abductor pollicis longus

Introduction

Muscle of the posterior compartment of the forearm.

Origin

• interosseous membrane
• posterior surface of the radius
• posterior surface of the ulna

Insertion

lateral side of the base of the 1st metacarpal

Action

• abducts thumb
• assists in extending thumb

Innervation

radial nerve

Pathology

• de Quervain's tenosynovitis is a stenosing tenosynovitis of the 1st dorsal retinacular compartment of the wrist involving tendons of the:
• extensor pollicis brevis
• abductor pollicis longus

More general terms

• skeletal muscle (voluntary muscle)