Tendon organ afferents in the knee joint nerve of the cat

This article is concerned with the question of whether some of the slowly adapting responses recorded in the mid-range of joint position from the posterior articular nerve (PAN) of the cat hindlimb and which are therefore candidates for joint position sensors, are in fact coming from muscle receptors of the popliteus muscle. Evidence is provided that in addition to afferents of primary endings of spindles, secondary endings of spindles and tendon organs are represented in PAN as well. Removal of the fleshy part of the popliteus muscle does not reliably remove muscle afferent contamination in PAN.