Name

# Abductor Pollicis Longus

Pronunciation

(ab-DUK-tor POL-uh-sus LONG-gus)

Origin/Proximal Attachment

Posterior surfaces of ulna & radius

Interosseous membrane

Antebrachial fascia

Insertion/Distal Attachment

Lateral aspect of base of 1st metacarpal

Action/Relevance

Abducts the 1st metacarpal

Assists to extend & rotate the thumb

Radially deviates the hand at the wrist

Flexes the hand at the wrist

Innervation

Radial nerve - posterior interosseous (C6, 7,8)

Notes

Muscle for abduction and extension of the thumb. Origin: posterior aspect of ulna, interosseous membrane of the forearm and middle posterior aspect of radius. Insertion: lateral aspect of the base of the first metacarpal.