Adductor pollicis

The adductor pollicis (Latin: musculus adductor pollicis) is a flat triangular-shaped muscle of the hand. Together with the abductor pollicis brevis, flexor pollicis brevis and opponens pollicis, it forms the thenar eminence. Therefore, the adductor pollicis is known as one of the four thenar muscles that lie on the lateral (radial) side of the palm. As the name suggests, the adductor pollicis provides the adduction of the thumb. This muscle has two heads - oblique and transverse.

Adductor pollicis
Origin

Oblique head - capitate bone, bases of 2nd and 3rd metacarpal bones

Transverse head - base of 3rd metacarpal bone

InsertionBase of proximal phalanx of thumb
ActionThumb adduction
InnervationDeep branch of ulnar nerve (C8, T1)
Blood supplyDeep palmar arch

Origin

The oblique head of the adductor pollicis muscle originates from the capitate bone and bases of the second and third metacarpal bones. The transverse head arises from the base of the third metacarpal bone.

Insertion

The adductor pollicis inserts on the base (medial side) of the proximal phalanx of the thumb.

Action

The adductor pollicis muscle provides the adduction of the thumb at the first carpometacarpal joint.

Innervation

The adductor pollicis is innervated by the deep branch of the ulnar nerve (C8, T1).

Blood supply

The adductor pollicis muscle receives arterial blood supply from the deep palmar arch that is formed by the radial artery and the deep palmar branch of the ulnar artery.