Activation of Golgi tendon organs by asynchronous contractions of motor units in cat leg muscles.

Discharges from individual tendon organs of peroneus tertius muscle activated by the isometric contractions of single motor units were recorded in anaesthetized cats. Pairs of motor units acting on the same tendon organ were stimulated asynchronously at frequencies eliciting unfused contractions. Tendon organ responses to such contractions did not display a linear relation between discharge frequency and contractile force recorded at the muscle tendon. In several instances, one of the motor units exerted a predominant influence on the response of the tendon organ, even though this unit did not produce the strongest activation of the receptor when stimulated on its own.