primarily focuses on team sports or competitions (such as football and basketball in Poland). The idea of the program is to create conditions that allow for the effective integration of athletes and partners, with all team members having equal status, the same common goals and experiences, and for the group to work together as a team, with each individual contributing equal effort in order to achieve success [9]. By fulfilling these conditions and maintaining a well-organized program it can be possible to establish friendships and partnerships between the team members and promote the acceptance of individuals with intellectual disabilities. Taking into consideration the benefits provided by the Unified Sports programs, it is not surprising that the organization has rapidly grown. In 2009, the program was operating in 28 countries in Europe/Eurasia with over 16,000 young athletes. So far, few studies have assessed the Unified Sports program and how it functions. A few notable mentions include the studies conducted by Castagno [10] and Norins et al. [11], which were also carried out in Poland. Therefore, there is need for additional research on assessing how Unified Sports fulfills its objectives and whether it contributes to the personal development of its participants. As such, the main objective of our study was to assess the impact of the Unified Sports program on personal development, as comprehensive personal development is only possible when it touches on all aspects of human functioning. The rationale for our study was underlined by the assumption that organized sport can provide an important source of support in disabled individuals’ development. However, we would like to emphasize that although the study was international in nature, it was not the goal of this study to assess the differences of the Unified Sports program between countries. On the contrary, we focused more on the search for similarities. It is believed that it is far more important to find common, universal factors that can support to the personal development of people with intellectual disabilities, regardless of cultural background, in order for the program to succeed when entering new European/Eurasian countries. Material and methods As the study was designed to identify the needs and capabilities of disabled individuals, it was decided to 272

employ the ever-more popular research method of quali­ tative methodology, where in the last 10 years its use has tripled [12]. Qualitative research allows for a more insightful look in identifying what problems disabled individuals have, mainly by allowing participants to freely express themselves unencumbered by research restrictions. In addition, it provides a broader context of the difficulties that arise in the lives of those who are disabled [7, 13]. The study began in April 2009 and lasted for fifteen months. Inclusion criteria when selecting which countries to study were as follows: for the Unified Sports program and its teams to have existed for at least one year, that the teams meet and train regularly as well as participate in competitions, that there should be a sufficient number of teams to allow a fair assessment in deciding on a representative Special Olympics team, that the program is professional in nature, and that there should not be other similar programs of this nature or having objectives similar to those of the Unified Sports program. A total of eight countries were found to meet this criteria, of which five were selected (Serbia, Poland, Hungary, Ukraine and Germany) due to their geographical distribution (in eastern, western and central Europe). In each of the participating countries, it was found that the Unified Sports practice sessions and sports tournaments usually took place in two or more different places, therefore, data were collected from both sources. The sports that best satisfied the study’s requirements were football in Serbia, Poland and Hungary and basketball in Ukraine and Germany. Data were collected using interviews with the players and partners (aged 12–25 years), coaches, parents and local community representatives. Interviews with coaches, parents and local community representatives were used to gather information on the functioning of the participants on the unified teams. Each of the interviewers had a set of questions aimed at gathering information on each of the disabled athletes’ in terms of their ability to function on a team and outside of it as well as his/her views on the Unified Sports program. The interview questions were predominantly open in nature, e.g., “What did you learn from being a member of a unified team”, “Did you have any negative experiences when participating in the Unified Sports program?, “Would you like more people to participant in Unified Sports – if so, why?”. Although the interviewer had a list of prepared questions asking for specific information, the main purpose of the experiment was to elicit a spontaneous response on any problems the athlete experienced in the Unified Sports program. The interviews were also conducted with the entire teams, in which the interviewer again attempted to elicit natural responses from both partners and athletes. The main advantage of this method was in the ability to compare what the interviewees said as an in-

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dividual and what was said in the presence of the entire team. Additional information was also collected on each athletes’ history as shared by other athletes and partners. The participants were also asked to describe in a spontaneous and unlimited manner about the course of their life. This method was primarily designed to note whether their participation in Unified Sports was an important part of their life. This study also made use of connection charts, whose objective was to identify the extent of the social contacts and support networks the athletes and partners encountered. The respondents were asked to graphically represent the places they most often stayed in and the people they met there. Demographic data were collected by use of a questionnaire. All data for each participant was collected one at a time with each method. After concluding the study, the data were analyzed by using a triangulation method. All interviews with the athletes, partners, coaches and parents were recorded digitally and in their native language and then uploaded to a computer and translated into English. Each of the translated “sections” were then forwarded to the study’s local project manager where they were transcribed and further analyzed. All data were transcribed verbatim by the project manager as well an secured with a password in order to ensure the anonymity of the respondents. The next stage consisted of analyzing the obtained data from the interviews by re-reading the responses in order to better understand the content. The qualita-

tive data from the interviews was read by more than one person from a group of expert evaluators in order to facilitate the selection of data that specifically dealt with the topics analyzed in this study and to avoid subjective evaluation. At this stage of analysis the data were also divided into the method subcategories (athletes, partners, coaches, parents, etc.), with the sections then subjected to another round of coding to ensure that no data were omitted during the first stage of data analysis. A breakdown of the number of individuals and what methods were used in presented in Table 1. On average, the teams analyzed in the study were composed of 60% disabled athletes and 40% non-disabled partners. This ratio varied from country to country, for example the smallest amount of partners was in Ukraine (36%), while the largest in Serbia (48%). In Poland, the number of partners was similar to the group average (38%). The vast majority of the team participants were men, both among the athletes (81%) and partners (84%). The small number of women may be due to the types of sports analyzed in this study. On the whole, there were more women in those countries whose teams played basketball than in countries where the main team sport was football. By far the largest number of participants were in the 16–18 age group (42%). It is worth mentioning that the partners were significantly younger than the athletes. A distribution of the participants’ age is show in Table 2.

Table 1. Numbers of participants examined in each country Method

Serbia

Poland

Ukraine

Germany

Hungary

Total

6 7 5 7 6 4 4 4 7 3 53

6 7 5 5 5 6 4 4 5 6 53

6 7 8 4 3 4 4 3 4 4 47

3 3 2 4 2 3 2 2 2 2 25

4 4 4 5 4 5 4 4 5 4 43

25 28 24 25 20 22 18 17 23 19 221

Athlete interviews Partner interviews Family member interviews Coach interviews Team interviews Local community representative interview Life history – athlete Life history – partner Connection chart – athlete Connection chart – partner Sample total

Table 2. Characteristics of the participants based on age Age groups

Total

12–15

16–18

19–21

22–25

Athletes

32 20.5%

65 41.7%

32 20.5%

27 17.3%

156

Partners

47 43.5%

45 41.7%

8 7.4%

8 7.4%

108

Total %

79 29.9%

110 41.7%

40 15.1%

35 13.3%

264

273

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Another significant factor, other than age, that differentiated the groups of athletes and partners was how long they were involved in the Unified Sports program. Only 14% of the partners were members for more than two years; the number of athletes involved in the program was decidedly higher (38%). This undoubtedly points to a higher turnover rate of partners in the program. The vast majority of the intellectually disabled athle­ tes (92%) attended special schools, most lived with their families (64%) or in special centers (24%). The socioeconomic status of the athletes’ families was significantly lower than that of the partners’ families. The athletes were also found to receive less support from their family. In addition, the social network variable that was considered in this study showed that the disabled athletes have far fewer friends and acquaintances than the partners, and that they did not regularly participate in social life or leisure activities. Results Based on the opinions of the respondents, it was found that the personal growth of the disabled athletes was stimulated in all three areas (physical, mental and social) of human functioning. Physical aspect Most of the athletes participating in the Unified Sports program are individuals who are active in sports and that they have a certain level of motor skills, acquired mainly through their participation in basic sports disciplines that are a part of the Special Olympics. Many of the partners also declared their previous involvement in sports clubs for disabled individuals. Despite the level of difficulty encountered in the games, both athletes and partners noticed an improvement in their fitness levels but also technical abilities. The disabled athletes also commented that the opportunity to train with nondisabled partners allowed them to increase their over physical fitness levels. This was evidenced in a number of comments: “Until recently, we had to take it easy during practice as the athletes quickly became tired. Now they want to train even when we, the partners, feel tired. “ (partner, Ukraine) This opinion was also held by the coaches: “The athletes grew in terms of their mobility, they are in better shape, they are becoming faster and have better technical skills.” (coach, Ukraine) Partners often stressed the fact that they were surprised at being able to improve their skills when competing against disabled athletes. As an example, one partner stated: “My skills have improved, I feel more tough, I run faster, I shoot better, so yes, I am better than I was before, we train hard and we have a good team.” (partner, Hungary) Analysis of the data also found that the disabled 274

athletes’ technical skills improved thanks to the joint practice sessions: “I think I play a lot better than before, my technique is much better, for example in ball control, passing, shooting and my contact with others players on the field.” (athlete, Serbia) Contact with other players, as was mentioned above, is a very important element of teamwork. This aspect of team play was also frequently highlighted by the participants as a factor that improved the quality of the team. For example, one of the coaches said: “This team is completely different from the teams I had coached earlier [able-bodied teams], as it is dependent on working together. Here, there is no room for individuality, because if there was, the team would cease to function. Everyone on this team understands that they are as one, and not individuals making up a team.” (coach, Serbia) The emphasis by coaches on the importance of teamwork over individual wants and needs was well understood by both partners and athletes: “The most important is to pay attention on how we can work together, even though we do not go to the same school and that we did not know each other before. On the field we make a great team.” (athlete, Serbia) Such an attitude fosters trust. This is especially important for athletes. They often emphasized the importance of feeling that they are a trusted member of the team, as someone who can be relied on. This is often a completely new role for individuals with intellectual disabilities, as in most contexts they have to rely on the help of others. The increased physical fitness level of disabled athletes creates a situation where they cease to perceive themselves only through their disability. Instead, their self-evaluation shifts in the direction of their motor skills and capabilities as a team member. One of the coaches stressed that: “You have to look at the different skills each individual provides if you want to create a team… it is very easy to see who you can rely on, who can run the longest, who hits the ball the hardest. You do not look at who attends a special school.” (coach, Serbia) Sport provides the same opportunities for all; it provides a completely different form of perception for people with intellectual disabilities. One’s level of intellectual ability ceases to be of importance, where attention is shifted to the skills and abilities needed in game play. Mental aspect The development of the mental aspect was found to be most commonly referenced by the respondents in three main areas – an increase in self-confidence, selfesteem and the ability to communicate with others. This is a very interesting phenomenon, especially in regards to the growth of self-esteem. In situations that frequently feature rivalry between disabled and nondisabled individuals, there is always the risk that those with disabilities would feature a drop in self-esteem due

