Dominant role of interface over knee angle for cushioning impact loading and regulating initial leg stiffness
Dominant role of interface over knee angle for cushioning impact loading and regulating initial leg stiffness
复制标题
DOI：
10.1016/s0021-9290(96)80003-0
复制
发表时间：
1996-12-01
影响因子：
2.4
通讯作者：
Lake, MJ
中科院分区：
文献类型：
--
作者：
Lafortune, MA;Hennig, EM;Lake, MJ
对于在受控初始条件下施加的体内冲击载荷，假设较大的初始膝关节角度（IKA）和较软的冲击界面将降低冲击载荷和初始腿部刚度。一个人的钟摆被用来提供控制的影响，21名受试者的右脚三IKA（0，20和40度）和三个接口（赤脚，软，硬伊娃泡沫）。分别用壁装式测力平台和皮肤安装式加速度计同时测量受试者小腿所经受的外部冲击力和冲击。腿的刚度来自使用冲击速度和墙壁反作用力数据。研究结果反驳了膝关节在调节初始腿部刚度中的作用，并且仅为假设的改进的缓冲提供了部分支持。接触时较大的膝关节屈曲减少了冲击力，但增加了通过小腿的冲击。相反，较软的接口产生了相当大的减少，在两个初始的腿刚度和严重程度的影响所经历的下肢。发现加载的力率与由脚跟脂肪垫和界面变形定义的肢体刚度高度相关（r = 0.95）。这些结果表明，界面干预更有可能保护运动系统免受冲击负荷比膝关节角度的策略。版权所有（C）1996 Elsevier Science Ltd.
For in vivo impact loadings administered under controlled initial conditions, it was hypothesized that larger initial knee angles (IKA) and softer impacting interfaces would reduce impact loading and initial leg stiffness. A human pendulum was used to deliver controlled impacts to the right foot of 21 subjects for three IKA (0, 20 and 40 degrees) and three interfaces (barefoot, soft and hard EVA foams). The external impact force and the shock experienced by the subjects' shank were measured simultaneously with a wall mounted force platform and a skin mounted accelerometer, respectively. Stiffness of the leg was derived using impact velocity and wall reaction force data. The results disproved the role of the knee joint in regulating initial leg stiffness and provided only partial support for the hypothesized improved cushioning. Larger knee flexion at contact reduced impact force but increased the shock travelling throughout the shank. Conversely, softer interfaces produced sizable reductions in both initial leg stiffness and severity of the impact experienced by the lower limb. Force rate of loading was found to be highly correlated (r = 0.95) to limb stiffness that was defined by the heel fat pad and interface deformations. These results would suggest that interface interventions are more likely to protect the locomotor system against impact loading than knee angle strategies. Copyright (C) 1996 Elsevier Science Ltd.