Anterior interosseous

Anterior interosseous nerve (AIN) is a branch of the median nerve that supplies the deep muscles in the anterior compartment of the forearm. It is a purely motor nerve, meaning it does not carry any sensory information.

Anatomy

The anterior interosseous nerve originates from the median nerve, just below the elbow. It travels down the forearm, running along the interosseous membrane, which is a thick connective tissue that separates the anterior and posterior compartments of the forearm. The nerve ends in the wrist, where it innervates several muscles.

Function

The anterior interosseous nerve innervates three muscles in the forearm: the flexor digitorum profundus, the flexor pollicis longus, and the pronator quadratus. These muscles are involved in flexion of the fingers and thumb, and pronation of the forearm.

Clinical significance

Damage to the anterior interosseous nerve can result in a condition known as anterior interosseous syndrome (AIS). This is characterized by weakness in the muscles innervated by the nerve, leading to difficulty in flexing the thumb and index finger. AIS can be caused by various factors, including trauma, compression, and certain medical conditions such as rheumatoid arthritis.

See also

• Median nerve
• Interosseous membrane of the forearm
• Anterior interosseous syndrome