The muscles of the forearm are mainly located around the ulnar radius, and in the forearm there are two bones parallel to the long axis of the forearm, the radius and the ulna. The patient can feel the two bones under the skin, especially the ulna is very good to touch, very close to the skin. When making a fist, the patient can use the other hand to touch the forearm here, and all the muscles that can be touched belong to the muscles of the forearm. The muscles of the forearm are divided into anterior and posterior groups, and most of these muscles originate from the medial or lateral epicondyle of the humerus. This is located just above the elbow joint and belongs to the distal end of the humerus. The stopping point of the muscles of the anterior wall, on the other hand, may be located on the bony surface of the ulnar radius, on the carpal bones distal to the wrist joint or on the phalanges of the fingers. The muscles of the forearm have the primary function of flexing and extending the elbow, wrist, and interphalangeal joints of the fingers. These muscles are important for the movement of the entire arm as well as for the fine movements of the hand.