Name
Pronunciation
(eks-TEN-sor POL-uh-sus BREV-is)
Origin/Proximal Attachment
Posterior surface of radius (below abductor pollicis longus) Interosseous membraneAntebrachial fascia
Insertion/Distal Attachment
Base of proximal phalanx of thumb
Action/Relevance
Extends the proximal phalanx & 1st metacarpal of the thumbRadially deviates the hand at the wrist
Innervation
Radial nerve - posterior interosseous (C6, 7+/-8))
Notes
Short muscle for extension of thumb. Origin: dorsal surface of radius and interosseous membrane of the forearm . Insertion: dorsal aspect of the base of the proximal phalanx of the thumb.