Summary Extensor Pollicis Brevis Origin Posterior surfaces of radius and interosseous membrane Insertion Base of proximal phalanx of thumb Action Extends proximal phalanx of thumb at metacarpophalangeal joint Innervation Posterior interosseous nerve (C7, C8) Arterial Supply Posterior interosseous artery
Extensor Pollicis Brevis summary OBC What is the origin? Origin Posterior surfaces of radius and interosseous membrane Show Bullets