Cutaneous afferent feedback from the posterior ankle contributes to proprioception

Abstract

Cutaneous mechanoreceptors in skin surrounding joints can respond to the skin strain generated by movement, and thus provide proprioceptive cues. The objective of this experiment was to determine the contribution of skin feedback from the posterior ankle to position sense during passive movements. In 28 healthy adults (12 male), a topical anesthetized (n=14) or placebo cream (n=14) was applied to an area of skin on the posterior ankle that undergoes stretch and compression during ankle dorsi- and plantar-flexion. Position sense was assessed before and after anesthetization using a passive joint matching task (target angles: 6°, 12°, and 18° dorsiflexion and plantar flexion). Results showed that reducing skin feedback caused the perception that the ankles were aligned when the anesthetized ankle was relatively more dorsiflexed, suggesting that posterior ankle skin primarily signals the magnitude of skin stretch. Larger movement into dorsiflexion was likely necessary to provide enough stretch of muscle and surrounding intact skin to compensate for reduced signals from the anesthetized skin region. Reducing skin feedback also increased matching variability during larger movements. These findings suggest that skin feedback from the posterior ankle has a significant contribution to position sense during passive movement. Therefore, the sensitivity of skin surrounding the ankle could be important to consider in populations with reduced peripheral skin sensitivity as a result of ageing or neurological disorders.