Structures

  • Extensor digitorum
  • Extensor digiti minimi
  • Extensor indicis
  • Lumbricals
  • Extensor pollicis brevis
  • Extensor pollicis longus
MuscleActionOriginInsertionInnervationBlood supply
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 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
Lumbricals- Flexion of metacarpophalangeal joints
- Extend interphalangeal joints
- Tendons of Flexor digitorum profundus- Extensor expansions of digits 2-5- medial two: deep branch of ulnar nerve
- Lateral two by digital branches of median nerve
- Superficial Palmar arch
- Common Palmar digital artery
- Deep Palmar arch
- Dorsal digital 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