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to them comparing their abilities and skills to the nondisabled. However, as was made clear in the interviews, this problem was found to not exist in the Unified Sports program. On the contrary, the joint practice sessions and rivalry during competitions were found to help raise the self-esteem of the athletes with intellectual disabilities. One of the athletes described his experience: “Yes, I believe in myself, I worked hard to be part of this team, and now I believe that if I work hard I can achieve many things.” (athlete, Hungary) The increase in self-esteem was found to correlate with a rise in athletes’ self-confidence and their ability to establish social contacts outside of sports activities. For example, two athletes stressed this point by saying: “It is easier for me to meet with others as I have got used to making contact with other people,” (athlete, Poland) or, “There is a girl I like, I talked about her with a few of my friends and they told me that I should talk to her. When I saw her in the city, I started to talk to her and asked her what her name was. I told her that I play on our team and she said that she heard about us and she saw us in town. I would have never talked to her otherwise.” (athlete, Serbia) The development in communication skills was not only relegated to the athletes, partners also noted certain changes in this area: “In the beginning, when I joined the team, it was difficult for me because I did not know anyone, I could not talk to them like I did with my friends, but after a few days, the problem disappeared and now it is very easy for me to communicate with them.” (partner, Ukraine) Although some cases of major changes in the personal development of the partners were found, it should be noted that these types of changes were rare: “I have become more confident and I think I can communicate with others more easily, especially with people with intellectual disabilities, because I did know knowing anything about them before but now they are my friends.” (partner, Hungary) The partners also noted that their perception of people with intellectual disabilities had changed: “Stereotypes about people with intellectual disabilities work only to keep us away from them, we are afraid they may be dangerous, but when you are a part of a unified team you can break down those stereotypes and see that they are just normal people.” (partner, Poland) A change in the attitude towards individuals with intellectual disabilities was attributed by partners to their partnership in the unified teams: “This is entirely thanks to Unified Sports [in response to changes in attitude towards people with disabilities], before I kept away from these people, but now, for me, they are the same.” (partner, Poland) In addition, the changes had far-reaching consequences on some partners’ everyday lives, which points to the strength of these newly formed attitudes: “I had to stop seeing some friends because they did not understand what I was doing here [on a unified team]. I realized that we have nothing in common if they

could not accept my commitment to the team.” (partner, Ukraine) Social aspect The development of individual skills and personal abilities was found to also occur in the social aspect of the disabled athletes by improving their relationships with other individuals. Friendship was a major and very important aspect mentioned in regards to participating in the program. In some cases, it created a strong bond between the athletes and partners, as well as between the athletes and coaches. There was mention that these newly formed relationships prospered outside the project: “Team integration is all about friendship, it is the most important. We are friends both on and off the field. We also have a strong relationship with our coaches, who I would also call my friends.” (partner, Poland) In a few cases, the athletes reported that they began to frequent public places that they rarely or never visited before, such as sports facilities: “We now go to the old market square and talk, or to the arcade or coffees shop. The guys from my team know a lot of different places and if we have time, we go there after practice.” (athlete, Serbia) However, it should be noted that in most cases the relationships that were created during the joint practice sessions did not translate into the athletes and partners meeting together in non-sport contexts. Most of the times when the athletes and partners met outside practice they either played sports or went on trips to see their favorite sports team as fans. One of the citied reasons for this by most of the respondents was in the distance that the individuals team members lived from each other: “After practice I only meet with those who live close to me. Many of us live in different parts of the city and it is not easy to meet after practice, you have to catch a bus or a train and that becomes more difficult.” (athlete, Serbia) A large disparity was noted between the amount of spare time the athletes and partners had during the connection chart aspect of this study; the latter group was found to have more time for extra-curricular activities, they were generally more active and they also possessed a greater group of friends and close friends: “The partners are very busy, they have a lot of things to do, school, work… we, as the athletes, have more available time and often have to wait for our partners.” (athlete, Ukraine) A summary of the results are provided in Table 3 to better illustrate what were the more important areas of functioning mentioned by the athletes and partners through their participation in the Unified Sports program. The program was found to influence both groups in a similar manner and promoted development in the same areas of functioning. The Unified Sports 275

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Table 3. Main functional aspects that developed through participation in the Unified Sports program Physical aspect

physical fitness technical ability teamwork

Mental aspect

increase in self-esteem (athletes) confidence social skills changes in attitude (partners)

Social aspect

mutual trust new social contacts making friends greater participation in public events (athletes)

program allowed both the athletes and partners to have more opportunities to develop their sports skills and social skills and positively affect their mental functioning. The latter aspect was found to somewhat differentiate between the two groups. For the athletes the largest developmental change was in an increase in self-esteem, while for partners it was the change in their attitude towards individuals with intellectual disabilities. Discussion The aim of this study was to evaluate the impact of Unified Sports on the personal development of all of the involved participants by using a qualitative method that would allow the respondents to freely express their thoughts, beliefs and perceptions with no constraints. All of the participants noted major changes in the three areas of human functioning that were analyzed in the study. First, both athletes and partners declared a positive change in their sports skills. This has also been confirmed by others authors, such as Riggen and Ulrich [14] and Castagno [10], who noted positive changes in the basketball skills of athletes with intellectual disabilities in the Unified Sports program. Castagno also found that these changes affected partners, who declared they also significantly improved their basketball skills. In his study conducted on a unified Polish football team, almost all of the disabled athletes (99%) reported that their skills improved as a result of their involvement in the team, while 82% of the partners also reported an increase in their football skills. In individuals with intellectual disabilities, physical activity was found to not only improve physical fitness, but, above all, contribute to better life satisfaction, higher self-efficacy and fewer cognitive-emotional problems [15]. This was also found, as part of the second area of human functioning, to be noted by the study participants (both partners and athletes). Particularly noticeable was growth in the development of personal skills 276

and an increase in self-confidence and self-esteem. Other researchers found similar results: Castagno [16, in 10] observed a significant improvement in the selfperception of children with and without intellectual disabilities after taking part in a 12-week fitness program. Other studies performed by the same author [10] showed an increase in self-esteem in both athletes and partners who were members of a unified team. However, our study did not observe an increase in partners’ selfesteem. Similar results were reported by Norins et al. [11] on a Polish group, where partners did not show the same level of change in their self-perception as athletes. In this study, 51% of the partners noted no change in this regard. However, an interesting change was observed in the attitudes towards people with intellectual disabilities. Our research has shown that the partners gradually noticed the abilities of the athletes on their teams and, as a result, changed their perception about their disabled colleagues. This change was narrowed down to the increase in the abilities of the disabled athletes on the field, which later expanded into other spheres of life. This is particularly important, as change in this area signifies one of the most important goals that underline the idea of unified sports. This idea is based on the assumption that this change is the result of having contact with individuals with intellectual disabilities [17]. Whether this change is positive or negative depends on the type and the context of the interaction that people are exposed to; contact that is well thought-out and requires peoples’ direct involvement has been found to have a positive impact on attitudes [18]. This has been confirmed in research carried out during the Special Olympics World Games in China [19], where a significant change in able-bodied individuals’ attitudes towards those with intellectual disabilities was observed. The largest changes were found in those individuals who were directly involved in the Olympics, such as volunteers or spectators. As Unified Sports only further engage non-disabled individuals, it can be assumed that the benefits would be even stronger. Random and unstructured contact with individuals with intellectual disabilities is not enough to promote change, it requires interactions that are organized, structured and constructive [20]. Moreover, it seems that a very significant impact on attitudes is the quality of the experiences and the feeling of happiness from both parties when meeting each other [21, 22]. A change in attitude is a long-term process, one that progresses gradually in shaping a coherent and sustainable context. This change needs to take place in favorable circumstances if contact with individuals with intellectual disabilities is to foster positive attitudes. As the results of the study show, the Unified Sports program offers such opportunities as it increases the chances that peoples’ attitudes can be changed and in opposite to situations where such contact is sporadic and unstructured.

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These conclusions have been confirmed by both this study and earlier studies. For example, Norins et al. [11] also observed changes in partners’ better understanding of disabled individuals. The vast majority of partners (92%) claimed that their involvement in Unified Sports helped them better understand those with intellectual disabilities. In response to being asked what they learned about individuals with intellectual disabilities, the players said they now perceive them as good athletes, friendly, funny and similar to themselves. In others studies, Arbour et al. [23] found that presenting the disabled as active and exercising individuals changed people’s former stereotypes. Individuals who exercise, when compared to those who do not, are eva­luated more positively in terms of their physicality and personality. The authors suggest that encouraging the disabled to take part in physical activity may be an effective method at combating the stigma and prevailing stereotypical image of disabled individuals. The third area in which the respondents declared significant changes was in the social sphere, where among one of the most important factors was the opportunity to gain new social contacts. This was frequently reported by the athletes but also perceived by their partners. Overall, the social and communication skills that athletes develop helped them participate in their local communities. According to Devine and Wilhite [24], children with disabilities experience the greatest amount of social inclusion in sport and recreational activities, where they are equally treated, they are able to experience mutual friendship, feel accepted and feel that the physical activity they practice is matched to their capabilities. It is felt that the Unified Sports program undoubtedly provides this conditions. It is worth noting that the social inclusion of individuals with intellectual disabilities is not something that is done for them, but rather something that naturally occurs when they find themselves being active participants in public life. What is also important is that sport and physical activity can help create these situations that can allow the establishment of friendships between able-bodied and disabled individuals. Sports rivalry can foster positive relationships between team members and has been reported as being the perfect backdrop to develop friendly relationships between the participants [25]. This has also been confirmed by Seymour et al. [26], whose study found that integrated physical education classes significantly contributed to the development of friendships between all of the participants. The opportunity to develop friendships is considered one of the most important factors in the process of social inclusion. Friendship, activated by having disabled children participate in sports, was found to play an important role in having these individuals develop a sense of acceptance and belonging as well as a rise in their self-esteem [27, 28].

