Name
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.