Maegele M, Müller S, Wernig A, Edgerton V R, Harkema S J
Department of Physiology, University of Bonn, Germany.
J Neurotrauma. 2002 Oct;19(10):1217-29. doi: 10.1089/08977150260338010.
We investigated the activation of lower limb motor pools by supraspinal and spinal networks after human spinal cord injury (SCI). We compared electromyographic (EMG) activity from six muscles during voluntarily attempted non-weight-bearing single-joint movements, multijoint movements approximating stepping in a supine position, and weight-bearing stepping on a treadmill with body weight support (BWST) in seven clinically incomplete and three clinically complete SCI subjects. Seven SCI subjects had previously completed Laufband therapy (a specific step training using variable levels of body weight support and manual assistance). Significant coactivation of agonists and antagonists and multijoint flexion or extension movements of the entire limb occurred during attempts at isolated knee or ankle single-joint movements in clinically incomplete SCI subjects. Further, some muscles that were not recruited during voluntary attempts at single-joint movements were activated during voluntary step-like multijoint movements (5/16 comparisons). This suggests that the residual voluntary motor control in incomplete SCI subjects evokes more generalized motor patterns (limb flexion or extension) rather than selective activation of individual muscles. Clinically incomplete and clinically complete SCI subjects could achieve greater activation of motor pools and more reciprocal patterns of activity between agonists and antagonists during weight bearing stepping than during non-weight-bearing voluntary movements. The EMG mean amplitudes were higher during stepping than during voluntary movements in 50/60 muscles studied (p < 0.05). These results suggest that stepping with knee and hip extension and flexion and alternating lower limb loading and unloading provides proprioceptive inputs to the spinal cord that increases motor recruitment and improves reciprocity between agonists and antagonists compared to voluntary efforts.
我们研究了人类脊髓损伤（SCI）后脊髓上和脊髓网络对下肢运动神经元池的激活情况。我们比较了7名临床不完全性脊髓损伤和3名临床完全性脊髓损伤受试者在自愿尝试非负重单关节运动、仰卧位近似踏步的多关节运动以及在带有体重支持（BWST）的跑步机上负重踏步时，六块肌肉的肌电图（EMG）活动。7名脊髓损伤受试者之前完成了Laufband治疗（一种使用不同程度体重支持和手动辅助的特定步态训练）。在临床不完全性脊髓损伤受试者尝试孤立的膝关节或踝关节单关节运动时，出现了显著的主动肌和拮抗肌共同激活以及整个肢体的多关节屈伸运动。此外，在单关节运动的自愿尝试中未被募集的一些肌肉，在类似踏步的多关节运动中被激活（5/16的比较）。这表明不完全性脊髓损伤受试者残余的自主运动控制引发了更广泛的运动模式（肢体屈伸），而不是单个肌肉的选择性激活。与非负重自主运动相比，临床不完全性和临床完全性脊髓损伤受试者在负重踏步时能够实现运动神经元池的更大激活以及主动肌和拮抗肌之间更具交互性的活动模式。在所研究的60块肌肉中，有50块肌肉在踏步时的肌电图平均振幅高于自主运动时（p < 0.05）。这些结果表明，与自主努力相比，膝关节和髋关节屈伸以及下肢交替加载和卸载的踏步为脊髓提供了本体感觉输入，增加了运动募集并改善了主动肌和拮抗肌之间的交互性。