Given these results and the respondents’ opinion, it is clear the Unified Sports program contributes to the creation of optimal conditions for individual development. Such an environment allows a disabled individual to take advantage of their environment in such a way that it can maximize their own personal resources while only minimally experiencing the encumbrances of their disability. In such a way, these individuals can build upon their self-efficacy and trust more in themselves and their environment. Sport and physical activity allows these individuals to further explore and build their own relationships; it provides them with the right means to take control of their personal, social and environmental conditions [29]. Thanks to a greater sense of ability, disabled individuals become more resistant to stigmatization while also being able to independently self-assess themselves and their actions free from outside opinion. Such a form of independence encourages them to undertake new activities while also building the perseverance needed to overcome difficulties stemming from their disability. The process by which members of a marginalized group are able to change their perception of themselves, develop skills, increase their abilities to act independently, gain greater control over their lives and become more active in improving their standard of living is frequently relegated as empowerment [30, 31]. This process always takes place in a specific social context, which itself may be a factor in supporting or hindering empowerment. When taking into consideration the presented results, it can be unequivocally stated that Unified Sports is entirely conducive in the development of this process. What is also important is that our study shows that the interaction mechanisms of Unified Sports remain the same regardless of the cultural context. Although minor or even sometimes significant differences can exist in the cultures and practices of different countries, the end result is pointed in the direction of improving the personal development of its participants in the same areas of functioning. This reflects the universal and comprehensive basis of the program, which makes it especially valuable in terms of expanding the program at an international level. One limitation that was found in this study was the small number of women that composed the sample population. This may be due to the types of sports that are part of the Unified Sports program. Including a larger number of disciplines, especially those that women frequently participate in, is one way at increasing the scope of the program in terms of gender. Conclusion It can be concluded that the Unified Sports program, based on the opinions of its participants, has a significant impact on personal development. Participation in 277

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the programs allows individuals to develop their communication skills, confidence, common experiences, knowledge of people and places, and physical fitness. It allows the participants to use these facets as tools that can contribute to their active involvement in life as well as the unconscious inclusion of individuals with intellectual disabilities. The program’s partners declared major developmental changes in their understanding of individuals with intellectual disabilities and their change in attitude towards such individuals. This can be considered particularly important as peer attitudes towards disabled individuals depends on the success of the social inclusion process [32]. Taking into account the results that were found in this study, further development and expansion of the Unified Sports program is warranted under the condition that the expansion process does not lose sight of its main principles. An absolute prerequisite for future success is upholding the program’s main tenets. Acknowledgements This study was conducted with funding from the U.S. Center for Disease Control and Prevention, under Cooperative Agreement U59 DD0003 awarded to Special Olympics International, Washington DC, USA. Our sincere thanks to the Special Olympics Europe/Eurasia Senior Manager for Youth Education and Unified Sports Sabine Menke and National Coordinators and Special Olympics partners in the five participating countries: Sven Albrecht, Florian Pochstein, Magdalena Bethge (Germany), Milana Je­ remic, Eminivic Fadijl (Serbia), Orsolya Karpati, Anita Viranyi, Eniko Regenyi, Judit Felegyhazi, Sara Pasztor (Hungary), Konstantine Slyniavchuk, Irina Kogut, Evgeniy Goncharenko (Ukraine) and Joanna Styczen (Poland).

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9. Dłużewska-Martyniec W., Adapted physical activity of people with mental retardation. In: Kowalik S. (ed.), Physical culture for people with disabilities [in Polish]. GWP, Gdańsk 2009, 425–465. 10. Castagno K.S., Special Olympics Unified Sports: Changes in male athletes during a basketball season. Adapt Phys Activ Q, 2001, 18 (2), 193–206. 11. Norins J., Harada C., Brecklinghaus S., Inclusion of young people with intellectual disabilities in Europe through Special Olympics Unified Sports. Special Olympics International, Washington 2007. 12. McReynolds C., Koch L., Qualitative research designs. In: Bellini J., Rumrill P. (ed.), Research in Rehabilitation Counseling: A Guide to Design, Methodology, and Utilization. Charles C. Thomas, Springfield 1999, 151–173. 13. Niesz T., Koch L., Rumrill P.D., The empowerment of people with disabilities through qualitative research. Work, 2008, 31 (1), 113–125. 14. Riggen K., Ulrich D., The effects of sports participation on individuals with mental retardation. Adapt Phys Activ Q, 1993, 10 (1), 42–51. 15. Heller T., Hsieh K., Rimmer J.H., Attitudinal and psychosocial outcomes of a fitness and health education program on adults with Down syndrome. Am J Ment Retard, 2004, 109 (2), 175–185. 16. Castagno K.S., A study of effects of an after school physi­ cal education program on self-concept of middle school EMR students. Unpublished doctoral dissertation, The University of Connecticut, Storrs 1991. 17. Tak-fai Lau J., Cheung C., Discriminatory attitudes to people with intellectual disability or mental health difficulty. Int Soc Work, 1999, 42 (4), 431–444, doi: 10.1177/ 002087289904200405. 18. Acton I.I., Zarbatany I., Interaction and performance within cooperative groups: effects on nonhandicapped students’ attitudes toward their mildly mentally retarded peers. Am J Ment Retard, 1988, 93 (1), 16–23. 19. Norins J., Parker R.C., Siperstein G.N., Impact of the Special Olympics World Games on the Attitudes of Youth in China. Available from: URL: http://www.specialolympics.org/uploadedFiles/LandingPage/WhatWeDo/ Resea rch _ St udies _ Descipt ion _ Pages/ EC N U%20 final%20report.pdf [accessed March 2010]. 20. Rees L., Spreen O., Harnadek M., Do attitudes towards persons with handicaps really shift over time? Comparison between 1975 and 1988. Ment Retard, 1991, 29 (2), 81–86. 21. Eigenbrood T., Retish P., Work experience employers’ attitudes regarding the employability of special education students. Career Dev Except Ind, 1988, 11 (1), 15–25, doi: 10.1177/088572888801100104. 22. McConkey R., McCormack B., Breaking Barriers: Educating people about disability. Souvenir Press, London 1983. 23. Arbour K.P., Latimer A.E., Martin Ginis K.A., Jung M.E., Moving beyond the stigma: The impression formation benefits of exercise for individuals with a physi­cal disability. Adapt Phys Activ Q, 2007, 24 (2), 144–159. 24. Devine M., Wilhite B., The meaning of disability: Implications for inclusive leisure services for youth with and without disabilities. JPRA, 2000, 18 (3), 35–52. 25. Smith A.L., Peer relationships in physical activity contexts: A road less traveled in youth sport and exercise

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psychology research. Psychol Sport Exerc, 2003, 4 (1), 25–39, doi: 10.1016/S1469-0292(02)00015-8. 26. Seymour H., Reid G., Bloom G.A., Friendship in inclusive physical education. Adapt Phys Activ Q, 2009, 26 (3), 201–219. 27. Place K., Hodge S.R., Social inclusion of students with physical disabilities in general physical education: A beha­ vioral analysis. Adapt Phys Activ Q, 2001, 18 (4), 389–404. 28. Spencer-Cavaliere N., Watkinson E.J., Inclusion understood from the perspectives of children with disability. Adapt Phys Activ Q, 2010, 27 (4), 275–293. 29. Giacobbi P.R., Stancil M., Hardin B., Bryant L., Physical activity and quality of life experienced by highly active individuals with physical disabilities. Adapt Phys Activ Q, 2008, 25 (3), 189–207. 30. Gutiérrez L.M., Working with women of color: An empowerment perspective. Soc Work, 1990, 35 (2), 149–153. 31. McWhirter E.H., Empowerment in counseling. J Counsel Dev, 1991, 69 (3), 222–227, doi: 10.1002/j.1556-6676. 1991.tb01491.x. 32. Block M.E., Obrusnikova I., Inclusion in physical education: A review of the literature from 1995–2005. Adapt Phys Activ Q, 2007, 24 (2), 103–124.

Paper received by the Editors: April 6, 2011 Paper accepted for publication: Mach 1, 2012 Correspondence address Maciej Wilski Katedra Kultury Fizycznej Osób Niepełnosprawnych Akademia Wychowania Fizycznego ul. Królowej Jadwigi 27/39 61-871 Poznań, Poland e-mail: [email protected]

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Physical education in the DECADE OF Education for Sustainable Development: a study with Brazilian physical education teachers and educators doi: 10.2478/v10038-012-0033-2

Renata Osborne Salgado de Oliveira University, Niterói, Brazil

Abstract Purpose. In light of the UN Decade of Education for Sustainable Development, an international proposal led by UNESCO beginning in 2005 and continuing until 2014, this study’s objective was to investigate how physical education, at a local level, can contribute to the goal of sustainable educational development. Methods. In order to analyze the research objective, a qualitative method was used. Sixteen professionals from public schools participated in the study. Seven schools and three administrative buildings were visited with data collected by means of interviews, observations and document analysis. Results. The following issues were addressed: school culture; the relationships between Environmental Education, Education for Sustainable Development and physical education; the cultivation of values through cooperative and competitive games; various challenges; and the opportunities for physical education within the UN’s Decade of Education for Sustainable Development initiative. Conclusions. This study concluded that: future partnerships with schools should be aware of and respect school culture; efforts should be made to facilitate schoolwork done outside of school; there is a need for investment in school resources as well in the continuing education of teachers; it is necessary to treat both Environmental Education and Education for Sustainable Development as one symbiotic entity and focus more on the execution of its prerogatives rather than nomenclature. Key words: Environmental Education, sustainability, sports, public schools

