跳远运动空中技术分析

Analysis of the In-the-Air Techniques in Long Jump

运用动态力学理论,建立单腿摆动力学模型和动力学方程,推导出人体在腾空阶段由于合理的肢体摆动使水平速度出现增量,从而证明人体重心在跳远腾空中的移动轨迹不是单质体空间运动轨迹,提出了由于肢体后直、前屈、速度快慢、力量大小的摆动而引起人体速度和位移变化的“动态抛物线”理论;并用加速度传感器测试系统测试运动的肢体摆动参数及身体在空中的速度变化,对“动态抛物线”理论进行了验证。这与传统的“起跳腾空后,身体重心运动轨迹在没有外力作用的情况下是不会改变的”理论迥然不同。利用这种理论,可以规范和完善跳远空中技术。

By using theory of dynamic mechanics,this study established a mechanics model and equation of one leg swing and got to a result that an increment in horizontal speed of the body appeared during the in-the -air stage due to a reasonable limbs swing, thus proved that the locus of the body's center of gravity was not a space movement of simple substance during the in - the - air stage. The theory of dynamic parabolas of body acceleration and change of displacement caused by the swing resulted in limbs straightening back,body bending forward,speed and strength was then put forward followed by a verification of the theory by testifying the swing of limbs and changes of body speed in the air using an accelerated sensor. This theory is completely different from the traditional theory which believes that' without an external force,the locus of the body's center of gravity will not change when in the air'.