Jones C A, Yang J F
Department of Physical Therapy, University of Alberta, Edmonton, Canada.
Exp Neurol. 1994 Aug;128(2):239-48. doi: 10.1006/exnr.1994.1133.
Reflexes evoked by stimulation of the posterior tibial nerve at the ankle during walking were investigated in 10 subjects with incomplete injury of the spinal cord. Low-intensity stimuli (1.5 to 1.7 times the motor threshold) were delivered during treadmill walking. Reflexes were recorded by surface electromyography from the tibialis anterior (TA) and soleus (SOL) muscles. Responses were evoked at early, medium, and late latencies in all subjects. The reflex activity at a medium latency (50 to 80 ms) was cyclically modulated in all of the subjects during walking in both muscles, but the pattern of modulation was different from that seen in normal subjects (Yang and Stein, J. Neurophysiol., 63, 1109-1117). Most spinal-cord-injured subjects did not show inhibitory responses in the TA; excitatory responses were seen in the swing phase and occasionally in the stance phase. Inhibitory responses were typically evoked in the SOL muscle during the stance phase, but abnormal excitatory responses were also seen during the swing phase in the majority of subjects. Excitatory responses were seen in some subjects during the stance phase as well. Functional walking ability and clinical measures of muscle tone were not correlated with the degree of reflex modulation in walking. The lack of correlation between these measures could be related to many factors including the small number of subjects, the subjectivity of clinical measures, and the different movement conditions under which these measures were taken. The results demonstrated that most spinal-cord-injured subjects retained the ability to modulate this reflex during walking, but the pattern of modulation was abnormal. Moreover, excitatory responses were more frequently evoked than inhibitory responses.
对10名脊髓不完全损伤的受试者在行走过程中踝关节处胫后神经刺激所诱发的反射进行了研究。在跑步机行走过程中施加低强度刺激（运动阈值的1.5至1.7倍）。通过表面肌电图记录胫骨前肌（TA）和比目鱼肌（SOL）的反射。所有受试者在早期、中期和晚期潜伏期均诱发了反应。在所有受试者行走过程中，两块肌肉在中等潜伏期（50至80毫秒）的反射活动均呈周期性调制，但调制模式与正常受试者不同（Yang和Stein，《神经生理学杂志》，63卷，1109 - 1117页）。大多数脊髓损伤受试者的TA未表现出抑制反应；在摆动期可见兴奋反应，偶尔在站立期也可见。站立期比目鱼肌通常诱发抑制反应，但大多数受试者在摆动期也可见异常兴奋反应。部分受试者在站立期也可见兴奋反应。功能性行走能力和肌张力的临床测量与行走时反射调制程度无关。这些测量之间缺乏相关性可能与多种因素有关，包括受试者数量少、临床测量的主观性以及进行这些测量时的不同运动条件。结果表明，大多数脊髓损伤受试者在行走过程中保留了调制这种反射的能力，但调制模式异常。此外，兴奋反应比抑制反应更频繁地被诱发。
