Input From Fast Adapting Skin Receptors in the Foot Interacts with Proprioception at the Ankle Joint
It has previously been shown that cutaneous sensory input from surrounding regions impairs proprioception at joints of the hand. The current experiment tested whether input from cutaneous afferents innervating mechanoreceptors in the foot sole and dorsum influenced proprioception at the ankle joint. The ability to passively match ankle joint position was measured while cutaneous vibration was applied to the foot sole (heel, metatarsals) or dorsum of the target foot. Vibration was applied at two different frequencies to preferentially activate Meissner’s corpuscles (45Hz, 80μm) or Pacinian corpuscles (255Hz, 10μm) at amplitudes ~3dB above mean perceptual thresholds. Ankle matching error and variability increased when cutaneous vibration was applied to the foot sole, with the most pronounced effects observed with heel vibration. Cutaneous vibration of the foot dorsum resulted in increased variability in ankle matching. These results indicate that there is interplay between exteroceptive and proprioceptive signals originating from the foot and ankle.