不同蹬地角立定跳远的运动学和动力学对比研究

Comparison of Kinematics and Dynamics on the Standing Long-jump from Different Take-off Angles

通过录像和测力台同步的方法,对5名受试者进行不同蹬地角形式的立定跳远测试,运用录像解析系统和三维测力平台的软件(V5.2)获得运动学和动力学数据,并对所得数据进行灰理论分析。结果显示:(1)起跳时的水平速度和垂直速度随着蹬地角的增大而减小。(2)在LPA下,髋、膝、踝3关节的角度相比其他两种方式(PA、HPA)较小,使得人体蹬离地面向前摆动总体的转动惯量减小,从而增大了向前的转动角速度。(3)无论是蹬伸冲量还是踏跳冲量在立定跳远中都可以评价踏跳效果,由于LPA下蹬伸阶段的平均力值比较小,肌肉收缩速度比较快,机械效率比较高,再加上蹬伸冲量比较大,因此踏跳效果好。(4)影响立定跳远成绩的关联度为蹬伸阶段的平均力值>蹬伸时间>蹬地角>起跳垂直速度>蹬伸冲量>起跳水平速度。

Five PE students were tested of different take-off angle in the standing long-jump by video, Kistler platform and SEMG synchronization. The kinematic and dynamic data was obtained by Simi Motion and Kistler platform software 5.2. The obtaining data was analyzed with the grey theory. The resuits showed four respects. First, the horizontal speed and the vertical speed decreased by increasing take-off angle. Second, the angle of hip, knee and an- kle-bone in the LPA was smaller than in the PA and HPA. So the total angle speed increased by the increasing the moment of inertia. Third, both the driving impulse and the take-off impulse can be used to estimate the effect of take-off. The flight distance increased by decreasing the average force in the phase of driving with increasing muscle shrinking speed and the increasing mechanical efficiency, in addition to increasing the driving impulse. Fourth, the correlation of performance and effect factor was found in the order from highest to lowest as average force in the phase of driving, the time of driving, takeoff angle, vertical speed of take-off, vertical impulse in the phase of driving, and horizontal speed of take-off vertical speed.