Abductor pollicis longus (Musculus abductor pollicis longus)
Educational content only — not medical advice.
Anatomy
A deep posteroradial forearm muscle; its tendon crosses the first dorsal compartment with the short extensor — a defining component of the anatomical snuffbox.
Origin & insertion
Posterior surfaces of ulna and radius and the interosseous membrane in their middle thirds.
Action
Abducts the thumb at the carpometacarpal joint and radially deviates the wrist with the long extensor.
Innervation
Radial nerve — posterior interosseous branch (C7–C8).
Clinical notes
First-compartment tenosynovitis (de Quervain) is the classic thumb-tendon inflammation of new mothers and heavy phone users, tested by Finkelstein manoeuvre.
Related structures
Educational references
FAQ
What is the role of the Abductor pollicis longus?
A deep posteroradial forearm muscle; its tendon crosses the first dorsal compartment with the short extensor — a defining component of the anatomical snuffbox.
Why is the Abductor pollicis longus clinically important?
First-compartment tenosynovitis (de Quervain) is the classic thumb-tendon inflammation of new mothers and heavy phone users, tested by Finkelstein manoeuvre.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details