柔道背负投技术转体动作运动学和力学分析

The Kinematics and Mechanics Analysis of Body Twist in Seoi-Nage

为了解柔道背负投动作中的力学规律,对背负投动作进行三维高速拍摄和视讯解析,对比A组(训练年限8年以上)和B组(训练年限5年以下)的数据,从时间分配、质心的垂直距离、重心的水平速度等方面分析背负投动作的力学特征,从躯干扭转角度、膝关节角度、踝关节轨迹方面分析转体动作的动量传递。得出结论:训练年限较短组转体和背摔所用时间较长,质心垂直高度下降幅度较大,而速度不及训练年限较长组;训练年限较长组在转体完成阶段,身体相对较正,与守方身体较为贴近,在上步、转体完成时段位移动幅度较大。

We use 3d high-speed camera and motion analysis to compare seoi-nage movement between group A and group B. considering time、vertical distance of COM、horizontal velocity of COM、3D trajectory of COM as mechanical characteristics of seoi-nage,trunk torsion angle、right knee joint angle、trajectory of ankle as the index of momentum transfer in body twist. Results: group B take longer time in body twist and the fall, vertical distance of COM decreased largely than group A, although it has lower horizontal velocity;group A’s body position is nearly 180 degree, and more closer with uke, the whole movement is larger than group B. rigid body turning fixing axes、particle system moment of are used to explain mechanical principle of seoi-nage.