Introduction The concept of sustainable development has emerged as an alternative to the previous pattern of economic development, which in the past has generated a great deal of environmental destruction. Sustainable development is intended to have economic growth compatible with nature conservation and community well-being. Sustainable development implies that there are limitations on the use of environmental resources as well as the need to respect the limited ability of the biosphere to absorb the impact of human activities. It is a difficult process of change, in which investment, technology and institutions must be reoriented to meet both present and future needs. In addition, it is largely dependent on political initiative [1]. Since the 1970s, Environmental Education has been discussed and practiced, with the United Nations organizing a series of international conferences that culminated in 2005 to discuss a new program labeled the Education for Sustainable Development. As a result, the United Nations Educational, Scientific and Cultural Organization (UNESCO) launched the Decade of Edu­ cation for Sustainable Development, which is to continue until 2014. The Education for Sustainable Development (ESD) program appears to be a continuation of the previous initiatives led by Environmental Education. ESD claims that while it has been built on the experiences of Environmental Education (EE), they are 280

not the same thing [2]. However, the boundaries between these programs are unclear. Marcinkowski [1] claims that a complex relationship has evolved between ESD and EE since the 1990s. In our opinion, the relationship between ESD and EE is still a matter of discussion. Freitas [3] states that the majority of experts who participated in the debates on ESD consider the program to be an evolution of EE. Nevertheless, various authors have challenged this new way of perceiving ESD. In the present study, we felt it was important to use both concepts, EE and ESD, to sustain the gains EE has made over the last forty years and due to the fact that many of ESD’s ideas actually originated from EE. In our opinion, the main difference between EE and ESD is that EE has developed a wide range of practices, varying from a simple behavior change orientation to a more complex philosophical, political approach, while ESD is more focused on a partnership between education and development. However, we do not agree with UNESCO [2] when it attempts to downgrade the concept of EE and present ESD as being broader. We think a focus on education and sustainable development is important for developing countries, especially Brazil. Therefore, we recognize that all are invited to participate in the Decade of Education for Sustainable Development and that a significant contribution from the realm of sports and physical education is expected. Both EE and ESD use interdisciplinary activities

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and projects that involve teamwork among teachers. According to Chen et al. [4], interdisciplinary teaching provides students with meaningful and relevant content, motivates students because they recognize that knowledge can be applied in real-life situations and provides opportunities for collaboration between teachers. Physical education scholars find that interdisciplinary teaching helps to reduce the marginalization of physical education, in that other teachers come to recog­ nize it as an integral part of school curriculum [4]. The environmental theme is complex; therefore, teaching it in schools can be a challenge. Collares [5] concluded from his study of Environmental Education in Brazilian public schools that teachers face difficulties in implementing environmental issues in their curriculum due to their own lack of training, the conservative tendencies of schools and lack of relevant instructional texts. Collares also reported that teachers were willing to work with the environmental theme but were uncertain how to successfully implement it in their classrooms. It seems that physical education teachers share the same difficulties as other teachers and that the activities they develop when working with the environmental theme are not shared with other teachers. Moreover, it is significant that physical education is still marginalized even though Brazilian curriculum standards claim that physical education is an essential component of basic education. When physical education is not integrated in the planning and evaluation of a school’s content, physical education teachers become isolated [6]. Thus, the purpose of this study was to investigate how physical education professionals envision their contribution to the theme of sustainable development and to identify the activities that they develop to achieve their objectives. The following questions guided the study: (a) what is a school’s context in terms of its culture, projects and relationships with the community? (b) What is the situation of physical education in the context of school? (c) From the perspective of the participants, what is the role of physical education in the Decade of Education for Sustainable Development? (d) What kinds of partnerships have been developed? (e) What difficulties are there? (f) Which physical activities are employed to address sustainable development? (g) What is the potential of physical education to promote sustainable development? Material and methods This research study was qualitative in nature. Marshall and Rossman [7] explain that this type of research should be conducted in a natural setting; it is interpretive, concerned with the meaning individuals give to their social interactions and is grounded in the lived experiences of people. In the same direction, Flick [8] affirms that qualitative research (a) has the complexity

of people’s interaction in daily life as the object of study; (b) investigates the perspectives of different participants, studying their knowledge and practices; (c) positions communication between the researcher and the participants as an essential part of the research process; and (d) uses a variety of methods of data collection. Although there are many genres of qualitative research, this study could be characterized as ethnogra­ phic in nature as it takes into account the concept of culture. However, such a cultural interpretation was performed only for a part of the analysis. Wolcott [9, p. 5] explains that “[…] the purpose of ethnographic research is to describe and interpret cultural behavior”; in other words, culture interpretation is the essence of ethnographic research. Participants and setting To select the research participants, a snowball or chain sampling strategy was used. This means that an initial group was selected from which more could be learned and these participants then recommended other participants at the request of the researcher [10]. Administrators and physical education teachers who had a good understanding of environmental and social issues were chosen by such a process. A total of sixteen professionals working in public schools in two cities in Brazil participated in the research study. Five worked in public schools in Rio de Janeiro and eleven worked in public schools in Niterói. Only two of the subjects were not physical education teachers. All were interviewed in their work setting, where a total of seven schools and three administrative buildings were visited. Data collection and analysis Data were collected through interviews, observation and document analysis. A structured interview guide [11] was created. Following the interviews, the researchers wrote field notes [12] based on the information that they gathered in the six schools and three education administrative centers. They also took 108 pictures and analyzed 20 documents, such as school newspapers, educational materials from schools partners as well as a manuscript written by a physical education teacher. To analyze the data, the researchers of this study created a chart with priori categories based on the research objectives and subcategories that emerged from the data. The principles recommended by Miles and Huberman [13], such as data reduction and data display, were used to guide data analysis. Triangulation of data from different sources (interviews, observations and document analysis) was used in order to establish the reliability of the data [12]. The research results were written in a fashion based on what Bauer and Gaskell [14] describe as the goal of 281

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qualitative research; rather than counting ideas or people, this approach explores different representations of the topic of investigation. Results The results of the observation and document analysis mainly elucidate the general context that surrounds the specific questions studied, while the findings from the interviews focused on responding to specific questions related to the process and role of physical education as a promoter of sustainable development. Observations and document analysis The schools that were visited were named after educators whose pictures were displayed on the schools’ walls. Diverse religious images and quotes from philo­ sophers and politicians were also displayed on the schools’ premises. The schools work on various themes related to the world and to citizenship and their social environments were found to be comfortable and full of creative teachers and students. A contrast in the available resources between the visited administrative buildings was found. While some were equipped with computers and adequate space to work, others were not. The study noted that various Environmental Education projects had already been undertaken in these schools, such as campaigns against fireworks and balloons, encouraging tree planting, solid waste recycling, oil recycling and teacher training. The schools worked with the community and private organizations as partners on these projects. One school received a prize due to a reforestation project. Document analysis provided an overview of the project diversity with public and private organizations within the community. According to one school’s newspaper, the school’s Environmental Day celebrations included a theater play, a lecture by an expert on Environmental Education and sanitation, a cleaning of the school and the planting of fruit and ornamental trees donated by local merchants. The school dedicated the whole month of June to activities related to the environment. The newspaper also included articles on recycling and the importance of good nutrition together with physical activity for a healthy life. Another newspaper, published by a non-governmental organization, reported on the Brazilian Indians’ struggle to maintain their land and culture in the face of the economic interests of mining and logging companies and monoculture farming, all of which have a negative impact on the environment. Other collected documents were part of the National Program for the Rational Use of Oil and Natural Gas, which aims to train teachers on how to address environmental issues such as non-waste, the efficient use of energy and care for the environment. The teachers attended a training 282

course and received teaching materials to use with the students. The documents also found that various community groups partnered together with the schools. The Brazilian Lawyers Organization, for example, distributed informational materials to teachers and students about their rights as citizens. There were also other initiatives such as one organized by the government to assist families with identity card procurement and activities on health and environmental conservation. On the one hand, it was observed that physical education did play an important role in school projects. For example, at one school, a project called “Gentleness Generates Gentleness”, cultivated positive values and behaviors that contribute to interpersonal relationships inside and outside of school. On the other hand, a certain weaknesses was observed in the realm of physical education. For example, a law that mandates the teaching of physical education had not been fully implemented. One administrative employee showed her concern on that matter. She commented that recreation in primary schools is led by individuals who are not trained in physical education. Another weakness was the lack of appropriate space for physical education classes. One good school, for example, had to use a community sport center to conduct physical education classes. Another school, which had its own sports center, wanted to enter into partnerships with neighborhood organizations and universities in order to expand the extracurricular activities they offered. One document specifically addressed physical education by discussing cooperative games as a way to overcome the competitive nature of sports in school. The article explained that cooperative games develop values such as solidarity, understanding and tolerance, which promote personal growth and a positive social environment. According to the author, this revolutionary pedagogical practice cultivates the idea that the students will have more success through cooperation rather than competition, and that this new attitude would contribute to a more just and fraternal society. Interviews Although the participants knew the term “sustainable development,” the majority of participants were not familiar with the Decade of Education for Sustainable Development. They believed, however, that such an initiative could promote positive values, foster a critical attitude toward poverty and environmental degradation, and enable all people to access important information by use of media. One participant commented that all individuals need to participate in sustainable development, independent of the time period established by the Decade initiative. Moreover, it was stated that the Decade of Education for Sustainable Development needs to “jump out of the paper” and penetrate

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schools to remedy social problems and help to establish a more egalitarian society. The difference between Environmental Education and Education for Sustainable Development is still unclear. Some convictions state that there are: (a) no differences or (b) that there are similarities as well as differences between the two approaches. For those who identified differences between the two programs, the opinions were: (a) the Education for Sustainable Development initiative is broader than Environmental Education or (b) Environmental Education is related more to preserving the environment, while Education for Sustainable Development provides mechanisms for economic development that do not harm the environment. Because there was not a clear distinction between Environmental Education and Education for Sustainable Development, the researchers opted to treat them as if it did not matter which one the participant chose when asked about the contribution of physical education in relation to these programs. One participant said that physical education develops the conscience through the cultivation of values such as respect, an acceptance of rules, cooperation, teamwork and learning how to lose or win through cooperative or competitive games. Another participant commented that physical education cannot by itself collaborate with Environmental Education and Education for Sustainable Development. The issue instead is to create dialogue, work together, establish partnerships and integrate multidisciplinary work with pedagogical school planning. It was also stated that the environment is a theme that cuts across all disciplines and that physical education should integrate sports practiced in nature to expand the curriculum beyond school walls. Certain characteristics of physical education, including its connections to the fields of health and education, appear to facilitate the concepts of Environmental Education or Education for Sustainable Development. Therefore, this study affirmed that physical education must connect to a diversity of issues and unite efforts to build a better society. From the participants’ perspectives, important partnerships can be carried out on various levels, such as between teachers, institutions, the private and public sectors as well as between families, schools and communities. However, they also commented that, in their experience, certain partnerships were undesirable as the objective of the partner was not entirely compatible with the school’s objective. Their examples included a table tennis confederation that was seeking talent in a school whose mission was in conflict with the school’s physical education prerogative of not selecting individuals out of a group but rather to make the sport available for all students. The participants provided suggestions for desirable partnerships between private and public organizations as well; with a goal to develop literature on physical education for the schools’ students, to offer

