Flexor & Extensor Muscles in the Forearm

Self Massaging Wrist

There are more than 14 different flexor and extensor muscles in your forearms. These muscles are responsible for moving your wrists toward and away from your body. There are also two muscles responsible for elbow flexion in your forearm. It is important to learn about these muscles and what they do so that you can better train them and improve your sports performance.

Wrist Extensors

There are a total of eight wrist extensors in the forearm. The names of these muscles are all preceded by the term extensor which means open up the joint angle, in this case the wrist. There is the digitorum, carpi radialis longus, carpi radialis brevis, carpi ulnaris, indicis, digiti minimi, pollicis longus and pollicis brevis. These muscles are all located on top of the forearm. While the primary function of your wrist extensors is wrist extension, these muscles also assist with the abduction and adduction movement of the wrist joint. Wrist abduction is the lateral movement of your wrists to the right and left.

Wrist Flexors

You have a total of six wrist flexor muscles. The names of five of these muscles are preceded by flexor except the palmaris longus. The other muscles are the digitorum superficialis, digitorum profundus, carpi radialis, carpi ulnaris and pollicis longus. While the names are similar to the wrist extensor muscles, their function is the opposite. Wrist flexor refers to closing the angle at the wrist joint. Like your wrist extensors the wrist flexors also assist with abduction and adduction of your wrist.

Brachioradialis and Brachialis

Two of the bigger muscles in your forearms are the brachioradialis and brachialis. These two muscles are often assisting muscles to your biceps which is the major flexor of your elbow joint. The brachioradialis is most active when your hand is in a neutral or hammer position when flexion of your elbow is occurring. Your brachialis is most active during isometric holds of the flexion and will aid in preventing extension at the elbow.


Wrist flexors are important in a wide variety of sports movements such as the follow-through on a basketball shot or snapping a ball as you pitch. Your wrist extensors are also important in sports for movements such as tennis backhand. The hand motion of sprinting requires rapid flexion of the elbow and your brachioradialis and brachialis will assist with this movement. All of these muscles relate to overall forearm strength and are important for gripping weight training objects such as dumbbells and barbells. When these muscles are weak, they can hamper your ability to train your larger muscles. This makes it important to train these muscles for sports and for holding heavier weights in the weight room.


If you're interested in working the muscles in your forearms consult ExRx.net and the American Council on Exercise's exercise library for examples.