【摘要】 研究运用三维运动学方法,获取评价抓举技术动作稳定性的量化指标,并对廖辉、石智勇等5名运动员8次成功试举与7次失败试举中每个特征时刻该指标进行对比分析,旨在从动作稳定性的角度分析抓举失败的原因。研究认为人/杠合重心与人体支撑面中心在前后方向的距离(两心差)是评价运动员抓举技术动作各阶段稳定性的重要指标,两心差越小,技术动作稳定性越强。抓举过程中运动员的两心差数值曲线呈现出双波峰双波谷的特点,较为合理的两心差变化趋势应该是:两心差于发力阶段初达到第一个波谷,惯性上升阶段初达到第一个波峰,于下蹲支撑初达到第二个波谷,杠铃速度最大时刻达到第二个波峰。大多数抓举试举失败都出现在接铃完成阶段,而下蹲支撑阶段两心差过大是导致运动员在接铃完成阶段无法对杠铃形成有效制动的重要原因。研究中成功试举在接铃完成阶段末两心差几乎为零;接铃完成末两心差过大,将导致运动员在上举时失去平衡。更多还原

【Abstract】 Applying the method of three-dimensional kinematics,this thesis obtains the quantitative indexes for evaluating the stability of snatch technique,and conducts a comparative analysis on the index from each characteristic moment of eight successful trial snatches as well as seven failed trial snatches from 5 athletes(Liao Hui,Shi Zhi-yong,etc.),with the aim to analyze causes of the snatch failure from the perspective of the movement stability.This thesis holds that the distance between the body-barbell resultant gravity center and bearing surface center(two-center distance)is an important index to evaluate the stability at every stage of the athlete’s snatching technique.The smaller the distance between the two centers is,the stronger the stability of the technical movement is.During the snatch process,the numerical curve of the athlete’s two-center distance presents the characteristics of double wave crests and double wave troughs.The reasonable trend of the two-center distance should be as follows:at the beginning of the strength-sending stage,the two-center distance reaches to the first wave trough;at the inertial ascending stage,it reaches to the first wave crest;at the beginning of squat support,it reaches to the second wave trough;at the time of maximum barbell velocity,it reaches to the second wave crest.Most of failures in snatches and trial snatches occur in catch 2,and the excessive two-center distance in catch 1 is the important reason why the athletes cannot form effective brake on barbell in catch 2.In this research,it is found that the two-center distance in the successful trial snatch is almost zero at the end of catch 2;it will cause the athletes to lose their balances when the twocenter distance is too long at the end of catch 2.更多还原