extensor carpi ulnaris

Introduction

Muscle of posterior compartment of forearm.

Origin

• humeral head: lateral epicondyle of humerus
• ulnar head: oblique line & posterior border of ulna

Insertion

base of 5th metacarpal bone

Action

extends & adducts hand at wrist

Innervation

radial nerve (posterior interosseous nerve)

More general terms

• skeletal muscle (voluntary muscle)