What is the Extensor Carpi Radialis Longus?

The extensor carpi radialis longus is a thin, long muscle that is found in the forearm. It is one of five primary muscles in the arm that are used to move and control the wrist joint. Its main function is to dorsiflex the wrist joint as well as abduct the hand. The muscle is commonly involved in overuse injuries of the forearm such as tendinitis which occur with a variety of sports such as rowing, badminton and tennis.

The origin of the extensor carpi radialis longus is at the humerus and the insertion is on the dorsal side of the second of the series of bones known as the metacarpals. It has its innervations via the radial nerve. As a muscle the extensor carpi radialis longus is relatively long and extends from the elbow down to the wrist. An example of a common use of the muscle is typing which recruits many of the muscles in the forearm.

To begin with, the muscle is mainly a tendon that continues along the arm. It then moves into a second tendon compartment before turning into muscle. The upper third of the muscle turns into a tendon before insertion.

Injuries to the extensor carpi radialis longus are relatively common as it’s a muscle that is used a lot in everyday life. Not only do sports such as tennis potentially damage it, but any repetitive action that puts the muscle under strain can eventually cause an overuse injury. Many people who work at computers suffer from tendinitis of the wrist extensors as these muscles are put in an artificially strained position for long periods of time.

Stretching is often an effective way of preventing tendinitis from occurring in the muscle. In some cases strengthening may also be required. To stretch the extensor carpi radialis longus the person should stand with his or her arm out in front before using the other hand to pull the fingers downwards with the wrist pointing up. A stretch should be felt along the forearm. Stretches such as these should be held for at least 30 seconds.

There are two extensor carpi radialis muscles &mdahs; the other being the extensor carpi radialis brevis. The word brevis is Latin for short. The brevis muscle inserts on the base of the third metacarpal rather than the second although it is used for many of the same movements such as typing. A common injury associated with the brevis muscle is tennis elbow.