Muscle
Abductor pollicis brevis
Thenar - abducts the thumb
High-yield
Thenar muscle; weak/atrophic in carpal tunnel syndrome. Recurrent (median) branch.
Overview
A superficial thenar muscle that abducts the thumb, tested in carpal tunnel syndrome. Recurrent branch of the median nerve.
Reference facts
- Origin
- Flexor retinaculum, scaphoid, and trapezium
- Insertion
- Lateral base of the proximal phalanx of the thumb
- Action
- Abducts the thumb at the carpometacarpal and MCP joints
- Innervation
- Recurrent branch of the median nerve (C8, T1)
- Blood supply
- Superficial palmar branch of the radial artery
Frequently asked questions
What does the abductor pollicis brevis do?
The abductor pollicis brevis abducts the thumb at the carpometacarpal and MCP joints.
What nerve innervates the abductor pollicis brevis?
The abductor pollicis brevis is innervated by the recurrent branch of the median nerve (C8, T1).
Where does the abductor pollicis brevis attach?
The abductor pollicis brevis originates from the flexor retinaculum, scaphoid, and trapezium and inserts on the lateral base of the proximal phalanx of the thumb.
What is the blood supply of the abductor pollicis brevis?
The abductor pollicis brevis is supplied by the superficial palmar branch of the radial artery.