Forearm Forearm The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in anatomy, technically, means only the region of the upper arm, whereas the lower "arm" is called the forearm. It is homologous to the region of the leg that lies between the knee and the ankle joints, the crus. The forearm contains two long bones, the radius and the ulna, forming the radioulnar
Posterior compartment of the forearm muscles because they both arise within the forearm and they both move the forearm. Extensor tendons pass through the extensor retinaculum at wrist joint in 6 synovial sheaths, also referred to compartments. The supinator and the anconeus are the two muscles in the posterior compartment of the forearm that do not pass through wrist extensor compartments. The muscles of the posterior compartment of the forearm are innervated by the radial nerve and its branches. The radial nerve arises from the posterior cord of the plexus. The somatomotor fibers of the radial nerve branch from the main radial nerve at the