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Image : “The front and back of a human right hand” by Evan-Amos. License: CC BY-SA 3.0
Many of the muscles that move the hand and fingers are reviewed in the Anatomy of the Upper Limb – Muscles of the Arm article.
The other muscles of the hand are divided into 4 groups: the lumbricals, interossei, thenars, and hypothenars.
Lumbricals
| Muscles | Origin | Insertion | Nerve supply | Function |
| Lumbricals (I-II) | Lateral 2 tendons of flexor digitorum profundus (FDP) (unipennate) |
Lateral surfaces of extensor expansions of digits 2–5 | Median nerve (T1) | Flex metacarpophalangeal and extend interphalangeal joints of digits 2–5 |
| Lumbricals (III-IV) | Medial 2 tendons of FDP (bipennate) | Deep branch of the ulnar nerve (T1) |
The lumbricals are 4 narrow muscle bellies that have no direct bony anchors. They also stabilize the metacarpophalangeal joints and prevent ulnar deviation.
Interossei Muscles
| Muscle | Origin | Insertion | Nerve supply | Function |
| Dorsal interossei | Dorsal sides of all metacarpals (bipennate) | Base of proximal phalanges and extensor expansions (digits 2–4, dorsal; digits 2, 4 and 5, palmar) | Deep branch of the ulnar nerve (T1) | Abduct digits 2–4 away from the axial line |
| Palmar interossei | Palmar sides of metacarpals 2, 4 and 5 | Adduct digits 2, 4 and 5 toward the axial line |
The radial artery traverses between the 2 heads of the dorsal interosseous muscle I. The 3 palmar interossei muscles are one-headed and lie between the metacarpal bones.
Thenar Muscles
| Muscles | Origin | Insertion | Nerve supply | Function |
| Opponens pollicis | Flexor retinaculum and tubercles of scaphoid and trapezium | Lateral side of the 1st metacarpal | Recurrent branch of the median nerve (C8) | Oppose thumb |
| Abductor pollicis brevis | Lateral side of proximal phalanx of digit 1 | Abducts thumb; supports the opposition | ||
| Flexor pollicis brevis | Flexes thumb | |||
| Adductor pollicis | Oblique head: Base of 2nd and 3rd metacarpals and capitate Transverse head: anterior surface of the 3rd metacarpal |
Medial side of proximal phalanx of thumb | Deep branch of the ulnar nerve (C8) | Adducts thumb |
Hypothenar Muscles
| Muscles | Origin | Insertion | Nerve supply | Function |
| Palmaris brevis | Transverse carpal ligament and palmar aponeurosis | Ulnar palm | Ulnar nerve | Wrinkles the skin of the medial palm |
| Abductor digiti minimi | Pisiform | Medial side of proximal phalanx of the 5th digit | Deep branch of the ulnar nerve (T1) | Abducts the 5th digit |
| Flexor digiti minimi brevis | Hook of hamate and flexor retinaculum | Flexes proximal phalanx of the 5th digit | ||
| Opponens digiti minimi | Medial border of the 5th metacarpal | Rotates and draws the 5th metacarpal anteriorly |
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