Human lumbosacral spinal cord interprets loading during stepping
Human lumbosacral spinal cord interprets loading during stepping
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DOI：
10.1152/jn.1997.77.2.797
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发表时间：
1997-02-01
影响因子：
2.5
通讯作者：
Edgerton, VR
中科院分区：
文献类型：
--
作者：
Harkema, SJ;Hurley, SL;Edgerton, VR
研究表明，人类腰骶脊髓可以产生阶梯状振荡肌电图（EMG）模式，但目前尚不清楚这些传出模式在多大程度上依赖于与双侧肢体运动和负荷相关的相位外周感觉信息。我们研究的作用，感觉信息有关的下肢负重调制脊髓损伤（SCI）的受试者在手动辅助踏在跑步机上的传出运动模式。四个不能走动的受试者，每个与慢性胸脊髓损伤，和两个非残疾受试者进行了研究。在人工辅助或无辅助踏在跑步机上与体重支持的负荷水平，肌电图模式，下肢运动学进行了研究。研究腰骶部运动池活动[比目鱼肌（SOL）、内侧腓肠肌（MG）和胫骨前肌（TA）]、肢体负荷、肌肉-肌腱长度和肌肉-肌腱长度变化速度之间的关系。SOL、MG和TA的EMG平均幅度与运动过程中下肢每步的峰值负荷直接相关。在正常、部分或没有检测到脊髓上输入的受试者中，对EMG振幅的影响在性质上相似。在SOL和MG中，在以下负荷水平下的响应最为一致：
Studies suggest that the human lumbosacral spinal cord can generate steplike oscillating electromyographic (EMG) patterns, but it remains unclear to what degree these efferent patterns depend on the phasic peripheral sensory information associated with bilateral limb movements and loading. We examined the role of sensory information related to lower-extremity weight bearing in modulating the efferent motor patterns of spinal-cord-injured (SCI) subjects during manually assisted stepping on a treadmill. Four nonambulatory subjects, each with a chronic thoracic spinal cord injury, and two nondisabled subjects were studied. The level of loading, EMG patterns, and kinematics of the lower limbs were studied during manually assisted or unassisted stepping on a treadmill with body weight support. The relationships among lumbosacral motor pool activity [soleus (SOL), medial gastrocnemius (MG), and tibialis anterior (TA)], limb load, muscle-tendon length, and velocity of muscle-tendon length change were examined. The EMG mean amplitude of the SOL, MG, and TA was directly related to the peak load per step on the lower Limb during locomotion. The effects on the EMG amplitude were qualitatively similar in subjects with normal, partial, or no detectable supraspinal input. Responses were most consistent in the SOL and MG at load levels of