沙滩排球上步扣球踏跳阶段的时相特征

Characteristics of Phase in Spike Jumping in Beach volleyball

时相特征是影响沙滩排球扣球起跳质量的重要因素,运用运动生物力学手段对其进行比较研究发现:沙滩排球上步扣球踏跳阶段依据人体下肢肌肉工作形式以及重心速度随时间的变化可划分为5个部分,即加速缓冲、减速缓冲、等长制动、加速蹬伸和减速蹬伸。其中沙滩排球加速缓冲与减速缓冲时间均过长,不利于缩短起跳时间,影响沙滩排球扣球的起跳效果。另外,沙滩排球扣球起跳的加速蹬伸时间占起跳时间的比重太小是影响在沙滩上起跳时间结构的关键因素。

Phase characteristics are important to the jumping quality of spike in beach volleyball, and we study it with the means of sports biomechanics. On the basis of the working form of muscle of lower limb and velocity variety with time of gravity center of the human body, the jumping phase is divided into 5 parts, i.e. accelerating cushion, deceleration cushion, balance brake, accelerating thrust and decelerating thrust. The duration of both accelerating cushion and deceleration cushion are so short that they spoil the effect of jumping for prolonging the duration of jumping. In addition, the proportion of the duration of accelerating thrust to jumping time is smaller so as to ruin the structure of jumping time of spike in beach volleyball.