INTRODUCTION: In ski jumping the take-off is a key position within the entire movement. The execution of take-off and the jump intensity (vertical take-off velocity) have a direct impact on the take-in of the flight posture and of the flight distance. Due to the changes in the materials (jump suits, ties, shoes) but also the use of standardized (ice) track systems realize the best athletes in the inrun position and in take-off an ever-increasing submission of the center of gravity (Müller, Kreibich & Wiese, 2014). In the analysis of the take-off-execution interested the question of how the action of force under these conditions, and whether there are differences between the top athletes. METHOD: With dynamometric measurement platforms (Dickwach & Wagner, 2004) we analyzed 21 elite athletes (25.0 years ± 4.0) at the jumping hill in Klingenthal for the force-length curve at the last 14 m in the inrun (curve and takeoff) in 2012/13 and 2013/14. From all jumps per athlete (n=3- 6) the average force-length curve was determined for each. On the basis of take-off intensity (vertical take-off velocity), the maximum force (Fmax) and the force-length curve characteristic of all 21 Springer were analyzed. RESULTS AND DISCUSSION: The analysis of the force-length curve based on the location of the maximum force shows three different characteristics: A - an "explosivesloping" curve with Fmax at the beginning of the jump (n=6); B - a stable high level of force over the take-off (n=9); C - a rising trend with Fmax at the end of the jump (n=6). The vertical take-off velocity is almost equal in all three groups (A: 2.73 ± 0.06 m/s; B: 2.67 ± 0.10 m/s; C: 2.70 ± 0.15 m/s) and the average of the world's best (ranked 1-10) 2010-2014 (Müller et al., 2014). The differences in the force curve are due to the ability to produce from deep inrun-position quickly high forces with a large submission of the center of gravity. Due to its smaller vertical component of the force top athletes succeed to achieve high vertical take-off velocity. The athletes of groups A and B show better race results, even over the whole season and thus form the absolute world class. CONCLUSION: By using dynamometric measurement platforms in the curve and takeoff we can analyse the force development during take-off and diagnose the force-length curve characteristic type. In combination with cinematic analyses an overall assessment of the take-off executions is possible which allows to make recommendations on effective training. --- The hosting University of Jyväskylä is planning to publish conference proceedings "Science and Nordic Skiing III". In case you are interested in this publication please contact the editors (Anni Hakkarainen anni.s.j.hakkarainen@jyu.fi) to become registered for the book.
© Copyright 2015 3rd International Congress on Science and Nordic Skiing - ICSNS 2015. 5-8 June 2015, Vuokatti, Finland. Veröffentlicht von University of Jyväskylä; University of Salzburg. Alle Rechte vorbehalten.