Extensor digitorum communis

Extensor digitorum communis

Latin	musculus extensor digitorum communis
Nerve	Posterior interosseous nerve

The extensor digitorum communis (EDC) is a muscle of the posterior compartment of the forearm that is primarily responsible for the extension of the fingers and the wrist. It is one of the key muscles involved in the movement of the hand and is essential for various functions such as gripping and releasing objects.

Anatomy

Origin

The extensor digitorum communis originates from the lateral epicondyle of the humerus, which is a common origin point for the muscles of the posterior compartment of the forearm. This origin is part of the common extensor tendon.

Insertion

The muscle inserts into the extensor expansion of the second to fifth digits. The extensor expansion is a complex structure that allows for the coordinated extension of the fingers.

Blood Supply

The blood supply to the extensor digitorum communis is primarily provided by the posterior interosseous artery, which is a branch of the common interosseous artery originating from the ulnar artery.

Innervation

The extensor digitorum communis is innervated by the posterior interosseous nerve, a branch of the radial nerve. This nerve provides the motor supply necessary for the muscle's function.

Function

The primary function of the extensor digitorum communis is to extend the fingers at the metacarpophalangeal joints and to assist in the extension of the wrist. It plays a crucial role in hand movements that require the opening of the hand, such as releasing a grip or spreading the fingers.

Clinical Significance

Injury

Injuries to the extensor digitorum communis can result in difficulty extending the fingers and wrist. Common injuries include tendonitis and lateral epicondylitis, also known as "tennis elbow," which can affect the common extensor tendon.

Surgical Considerations

In cases of severe injury or tendon rupture, surgical intervention may be necessary to repair the extensor mechanism. Understanding the anatomy of the extensor digitorum communis is crucial for surgeons performing such procedures.

Related Muscles

The extensor digitorum communis works in conjunction with other muscles of the forearm, such as the extensor indicis, extensor digiti minimi, and extensor carpi radialis longus and extensor carpi radialis brevis, to facilitate complex hand movements.

See Also

• Forearm muscles
• Hand anatomy
• Radial nerve