Biomechanical Analysis of Sub-Elite Performers in the Women’S Long Jump
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© by IAAF Biomechanical analysis of 22:4; 19-28, 2007 sub-elite performers in the women’s long jump By Vassilios Panoutsakopoulos and Iraklis Kollias Vassilios Panoutsakopoulos is a Ph.D. candidate in biomechanics Biomechanical analysis of sub- and teaches track and field in the elite competitions enriches the Deptartment of Physical Educa- pool of knowledge about tech- tion and Sport Science at the Aris- nique in athletics events. The pur- totle University of Thessaloniki. pose of this study was to describe His research interests are teaching the kinematics of the approach methodology and the optimisa- and take-off of competitors in the tion of sport performance. women’s long jump competition at the 2006 European Cup 1st Prof. Dr. Iraklis A. Kollias is a League-Group B. It was found Director of the Biomechanics that all the participants utilise Laboratory of the Deptartment of the “longer penultimate-shorter Physical Education and Sport last stride” ratio previously Science at the Aristotle University described for top-level perform- of Thessaloniki. He competed in ers. All but one increased their the shot put for the Greek Nation- horizontal velocity during the last al team from 1971 to 1978. His stride. Mean horizontal and verti- major fields of research are 3-D AUTHORS cal take-off velocities were analysis of sports technique and 8.71m/sec (standard deviation: the development of specific 0.26) and 2.45m/sec (0.12) instrumentation for sport analysis. respectively, resulting in a mean take-off angle of projection of 18.1 degrees (0.7). The values of the selected biomechanical parameters were either in range ABSTRACT Introduction (i.e. loss of horizontal velocity during contact with the board, large amount of information con- energy loss in take-off) or lower cerning the long jump has been (i.e. take-off velocity, angle of A acquired from biomechanical analy- projection) than results obtained sis of elite competitors at major athletics at higher-level events such as the events around the world. Data is available World Championships or Olympic for competitors at the Olympic Games13-14, Games. IAAF World Championships in Athletics15-16, IAAF World Junior Championships4, World Student Games6,17, USA national champi- 18-19 New Studies in Athletics • no. 4/2007 onships and the UK national champion- 19 Biomechanical analysis of sub-elite performers in the women’s long jump ships20-21. However, there is a lack of data energy, stored in the leg extensor muscles in concerning the technique employed by sub- the early stages of the contact8-10, assists in elite long jumpers competing in internation- generating an additional amount of vertical al events. This missing information is impor- velocity at take-off6. tant as sub-elite athletes can be assisted in their preparations by knowledge that allows Placement of the foot on the board leads comparisons with the world’s best. to a high braking force, which causes a for- ward rotation about a transverse axis The aims of this study are: a) to describe through the CM11. This forward angular the kinematics of the participant’s run-up momentum must be controlled in order to and the take-off by presenting biomechani- avoid a loss in the distance of the jump2. cal parameters exhibited in the women’s Therefore, long jumpers must counteract the long jump competition at the 1st league of effects of the forward rotation and maintain the 2006 European Cup, and b) to comment their body orientation during the flight by on the results when they are compared with executing appropriate arm and leg move- findings from the literature4, 6, 13-21. ments12. The most common flight techniques 1 1 are the 2 /2 hitch-kick, 3 /2 hitch-kick and the The technical factors affecting per- hang. formance in the long jump include the accuracy of the approach, the technique Methods used during the final strides of the approach, the role of elastic energy in the take-off, the The women’s long jump competition at the initiation and control of the jumper's angu- 2006 European Cup 1st League-Group B lar momentum, and the technique used in Event, held in Thessaloniki, Greece, on 18 the landing1. June 2006 was studied. The jumps were recorded with a digital JVC GR-DVL 9600EG The horizontal velocity of the approach is (Victor Co., Japan) video camera operating at strongly correlated with the jump distance2 a sampling frequency of 100 fields/sec. The and thus the jumper’s aim is to develop and camera was placed perpendicular to the maintain horizontal velocity for as long as plane of motion and recorded the last two possible when reaching the