Fig. 9. Effects on flexor tibiae motor neurons when the lump receptor was stimulated by pulling on the flexor tendon. (A) A fast motor neuron was hyperpolarised when spikes from the lump receptor occurred. (B) A second fast flexor was not affected by the stimulation. (C) A tonic sequence of spikes in a slow flexor evoked by the intracellular injection of depolarising current was not altered by spikes from the lump receptor. Grey lines indicate the membrane potential of a motor neuron before stimulation of the lump receptor.