HUMAN FLEXOR POLLICIS LONGUS - ROLE OF PERIPHERAL INPUTS IN WEIGHT-MATCHING

We investigated the role of local cutaneous signals and of co-contract ion of antagonists in repeated judgements of heaviness of weights lift ed by flexor pollicis longus. A reference weight lifted by right thumb flexion was matched to a weight lifted by left thumb flexion. Anaesth esia of the right thumb, or of the superficial radial, dorsal ulnar or mixed radial nerves failed to impair accuracy of weight judgements. H owever, perceived heaviness significantly increased by 85% and 20% fol lowing anaesthesia of the thumb and dorsal radial surface of the hand, respectively, confirming a role for cutaneous inputs from these areas in motor control of the thumb.