NEURONAL MECHANISMS OF HUMAN LOCOMOTION
NEURONAL MECHANISMS OF HUMAN LOCOMOTION
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DOI：
10.1152/jn.1979.42.5.1212
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发表时间：
1979-01-01
影响因子：
2.5
通讯作者：
NOTH, J
中科院分区：
文献类型：
--
作者：
DIETZ, V;SCHMIDTBLEICHER, D;NOTH, J
记录了不同速度下人体腿部肌肉的表面电图。将肌电图与同时记录的足部垂直力和踝关节角度进行比较。在跑步过程中，腓肠肌电活动在接触地面35 ~ 45 ms后急剧增加，并在肌肉拉伸结束时达到最大值。这种活动叠加在缓慢增加的激活水平上，在接触地面前120-180毫秒开始。在站立期结束时，腓肠肌变得不活动，同时，胫骨前肌的活动突然增加。假设腓肠肌肌电图的急剧增加反映了. α的脊髓拉伸反射。支持-motoneurons。快跑站立期腓肠肌肌电图峰值水平比最大自主收缩期活动高2-3倍。在不同频率刺激胫骨神经时，最大等距力比最大自主等距收缩高约30-40%。肌电图在接触地面后35-45 ms的增加在跑步时明显减少，在局部缺血导致Ia传入神经部分阻塞后，此时自愿收缩的强度显示不受缺血的影响。用电刺激胫神经模拟跑步时腓肠肌的活动。改变刺激速度，以近似于跑步时的肌电图。这表明，在快速弹簧测量的最短距离阶段，脊髓拉伸反射可以变得机械有效（.apprx）。120 ms)。
The surface electomyogram (EMG) of human leg muscles was recorded during running at different speeds. The EMG was compared with the simultaneously recorded vertical force exerted by the foot and with the angle of the ankle joint. During running, the electrical activity of the gastrocnemius muscle increased sharply 35-45 ms after ground contact and reached its maximum at the end of muscle stretch. This activity was superimposed on a slowly increasing level of activation, which began 120-180 ms before gound contact. At the end of the stance phase, gastrocnemius became inactive and, simultaneously, there was a sudden increase in tibialis anterior activity. The assumption that the steep increase in the gastrocnemius EMG reflects the spinal stretch reflex of .alpha.-motoneurons is supported. The peak level of gastrocnemius EMG in the stance phase of fast running was 2-3 times higher than the activity during maximum voluntary contraction. With stimulation of the tibial nerve at different rates, the maximum isometric force as about 30-40% higher than the maximum voluntary isometric contraction. The increase in EMG at 35-45 ms after ground contact was markedly diminished during running, after partial blockage of Ia afferents by ischemia, at a time when the strength of voluntary contraction was shown to be uninfluenced by the ischemia. The gastrocnemius activity during running was simulated by electric stimulation of the tibial nerve. The rate of stimulation was varied so as to approximate to the EMG profile during running. This indicated that a spinal stretch reflex could become mechanically effective within the shortest distance phase measured in a fast spring (.apprx. 120 ms).