石智勇超挺举世界纪录关键技术的运动学参数分析

Kinematic Parameter Analysis of SHI Zhiyong’s Surpassing the World Record in the Clean and Jerk

针对石智勇2次超挺举世界纪录的关键技术进行运动学分析及诊断,为其备战东京奥运会提供科技助力。在比赛现场采用高速摄像机进行定点定焦拍摄,通过SIMI°Motion7.50对视频进行三维运动学解析。结果显示:(1)在提铃至胸阶段,石智勇挺举199 kg时引膝幅度更大,伸髋伸膝角速度峰值更快,均有利于提升发力效果,但过快的杠铃回落速度可能对接铃的稳定性构成隐患。(2)在预蹲上挺阶段,石智勇挺举199 kg时伸髋伸膝角速度峰值进一步提高,上挺发力效果更好。此外,由石智勇上挺杠铃高度峰值预测其成绩存在进一步提高的可能性。(3)在稳定性参数中,石智勇2次试举时杠铃重心Y轴偏移均控制理想,但2次试举发力时段末的"两心"距离均偏大,可能与甩臂提肘技术有关。因此,下肢伸髋伸膝肌群爆发力和协调性的提升可能是石智勇再超挺举世界纪录的关键。

The key techniques of SHI Zhiyong’s 2-time surpassing world records of the clean and jerk were analyzed to provide scientific and technological support for the preparation of Tokyo Olympic Games.Two highspeed cameras were used in the competition scene to shoot the fixed-focus of the competitions.A SIMI°Motion7.50 three-dimensional motion analysis system was used to analyze SHI Zhiyong’s clean and jerk movements video.In the clean stage,the knee flexion amplitude was larger,and the peak angular velocity of hip and knee extension was faster when SHI ZhiyongY lifted 199 kg.These may be beneficial for promoting the power effect of the second pulling.However,the maximum falling velocity of the barbell may be a potential problem of the catch stability.In the jerk stage,the peak angular velocity of hip and knee extension was further improved,and the peak velocity of barbell increased when SHI Zhiyong lifted 199 kg.In addition,a possibility of further performance improvement may be predicted by the peak height of the barbell.As for the stability parameters,the Y-axis offset of barbell center of gravity was controlled perfectly in the two lifts.However,the distance between the barbell center of gravity and the body center of gravity was too large at the end of the two pulling periods,which may be related to the technique of lifting elbow and turning wrist.Enhancement of the explosive power and coordination of the hip and knee extensor muscles could be a key technique assisting SHI Zhiyong to surpass the world record again.