竞技武术套路自选项目C级跳跃难度起跳阶段人体重心运动学特征的生物力学对比研究——以自选长拳高难度323C动作为例

A Comparative Biomechanical Analysis on Kinematic Characteristics of Human Body Gravity Center in Take-off Phase of Selective Program C in Competitive Wushu Routine——Taking high-difficulty 323C in Selective Long Boxing as an Example

高难度323C起跳技术是影响该难度动作高质量完成的关键环节,其动作人体重心的运动学基本特征与要素是重要的评价依据之一。运用运动生物力手段对起跳阶段人体重心的运动学特征进行比较研究发现:助跑结束时获得的水平速度并不是越大越好,而缓冲时段水平速度的损失也不是越小越好。一级运动员右腿摆动慢,上步不积极,左腿蹬摆不充分,左臂摆幅小是导致左脚离地时刻水平速度增长小的关键所在。右脚离地时刻水平速度的损失率与垂直速度呈显著正相关,武英级起跳时左腿加速摆动与右腿快速蹬伸的协调配合是起跳离地时获得较大垂直速度的最重要原因。蹬伸时段重心水平位移与左脚离地时刻水平速度和垂直速度之间呈显著性相关;缓冲时段一级运动员没有武英级身体重心下降低,但用时还长,然而蹬伸时间没有显著差异,这是一级运动员没有武英级完成动作好的最根本所在。

Take-off technique in high-difficulty 323C is the key to high-quality completion of this movement; the kinematical basic feature of body gravity center is important to evaluation. This paper does a comparative analysis the biomechanical features of human body＇s gravity center. It discovers that when the run-up is finished, the horizontal speed that is got is not the higher the better; while the reduced horizontal speed in buffering phase is not the less the better. The fact that Band- 1 athlete swings fight leg slowly and does not step forward actively, his left leg does not stretch adequately, the swing range of left ann is small, which is the key to the small increased horizontal speed for the left foot in the phase of leaving ground. And when the right leg is taking off the ground, the loss of horizontal velocity is positively correlated with the vertical velocity. In the process of take-off, the proper negotiation of left leg＇ s swing at the increased speed and right leg＇ s quick stretch is essential to that the elite athlete receives more vertical speed in the process of take-off and leaving ground. There is sig- nificant correlation between horizontal displacement of gravity center in the stage of stretch, and horizontal velocity of gravity center and vertical velocity of gravity center in the left leg when taking off the ground. The height of gravity center of body of Band-1 athlete is higher than that of clite athlete, and Band-1 athlete is longer than elite athlete in the buffering stage of jtmping, but there is no significant difference at the time of stretch.