Upper limb
Median nerve
Nervus medianus
- Origin
- Formed in the axilla by the convergence of the lateral root (lateral cord, C5–C7) and medial root (medial cord, C8–T1) of the brachial plexus
- Insertion
- Descends the medial arm, enters the cubital fossa, passes between the two heads of pronator teres, travels down the forearm between FDS and FDP, traverses the carpal tunnel, and terminates into motor recurrent and sensory digital branches
- Function
- Motor to forearm pronators, wrist flexors (except FCU), finger flexors (except medial FDP), thenar muscles (APB, OP, superficial FPB), and lumbricals I & II; sensory to the palmar aspects of digits I–III and lateral half of IV, plus their dorsal nail beds
- Innervation
- Mixed sensorimotor nerve with dense sympathetic vasomotor and sudomotor distribution to the hand
- Movement & chain
- Essential for precision pinch, thumb opposition, powerful grasp, and forearm pronation
- Palpation
- Palpable in the medial bicipital groove of the arm and proximal to the wrist crease between flexor carpi radialis and palmaris longus tendons
- Clinical
- Carpal tunnel syndrome (CTS: paresthesias in radial 3.5 digits, thenar wasting, positive Phalen/Tinel tests), pronator syndrome, anterior interosseous nerve syndrome, Hand of Benediction upon fist clenching
- Segmental innervation
- C5, C6, C7, C8, T1 spinal cord levels
- In clinical practice
- Most commonly entrapped peripheral nerve; managed with neutral wrist splinting, nerve gliding exercises, ultrasound-guided steroid injections, and surgical carpal tunnel release
- Region in the model
- Upper limb