transportation for extra class activities and to develop sport activities after school hours. The difficulties in associating physical education with sustainable development have to do with teacher training, the devaluation of physical education and a lack of resources. According to the participants, low wages, which lead to the need to work in more than one school, make it difficult for teachers to be able to invest in continuing training. It was also mentioned that schools lack the appropriate space for physical education classes. Moreover, other academic subjects are more valued than physical education and that physical education is not always connected with the overall pedagogical plan of the school. One specific challenge encountered was the common practice of some physical education teachers giving students a ball for them to do whatever they wanted with it. This leads to the expectation that physical education class is a time for fun and not a class in which concepts should be taught. One participant explained that students think physical education class is a time to “play ball”, in other words, to play soccer. The cultural tradition of physical education for students is to, literally, “roll the ball.” This unfortunately results in the creation of a soccer and volleyball “monoculture”. The participants in this study felt that the range of options for physical education of children and youth should be expanded. They stated that physical education teachers should work with concepts and make physical education content meaningful. Concerning the difficulties related to the school system, participants reported that it was not possible to carry out work outside the school due to a lack of financial resources. Another challenge is the need for instructional materials, such as a physical education textbook, for students. Some examples mentioned by the interviewees of physical education attuned to the goal of sustainable development were: (a) working with its values and guidelines in outdoor physical activities; (b) taking walks in the neighborhood to become aware of environmental problems such as garbage disposal and sewage treatment; (c) developing recreational activities with scrap material incorporating an environment theme; (d) developing alternative materials for practicing sports; (e) making use of cooperative games and sports with modi­ fied rules in order to facilitate participation and inclusion; and (f) developing dance activities that work with the environment theme. Cooperation and competition were issues frequently discussed by the participants. One participant said that it is important to learn to cooperate before taking part in competition. Another participant affirmed that sports are not only about competition; he also claimed that this message needs to be better understood and used to promote cooperation and solidarity. It was stated that children need to learn to have fun, to “pass the ball” 283

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and to understand that his or her happiness depends on the happiness of others. The participants believed that physical education can help children and youth in adopting a healthy lifestyle. They also believed that physical education teachers should work together with other teachers so that physical education develops along other academic disciplines. It was also said that physical education should work with the sustainable development theme, but that this does not have to be the primary focus. Discussion School culture, community and physical education Within the examined schools, a practice of celebrating the educators of previous generations and of promoting dialogue between the ideas of religious men, politicians and philosophers was found to be a part of the schools’ organizational culture. Each school seemed to possess a spirit that was manifested in its classrooms, murals and walls. Deal and Peterson [15] explain that organizations have identities manifested by their members’ behaviors, ideas and rules. This cultural concept helps us understand what these patterns are, how they are established and how they influence productivity. The culture of a school is a complex system developed over a certain amount of time that includes a school’s history, its present and its future. This culture can be transformed and is composed of unwritten rules, informal expectations, values, beliefs, preconceived ideas, ways in which people interact as well as its mission and objectives. It is present in daily rituals, ceremonies, in the school’s architecture and in its signs. The culture of a school produces something similar to that which is experienced in tribes or clans. People develop profound relationships, values and traditions that give meaning to daily life [15]. This study observed that the examined schools were environments open to the community; where groups from various kind of organizations from private, government and community spheres of life participate with the public school. While the involvement of the community in the school is treated as almost customary, it was found that public school students rarely interacted with their own community in order to expand their learning. This option was found to be very difficult for most due to a lack of school resources. The community education concept is useful to understand the relationship between the school and the community. Kerensky [16] explains that education is a creative and holistic process that involves the whole community. Public schools that understand this community education concept perceive their community as a partner. 284

What, then, is the role of physical education in the context of school? What is its place and how does it behave in relation to the school culture? Regrettably, a devaluation of physical education emerged both in the study observations and in the statements of the interviewees. The first fact to be discussed was that although Brazilian law mandates physical edu­ cation, there is a lack of physical education teachers in primary schools. Carvalho [17] had already identified this problem in her research on a Brazilian project that involved volunteering in schools. The state was providing some physical education teachers but not enough to cover all grades. Moreover, they were also not providing any art teachers. The school Carvalho studied managed to hold physical education and art classes with the help of individual volunteers and with help from local organizations. However, these disciplines are mandatory and, therefore, should have been covered by the state according to the Brazilian Education Laws [6]. This situation contributed to a devaluation of those teachers who work in these fields, fewer work opportunities for them and a lack of education content for public school students. Plank, cited by Carvalho [17], criticized the Brazilian education system saying that there is an incoherence between the educational objectives affirmed in the Brazilian official mandates and those that are actually pursued. He added that the education system in Brazil is less developed than in other South American countries and that this disparity is emphasized by the traditionally weak protection of citizens’ rights in Brazil. This weakness, in our opinion, is not related to a lack of physical education teachers. There is a lack of resources and infrastructure as well as a widespread feeling that physical education is less valuable than other disciplines. It is also believed that physical education teachers are partly responsible for the devaluation of physical education, as many of these teachers do not involve themselves in schools meetings and do not develop meaningful content in their classes. Relationships between Environmental Education, Education for Sustainable Development and physical education For the research participants, the differences between Environmental Education and Education for Sustainable Development remain unclear. Hesselink, as cited in Freitas [3], identified four positions in the debate over Education for Sustainable Development (ESD) and Environmental Education (EE): (a) that ESD is a new stage of EE, (b) that EE is part of ESD, (c) that ESD is part of EE and (d) that EE and ESD are partially congruent. Micheown and Hopkins, as cited by Freitas [3], affirmed that the answer to the question “which hat is bigger”, in regards to EE or ESD, depends on the pers­ pective one is looking from, and consider that this ques-

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tion is not really important. We, the authors, concur with this opinion. For Sauvé [18], the principles of Environmental Education already include sustainable development, and the new orientation of Education for Sustainable Development does not seem to add new objectives to Environmental Education. The characteristics of both seem to be the same: holism, interdisciplinary programs, a clarification of values, critical thinking, active learning and working within a local context. We agree that their characteristics seem to be the same, but we also understand that the focus of ESD is more on education and development. The ESD link to other United Nations initiatives, such as Millennium Development Goals, Education for All and the United Nations Literacy Decade, aims to enhance the quality of basic education. The case of the undesirable partnership described in the Results of this study is also worthy of discussion. In that example, a partner institution had the objective of selecting talented students instead of making a sport accessible to all. The conflict between the role of sports in schools and high performance sports programs has already been discussed by Bracht and Al­meida [19]. They studied a program of sports in schools that resulted from such partnerships. The authors reported that this was a tense relationship, in which physical education was subordinate to the interests of high performance sports, thereby weakening the peda­gogical project of physical education within the school context. The difficulties in using physical education to foster the concepts of sustainable development are a consequence of both historical and infrastructural aspects: (a) the devaluation of the physical education teacher, (b) a lack of resources, (c) a lack of training for teachers and (d) a recurrent practice of viewing physical education as an unnecessary class in which the children only play. In regard to these aspects, Darido and Neto [20] lament the practice of some teachers who only provide a ball to students and simply monitor the time length of whatever activity children decide to play. As such, the teachers do not intervene in their physical education class. Kunz, as cited in Darido and Neto [20], called this a recreational model. This is a consequence of academic discourse that criticizes what should not be done in physical education classes, but does not present any alternative proposals, and public policies that do not offer adequate work infrastructure nor support teacher training. In our opinion, the recreational model adopted by some irresponsible teachers leads to a poor approach and does not produce change and perpetuates a relationship of mediocrity, in which the school system does not give much and the teacher responds by giving even less. These teachers should be reprehended and such situations should immediately be remedied. The need to invest in continuing education and creating instruc-

tional materials for physical education is seen in public schools in other cities as well. A study conducted in public schools in São Paulo found a lack of teaching materials and appropriate working conditions and recommended partnerships between universities and public schools in order to discuss and improve school physical education [21]. To better serve the cause of sustainable development, physical education should not only emphasize cooperative games, but should also seek to understand sports on a deeper level. In this regard, Murad [22] provides a sociological analysis of cooperative games in relation to competitive sports. He explains cooperative games as play activities based on Hegel’s idea of “balancing” and one based on the pedagogical pillars of Piaget. The best form of social interaction is cooperation as this helps to reduce competition and neutralize conflict. Such cooperation, the author explains, with reference to Piaget, is essential in the process of learning and cognitive development. The mission of the school would be to create citizens who are, among other things, able to question and identify injustice. On the other hand, Murad said it is necessary to deal with the element of competition because it is also part of the human condition. According to Simmel, as cited in Murad [22], an absolutely harmonious group does not correspond to real life. Society needs harmony and disharmony as well as association and competition. For Figueiredo [23], it is the task of physical education to promote cooperative behavior, recreational activities, socialization between boys and girls in order to undermine patriarchy, and a sense of commitment between members of different generations. Therefore, the author recommends: (a) cooperative games, working with the principle of “playing with another” and not “playing against another”; (b) traditional games, which value the regional culture and the legacy of past gene­ rations; (c) frescobol (paddleball), a game where there are no rivals but partners; and (d) capoeira, a Brazilian practice of dance and fight that originated from the slave period and is still a part of Brazilian history as well as presenting a vision of the world that questions the standards of modern Western society. As a side note, we the authors would add peteca (shuttlecock), alongside paddleball, to this list, which is a game that origi­ nated from indigenous culture and is also played between partners. However, Figueiredo [23] adds that it is not enough to choose certain activities; the intentio­ nality of the teacher is fundamental in the educational process in order to encourage students to think critically. This study highlighted the potential of physical education to contribute to a healthy lifestyle, which includes regular physical exercise and proper nutrition. In this sense, according to Gadotti [24], rather than educating individuals on sustainable development, which relates to how society produces and reproduces its exis­ 285

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tence, one must educate towards a sustainable way of life. Such a societal transformation is made possible only by individual change. These lifestyle changes include reducing consumerism and consuming food in a sustainable manner, where Gadotti remarks that schools have the potential to educate children and youth in this direction. Conclusion The first consideration of this study relates to school culture. To understand any phenomenon within a school context, it is necessary to be aware of and respect the culture of a school, not as something sacred but as something alive and constantly reinventing itself. Individuals and institutions with different objectives and agendas should enter into partnerships with schools, but these relationships require care. There is a need for caution in establishing partnerships considering the differences in priorities between the school and its potential partners. The trend of the community visiting the school is more frequent than the reverse, where the school visits the community. In our opinion, students would benefit from schoolwork done outside the school. Therefore, efforts should be made to facilitate this interaction. The second consideration refers to the difficulties that physical education needs to overcome in the school system: a lack of resources and teachers, the view of physical education class as playtime, without any important meaning, and the inaccurate perception of phy­ sical education as having less value in comparison to other subjects. Hence, there is a need for investment in greater resources and materials for teaching physical education, supervision on the work developed by teachers, as well as for investments in continuing education. The third consideration concerns the similarities and differences between Environmental Education and Education for Sustainable Development. Our opinion is that it is necessary to treat both initiatives as one. In other words, when discussing these concepts, it is necessary to address both environment and development issues as mutually inclusive. Therefore, while the processes and programs established by Environmental Education must be valued, the contributions of Education for Sustainable Development should also be considered. Execution is more important than nomenclature. The fourth consideration refers to the possibility of physical education activities contributing to the Decade of Education for Sustainable Development. We presented some examples and ideas and believe that phy­ sical education must address both environmental and developmental issues. The success of these programs depends on teacher training, creativity and educational philosophy.

