clawhand [AS, clawu + hand] , refers to an abnormal posture of the hand, characterized by hyperextension of the metacarpal phalangeal joints and flexion (or ‘‘clawing’’) of the middle and distal interphalangeal joints. Indicative of a low-level or distal lesion of the ulnar nerve, with consequent paresis or paralysis of the ulnar innervated intrinsic muscles of the hand. There is a loss of the normal balance between the extrinsic digit extensors and the intrinsic digit flexors and flattening of the normal arches of the hand. Claw hand posture is typically less noticeable in the index and long digits because the lateral two lumbricals, which flex the MCP joints of the index and long digits, are innervated by the median nerve. Also called main en griffe.
