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| Muscle | Origin | Insertion | Action | Nerve |
| Superficial layer |
| anconeus | lateral epicondyle of humerus | posterior ulna (lateral olecranon extending to lateral part of ulna) | extension of forearm at elbow; supports elbow when in full extension | radial nerve (C6, C7, C8) |
| extensor carpi radialis longus | lower lateral supracondylar ridge (below brachioradialis) | base of 2nd metacarpal | extension of hand at wrist; radially deviation (abduction) of hand at wrist; flexion & supination of forearm at elbow (weak action) | radial nerve (C5, C6) |
| extensor carpi radialis brevis | lateral epicondyle via common extensor tendon | base of 3rd metacarpal | extension of hand at wrist; radial deviation (abduction) of hand at wrist; flexion of forearm at elbow joint (weak action) | radial nerve (C7, C8) |
| extensor digitorum | lateral epicondyle of humerus (via common extensor tendon) | phalanges #2-5 (dorsal expansion hood) | extension of fingers #2-5 (at MCP, PIP & DIP joints); extension of hand at wrist; extension of forearm at elbow (weak) | radial nerve (C7, C8) |
| extensor digiti minimi | lateral epicondyle of humerus (via common extensor tendon) | middle & distal phalanges of 5th digit (extensor expansion) | extension of little finger (5th digit); extension of hand at wrist; extension of elbow (weak action) | radial nerve (C6, C7, C8) |
| extensor carpi ulnaris | humeral head: lateral epicondyle (via common extensor tendon); ulnar head: posterior shaft of ulna | base of 5th metacarpal (posterior side) | ulnar deviation of hand at wrist; extension of hand at wrist; extension of forearm at elbow (weak action) | radial nerve (C6, C7, C8) |
| Deep Layer |
| abductor pollicis longus | posterior surfaces of ulna, radius & interosseous membrane (middle 1/3 of forearm) | base of 1st metacarpal (lateral side) | abduction of thumb at metacarpophalangeal joint; radially deviation (abduction) hand at wrist; assists with extension & rotation of thumb; assists with flexion & supination of hand at wrist | radial nerve (C7, C8) |
| extensor pollicis brevis | posterior distal 1/3 surfaces of radius & interosseous membrane | base of proximal phalanx of thumb | extension of proximal phalanx & 1st metacarpal of thumb; radially deviation (abduction) of hand at wrist | radial nerve (C7, C8) |
| extensor pollicis longus | posterior middle 1/3 of ulna & interosseous membrane | distal phalanx of thumb | extension of thumb (at CMC, MCP, IP joints); assists in extension & radial deviation (abduction) of hand at wrist | radial nerve (C7, C8) |
| extensor indicis | posterior distal 1/3 of ulna & interosseous membrane | base of middle & distal phalanx of index finger (via extensor expansion & extensor digitorum muscle tendon) | extension of index finger (at MCP, PIP & DIP joints); extension of hand at wrist; adduction of index finger (weak) | radial nerve (C7, C8) |
Vertebral Column