踺子转体180°前手翻接直体前空翻转体类跳马动作的运动学分析

目的:研究踺子转体180°前手翻接直体前空翻类跳马动作,揭示这类跳马的运动学规律和技术特点.方法:对程菲和洪淑贞完成的"踺子转体180°前手翻接直体前空翻转体180"(简称"R180"),以及程菲完成的"踺子转体180°前手翻接直体前空翻转体540°"("程菲跳")进行三维运动学分析,对三组跳马动作身体重心的水平速度和垂直速度、主要关节的位移、关节角度、身体翻转角速度等运动学参数进行对比分析.结果:三组动作踏板时重心水平速度基本相同,踏板及推手阶段关键位置的关节角度相近,但"程菲跳"推离马重心垂直速度和第二腾空时间明显高于"R180",第二腾空转体角速度略大于"R180"的3倍,而翻腾角速度略小.结论:踺子转体180°前手翻接直体前空翻类跳马动作触马前的技术动作基本相同,难度较高的技术动作需要更高的推离马垂直速度和更快的第二腾空转体角速度.

Kinematical Analysis on Category of Movement-round-off with 1/2 Twist and Forward Handspring and Salto Stretched with a Twist

Objective: The purpose of this study was to analyze the characteristics of kinematics and technique of this kind of vault, the Movement-round-off with 1/2 Twist and Forward Handspring and Salto Stretched with a Twist. Method:Using 3D motion analysis, kinematics of "Movement-round-off with 1/2 Twist and Forward Handspring and Salto Stretched with 1/2 turn" (R180) performed by CHENG Fei and HONG Shujong, and "Movement-round-off with 1/2 Twist and Forward Handspring and Salto Stretched with 3/2 turn" (CHENG Fei vaulting) performed by CHENG Fei, was investigated. The corresponding horizontal velocities and vertical velocities of the center of gravity's body, main joint displacements, joint angles, angular velocities of body turning et al, of the three vaults, was compared. Results:The hori-zontal velocities of the three vaults were close at the moment of feet touching board, and joint angles were similar at feet touching board and hands pushing off. However, the vertical velocity and second flight duration of "CHENG Fei vaulting" were greater than those of "R180", the twist angular velocity during the second flight were more than 3 times of "R180",while som-ersault angular velocity was less a bit than "R180". Conclusion: The study suggests that the techniques of the category of Movement-round-off with 1/2 Twist and Forward Handspring and Salto Stretched with a Twist are basically the same before hands touching the horse. It also suggests that the more difficult the vault is the faster vertical velocity at the moment of hands pushing and twist angular velocity of the second flight are.