Structures
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
- Extensor pollicis brevis
- Extensor pollicis longus
- Extensor indicis
| Muscle | Action | Origin | Insertion | Innervation | Blood supply |
|---|---|---|---|---|---|
| Extensor carpi radialis longus | - Extends and abducts wrist | - Lateral supracondylar ridge of humerus | - Base of 2nd metacarpal | - Radial nerve: C6,7 | - Radial artery |
| Extensor carpi radialis brevis | - Extends and abducts wrist | - Lateral epicondyle of humerus | - Base of 3rd metacarpal | - Radial nerve: C7,8 | - Radial artery |
| Extensor digitorum | - Extends digits 2-5 - Extends wrist | - Lateral epicondyle of humerus | - Extensor expansions of medial four digits | - Posterior interosseous nerve: C7,8 | - recurrent and Posterior interosseous arteries |
| Extensor digiti minimi | - Extends 5th digit - Weak wrist extension | - Lateral epicondyle humerus | - Extensor expansion of 5th digit at metacarpophalangeal and interphalangeal joints | - Posterior interosseous nerve: C7,8 | - recurrent interosseous artery |
| Extensor carpi ulnaris | - Extends and adducts wrist | - Lateral epicondyle of humerus - Posterior border of ulna | - Base of 5th metacarpal | - Posterior interosseous nerve: C7,8 | - Ulnar artery |
| Extensor pollicis brevis | - Extends proximal phalanx of thumb at carpometacarpal joint - Weak wrist extension | - posterior surface of radius and interosseous membrane | - Base of proximal phalanx of thumb | - Posterior interosseous nerve: C7,8 | - Posterior interosseous artery |
| Extensor pollicis longus | - Extends distal phalanx of thumb at carpometacarpal and interphalangeal joints - Weak wrist extension | - Posterior surface of middle 1/3 of ulna and interosseous membrane | - Base of distal phalanx of thumb | - Posterior interosseous nerve: C7,8 | - Posterior interosseous artery |
| Extensor indicis | - Extends 2nd digit - Weak wrist extension | -posterior surface of ulna and interosseous membrane | - Extensor expansion of 2nd digit | - Posterior interosseous nerve: C7,8 | - Posterior interosseous artery |
| Extensor indicis | - Extends 2nd digit - Weak wrist extension | -posterior surface of ulna and interosseous membrane | - Extensor expansion of 2nd digit | - Posterior interosseous nerve: C7,8 | - Posterior interosseous artery |