A case study of reaching by a user of a manually-operated artificial hand.

Reaching involves both transport of the hand toward an object and opening of the hand by an appropriate amount before arrival at the object. Movements of a manually-controlled artificial left-hand are compared with movements of the natural right-hand of a proficient user of an artificial hand. Although picking up of objects was slower with the artificial hand, similarities in opening and transport movements were observed in the two hands. Depsite major mechanical differences in the systems subserving movement in the artificial and natural hands, the similarities extended to the separate movements of the thumb and finger. The strategy of artificial hand control employed by this subject is discussed and related to training new users of artificial hands.