Multi-Digit Coordination in Absence of Cutaneous Sensory Feedback During Grasping Tasks

Abstract

Motor learning and adaptation to object properties and task requirements requires integration of cutaneous sensory feedback with motor commands. Joint mechanics constantly change, with individual joints or muscles compensation so performance output is the same per task. Effects of mixed cutaneous sensory feedback on multi-digit coordination is not well understood. Investigators sought to determine the influence absent cutaneous sensory feedback has on motor learning and adaptation, and how the CNS coordinates multi-digit mechanical output to adapt to manual tasks, with partially intact digital sensory feedback. 19 participants were randomly assigned for three-digit anesthesia administration (TIM- thumb, index, middle; TRL- thumb, ring, little). Experimental tasks were repeated on two visits (control and anesthesia): grasping and lifting an object, and a functional task. Under partial digital anesthesia, total maximal voluntary contraction (MVC) was lower, and decreased force production was seen in all five digits (