Name Abductor pollicis longusPronunciation (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) | 
