【摘要】 目的考察不同拖拉阻力负荷下,短跑途中跑下肢髋膝踝三关节的动力学变化,探讨拖拉阻力训练对发展关节肌群力量的生物力学机制,从而为运动训练实践提供理论指导。方法采用高速摄像与测力台同步的方法,记录8名短跑运动员在0 N、50 N、80 N和110 N4种阻力条件下途中跑阶段的运动学与动力学数据。结果施加拖拉阻力与不施加拖拉阻力相比,支撑阶段人体重心最大水平速度、步长、着地躯干角、髋角与膝角均呈显著性下降,步频与着地踝角则不存在显著性差异;施加拖拉阻力后,下肢各关节力矩与功率指标峰值均表现为不同程度的下降趋势。结论拖拉阻力跑时,运动员途中跑阶段下肢各关节的力矩及功率输出明显降低,这与阻力条件下重心水平速度的下降有直接关系。更多还原

【Abstract】 Objective The purpose of this study is to investigate the changes of lower extremity kinetics during maximum velocity phase of sprint under four towing loads: 0 N,50 N,80 N and 110 N. Methods: Eight sprint athletes perform a 80m sprinting for each of four towing loads,kinematics and kinetics are recorded with high-speed camera( 200 Hz) and force plate( 1 000 Hz) simultaneously at 50m from start point. Results: Compared to un-resisted condition( 0 N),the maximum horizontal velocity during support phase,step length,trunk,hip and knee angles at contact were significantly decreased for all resisted conditions( 50 N,80 N and 110 N). The stride frequency and ankle angle at contact were no differences among conditions. The joint moments and powers for hip,knee and ankle were decreased with towing loads increased. Conclusions The decrease of the joint moments and powers attributes to the decrease of horizontal velocity in maximum velocity phase of sprint.更多还原