Reflex compensation for variations in the mechanical properties of a muscle.

Soleus muscles of anesthetized cats were stretched and released by different amounts while their motor axons were stimulated. Muscle force increased, then gave way in response to large stretch. In the presence of active stretch reflexes in decerebrate cats, the give in force was absent. We demonstrate that autogenetic reflexes can compensate for variations in muscular stiffness revealed when responses to stretch and release are compared.