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