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Acknowledgements We wish to thank FAPERJ (a foundation that supports research in Rio de Janeiro) for funding this research, the physical education teachers who were interviewed, and the students at UNIVERSO who participated in this study.

References 1. Marcinkowski T.J., Contemporary challenges and opportunities in Environmental Education: where are we headed and what deserves our attention? J Environ Educ, 2010, 41 (1), 34–54, doi: 10.1080/00958960903210015. 2. UNESCO. United Nations Decade of Education for Sustainable Development 2005–2014: Draft International Implementation Scheme. Available from: URL: http://portal. unesco.org/education/admin [accessed: May 11, 2005]. 3. Freitas M., Evolution of the sustainable development concept [in Portuguese]. Perspectiva, 2004, 22 (2), 547–575. Available from: URL: http://www.ced.ufsc.br/nucleos/ nup/perspectivas.html [accessed May 11, 2005]. 4. Chen W., Cone T.P., Cone S.L., A collaborative approach to developing an interdisciplinary unit. Journal of Teaching in Physical Education, 2007, 26, 103–124. 5. Collares M.E.B., The environmental education as an inter and transdisciplinar theme in the educational process: a case study in Petrópolis [in Portuguese]. Master’s Dissertation in the Engineering Department of the Federal Fluminense University, Niterói 2002. 6. Brasil. Act guidelines and bases for national education 9.394, of december 20th 1996 [in Portuguese]. Brasília. Available from: URL: http://portal.mec.gov.br/seed/arquivos/pdf/tvescola/leis/lein9394.pdf [accessed: August 22, 2012]. 7. Marshall C., Rossman G.B., Designing qualitative research. Sage, Thousand Oaks 1999. 8. Flick U., An introduction to qualitative research [in Portuguese]. 2nd ed., Bookman, Porto Alegre 2004. 9. Wolcott H.F., On Ethnographic intent. In: Spindler G., Spindler L. (eds.), Interpretive Ethnography of Education: At Home and Abroad. Erlbaum, Hillsdale 1987. Available from: URL: http://www.indiana.edu/~educy520/readings/wolcott87.pdf [accessed: November 11, 2011]. 10. Merriam S.B., Qualitative research and case study applications in education. 2nd ed. rev., Jossey-Bass, San Francisco 1998. 11. Neto O.C., Fieldwork as discovery and creation. In: Mi­ nayo M.C.S. (ed.), Social research: theory, method and creativity [in Portuguese]. Vozes, Petrópolis 2002, 51–66. 12. Patton M.Q., Qualitative evaluation and research methods. Sage, Newbury Park 1990. 13. Miles M.B., Huberman A.M., Qualitative data analysis: an expanded sourcebook. Sage, Thousand Oaks 1994. 14. Bauer M.W., Gaskell G., Qualitative research with text, image and sound [in Portuguese]. Vozes, Petrópolis 2007. 15. Deal T.E., Peterson K.D., Shaping school culture. JosseyBass, San Francisco 1999. 16. Kerensky V.M., Community educators: The high touch people. Community Education Bulletin, 1982. An Occa­ sional Paper, June 1982. 17. Carvalho R.O., The development of a community-school partnership in a Brazilian elementary school: a case study. Doctorate thesis in Education, Florida Atlantic University, Boca Raton 2002.

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18. Sauvé L., Environmental education and sustainable development: a complex analysis [in Portuguese]. Revista de Educação Pública, 1997, 10. Available from: URL: http://cgi.ufmt.br/revista [accessed: May 18, 2005]. 19. Bracht V., Almeida F.Q., The politics of school sport in Brazil [in Portuguese]. Revista Brasileira de Ciências do Esporte, 2003, 24 (3), 87–101. Available from: URL: http://www.rbceonline.org.br/revista/index.php?journ al=RBCE&page=article&op=view&path%5B%5D=76 5&path%5B%5D=439. [accessed: July 1, 2010]. 20. Darido S.C., Neto L.S., The physical education context in schools [in Portuguese]. In: Darido S.C., Rangel I.C.A. (eds.), Physical education in schools: implications for pe­ dagogical practice [in Portuguese]. Guanabara Koogan, Rio de Janeiro 2005, 1–24. 21. Tokuyochi, Portrait of Physical Education teachers from state schools in the state of Sao Paulo [in Portuguese]. Motriz, 2008, 14 (4), 418–428. Available from: URL: http:// cecemca.rc.unesp.br/ojs/index.php/motriz/article/view/ 1361/1900. [accessed: July 1, 2012]. 22. Murad M., Sociology and Physical Education: conversations, body language, sports [in Portuguese]. FGV, Rio de Janeiro 2009. 23. Figueiredo R.P., Physical Education for environmental education: a relationship to be built on transience [in Portuguese]. Master’s Dissertation in the Brasília University, Brasília, 2002. 24. Gadotti M., Educating for a sustainable life [in Portuguese]. Pátio Revista Pedagógica, 2008, 12, 12–15. Available from: URL: http://www.revistapatio.com.br/sumario_conteudo.aspx?id=629 [accessed: August 30, 2011].

Paper received by the Editors: October 28, 2010 Paper accepted for publication: May 10, 2012 Correspondence address Renata Osborne Rua Jangadeiros 37 apto 701 CEP 22420-010 Ipanema, Rio de Janeiro, Brazil e-mail: [email protected]

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PUBLISHING GUIDELINES – Regulamin publikowania prac

The Editorial Office of Human Movement accepts original empirical as well as comparative research papers on human movement science from varying scientific fields (including sports medicine, exercise physiology, biomechanics, kinesiology, sociology, psychology, pedagogy) covering edu­cation in health, physical education, recreation and tourism, rehabilitation and physiotherapy. The Journal also invites such contributions as letters to the Editor, reports from scientific conferences and book reviews. The publication of submitted contributions to Human Movement is free of charge. The original version of the journal is offered in print form. All proposals should be prepared using the guidelines set forth below and sent electronically to: [email protected] The author is also obliged to submit a signed declaration (downloadable from our website) that the submitted work has not been and will not be published in any other publications without the consent of the Editorial Office and that they agree for their work to be published in Human Movement. Articles with more than one author need only one declaration, signed by the principal author on behalf of all the co-authors. The Editorial Office will not accept articles that were “ghostwritten” or feature “guest authorship”, and any irregularities will be reported and disclosed by the Editorial Office.

Redakcja kwartalnika Human Movement przyjmuje do publikacji oryginalne prace empiryczne oraz przeglądowe dotyczące ruchu człowieka z różnych dziedzin nauki (m.in. medycyny sportu, fizjologii wysiłku fizycznego, biomechaniki, antropomotoryki, socjologii, psychologii, pedagogiki) z zakresu wychowania fizycznego, zdrowotnego, rekreacji i turystyki, rehabilitacji, fizjoterapii. Przyjmowane są również listy do Redakcji, sprawozdania z konferencji naukowych i recenzje książek. Publikowanie prac w Human Move­ment jest bezpłatne. Wersją pierwotną czasopisma jest wersja papierowa. Wszystkie prace powinny być przygotowane wg opisanych niżej zasad i przesłane w wersji elektronicznej na adres: [email protected] Autor jest zobowiązany ponadto do przesłania pod­pi­sa­ ne­go oświadczenia (formularz do pobrania ze strony in­ter­ ne­to­wej), że treść artykułu nie była i nie będzie publiko­ wana w tej formie w innych wydawnictwach bez zgody Redakcji czasopisma Human Movement oraz że zgadza się na ogło­sze­nie jej w tym kwartalniku. Przy pracach zespo­ łowych oświad­czenie w imieniu wszystkich współautorów składa główny autor. Redakcja nie przyjmie artykułu, w którym występują zja­ wiska „ghostwritting” i „quest authorship”, a wszelkie nie­ prawidłowości będą ujawniane przez Redakcję.

Articles submitted for publication in the quarterly Human Movement are peer-reviewed. The peer-review procedure used at Human Movement is in accordance with the guidelines set out by the Polish Ministry of Science and Higher Education. The author may provide the names of potential reviewers, but the Editorial Office reserves the right in their selection of reviewers. Reviewers will not know the author’s name nor will the authors know the reviewer’s name. Based on the reviewers’ assessment of the submitted work, the Editorial Office will decide whether an article is to be published or not. The Editorial Office’s decision is final.

Artykuły zamieszczane w kwartalniku Human Movement są recenzowane. Procedury recenzowania są zgodne z wytycznymi Ministerstwa Nauki i Szkolnictwa Wyższego, umieszczonymi na stronie: http://pbn.nauka.gov.pl. Autor może podać nazwiska potencjalnych recenzentów, lecz Redakcja zastrzega sobie prawo ich doboru. Recenzenci nie znają nazwisk autorów ani autorzy nie znają nazwisk recenzentów. W zależności od oceny recenzentów Redakcja podejmuje decyzję, czy artykuł zostanie opublikowany czy nie. Decyzja Redakcji jest ostateczna.

Authors are not remunerated for published works. Authors will receive a copy of Human Movement in which their work was published.

