Abductor pollicis brevis muscle

Last revised by Daniel J Bell on 21 Aug 2019

The abductor pollicis brevis muscle is a thin subcutaneous muscle located laterally in the thenar eminence of the hand, and is one of the intrinsic muscles of the hand.


  • origin: mainly from the flexor retinaculum
  • insertion: its medial fibers are attached by a thin, flat tendon to the radial side of the proximal phalangeal base in the pollex and lateral fibers join the pollicial dorsal digital expansion
  • innervation: lateral branch of median nerve (C8 and T1)
  • action: abducts the thumb and medially rotates it at the carpometacarpal and metacarpophalangeal joints

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.