Ankle Load Modulates Hip Kinetics and EMG During Human Locomotion
Ankle Load Modulates Hip Kinetics and EMG During Human Locomotion
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DOI：
10.1152/jn.90949.2008
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发表时间：
2009-04-01
影响因子：
2.5
通讯作者：
Schmit, Brian D.
中科院分区：
文献类型：
--
作者：
Gordon, Keith E.;Wu, Ming;Schmit, Brian D.
戈登 K、吴 M、卡恩 JH、达赫 YY、施密特 BD。踝关节负荷在人体运动过程中调节髋部动力学和肌电图。 J Neurophysiol 101: 2062-2076, 2009。首次发表于 2009 年 2 月 4 日； doi：10.1152/jn.90949.2008。本研究的目的是探讨孤立踝足负荷在调节有或没有脊髓损伤 (SCI) 的人类运动模式中的作用。我们使用动力踝足矫形器在机器人辅助空步过程中单侧加载踝关节和足部。负载扰动包括施加的背屈扭矩，旨在刺激源自踝关节跖屈肌和脚底压力感受器的生理负载传感器。我们假设：1）对负载的响应将是阶段特异性的，当在行走的站立阶段提供单侧踝足负载时，同侧伸肌活动和关节扭矩会增强；2）受试者产生的髋力矩的相位将通过改变步态周期内施加的踝足负载的时间来调节。正如预期的那样，与没有踝足负荷相比，在站立阶段给予踝足负荷时，SCI 和非残疾受试者的峰值髋部伸展力矩显着增加 (P < 0.05)（分别增加 142% 和 43%）。在 SCI 受试者中，这种增强的髋部伸展反应伴随着站立期臀大肌活动的显着增加 (P < 0.05)（增加 27%）。此外，当在步态周期内提前或晚 200 毫秒施加踝足负荷时，SCI 受试者的髋部力矩曲线表现出显着的相移（类似于 100 毫秒）（P < 0.05；即，较早施加踝足负荷时，髋部伸展力矩的出现会更早）。这项研究为脊髓损伤患者如何利用踝足负荷传入的感觉反馈来调节步态过程中的髋关节力矩和肌肉活动提供了新的见解。
Gordon K, Wu M, Kahn JH, Dhaher YY, Schmit BD. Ankle load modulates hip kinetics and EMG during human locomotion. J Neurophysiol 101: 2062-2076, 2009. First published February 4, 2009; doi:10.1152/jn.90949.2008. The purpose of this research was to examine the role of isolated ankle-foot load in regulating locomotor patterns in humans with and without spinal cord injury (SCI). We used a powered ankle-foot orthosis to unilaterally load the ankle and foot during robotically assisted airstepping. The load perturbation consisted of an applied dorsiflexion torque designed to stimulate physiological load sensors originating from the ankle plantar flexor muscles and pressure receptors on the sole of the foot. We hypothesized that 1) the response to load would be phase specific with enhanced ipsilateral extensor muscle activity and joint torque occurring when unilateral ankle-foot load was provided during the stance phase of walking and 2) that the phasing of subject produced hip moments would be modulated by varying the timing of the applied ankle-foot load within the gait cycle. As expected, both SCI and nondisabled subjects demonstrated a significant increase (P < 0.05) in peak hip extension moments (142 and 43% increase, respectively) when given ankle-foot load during the stance phase compared with no ankle-foot load. In SCI subjects, this enhanced hip extension response was accompanied by significant increases (P < 0.05) in stance phase gluteus maximus activity (27% increase). In addition, when ankle-foot load was applied either 200 ms earlier or later within the gait cycle, SCI subjects demonstrated significant phase shifts (similar to 100 ms) in hip moment profile (P < 0.05; i.e., the onset of hip extension moments occurred earlier when ankle-foot load was applied earlier). This study provides new insights into how individuals with spinal cord injury use sensory feedback from ankle-foot load afferents to regulate hip joint moments and muscle activity during gait.