Abductor pollicis brevis

The abductor pollicis brevis (Latin: musculus abductor pollicis brevis) is a small and short muscle of the hand. It is located on the lateral (radial) side of the palm and participates in forming the thenar eminence. Therefore, together with the adductor pollicis, opponens pollicis and flexor pollicis brevis, the abductor pollicis brevis is one of the four thenar muscles (muscles of the thumb). The abductor pollicis brevis stretches between the scaphoid and trapezium (carpal bones) and proximal phalanx of the thumb. As the name suggests, the abductor pollicis brevis provides thumb abduction.

Abductor pollicis brevis
OriginFlexor retinaculum, tubercles of scaphoid and trapezium bones
InsertionBase of proximal phalanx of thumb
ActionThumb abduction
InnervationRecurrent branch of median nerve (C8, T1)
Blood supplySuperficial palmar arch

Origin

The abductor pollicis brevis muscle originates from the flexor retinaculum and tubercles of the scaphoid and trapezium bones.

Insertion

The abductor pollicis brevis inserts on the base of the proximal phalanx of the first finger.

Action

The abductor pollicis brevis provides the abduction of the thumb at the first carpometacarpal joint.

Innervation

The abductor pollicis brevis is innervated by the recurrent branch of the median nerve (C8, T1).

Blood supply

The abductor pollicis brevis muscle receives arterial blood supply from the superficial palmar arch that is mainly formed by the radial artery.