Abbruzzese M, Rubino V, Schieppati M
Department of Neurology, University of Genoa, Italy.
Electroencephalogr Clin Neurophysiol. 1996 Aug;101(4):339-48. doi: 10.1016/0924-980x(96)95682-9.
The effect of low intensity electrical stimulation of the posterior tibial nerve (PTN) at the ankle on the active triceps surae (TS) muscles was studied in normal subjects, both in a prone position and while standing. PTN stimulation regularly evoked the H-reflex in the flexor digitorum brevis and, in the prone position, a short-latency facilitatory effect in the soleus muscle. During standing, the facilitatory effect was preceded by a clear-cut reduction in electromyograph (EMG) activity. The inhibition-facilitation sequence was evoked in the gastrocnemii under both conditions, on average, though individual differences were present. An EMG modulation similar to that observed under standing conditions was present also in the prone position when subjects pressed the sole of the foot against the wall. Stimulation of sural or digital nerves did not evoke similar effects. It is concluded that foot muscle afferents establish oligosynaptic connections transmitting mixed effects to the TS motoneuronal pool, and that contact with the sole of the foot plays an enabling role for the inhibitory pathway directed to the soleus muscle.
在正常受试者中，研究了在踝关节处对胫后神经（PTN）进行低强度电刺激对主动腓肠肌（TS）的影响，测试体位包括俯卧位和站立位。PTN刺激通常会诱发趾短屈肌中的H反射，在俯卧位时，比目鱼肌会出现短潜伏期的易化效应。在站立过程中，这种易化效应之前会出现肌电图（EMG）活动的明显降低。在两种体位下，腓肠肌平均都会出现抑制-易化序列，不过存在个体差异。当受试者用脚底抵住墙壁时，在俯卧位也会出现类似于站立位时观察到的EMG调制。刺激腓肠神经或指神经不会引发类似效应。得出的结论是，足部肌肉传入神经建立了寡突触连接，将混合效应传递至TS运动神经元池，并且与脚底的接触对指向比目鱼肌的抑制通路起到促进作用。
