Forearm is divided into two basic compartments. They are called anterior and posterior compartments. This is done by the bones called such as radius and ulna which are bound by interosseous membrane. The compartments are also known for their functions. The posterior group is known for extensor muscles and anterior is known for flexion. The muscles included in anterior are: pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum, flexor digitorum profundus, flexor pollicis longus and pronator quadratys. The area also includes median nerve and ulnar artery.