Adapting locomotion to different surface compliances: Neuromuscular responses and changes in movement dynamics
Adapting locomotion to different surface compliances: Neuromuscular responses and changes in movement dynamics
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DOI：
10.1152/jn.00019.2005
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发表时间：
2005-09-01
影响因子：
2.5
通讯作者：
Patla, AE
中科院分区：
文献类型：
--
作者：
Marigold, DS;Patla, AE
了解神经系统如何处理具有不同物理特性的表面（例如运动过程中挑战平衡的顺应性）非常重要，因为我们每天都会不断面临这些情况。本研究的目的是检查质心 (COM) 和下肢动力学的控制以及在意外的顺应性表面上运动期间肌肉活动的恢复响应调制，特别是在不同顺应性水平上的缩放行为。八名年轻人沿着人行道行走，意外地踩到了行进路径中间的柔顺表面。存在三种不同水平的表面顺应性，参与者在每次试验期间体验到无顺应性表面或以块状或随机方式呈现的三个顺应性表面之一。收集全身运动学以及所选双侧下肢和躯干肌肉的表面肌电图（EMG）。第一次顺应性表面试验的恢复反应表明，肌肉起始潜伏期在 97 至 175 毫秒之间，并且在顺应性表面上时活动受到调节。与顺应表面接触后，垂直 COM 轨迹未保留：峰值垂直 COM，而在顺应表面上则低于在稳定地面上时的水平。脚趾离地后受干扰的肢体膝盖弯曲随着表面顺应性的增加而增加，这使得脚趾与地面的间隙与对照试验相似。结果表明，离开柔顺表面是由中枢神经系统主动调节的，旨在维持动态稳定性。
Knowledge of how the nervous system deals with surfaces with different physical properties such as compliance that challenge balance during locomotion is of importance as we are constantly faced with these situations every day. The purpose of this study was to examine the control of center of mass (COM) and lower limb dynamics and recovery response modulation of muscle activity during locomotion across an unexpected compliant surface and in particular, scaling behavior across different levels of compliance. Eight young adults walked along a walkway and stepped on an unexpected compliant surface in the middle of the travel path. There were three different levels of surface compliance, and participants experienced either no compliant surface or one of the three compliant surfaces during each trial that were presented in a blocked or random fashion. Whole body kinematics were collected along with surface electromyography (EMG) of selected bilateral lower limb and trunk muscles. The recovery response to the first compliant-surface trial demonstrated muscle onset latencies between 97 and 175 ms, and activity was modulated while on the compliant surface. Vertical COM trajectory was not preserved after contact with the compliant surface: peak vertical COM, while on the compliant surface was lower than when on stable ground. Perturbed-limb knee flexion after toe-off increased with increased surface compliance, which enabled toe clearance with the ground to be similar to control trials. The results suggest that stepping off of a compliant surface is actively modulated by the CNS and is geared toward maintaining dynamic stability.