The extensor carpi radialis longus is a muscle located within the posterior forearm in the superficial compartment. Its lateral position in the forearm produces extension and abduction of the wrist.
The tendon of the extensor carpi radialis longus passes through the second extensor compartment at the wrist. The structure of the muscle consists of an origin point from the lateral supracondylar ridge of the humerus and an insertion point at the base of the second metacarpal. It is innervated by the radial nerve and supplied by the radial artery.
The primary function of the extensor carpi radialis longus is to produce extension and abduction of the wrist. The joint actions of the extended flexion and abduction occur at the radiocarpal joint and midcarpal joint. During contraction, the muscle lengthens and applies a radial force to the wrist, producing the extension and abduction. When the muscle relaxes, the force is released, causing the wrist to return to a neutral position.
The extensor carpi radialis longus is an essential component of thumb and finger movements. It helps to maintain stability and support when grasping objects. The muscle functions as a stabilizer during activities such as typing and other keyboard tasks, as well as rotational movements such as open and close jars or turning doorknobs.
The extensor carpi radialis longus can be affected by numerous injuries or disorders. A common injury to the muscle may be a tear due to over-stretching or overuse. This can cause pain and swelling in the forearm and elbow and can restrict movement of the wrist. Repetitive strain injuries, such as carpal tunnel syndrome or tendonitis, can also affect the muscle. Other potential injuries may include a dislocated shoulder, or a fracture in the arm bone.
The extensor carpi radialis longus can be strengthened through various exercises. Wrist curls and reverse wrist curls help strengthen the muscle, as well as a variety of rotational exercises. It is important to warm up the muscle before exercising to prevent injury. Performing static stretches on a regular basis can help to increase flexibility of the muscle and help reduce the risk of injury.
Figure 1 shows the muscles of the superficial layer of the posterior forearm. The extensor carpi radialis longus is located between the brachioradialis and the extensor carpi radialis brevis.
The extensor carpi radialis longus plays an important role in forearm and wrist movement as well as stability and support during various activity. Injury to the muscle can lead to decreased function of the wrist and should be taken seriously. Proper care and routine exercise can help to strengthen the muscle and reduce the risk of injury.
