背越式弧线助跑起跳腾空产生旋转角动量的力学分析

THE MECCHANICaL ANALYSIS OF ROTARY ANGULAR MOMENTUM PRODUCED BY THE CURVE RUN - UP AFTER TAKE - OFF IN FOSBURY - FLOP

背越式跳高至起跳开始，身体重心沿着起跳角形成的固定抛物轨迹运行，身体围绕自身的轨迹旋转达到尽可能的高度在旋转过程中，经纵轴的背对横杆和水平轴的面部朝上，身体绕两个轴线动作的扭转过杆，结合助跑的水平速度与两个轴线的身体动作，在某种程度上我们要应有个清楚的概念，身体扭旋过杆是由角动量产生的和角动量的形成又如何影响着身体的扭旋．

After trake - off, the center gravity of Fosbury - flop follows a fixed path - As the c. g travels along the parabola , the body should rotate around the c g. in a way that will allow the clearance of a bar set as high as possible. The rotation consists of a 'twist'(longitudinal axis of the body)which turns the back of the jumper toward the bar, and a 'somersault' (transverse axis) which leads to a face - up layout position at the peak of the jump. To a great extent ,the combination of these two motions of the body that makes us have a clear concept of the angular momentum and how it affects the rotation produced by the angular momentum.