| Origin |
Lateral epicondyle of humerus |
| Insertion |
Extensor expansions of medial four digits |
| Action |
Extends medial four digits at metacarpophalangeal joints; Extends hand at wrist joint |
| Innervation |
Posterior interosseous nerve (C7
and C8), the continuation of the deep branch of the radial nerve
|
Arterial
Supply |
Interosseous recurrent and posterior interosseous arteries |