The influence of joint afferent discharge on locomotion, proprioception and activity in conscious cats.

Injection of local anaesthetic into the knee joint cavity in a series of 14 cats produced obvious abnormalities of posture and gait in half the animals. However, on employing a more sensitive testing procedure, 7 out of 8 animals exhibited reduced proprioceptive acuity after knee joint anaesthesia, and all animals tested showed marked reduction in motor activity after this procedure. Control procedures revealed that these effects were due to the local anaesthetic agent, and that this remained localized to the knee joint and did not diffuse out to block cutaneous and muscle afferents. Thus, joint afferents would appear to play a significant role in the regulation of posture and movement.