Muscle
Abductor pollicis longus
Deep thumb abductor
High-yield
Forms the anterior (radial) border of the anatomical snuffbox; involved in de Quervain tenosynovitis.
Overview
A deep outcropping muscle that abducts the thumb and forms the anterior boundary of the anatomical snuffbox.
Reference facts
- Origin
- Posterior surfaces of the ulna, radius, and interosseous membrane
- Insertion
- Base of the 1st metacarpal
- Action
- Abducts and extends the thumb at the carpometacarpal joint
- Innervation
- Posterior interosseous nerve (C7, C8)
- Blood supply
- Posterior interosseous artery
Frequently asked questions
What does the abductor pollicis longus do?
The abductor pollicis longus abducts and extends the thumb at the carpometacarpal joint.
What nerve innervates the abductor pollicis longus?
The abductor pollicis longus is innervated by the posterior interosseous nerve (C7, C8).
Where does the abductor pollicis longus attach?
The abductor pollicis longus originates from the posterior surfaces of the ulna, radius, and interosseous membrane and inserts on the base of the 1st metacarpal.
What is the blood supply of the abductor pollicis longus?
The abductor pollicis longus is supplied by the posterior interosseous artery.