What Is the Extensor Carpi Radialis Longus?

Medically Reviewed by Murtaza Cassoobhoy, MD on May 25, 2023
Written by WebMD Editorial Contributor
4 min read

The extensor carpi radialis longus (ECRL) is a muscle in your forearm that works in conjunction with the other muscles and tendons in your arm to help move your wrist and hand. It is in the same muscle family as the extensor carpi radialis brevis (ECRB). Both muscles need to be strong to move the arm, wrist, and hand appropriately. 

The ECRL is a particularly long muscle. It’s attached at the base of the humerus on one end and the second metacarpal bone on the other end. 

Along with the ECRB, the ECRL is in a family of muscles called radial wrist extensors. Radial wrist extensors help with movement in your elbow, forearm, wrist, and hands. Any time you pick up an object, write with a pencil, or throw a ball, you’re using these muscles. 

A recent study found that over 50% of radial wrist extensors such as ECRLs had some sort of anomaly. For the most part, these anomalies are not harmful, and they may actually help your body under certain circumstances. 

One common anomaly was the presence of tendons connecting the ECRL to the ECRB. Another common anomaly was the presence of an extra tendon, which has come to be known as the extensor carpi radialis intermedius (ECRI). 

This is important because ECRIs can be used for tendon transfers, which have been shown to help rehabilitate certain people with paralytic conditions. 

There are many other muscles and tendons that work together when you use your arm, so if you have a problem in that area, it can be hard to know if the issue is due to a pulled muscle, a weak muscle, a weak tendon, or some combination. However, there are certain medical conditions that may suggest your radial wrist extensors are weak and need to be strengthened.‌

Tennis Elbow, also known as lateral epicondylitis, is a condition that can develop when you overuse the muscles and tendons in your forearm. This condition can cause pain and a burning sensation in your elbow and arm. 

Although it got its name, “tennis elbow,” because it’s a common injury among tennis players, you don’t have to be a tennis player to suffer from tennis elbow. Any job or activity that relies on repetitive forearm motion — including painting, carpentry, and knitting — can lead to tennis elbow. ‌

The condition is caused by inflammation in the tendons and muscles that control arm movement. It can be treated with a combination of rest, physical therapy, NSAID pain relievers, and — in some cases — surgery.

Carpal Tunnel Syndrome, also known as median nerve compression, develops when there is too much pressure on your median nerve, which runs through your arm. Symptoms of carpal tunnel syndrome include:‌

  • Numbness or tingling in the hand
  • Weakening grip
  • Suddenly dropping items and feeling like your hand “gave out” 
  • Numbness or tingling that runs all the way up to the shoulders

A number of things can cause carpal tunnel syndrome, including repetitive motion (like typing), pregnancy, or inflammatory conditions. Other times, you may not be able to pinpoint the exact cause of your carpal tunnel syndrome. 

When you start feeling pain in your arm, you can let it rest for a few days and use ice and NSAID pain relievers to bring the swelling down. ‌

If that doesn’t work, you may need to see a doctor. Imaging tests can help pinpoint the cause of your arm pain and determine which muscles, tendons, or nerves are being affected. From there, they can help you develop a plan to regain the use of your arm and reduce pain. 

The best exercises to improve strength in your extensor carpi radialis longus are exercises that require you to move your wrist, hands, elbows, and forearms. Some ideas include: 

  • Holding your arm out straight and gently pulling back on your fingertips
  • Holding your arm out straight and gently pushing down on your hand
  • Rotating your wrists in slow, deliberate circles
  • Holding a weight or a can of food in your hand and slowly lifting it toward your chest and lowering it down straight again
  • Laying on the floor on your stomach, prop yourself up on your forearms and hold yourself in a plank position
  • Getting down on your hands and knees, slowly bend your arms to lower your chest toward the floor and then push up again, being sure to keep your back straight‌

If you think you may have injured your extensor carpi radialis longus or are feeling any discomfort in your forearm, please visit your doctor.