Autorzy nie otrzymują honorarium za opublikowanie pracy. Każdy autor dostaje jeden egzemplarz numeru Human Movement, w którym ukazał się jego artykuł.

Detailed guidelines for submitting articles to Human Movement

Szczegółowe zasady przygotowania artykułu do Human Movement

1. The article may be written in English or Polish. Articles in Polish, after being positively assessed by the Editorial Office, are translated into English. 2. Empirical research articles, together with their summary and any tables, figures or graphs, should not exceed 20 pages in length; comparative articles are limited to 30 pages. Page format is A4 (about 1800 characters with spaces per page). Pages should be numbered. 3. Articles should be written using Microsoft Word with the following formats: – Font: Times New Roman, 12 point – Line spacing: 1.5 – Text alignment: Justified – Title: Bold typeface, centered

1. Prace mogą być napisane w języku polskim lub angielskim. Teksty polskie po uzyskaniu pozytywnej recenzji są tłumaczone przez Redakcję na język angielski. 2. Tekst prac empirycznych wraz ze streszczeniem, rycinami i tabelami nie powinien przekraczać 20, a prac przeglądowych – 30 stron znormalizowanych formatu A4 (ok. 1800 znaków ze spacjami na stronie). Strony powinny być ponumerowane. 3. Artykuł należy przygotować w edytorze tekstu Microsoft Word według następujących zasad: – krój pisma: Times New Roman, 12 pkt; – interlinia: 1,5; – tekst wyjustowany; – tytuł zapisany pogrubionym krojem pisma, wyśrodkowany.

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4. The main title page should contain the following: – The article’s title in Polish and English – A shortened title of the article written in English (up to 40 characters in length including spaces), which will be placed in the running head – The name and surname of the author(s) with their affiliations written in the following way: the name of the university, city name, country name. For example: The University of Physical Education, Wrocław, Poland – Address for correspondence (author’s name, address, e-mail address and phone number) 5. The second page should contain: – The title of the article – An abstract, written in English, of approximately 250 words divided into the following sections: Purpose, Methods, Results, Conclusions – Three to six keywords to be used as MeSH descriptors (terms) 6. The third page should contain: – The title of the article – The main text 7. The main body of text in empirical research articles should be divided into the following sections:

4. Strona tytułowa powinna zawierać: – tytuł pracy w języku polskim i angielskim; – skrócony tytuł artykułu w języku angielskim (do 40 zna­­ ków ze spacjami), który zostanie umieszczony w żywej paginie; – imię i nazwisko autora (autorów) z afiliacją zapisaną wg następującego schematu: – nazwę uczelni, nazwę miejscowości, nazwę kraju, np. Akademia Wychowania Fizycznego, Wrocław, Polska; – adres do korespondencji (imię i nazwisko autora, jego adres, e-mail oraz numer telefonu). 5. Następna strona powinna zawierać: – tytuł artykułu; – streszczenie w języku angielskim (około 250 wyrazów) składające się z następujących części: Purpose, Methods, Results, Conclusion; – słowa kluczowe w języku angielskim (3–6) – ze słownika i w stylu MeSH. 6. Trzecia strona powinna zawierać: – tytuł artykułu; – tekst główny. 7. Tekst główny pracy empirycznej należy podzielić na następujące części:

Introduction The introduction prefaces the reader on the article’s subject, describes its purpose, states a hypothesis, and mentions any existing research (literature review)

Wstęp We wstępie należy wprowadzić czytelnika w tematykę artykułu, opisać cel pracy oraz podać hipotezy, stan badań (przegląd literatury).

Material and methods This section is to clearly describe the research material (if human subjects took part in the experiment, include their number, age, gender and other necessary information), discuss the conditions, time and methods of the research as well identifying any equipment used (providing the manufacturer’s name and address). Measurements and procedures need to be provided in sufficient detail in order to allow for their reproducibility. If a method is being used for the first time, it needs to be described in detail to show its validity and reliability (reproducibility). If modifying existing methods, describe what was changed as well as justify the need for the modifications. All experiments using human subjects must obtain the approval of an appropriate ethnical committee by the author in any undertaken research (the manuscript must include a copy of the approval document). Statistical methods should be described in such a way that they can be easily determined if they are correct. Authors of comparative research articles should also include their methods for finding materials, selection methods, etc.

Materiał i metody W tej części należy dokładnie przedstawić materiał badawczy (jeśli w eksperymencie biorą udział ludzie, należy podać ich liczbę, wiek, płeć oraz inne charakterystyczne cechy), omówić warunki, czas i metody prowadzenia badań oraz opisać wykorzystaną aparaturę (z podaniem nazwy wytwórni i jej adresu). Sposób wykonywania pomiarów musi być przedstawiony na tyle dokładnie, aby inne osoby mogły je powtórzyć. Jeżeli metoda jest zastosowana pierwszy raz, należy ją opisać szczególnie precyzyjnie, przedstawiając jej trafność i rzetelność (powtarzalność). Modyfikując uznane już metody, trzeba omówić, na czym polegają zmiany, oraz uzasadnić konieczność ich wprowadzenia. Gdy w eksperymencie biorą udział ludzie, konieczne jest uzyskanie zgody komisji etycznej na wykorzystanie w nim zaproponowanych przez autora metod (do maszynopisu należy dołączyć kopię odpowiedniego dokumentu). Metody statystyczne powinny być tak opisane, aby można było bez problemu stwierdzić, czy są one poprawne. Autor pracy przeglądowej powinien również podać metody poszukiwania materiałów, metody selekcji itp.

Results The results should be presented both logically and consistently, as well as be closely tied with the data found in tables and figures.

Wyniki Przedstawienie wyników powinno być logiczne i spójne oraz ściśle powiązane z danymi zamieszczonymi w tabelach i na rycinach.

Discussion Here the author should create a discussion of the obtained results, referring to the results found in other literature (besides those mentioned in the introduction), as well as emphasizing new and important aspects of their work.

Dyskusja W tym punkcie, stanowiącym omówienie wyników, autor powinien odnieść uzyskane wyniki do danych z literatury (innych niż omówione we wstępie), podkreślając nowe i znaczące aspekty swojej pracy.

Conclusion In presenting any conclusions, it is important to remember the original purpose of the research and the stated hypotheses,

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and avoid any vague statements or those not based on the results of their research. If new hypotheses are put forward, they must be clearly stated.

ogólnikowych i niepopartych wynikami własnych badań. Stawiając nowe hipotezy, trzeba to wyraźnie zaznaczyć.

Acknowledgements The author may mention any people or institutions that helped the author in preparing the manuscript, or that provided support through financial or technical means.

Podziękowania Można wymienić osoby lub instytucje, które pomogły autorowi w przygotowaniu pracy bądź wsparły go finansowo lub technicznie.

Bibliography The bibliography should be composed of the article’s citations and be arranged and numbered in the order in which they appear in the text, not alphabetically. Referenced sources from literature should indicate the page number and enclose it in square brackets, e.g., Bouchard et al. [23]. The total number of bibliographic references (those found only in research databases such as SPORTDiscus, Medline) should not exceed 30 for empirical research papers (citing a maximum of two books); there is no limit for comparative research papers. There are no restrictions in referencing unpublished work.

Bibliografia Bibliografię należy uporządkować i ponumerować według kolejności cytowania publikacji w tekście, a nie alfabetycznie. Odwołanie do piśmiennictwa należy oznaczyć w tek­­ście numerem i ująć go w nawias kwadratowy, np. Bouchard et al. [23]. Bibliografia (powołania zawarte tylko w bazach danych, np. SPORTDiscus, Medline) powinna się składać najwyżej z 30 pozycji (dopuszcza się powołanie na 2 publikacje książ­ kowe), z wyjątkiem prac przeglądowych. Niewskazane jest cytowanie prac nieopublikowanych.

Citing journal articles Bibliographic citations of journal articles should include: the author’s (or authors’) surname, first name initial, article title, abbreviated journal title, year, volume or number, page number, doi, for example:

Opis bibliograficzny artykułu z czasopisma Opis bibliograficzny artykułu powinien zawierać: naz­ wisko autora (autorów), inicjał imienia, tytuł artykułu, tytuł czasopisma w przyjętym skrócie, rok wydania, tom lub numer, strony, numer doi, np.

Tchórzewski D., Jaworski J., Bujas P., Influence of long-lasting balancing on unstable surface on changes in balance. Hum Mov, 2010, 11 (2), 144–152, doi: 10.2478/v10038-0100022-2.

Tchórzewski D., Jaworski J., Bujas P., Influence of long-lasting balancing on unstable surface on changes in balance. Hum Mov, 2010, 11 (2), 144–152, doi: 10.2478/v10038-0100022-2.

If there are six or less authors, all the names should be mentioned; if there are seven or more, give the first six and then use the abbreviation “et al.” If the title of the article is in a language other than English, the author should translate the title into English, and then in square brackets indicate the original language; the journal title should be left in its native name, for example:

Gdy autorami artykułu jest sześć lub mniej osób, należy wymienić wszystkie nazwiska, jeżeli jest ich siedem i więcej, należy podać sześć pierwszych i zastosować skrót „et al.”. Tytuł artykułu w języku innym niż angielski autor powinien przetłumaczyć na język angielski, a w nawiasie kwadratowym podać język oryginału, tytuł czasopisma należy zostawić w oryginalnym brzmieniu, np.

Jaskólska A., Bogucka M., Świstak R., Jaskólski A., Mechanisms, symptoms and after-effects of delayed muscle soreness (DOMS) [in Polish]. Med Sport, 2002, 4, 189–201.

Jaskólska A., Bogucka M., Świstak R., Jaskólski A., Mechanisms, symptoms and after-effects of delayed muscle soreness (DOMS) [in Polish]. Med Sport, 2002, 4, 189–201.

The author’s research should only take into consideration articles published in English.

W pracy powinny być uwzględnianie tylko artykuły publikowane ze streszczeniem angielskim.

Citing books Bibliographic citations of books should include: the author (or authors’) or editor’s (or editors’) surname, first name initial, book title translated into English, publisher, place and year of publication, for example:

Opis bibliograficzny książki Opis bibliograficzny książki powinien zawierać: nazwisko autora (autorów) lub redaktora (redaktorów), inicjał imienia, tytuł pracy przetłumaczony na język angielski, wydawcę, miejsce i rok wydania, np.

