Name
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.