不同重力环境下足底受力的步态差异分析

Difference of plantar force parameters in gait analysis between simulated zero-gravity and normal gravity locomotions

目的:明确模拟零重力环境下人体行走和跑步时的足底受力特征。方法:8名健康成年受试者分别在零重力跑台和正常重力跑台上进行3km/h、7km/h和10km/h的行走和跑步活动。利用鞋垫式足底压力测量系统对运动过程中的足底受力情况进行采集分析。结果:模拟零重力环境下步行的步态周期时间与正常重力环境并无显著差别。随着速度的增加,步态周期时间有明显的下降,不同速度之间差异明显(P<0.05)。但与地面正常重力环境比较,模拟零重力环境下的支撑相明显缩短(P<0.01)。足底压力结果显示,随着速度的增加,足底最大受力和垂直冲量均有显著的升高,不同速度之间相差明显(P<0.01),模拟零重力环境下明显小于正常重力环境(P<0.05)。时相对称性和垂直冲量比等平衡性指标显示模拟失重环境下人体的运动平衡功能明显低于正常重力环境(P<0.05),但不同速度之间差异不显著。结论:模拟零重力环境足底生物力学特征发生改变,可能是太空失重环境下体育训练后骨丢失和肌萎缩的原因之一。

Objective： To study the differences in plantar force characteristics on walking and running between simulated zero gravity and normal gravity environments.Method： Eight healthy male volunteers took part in this test. They walked and ran on a horizontal suspension treadmill （simulated weightlessness, SW） and a traditional treadmill （normal gravity, NG） with three different veloci-ties （3, 7 and 10 km/h）. During these exercises, the insole measurement system was used to explore the plantar force distribution.Result： There was no difference of stride time between SW and NG. The stride time became shorter with increase of speed. There were significant differences among three velocities respectively （P 〈0.01）. The results ofpeak force and vertical impact showed that data in SW were much less than that in NG （P 〈 0.05）. While the speed increased, the force and impact became higher. The phase symmetry index and the ratio of vertical impactresults also indicated that the body control became more instable in SW than that in NG. Conclusion：The simulated zero gravity could induce the changes of plantar force characters during exercises,which might be one reason for exercise can＇t completely prevent bone loss and muscle atrophy caused by weightlessness.Author＇s address School of Mechanical and Vehicular Engineering, Beijing Institute of Technology, Beijing