The posterior interosseous nerve (or dorsal interosseous nerve/deep radial nerve) is a

nerve A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the Electrochemistry, electrochemical nerv ...

in the forearm. It is the continuation of the deep branch of the radial nerve, after this has crossed the supinator muscle. It is considerably diminished in size compared to the deep branch of the radial nerve. The nerve fibers originate from cervical segments C7 and C8 in the spinal column.

Structure

Course

It descends along the

interosseous membrane An interosseous membrane is a thick dense fibrous sheet of connective tissue that spans the space between two bones, forming a type of syndesmosis joint. Interosseous membranes in the human body: * Interosseous membrane of forearm * Interosseo ...

, anterior to the

extensor pollicis longus muscle In human anatomy, the extensor pollicis longus muscle (EPL) is a skeletal muscle located dorsally on the forearm. It is much larger than the extensor pollicis brevis, the origin of which it partly covers and acts to stretch the thumb together wit ...

, to the back of the carpus, where it presents a gangliform enlargement from which filaments are distributed to the ligaments and articulations of the carpus.

Supply

The posterior interosseous nerve supplies all the muscles of the

posterior compartment of the forearm The posterior compartment of the forearm (or extensor compartment) contains twelve muscles which primarily extend the wrist and digits. It is separated from the anterior compartment by the interosseous membrane between the radius and ulna. Struc ...

, except anconeus muscle, brachioradialis muscle, and extensor carpi radialis longus muscle. In other words, it supplies the following muscles: *

Extensor carpi radialis brevis muscle In human anatomy, extensor carpi radialis brevis is a muscle in the forearm that acts to extend and abduct the wrist. It is shorter and thicker than its namesake extensor carpi radialis longus which can be found above the proximal end of the ext ...

— deep branch of radial nerve *

Extensor digitorum muscle The extensor digitorum muscle (also known as extensor digitorum communis) is a muscle of the posterior forearm present in humans and other animals. It extends the medial four digits of the hand. Extensor digitorum is innervated by the posterior in ...

Extensor digiti minimi muscle The extensor digiti minimi (extensor digiti quinti proprius) is a slender muscle of the forearm, placed on the ulnar side of the extensor digitorum communis, with which it is generally connected. It arises from the common extensor tendon by a t ...

* Extensor carpi ulnaris muscle * Supinator muscle — deep branch of radial nerve *

Abductor pollicis longus muscle In human anatomy, the abductor pollicis longus (APL) is one of the extrinsic muscles of the hand. Its major function is to abduct the thumb at the wrist. Its tendon forms the anterior border of the anatomical snuffbox. Structure The abducto ...

* Extensor pollicis brevis muscle *

Extensor pollicis longus muscle In human anatomy, the extensor pollicis longus muscle (EPL) is a skeletal muscle located dorsally on the forearm. It is much larger than the extensor pollicis brevis, the origin of which it partly covers and acts to stretch the thumb together wit ...

* Extensor indicis muscle The posterior interosseous nerve provides

proprioception Proprioception ( ) is the sense of self-movement, force, and body position. Proprioception is mediated by proprioceptors, a type of sensory receptor, located within muscles, tendons, and joints. Most animals possess multiple subtypes of propri ...

to the joint capsule of the distal radioulnar articulation, but not

pain Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...

sensation.

Clinical significance

The posterior interosseous nerve may be entrapped at the arcade of Frohse, which is part of the supinator muscle. This nerve can be injured in Monteggia fracture due to dislocation of the proximal head of radius bone. Posterior interosseous neuropathy is purely a motor syndrome resulting in finger drop due to no extension of IP joints and radial wrist deviation on extension.

References

. Nerves of the upper limb {{neuroanatomy-stub

Structure

Course

Supply

Clinical significance

See also

References