短跑支撑阶段运动生物力学分析

Sport Biomechanical Analysis of Dash Supporting Phase

采用测力、高速录像及特殊的数据平滑处理方法研究短跑运动员途中跑技术的运动学和动力学特征,进行田径技术原理的探索。结果表明,支撑时期可以分为着地阶段和蹬伸阶段,蹬伸阶段可分前蹬,后蹬前段,后蹬后段。途中跑前蹬段是人体重心垂直方向向上加速的重要时刻,前蹬时下肢一定程度的垂直加速用力虽影响水平速度,但对提高垂直速度有积极意义,前蹬和后蹬前段是身体重心垂直向上加速运动的阶段。着地缓冲后的前蹬用力也是实现良好成绩的技术之一。途中跑着地和前蹬阶段失去的水平速度损失完全可以从后蹬中得到补充。着地点过近对前支撑阶段获得重要的垂直速度不利,支撑阶段离地前的20ms身体重心速度已经开始下降。

The ways of force measurement,hi-speed video record and special data processing were adopted to study kinematic and kinetic characteristics of dash man＇s running technique.The result shows that the supporting phase can be divided into landing phase and extending phase.The extending phase includes front support phase,the first half of the push phase and the latter half of the push phase.The front support phase is an important moment for vertical acceleration.Though the vertical acceleration of the lower extremities decreases the horizontal speed,it plays a positive role in promoting vertical velocity,which is acquired in front support phase and the first half of the push phase.Powerful pushing after landing support is important in achieving good results.The horizontal velocity loss in landing and front support phase can be compensated in the latter half of the push phase.It is unfavorable for obtaining vertical velocity if the landing position is near the center of gravity.Vertical velocity decreases at the moment of 20ms before the foot leaves the ground.