Test each nerve for power in a named muscle, sensation in its autonomous zone and the sign of its characteristic deformity.
Median Nerve
- Anterior interosseous branch. Weak pinch with loss of pulp to pulp contact, so the OK sign fails. Tests flexor pollicis longus and index profundus
- Recurrent motor branch. Thumb abduction at right angles to the palm against resistance. Tests abductor pollicis brevis
- Sensation. Pulp of the index finger
- Signs. Ape hand with thenar wasting. Benediction sign on attempted fist in a high lesion. Positive Tinel and Phalen tests at the carpal tunnel
Ulnar Nerve
- Motor. Index abduction against resistance. Tests first dorsal interosseous
- Froment sign. Flexion of the thumb interphalangeal joint during lateral pinch. Adductor pollicis is weak and flexor pollicis longus substitutes
- Wartenberg sign. Little finger held abducted from weak third palmar interosseous
- Claw hand. Ring and little finger hyperextended at the metacarpophalangeal joints. Less marked in high lesions
- Sensation. Pulp of the little finger
- Cubital tunnel. Tinel test and elbow flexion test
Radial Nerve
- Motor. Wrist and finger extension against resistance. Wrist drop in high lesions
- Posterior interosseous nerve. Finger drop with radial deviation on wrist extension. Sensation is normal and extensor carpi radialis longus is spared
- Spiral groove lesion. Triceps is spared
- Sensation. First dorsal web space
Proximal Nerves
- Axillary nerve. Deltoid contraction and sensation over the lateral upper arm
- Musculocutaneous nerve. Elbow flexion with the forearm supinated and sensation over the lateral forearm
- Root levels. C5 shoulder abduction. C6 wrist extension. C7 elbow extension. C8 finger flexion. T1 finger abduction
Sensory Testing
- Two-point discrimination. Normal is under 6 mm at the fingertip
- Semmes-Weinstein monofilaments. Grade light touch threshold and follow recovery
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 21 October 2026.