Usually the tingling you get when bumping the nerve last a few seconds only but the ulnar nerve also can be the cause of more serious and permanent problems in the fingers and hand.Īn injury to the elbow such as a dislocation or fracture can damage or irritate the ulnar nerve. As it passes around the elbow it is exposed. The ulnar nerve travels to the hand via the inside back part of the elbow where it can be bumped (hitting your “funny bone”). Proximal and distal lesions of the ulnar nerve lead to claw hand deformity.The ulnar nerve is an important nerve because it supplies feeling to the little and ring fingers of the hand and activates many of the small muscles in the hand (allowing strong gripping of objects in the hand). Tinel sign: tapping on the medial epicondyle of the humerus elicits marked paresthesias in the ulnar portion of the hand.Due to loss of function of the adductor pollicis muscle and predominance of the extensor pollicis longus and the abductor pollicis brevis.Hyperextension of the MCP joint of the thumb with key pinch movement.

Due to weakness of the third palmar interosseous muscle.Persistent abduction of the little finger.Due to weakness of the adductor pollicis muscle and the unopposed action of flexor pollicis longus.Flexion of the thumb at the interphalangeal joint elicited when tightly pressing together the tips of the index finger and thumb, or when tightly adducting the thumb against the 2nd metacarpal (e.g., pinching a piece of paper using the thumb).Mainly seen in distal ulnar nerve injuries.Present at rest, increases when the patient is asked to extend the fingers.Palsy of the 3 rd and 4 th lumbricals with preserved function of the extrinsic flexors.Zone III: lesions at the distal sensory branch cause sensory symptoms only.Zone II: lesions at the deep motor branch cause motor symptoms only.Sensory features similar to those caused by proximal lesions at the elbow.Motor and sensory symptoms (i.e., sensory loss in the palmar surface of the little finger and medial aspect of the ring finger) possible.

Zone I: lesions proximal to the bifurcation of the ulnar nerve.

Compression of the ulnar nerve at the wrist is divided into three zones and exam findings often correlate with the site of injury.

Variable paresthesia or sensory loss of the palmar and dorsal aspects of the medial side of the hand, little finger, and ulnar side of the ring finger.

Paresthesia or sensory loss of palmar and dorsal aspects of the medial side of the hand, little finger, and ulnar side of the ring finger.Entrapment at the wrist: weakness and atrophy of the intrinsic hand muscles innervated by the ulnar nerve.Less common than sensory complaints and range from mild to severe weakness.Paresthesia or sensory loss of the palmar and dorsal aspects of the medial side of the hand, little finger, and ulnar side of the ring finger.Weakness and atrophy of the intrinsic hand muscles innervated by the ulnar nerve.Muscle atrophy and weakness (less common than sensory symptoms).Masses at the Guyon canal (e.g., ganglion cysts).Blunt trauma at the wrist (e.g., hook of hamate fracture causing Guyon canal compression).See also, '' Compression neuropathies in sport.''.Cycling (likely caused by direct pressure from the handlebars).Metabolic conditions associated with neuropathy (e.g., diabetes).Masses at the cubital tunnel (e.g., hematomas).Sports injuries (e.g., baseball, bodybuilding).Prolonged flexion of or other stress on the elbow.At the medial epicondyle of the humerus (cubital tunnel).

Ulnar nerve compression