Forearm Anatomy: Compartments and Muscles

Study Notes

Consists of pronator teres, flexor carpi radialis, palmaris longus, and flexor carpi ulnaris
Muscles supplied by median nerve, except flexor carpi ulnaris and medial part of flexor digitorum profundus (supplied by ulnar nerve)

Pronator teres: originates from medial epicondyle of humerus and coronoid process of ulna, inserts into lateral aspect of shaft of radius, and is supplied by median nerve
Flexor carpi radialis: originates from medial epicondyle of humerus, inserts into bases of second and third metacarpal bones, and is supplied by median nerve
Palmaris longus: originates from medial epicondyle of humerus, inserts into flexor retinaculum and palmar aponeurosis, and is supplied by median nerve
Flexor carpi ulnaris: originates from medial epicondyle of humerus, inserts into pisiform, hook of hamate, and base of fifth metacarpal bone, and is supplied by ulnar nerve

Consists of flexor digitorum superficialis
Flexor digitorum superficialis: originates from medial epicondyle of humerus and coronoid process of ulna, inserts into middle phalanx of medial four fingers, and is supplied by median nerve

Consists of flexor pollicis longus, flexor digitorum profundus, and pronator quadratus
Flexor pollicis longus: originates from anterior surface of shaft of radius, inserts into distal phalanx of thumb, and is supplied by anterior interosseous nerve
Flexor digitorum profundus: originates from anteromedial surface of shaft of ulna, inserts into distal phalanges of medial four fingers, and is supplied by ulnar (medial half) and median (lateral half) nerves
Pronator quadratus: originates from anterior surface of shaft of ulna, inserts into anterior surface of shaft of radius, and is supplied by anterior interosseous nerve

Common interosseous artery is the main branch of ulnar artery in the forearm
Radial artery is the smaller terminal branch of the brachial artery
Radial artery passes downward and laterally in the forearm and lies on the anterior surface of the radius

Muscular branches to neighboring muscles
Radial recurrent artery that takes part in arterial anastomosis around the elbow joint
Palmar and dorsal carpal arteries
Superficial palmar branch that joins the ulnar artery to form the superficial palmar arch

Median nerve leaves the cubital fossa by passing between the two heads of the pronator teres
Median nerve branches: muscular branches, articular branches to the elbow joint, anterior interosseous nerve, and palmar cutaneous branch
Ulnar nerve passes behind the medial epicondyle of the humerus and enters the palm of the hand by passing in front of the flexor retinaculum