Posterior compartment of the forearm

Posterior compartment of the forearm
Extensor compartment of the forearm and hand
Details
System	Musculoskeletal system
Artery	radial artery, radial recurrent artery , profunda brachii, posterior interosseous artery
Nerve	radial nerve,posterior interosseous nerve
Identifiers
Latin	compartimentum antebrachii posterius
TA	A04.6.01.007
FMA	38411
Anatomical terminology []

The posterior compartment of the forearm (or extensor compartment) contains 12 muscles which are chiefly responsible for extension of the wrist and digits, and supination of the forearm. It is separated from the anterior compartment by the interosseous membrane between the radius and ulna.

There are generally 12 muscles in the posterior compartment of the forearm, which can be divided further into the superficial, the intermediate and the deep layer. Most of the superficial and the intermediate muscles share a common origin which is the outer part of the elbow, the lateral epicondyle of humerus. The deep muscles arise from distal part of ulna and the surrounding interosseous membrane.

The brachioradialis, flexor of the elbow, is unusual in that it is located in the posterior compartment, but it is actually in the anterior compartment of the forearm. The anconeus, assisting in extension of the elbow joint, is by some considered part of the posterior compartment of the arm.

The majority of muscles found in the posterior compartment are extrinsic, meaning its origin has some distance from the part that it moves. The brachioradialis and the anconeus are considered intrinsic muscles because they both arise within the forearm and they both move the forearm.

Extensor tendons pass through the extensor retinaculum at wrist joint in 6 synovial sheaths, also referred to compartments.

The supinator and the anconeus are the two muscles in the posterior compartment of the forearm that do not pass through wrist extensor compartments.

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