| Muscles Acting On The Wrist |
| |
Origin |
Insertion |
Innervation |
Action |
| Flexor carpi ulnaris |
Humeral head: medial epicondyle via common flexor tendon. Ulnar head: medial border of olecranon & upper 2/3 of border of ulna |
Pisiform, hook of hamate & base of 5th metacarpal |
Ulnar nerve (C7 – T1) |
Flexes & adducts wrist |
| Flexor carpi radialis |
Medial epicondyle via common flexor tendon |
Front of base of 2nd & 3rd metacarpals |
Median nerve (C6 – C7) |
Flexes & abducts wrist |
| Palmaris longus |
Medial epicondyle via common flexor tendon |
Flexor retinaculum, palmar aponeurosis |
Median nerve (C7 – C8) |
Flexes wrist |
| Flexor digitorum superficialis |
Humeroulnar head: Medial epicondyle via common flexor tendon, coronoid process of ulna, MCL. Radial head: upper 2/3 of anterior border of radius |
Tendons divide & insert into middle phalanx of 2nd – 5th digits |
Median nerve (C8 – T1) |
Flexes fingers & wrist |
| Flexor digitorum profundus |
Medial side of coronoid process of ulna, upper ¾ of anterior & medial surfaces of ulna |
Base of palmar surface of distal phalanx of 2nd – 5th digits |
Medial head – ulnar nerve (C8 – T1), Lateral head – anterior interosseous branch of median nerve (C8 – T1) |
Flexes fingers & wrist |
| Flexor pollicis longus |
Anterior surface of radius |
Palmar surface of distal phalanx of thumb |
Anterior interosseous branch of median nerve (C7 – C8) |
Flexes thumb & wrist |
| Extensor carpi radialis longus |
Lower 1/3 of lateral supracondylar ridge of humerus |
Posterior surface of base of 2nd metacarpal |
Radial nerve (C6 – C7) |
Extends & abducts wrist |
| Extensor carpi radialis brevis |
Lower 1/3 of lateral supracondylar ridge of humerus |
Posterior surface of base of 2nd metacarpal |
Posterior interosseous branch of radial nerve (C7 – C8) |
Extends & abducts wrist |
| Extensor carpi ulnaris |
Lateral condyle via common extensor tendon |
Medial side of 5th metacarpal base |
Posterior interosseous nerve (C7 – C8) |
Extends & adducts wrist |
| Extensor digitorum |
Lateral condyle via common extensor tendon |
Lateral & dorsal surfaces of 2nd – 5th digits |
Posterior interosseous branch of radial nerve (C7 – C8) |
Extends finger & wrist |
| Extensor indicis |
Lower part of posterior surface of ulna |
Dorsal digital expansion on back of proximal phalanx of index finger |
Posterior interosseous nerve (C7 – C8) |
Extends index finger & wrist |
| Extensor digiti minimi |
Lateral condyle via common extensor tendon |
Dorsal digital expansion of 5th digit |
Posterior interosseous nerve (C7 – C8) |
Extends 5th digit & wrist |
| Extensor pollicis longus |
Middle 1/3 of posterior surface of ulna |
Dorsal surface of distal phalanx of thumb |
Posterior interosseous nerve (C7 – C8) |
Extends thumb & wrist, abducts wrist |
| Extensor pollicis brevis |
Posterior surface of radius |
Dorsolateral base of proximal phalanx of thumb |
Posterior interosseous nerve (C7 – C8) |
Extends thumb & wrist, abducts wrist |
| Abductor pollicis longus |
Upper part of posterior surface of ulna, middle 1/3 of posterior surface of radius |
Radial side of 1st metacarpal base, trapezium |
Posterior interosseous nerve (C7 – C8) |
Abducts & extends thumb, abducts wrist |
| Lumbricals |
Tendons of flexor digitorum profundus |
Lateral margin of dorsal digital expansion of extensor digitorum |
1st & 2nd = median nerve (C8 – T1), 3rd & 4th = ulnar nerve (C8 – T1) |
Flexes metacarpophalangeal joints, extends interphalangeal joints |
| Flexor digiti minimi brevis |
Hook of hamate, flexor retinaculum |
Ulnar side of base of proximal phalanx of little finger |
Ulnar nerve (C8 – T1) |
Flexes little finger |
| Dorsal interossei |
Adjacent sides of 2 metacarpal bones |
Base of proximal phalanges & dorsal digital expansions |
Ulnar nerve (C8 – T1) |
Abducts index, middle & ring fingers, flexes metacarpophalangeal joint, extends interphalangeal joint |
| Palmar interossei |
Shaft of metacarpal of digit on which it acts |
Dorsal digital expansion & base of proximal phalanx of same digit |
Ulnar nerve (C8 – T1) |
Adducts thumb, index, ring & little finger |
| Abductor digiti minimi |
Pisiform, tendon of flexor carpi ulnaris, pisohamate ligament |
Ulnar side of base of proximal phalanx of little finger |
Ulnar nerve (C8 – T1) |
Abducts little finger |
| Opponens digiti minimi |
Hook of hamate, flexor retinaculum |
Medial border of 5th metacarpal |
Ulnar nerve (C8 – T1) |
Abducts 5th digit, pulls it forward & laterally rotates it |
| Flexor pollicis brevis |
Flexor retinaculum, tubercle of trapezium, captitate, trapezoid |
Base of proximal phalanx of thumb |
Median nerve (C8 – T1), sometimes ulnar nerve (C8 – T1) |
Flexes metacarpophalangeal joint of thumb |
| Abductor pollicis brevis |
Flexor retinaculum, tubercles of scaphoid & trapezium, APL tendon |
Radial side of base of proximal phalanx of thumb |
Median nerve (C8 – T1) |
Abducts thumb |
| Opponens pollicis |
Flexor retinaculum, tubercles of scaphoid & trapezium, APL tendon |
Radial side of base of proximal phalanx of thumb |
Median nerve (C8 – T1) |
Rotates thumb into opposition with fingers |
