What Is the Flexor Digitorum Superficialis?
The flexor digitorum superficialis is a muscle contained within the anterior compartment of the forearm, located on the palm side of the arm. Of the eight muscles found here, five are considered to be in the superficial layer, or close to the skin, and three are in the deep layer, or close to the bone. As this muscle is so deep in the superficial layer, it is sometimes classified as an intermediate muscle of the anterior forearm and is a flexor of the four fingers as well as the wrist joint. Situated just beneath the flexor carpi radialis, the palmaris longus, and the flexor carpi ulnaris, all flexors of the wrist, as well as the pronator teres, a rotator of the forearm, the flexor digitorum superficialis has two heads, or sections, and therefore two points of origin. The humeroulnar head, sometimes considered itself to be two separate heads, has its origin on the medial epicondyle of the humerus, one of two rounded bony protrusions at the base of the humerus bone in the upper arm, as
