Nerve Injury in the Hand

Abstract

The peripheral nerves of the hand include the median nerve, the ulnar nerve, and the sensory branch of the radial nerve. The median nerve and the ulnar nerve produce their motor branches to the intrinsic muscles of the hand at the level of the carpal bones. Their sensory branches become the proper palmar digital nerves and they are distributed to the fingers. The median nerve innervates the palmar side of the thumb, the index finger, the middle finger, and the radial side of the ring finger. The ulnar nerve innervates the little finger and the ulnar side of the ring finger. However, there are some anomalous innervations regarding the sensory area. For example, the ulnar nerve sometimes innervates the radial side of the ring finger and the middle finger. The palmar digital nerves innervate the dorsal skin of the digits (except the thumb), which is distal from the mid-metacarpus. The proper palmar digital nerve to the thumb is distributed only to the palmar side and the nail bed. The dorsal aspect of the thumb is innervated by the sensory branch of the radial nerve.