Name

# Abductor Pollicis Brevis

Pronunciation

(ab-DUK-tor POL-uh-sus BREV-is)

Origin/Proximal Attachment

Distal border of flexor retinaculum

Trapezium &scaphoid tubercles

Insertion/Distal Attachment

Lateral aspect of base of proximal phalanx of thumb

+/- slip to tendon of extensor pollicis longus

Action/Relevance

Abducts thumb (at MCP joint)

Assists to flex thumb (at MCP joint)

If attached to extensor pollicis longus may assist to extend thumb

Innervation

Median nerve - recurrent branch (C8, T1)

Notes

Muscle for abduction of the thumb. Origin: flexor retinaculum of wrist , scaphoid tubercle and trapezium. Insertion: the base of the radial aspect of proximal phalanx of the thumb.