KINETICS OF THE LOWER-EXTREMITIES DURING DROP LANDINGS FROM 3 HEIGHTS
KINETICS OF THE LOWER-EXTREMITIES DURING DROP LANDINGS FROM 3 HEIGHTS
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DOI：
10.1016/s0021-9290(05)80003-x
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发表时间：
1993-09-01
影响因子：
2.4
通讯作者：
MCNITTGRAY, JL
中科院分区：
文献类型：
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作者：
MCNITTGRAY, JL
在这项研究中，体操运动员（n = 6）和休闲运动员（n = 6）的着陆偏好，通过比较的下肢动力学的变化，从三个高度（0.32-1.28米）进行下降着陆。选择踝、膝和髋伸肌的净关节力矩和做功作为变量，代表对负责控制屈曲和消散负荷的肌肉的需求。使用高速胶片（202.4 fps）和测力板（1000 Hz）同时采集运动学和动力学二维数据。使用反作用力和下肢关节运动来计算净关节力、净关节力矩、净关节力矩功率以及踝、膝和髋伸肌所做的功。结果表明，伸肌关节力矩往往达到峰值后，接触速度的增加，但独立的速度或组的时间序列的事件。随着冲击速度的增加，伸肌净峰值力矩和伸肌所做的功显著增加。与休闲运动员相比，体操运动员的踝关节和髋关节峰值伸肌力矩明显更大。两组之间在伸肌上所做的工作没有显著差异。显著的相互作用效应表明，体操运动员选择通过在比休闲运动员更高的冲击速度下使用更大的踝关节和髋关节伸肌力矩来消散接触时的载荷，而休闲运动员选择通过使用更大程度的髋关节屈曲来调整他们的策略（McNitt-Gray，Int. J. Sport Biomech. 7，201-204，1991）和比体操运动员更长的着陆阶段持续时间。体操运动员比业余运动员对踝关节和髋关节伸肌的要求更高，这可能是因为在竞技体操落地时需要保持平衡，或者可能是因为业余运动员在从高处落地时无法在踝关节或髋关节产生更大的伸肌力矩。
In this study, the landing preferences of gymnasts (n = 6) and recreational athletes (n = 6) were determined by comparing the changes in lower extremity kinetics of drop landings performed from three heights (0.32-1.28 m). Net joint moments and work done on the extensor muscles of the ankle, knee, and hip were selected as variables representative of the demand placed on the muscles responsible for controlling flexion and dissipating the load. Kinematic and kinetic two-dimensional data were acquired simultaneously using high-speed film (202.4 fps) and a force plate (1000 Hz). Reaction forces and lower extremity joint motions were used to calculate net joint forces, net joint moments, net joint moment powers, and work done on the extensor muscles of the ankle, knee, and hip. Results indicated that the extensor joint moments tended to peak earlier after contact with increases in velocity, but the temporal sequence of events was maintained independently of velocity or group. As impact velocity increased, net peak extensor moments and work done on the extensor muscles significantly increased. Significantly larger ankle and hip peak extensor moments were observed for the gymnasts across velocities as compared to the recreational athletes. No significant differences in work done on the extensor muscles were noted between groups. Significant interaction effects indicate that gymnasts chose to dissipate the loads at contact by using larger ankle and hip extensor moments at higher impact velocities than the recreational athletes, whereas recreational athletes chose to adjust their strategy by using greater degrees of hip flexion (McNitt-Gray, Int. J. Sport Biomech. 7, 201-204, 1991) and longer landing phase durations than the gymnasts. The greater demands placed on the ankle and hip extensors by the gymnasts, as compared to the recreational athletes, may be explained by the need to maintain balance during competitive gymnastics landings or, perhaps, by the inability of recreational athletes to produce larger extensor moments at the ankle or hip during landings from great heights.