Evaluation of reciprocal inhibition of the soleus H-reflex during tonic plantar flexion in man
Evaluation of reciprocal inhibition of the soleus H-reflex during tonic plantar flexion in man
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DOI：
10.1016/s0165-0270(98)00044-2
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发表时间：
1998-10-01
影响因子：
3
通讯作者：
Nielsen, J
中科院分区：
文献类型：
--
作者：
Petersen, N;Morita, H;Nielsen, J
在健康受试者中，在增加强直性跖屈水平的情况下，评价了踝背屈肌到踝跖屈肌的相互抑制的变化。刺激腓总神经（CPN）引起比目鱼肌肌电图的校正和平均的短潜伏期抑制（平均抑制潜伏期：40 ms）和比目鱼肌H反射的短潜伏期抑制（条件反射测试间隔：2-3 ms）。当CPN刺激的强度低于约1.2 x运动阈值（x MT）时，可以看到比目鱼肌EMG（表示为抑制期间EMG的量占背景EMG的百分比）和比目鱼肌I-I反射（表示为条件反射的大小占对照H反射大小的百分比）的抑制随着跖屈水平的增加而减少。在高于约1.2 x MT的刺激强度下，EMG和H反射的抑制非常强，并且不受收缩的调节。有人建议，减少相互抑制的跖屈水平的增加是由于减少兴奋性的Ia抑制性interneurons负责的抑制。它强调的是，次最大刺激是必要的，以证明这种调制的抑制和相互抑制运动性能的功能性贡献不能透露人工电刺激外周神经诱发的抑制量。(C)1998 Elsevier Science B. V.保留所有权利。
Changes in reciprocal inhibition from ankle dorsiflexors to ankle plantar flexors were evaluated at increasing levels of tonic plantar flexion in Il healthy subjects. Stimulation of the common peroneal nerve (CPN) evoked a short-latency depression of the rectified and averaged soleus electromyogram (average latency of depression: 40 ms) and a short-latency inhibition of the soleus H-reflex (conditioning-test interval: 2-3 ms). When the intensity of the CPN stimulation was below approximately 1.2 x motor threshold ( x MT) the inhibition of both the soleus EMG (expressed as the amount of EMG during the inhibition as percentage of the background EMG) and the soleus I-I-reflex (expressed as the size of the conditioned reflex as percentage of the control H-reflex size) were seen to decrease with increasing levels of plantar flexion. At intensities of stimulation higher than approximately 1.2 x MT the inhibition of the EMG and the H-reflex was very strong and was not modulated with contraction. It is suggested that the decrease of reciprocal inhibition with increasing levels of plantar flexion is due to a decreased excitability of the Ia inhibitory interneurones which are responsible for the inhibition. It is emphasized that submaximal stimulation is necessary to demonstrate this modulation of inhibition and that the functional contribution of reciprocal inhibition to motor performance cannot be revealed from the amount of inhibition evoked by artificial electrical stimulation of a peripheral nerve. (C) 1998 Elsevier Science B.V. All rights reserved.