take-off board. strides of the approach and the take-off To fulfil this requirement, elite long jumpers from the board. A second digital JVC GR-DVL adjust their body position in order to prepare 9600EG video camera, also operating at 100 for take-off during the penultimate stride fields/sec, captured the flight and the land- simply by increasing their stride length and ing in the pit. The latter was used for a qual- by decreasing the height of their body’s cen- itative analysis of the flight phase, utilising tre of mass (CM)3. The last stride is thus the Analysis Sheet proposed by TIDOW22. quite a bit shorter, leading to the so-called “longer penultimate-shorter last stride” Calibration for the 2D-DLT kinematic ratio. The lowering of the height of the CM analysis was conducted by placing a 2.5m x leads to a larger vertical displacement of the 2.5m frame with 16 control markers perpen- CM during contact at the board, resulting in dicular to the camera axis23. The X-axis rep- a greater vertical take-off velocity and a resented the direction of the runway. Y-axis smaller loss of horizontal velocity4. was vertical and perpendicular to the x-axis. Transformation of the initial kinetic ener- All trials were recorded but the best valid gy is needed in order to perform the take- jump for each athlete was selected for fur- off5. Some loss of the jumper’s total energy is ther analysis. Digitisation, smoothing and expected during this process6 but there is an analyses were conducted using the APAS XP optimum limit to this loss in an effective software (Ariel Dynamics Inc., Trabuco 7 jump . The efficient re-utilisation of elastic Canyon, CA). New Studies in Athletics • no. 4/2007 20 Biomechanical analysis of sub-elite performers in the women’s long jump Results • Take-off: the push-off phase from the Definitions take-off board Long jump distances discussed in this study are defined as follows: Competition Results • Official distance (OFD, IAAF rule 185§3): The mean OFD was 6.27m (range: 6.71m – the horizontal distance from the pit edge 5.81m; standard deviation: 0.34m), with the the take-off board to the nearest break winner Deventzi achieving a new personal best in the landing area made by any part of of 6.71m (Table 1). Although the mean OD was the body24 lower than the 6.64m (0.16) of the top eight at • Toe-to-board distance (TTB): the hori- the 2006 European Athletics Championships in zontal distance from the take-off Gothenburg or to 6.51m (0.20) of the top eight foot’s toe to the pit edge of the take-off of the 2006 IAAF World Cup in Athens, the com- board16 petition was of high standard, since the athletes • Effective distance (EFD): the sum OFD + achieved 97.1% of their personal bests at that TTB4 time25. Furthermore, three of the analysed ath- • Effective take-off distance (EFto): the letes went on to win silver medals at the Euro- horizontal distance from the athlete’s pean Athletics Championships later in the sea- CM to the toe of the take-off foot at son: Gomez in the long jump, Deventzi in the take-off18 triple jump, Ruckstuhl in the heptathlon. • Time instant of touchdown: the first video field in which the landing foot clearly contacts the ground Approach • Time instant of takeoff: the first video field All participants seemed to utilise the in which the foot has clearly left the ground “long-short” ratio. In average, the last stride Table 1: Participants, personal bests (PB) prior to the event*, result/official distance (OFD) and relative wind velocity for the analysed trials Athlete PB Result/OFD Wind Trial (m) (m) (m/sec) Hrisopiyi DEVENTZI (GRE) 6.56 6.71 0.60 4 Naide GOMEZ (POR) 6.72 6.70 1.20 1 Tünde VASZI (HUN) 6.86 6.52 1.80 3 Karin RUCKSTUHL (NED) 6.58 6.23 -0.50 4 Nina KOKOT (SLO) 6.23 6.19 -0.50 3 Tereza MARINOVA (BUL) 6.46 6.14 -1.00 2 Viktorija ZEMAITYTE (LTU) 6.23 5.89 -0.40 4 Mukadder ULUSOY (TUR) 6.07 5.81 1.40 3 mean 6.46 6.27 std. dev. 0.27 0.34 New Studies in Athletics • no. 4/2007 * as of 15 June 2006, according to www.thessaloniki2006.gr 21 Biomechanical analysis of sub-elite performers in the women’s long jump Table 2: Length (S) and horizontal velocity (Vx) of the center of mass at take-off and the differences observed (¢) for the penultimate (2L) and the last stride (1L) Athlete OFD 2LS 1LS ǵ S Vx2Lto Vx1Lto ǵ Vx (m) (m) (m) (m) (m/sec) (m/sec) (m/sec) DEVENTZI 6.71 2.34 2.15 -0.19 9.23 9.32 0.09 GOMEZ 6.70 2.38 2.06 -0.32 8.67 8.96 0.29 VASZI 6.52 2.26 1.81 -0.45 9.06 9.23 0.17 RUCKSTUHL 6.23 2.58 2.22 -0.36 8.79 9.21 0.42 KOKOT 6.19 2.34 1.99 -0.35 9.05 9.13 0.08 MARINOVA 6.14 2.48 2.15 -0.33 9.03 8.88 -0.15 ZEMAITYTE 5.89 2.39 2.25 -0.14 8.33 8.61 0.28 ULUSOY 5.81 2.34 2.15 -0.19 8.43 8.66 0.23 mean 6.27 2.39 2.10 -0.29 8.82 9.00 0.18 std.