The median nerve provides sensory and motor innervation to the anterior compartment of the forearm and hand.
- Motor branches
- Pronator teres
- Flexor carpi radialis
- Flexor carpi sublimis
- Anterior interosseus (motor)
- Flexor pollicis longus
- Flexor digitorum profundus to 2nd & 3rd fingers
- Pronator quadratus
- Palmar cutaneous
- Sensory distribution: Skin over thenar eminence
- Terminal motor
- Abductor pollicis brevis
- Opponens pollicis
- Lumbricals: 1st & 2nd
- ± Flexor pollicis brevis: Also innervated by ulnar nerve
- Terminal sensory
- Sensory to palmar surface of thumb, 2nd, 3rd & lateral 1/2 of 4th finger
Physical exam for different muscles supplied by median nerve
- Flexor digitorum superficialis: patient flexes fingers at PIP joint against resistance
- Flexor digitorum profundus: patient flexes fingers at DIP joint against resistance
- Flexor pollicis longus (anterior interosseous nerve): flexes distal phalanx of thumb against resistance
- Abductor pollicis brevis: patient abducts thumb at right angles to palm against resistance
- Opponens pollicis: patient touches base of little finger with the thumb, examiner tries to pull apart
- 1st lumbrical interosseous: patient extends finger at the PIP joint against resistance with the MCP joint hyperextended and fixed
