[Responses to the spindles of "fast" and "slow" muscles to mechanical stimulation in the presence of hypokinesia].

The activity of muscle spindles was investigated in fast (extensor digitorum longus) and "slow" (soleus) muscles of the cat hind limb 2-5 weeks after immobilization. The spontaneous activity of spindles in both muscles remained unchanged. The background activity, the frequency of dynamic and static phases of stretching in primary as well as in secondary endings was much higher in immobilized muscle than in control. This increase in spindle activity was more pronounced in the "slow" muscle.