Posterior compartment of the forearm

Posterior compartment of the forearm
Cross-section through the middle of the forearm. (Anterior compartment is at top; posterior compartment is at bottom.)
Latin	compartimentum antebrachii posterius
Artery	radial artery, radial recurrent artery , profunda brachii, posterior interosseous artery
Nerve	radial nerve, posterior interosseous nerve

The posterior compartment of the forearm (or extensor compartment) contains the following muscles:

Muscles

Level	Muscle	E/I
(see below)	brachioradialis	I
superficial	extensor carpi radialis longus	E
superficial	extensor carpi radialis brevis	E
superficial	extensor carpi ulnaris	E
intermediate	extensor digitorum	E
intermediate	extensor digiti minimi	E
deep	abductor pollicis longus	E
deep	extensor pollicis brevis	E
deep	extensor pollicis longus	E
deep	extensor indicis	E
deep	supinator	I
deep	anconeus	I

• "E/I" refers to "extrinsic" or "intrinsic".

The Brachioradialis, flexor of the forearm, is unusual in that it is located in the posterior compartment, but it is actually in the anterior portion of the forearm.

Innervation

All muscles of the posterior compartment of the forearm are innervated by the radial nerve of the posterior cord of the brachial plexus. The somatomotor fibers of the radial nerve branch from the main radial nerve at the level of the radial groove of the humerus.

See also

• Compartment syndrome
• Anterior compartment of the forearm

Additional images

• 

  Transverse section across distal ends of radius and ulna.

• 

  Transverse section across the wrist and digits.