跳遠踏板起跳階段運動生物力學分析

Abstract

跳遠依運動技術分析可分為助跑、起跳、空中動作、落地四個階段結合成跳遠的過程。其中以助跑與起跳階段對跳遠的過程最為關鍵，利用助跑速度，起跳腳以全腳掌踏板時，做出快而有力爆發性地完成起跳，創造較大的起跳瞬間重心速度及起跳角度。優秀跳遠選手常常也是好的短跑選手，但優秀的短跑選手不一定是好的跳遠選手，原因何在? 研究目的：在探討優秀跳遠選手與短跑選手（非跳遠專長）踏板起跳時，在執行跳遠之運動及內、外力特徵。研究方法：一台Redlake高速攝影機(125Hz)拍攝踏板起跳動作與一塊Kistler測力板(1250Hz) 同步、另一台SONY數位攝影機(60Hz) )拍攝助跑最後兩步動作，以Kwon3D 影像分析軟體處理並以Butterworth 4th-order Zero Lag Digital程式（cutoff frequency：6Hz）進行修勻。結果：優秀跳遠選手在跳遠成績、起跳瞬間重心垂直速度、起跳角度、踏板起跳階段重心垂直速度變化量、踏板瞬間髖關節淨力矩、髖關節功率、支撐瞬間踝關節功率顯著大於短跑選手。在相關统計方面，最後第二步最大水平重心速度、踏板瞬間重心水平速度、起跳瞬間重心垂直速度、重心合速度、起跳角度、踏板起跳階段重心垂直速度變化量、水平總衝量、制動衝量、推蹬衝量、垂直總衝量、踏板瞬間踝關節淨力、髖關節淨力矩、髖關節之功率、支撐瞬間踝關節功率與跳遠成績呈顯著正相關。踏板起跳階段重心水平速度變化量、支撐時間、最大垂直力量值所產生時間、推蹬時間、支持瞬間髖關節淨力、踏板瞬間膝關節淨力矩與跳遠成績呈顯著負相關。結論：在相同助跑速度之下，跳遠選手在跳遠成績優於短跑選手，在於跳遠選手有較佳的起跳瞬間重心垂直速度、起跳角度、踏板起跳階段重心垂直速度變化量、較短支撐時間和推蹬時間、有較佳的踏板瞬間髖關節淨力矩、髖關節功率、支撐瞬間踝關節功率及有較小的踏板瞬間膝關節淨力矩。Purpose: To investigate the biomechanical characteristics of long jump takeoff between elite long jumpers and sprinters. Method : A Redlake high-speed camera(125Hz) was synchronized with a Kistler force platform (1250Hz) to collect the long jump takeoff data. Another Sony digital camera (60Hz) was used to collect approach speed data. The kinematics data were analyzed by using Kwon3D software and the raw data were smoothing by a Butterworth 4th-order Zero Lag Digital formula (cutoff frequency：6Hz).Result: The elite long jumpers have greater values than the sprinters on jumping distance, vertical velocity of body center of gravity (CG)at take off ,takeoff angle, change of vertical velocity of body CG at takeoff ,net hip moment and power at touch down, ankle power at support phase. In addition, the peak horizontal velocity of CG at last second step, body CG horizontal and vertical velocity at takeoff, takeoff angle, change of body CG vertical velocity at takeoff, horizontal braking, propelling, total and vertical impulse, net ankle force and net hip moment at takeoff, hip power at touch down and ankle power at support phase have the positive relationship with jumping distance. However, the body CG change of vertical velocity at takeoff, the support time, time to the peak vertical force, propelling time, net hip force at support phase, and net knee moment at touch down have negative relationship with jumping distance. Conclusion: Under the similar approach run speed, the elite long jumpers have greater jumping distance, vertical velocity of CG at takeoff, takeoff angle, change of vertical velocity of CG at takeoff, net hip moment and power at touch down, ankle power at support phase than the sprinters. The elite long jumpers also have shorter support time and propelling time and smaller net knee moment at touch down than the sprinters.