模拟跳伞着陆冲击力与冲击时间的关系

在实验室模拟条件下,研究着陆冲击力与着陆冲击时间的关系。被试者为3名年轻健康的男伞兵。当其负荷26.5k或无负荷,分别从1.0,1.5和2.0m的平台上跳下时,用高速摄影法记录他们身上的标记。计算结果表明:(1)作用在各活动节段上的着陆冲击力,随着陆冲击时间的延长而减少,作用在足部的着陆冲击力峰值与着陆冲击时间亦有相同的关系;(2)着陆冲击时间为0.08～O.26s时,上述诸力与其在0.08s时的值相比,减少40.6～64.1％;(3)作用在足部的着陆冲击力峰值与着陆冲击时间的关系曲线,与其回归方程的曲线相比,非常接近。

Relationship between landing Impact Force and Landing Impact Time in Simulated Parachuting

Under simulated condition in laboratory the relationship between landing impact force and landing impact time was studied. The subjects were three male parachu-ters who were young and healthy. While jumping down from a 1,0, 1.5 and 2.0 metre platform with a load of 26.5 kg or unloaded respectively, they were being photographed by high-speed photogjaphy to record the marks on their body. After calculating the landing impact force acting on the various body segments and the peak of landing impact force acting to the feet, we found the relationships Between the landing impact time and above-mentioned froces. The results show:(1) teh landing impact force sustained in the various body segments and the peak of landing impact force in the feet were reduced with the landing impact time increasing; (2) when the langing impact time was from 0.08 to 0.26 s, the above-mentioned forces were reduced from. 40.6% to 60.1 %, as compared to their values at 0.08 s; (3) the relationship curve between the peak of landing impact forces acting to the feet and the landing impact time was very close as compared with that from ifself regression equation.