Osiński W., Anthropomotoric [in Polish]. AWF, Poznań 2001.

Osiński W., Anthropomotoric [in Polish]. AWF, Poznań 2001.

Heinemann K. (ed.), Sport clubs in various European countries. Karl Hofmann, Schorndorf 1999.

Heinemann K. (ed.), Sport clubs in various European countries. Karl Hofmann, Schorndorf 1999.

Bibliographic citations of an article within a book should include: the author’s (or authors’) surname, first name initial, article title, book author (or authors’) or editor’s (or editors’) surname, first name initial, book title, publisher, place and year of publication, paga number, for example:

Opis bibliograficzny rozdziału w książce powinien za­wie­ rać: nazwisko autora (autorów), inicjał imienia, tytuł roz­ działu, nazwisko autora (autorów) lub redaktora (redaktorów), inicjał imienia, tytuł pracy, wydawcę, miejsce i rok wydania, strony, np.

McKirnan M.D., Froelicher V.F., General principles of exercise testing. In: Skinner J.S. (ed.), Exercise testing and exercise prescription for special cases. Lea & Febiger, Philadelphia 1993, 3–28.

McKirnan M.D., Froelicher V.F., General principles of exercise testing. In: Skinner J.S. (ed.), Exercise testing and exercise prescription for special cases. Lea & Febiger, Philadelphia 1993, 3–28.

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Citing conference materials Citing conference materials (found only in international research databases such as SPORTDiscus) should include: the author’s (or authors’) surname, first name initial, article title, conference author’s (or authors’) or editor’s (or editor’s) surname, first name initial, conference title, publisher, place and year of publication, page number, for example:

Opis bibliograficzny materiałów zjazdowych Opis bibliograficzny materiałów zjazdowych (umieszczanych tylko w międzynarodowych bazach danych, np. SPORTDiscus) powinien zawierać: nazwisko autora (autorów), inicjał imienia, tytuł, nazwisko autora (autorów) lub redaktora (redaktorów), tytuł pracy, wydawcę, miejsce i rok wydania, strony, np.

Rodriguez F.A., Moreno D., Keskinen K.L., Validity of a twodistance simplified testing method for determining critical swimming velocity. In: Chatard J.C. (ed.), Biomechanics and Medicine in Swimming IX, Proceedings of the IXth World Symposium on Biomechanics and Medicine in Swimming. Université de St. Etienne, St. Etienne 2003, 385–390.

Rodriguez F.A., Moreno D., Keskinen K.L., Validity of a twodistance simplified testing method for determining critical swimming velocity. In: Chatard J.C. (ed.), Biomechanics and Medicine in Swimming IX, Proceedings of the IXth World Symposium on Biomechanics and Medicine in Swimming. Université de St. Etienne, St. Etienne 2003, 385–390.

Citing articles in electronic format Citing articles in electronic format should include: author’s (or authors’) surname, first name initial, article title, abbreviated journal title, journal volume or number, year of publication, website address where it is available, doi number, for example:

Opis bibliograficzny artykułu w formie elektronicznej Opis bibliograficzny artykułu w formie elektronicznej po­winien zawierać: nazwisko autora (autorów), inicjał imienia, tytuł artykułu, tytuł czasopisma w przyjętym skrócie, tom lub numer, rok wydania, adres strony, na której jest dostępny, numer doi, np.

Donsmark M., Langfort J., Ploug T., Holm C., Enevold­sen L.H., Stallknech B. et al., Hormone-sensitive lipase (HSL) expression and regulation by epinephrine and exercise in skeletal muscle. Eur J Sport Sci, 2 (6), 2002. Available from: URL: http://www.humankinetics.com/ejss/bissues. cfm/, doi: 10.1080/17461391.2002.10142575.

Donsmark M., Langfort J., Ploug T., Holm C., Enevold­sen L.H., Stallknech B. et al., Hormone-sensitive lipase (HSL) expression and regulation by epinephrine and exercise in skeletal muscle. Eur J Sport Sci, 2 (6), 2002. Available from: URL: http://www.humankinetics.com/ejss/bissues. cfm/, doi: 10.1080/17461391.2002.10142575.

8. The main text of any other articles submitted for consideration should maintain a logical continuity and that the titles assigned to any sections must reflect the issues discussed within.

8. Tekst główny w pracach innego typu powinien zachować logiczną ciągłość, a tytuły poszczególnych części muszą odzwierciedlać omawiane w nich zagadnienia.

9. Footnotes/Endnotes (explanatory or supplementary to the text). Footnotes should be numbered consecutively throughout the work and placed at the end of the main text.

9. Przypisy (objaśniające lub uzupełniające tekst) powinny być numerowane z zachowaniem ciągłości w całej pracy i umieszczone na końcu tekstu głównego.

10. Tables, figures and photographs – Must be numbered consecutively in the order in which they appear in the text and provide captions – Should be placed within the text – Additionally, figures or photographs must be attached as separate files in .jpg or .pdf format (minimum resolution of 300 dpi) – May not include the same information/data in tables and also figures – Illustrative materials should be prepared in black and white or in shades of gray (Human Movement is published in such a fashion and cannot accept color) – Symbols such as arrows, stars, or abbreviations used in tables or figures should be clearly defined using a legend.

10. Tabele, ryciny i fotografie – należy opatrzyć numerami i podpisami; – należy umieścić w tekście artykułu; – dodatkowo ryciny i fotografie trzeba dołączyć w postaci osobnych plików zapisanych w formacie *.jpg lub *.pdf (gęstość co najmniej 300 dpi); – nie można powtarzać tych samych wyników w tabelach i na rycinach; – materiał ilustracyjny powinien zostać przygotowany w wersji czarno-białej lub w odcieniach szarości (w taki sposób jest drukowane czasopismo Human Movement); – symbole, np. strzałki, gwiazdki, lub skróty użyte w tabelach czy na rycinach należy dokładnie objaśnić w legendzie.

Manuscripts not prepared as per the requirements set forth in “Publishing Guidelines” will be returned to the author for correction. The Editorial Office reserves the right to make any language corrections or remove abbreviations found in the manuscript. Once the Editorial Office accepts an article for publication, a proof will be sent to the author for approval. It is the author’s responsibility to accept any changes or submit any corrections within one week of receiving the proof.

Praca przygotowana niezgodnie z wymogami „Regulaminu publikowania prac” zostanie odesłana autorowi do poprawy. Redakcja zastrzega sobie prawo usuwania usterek językowych oraz dokonywania skrótów. Artykuł po opracowaniu redakcyjnym zostanie przekazany autorowi do akceptacji. Obowiązkiem autora jest przesłanie ewentualnych uwag i poprawek w ciągu jednego tygodnia.

Prior to printing, the author will receive their article in .pdf format. It is the author’s responsibility to immediately inform the Editorial Office if they accept the article for publication. At such a point in time, only minor corrections can be accepted from the author.

Przed drukiem autor otrzyma swój artykuł do akceptacji w formie pliku pdf. Obowiązkiem autora jest niezwłoczne przesłanie do Redakcji Human Movement informacji o akceptacji artykułu do druku. Na tym etapie będą przyjmowane tylko drobne poprawki autorskie.

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HUMAN MOVEMENT Publishing guidelines – Regulamin publikowania prac

The Journal is subject to copyright as per the Berne Convention and the International Copyright Convention, except where not applicable pursuant to a country’s domestic law.

Publikacje podlegają prawu autorskiemu wynikającemu z Konwencji Berneńskiej i z Międzynarodowej Konwencji Praw Autorskich, poza wyjątkami dopuszczanymi przez prawo krajowe.

The Editorial Office accepts advertising in Human Movement, which may be located on the second or third page of the cover or as additional separate pages. Ad rates are negotiated separately.

Redakcja przyjmuje zamówienia na reklamy, które mogą być umieszczane na 2. i 3. stronie okładki lub na dodatkowych kartach sąsiadujących z okładką. Ceny reklam będą negocjo­wane indywidualnie.

Authors should contact the Editorial Office of Human Movement only by email.

Autorzy powinni się kontaktować z Redakcją Human Move­­ ment wyłącznie za pośrednictwem poczty elektronicznej.

THE RULES OF SUBSCRIBING THE HUMAN MOVEMENT JOURNAL ZASADY PRENUMERATY CZASOPISMA HUMAN MOVEMENT The price of annual subscription (four issues) for individual sub­scribers is PLN 54 and PLN 110 for institutions. All subscriptions are payable in advance. Subscribers are requested to send payment with their order whenever possible. The orders should be sent to the Editorial Office: e-mail: [email protected] or Human Movement Editorial Office University School of Physical Education al. I.J. Paderewskiego 35 51-612 Wrocław, Poland

Cena rocznej prenumeraty (cztery numery) dla odbiorców in­dy­w idualnych w kraju wynosi 54 zł brutto, dla instytucji 110 zł brutto. Zamówienie wraz z potwierdzeniem dokonania wpłaty należy przesłać na adres mailowy: [email protected] lub

The issues of the journal are sent by post after receiving the appropriate transfer to the account:

Numery czasopisma wysyłamy pocztą po otrzymaniu od­ po­w ied­niej wpłaty na konto:

BPH PBK S.A. O/Wrocław 42 1060 0076 0000 3210 0014 7743 Akademia Wychowania Fizycznego al. Paderewskiego 35, 51-612 Wrocław, Poland with the note: Human Movement subscription.

BPH PBK S.A. O/Wrocław 42 1060 0076 0000 3210 0014 7743 Akademia Wychowania Fizycznego al. Paderewskiego 35, 51-612 Wrocław z dopiskiem: Prenumerata Human Movement.

We ask the subscribers to give correct and clearly written addresses to which the journal is to be sent.

Prosimy zamawiających o bardzo wyraźne podawanie adresów, pod które należy wysyłać zamawiane egzemplarze czasopisma. Pojedyncze egzemplarze można zamówić w ten sam sposób, wpłacając 16 zł brutto (odbiorca indywidualny) i 30 zł brutto (instytucja) na podane konto.

Single copies can be ordered in the same way, by transferring PLN 16 (individual subscribers) and PLN 30 (institutions) to the above mentioned account. 292

Redakcja czasopisma Human Movement Akademia Wychowania Fizycznego al. I.J. Paderewskiego 35 51-612 Wrocław

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