The abductor pollicis longus is a muscle within the deep compartment of the posterior forearm.
The tendon of the abductor pollicis longus passes through the 1st extensor compartment at the wrist, where it contributes to the radial border of the anatomical snuffbox.
- Attachments: Originates from the interosseous membrane and the adjacent posterior surfaces of the radius and ulna. It attaches to the lateral aspect of the base of the first metacarpal.
- Actions: Abduction of the thumb.
- Innervation: Radial nerve (posterior interosseous branch).
- Blood supply: Ulnar artery.