Evidence for soleus H-reflex depression induced by ballistic head rotation.
In this study, we described a sequence of changes of the electromyographic (EMG) and depression of the soleus (Sol) H-reflex that precede and follow the onset of ballistic head rotation in freely standing human subjects. During head rotation, a sequence of EMG changes occurred simultaneously in Sol and in biceps femoris muscle (BF). Specifically, changes to Sol EMG included deactivations (EMG silent period) and H-reflex depression coincident with BF excitation. Thus, in the case of ballistic head movement, control commands for anticipatory postural adjustment appear to excite BF and inhibit Sol in a similar way to that previously described for the onset of arm movement.
D000328:Adult; D004576:Electromyography; D006181:H-Reflex / Q000502:physiology*; D006257:Head / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology; D009068:Movement / Q000502:physiology*; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D011187:Posture / Q000502:physiology