The adductor pollicis is one of the intrinsic muscles of the hand which adducts the thumb. It has two heads, the oblique head and the transverse head.
The intrinsic muscles of the hand are involved with precision movements and consist of the following muscles:
- Thenar muscles: flexor pollicis brevis, abductor pollics brevis, opponens pollicis
- Hypothenar muscles: abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi
- Lumbricals
- Interosseus muscles
- Other: palmaris brevis, adductor pollicis
The intrinsic muscles of the hand are innervated by the deep branch of the ulnar nerve, except the thenar muscles and the lateral two lumbricals. A mnemonic for remembering this is Meat LOAF, Meat = Median nerve innervates the Lateral lumbricals, Opponens pollicis, Abductor pollicis brevis and Flexor pollicis brevis
Origin
- Transverse head: anterior shaft of third metacarpal
- Oblique head: Adjacent bases of second and third metacarpals and capitate
Insertion
- medial side of the base of the proximal phalanx of the thumb and associated extensor hood.
Action
- Adduction of the thumb at the carpometacarpal joint
Innervation
- Deep Branch of Ulnar Nerve
Blood Supply
- arteria princeps pollicis
- arteria radialis indicis
- branches from the deep palmar arch.