17 - Proprioception and Its Contribution to Manual Dexterity

Abstract

The proprioceptive or kinesthetic sensory system is involved in processing information that arises both centrally and peripherally about limb movements, changes in limb position, and muscle force. During vibration, a limb can be perceived to be in an anatomically impossible position, which suggests that perceptually the limits of the sense of position are not set by the anatomical constraints of joint excursion, and that the cortical sensory centers will extrapolate. Following a digital nerve block in which both joint and cutaneous afferent input is eliminated, but the muscles in the forearm controlling flexion and extension movements of the fingers are unaffected, there is a loss of proprioceptive acuity. It is observed that when the proximal interphalangeal joint of the index finger is anesthetized by an intra-articular injection of a local anesthetic, the ability to match the position of the joint deteriorates. The greatest errors are associated with perceiving the location of the finger when it is positioned near the extremes of its range of joint motion. The analysis of surgical performance should provide a basis for evaluating the performance of microsurgical robotic systems, for which it is essential to know the accuracy and consistency with which various tasks are carried out by their human counterparts.