Muscles - Arm and Forearm

Muscles of the Arm and Forearm Coracobrachialis Origin - Coracoid process Insertion - Middle third of medial surface of humerus Nerve - Musculocutaneous Action - Flexes and adducts arm Biceps brachii Origin - Long head, supraglenoid tubercle; short head, coracoid process Insertion - Radial tuberosity of radius Nerve - Musculocutaneous Action - Flexes arm and forearm, supinates forearm Brachialis Origin - Lower anterior surface of humerus Insertion - Coronoid process of ulna and ulnar tuberosity Nerve -Musculocutaneous Action - Flexes forearm Triceps Origin - Long head, infraglenoid tubercle; lateral head, superior to radial groove of humerus; medial head,Insertion - inferior to radial groove Insertion - Posterior surface of olecranon process of ulna Nerve - Radial Action - Extends forearm Anconeus Origin - Lateral epicondyle of humerus Insertion - Olecranon and upper posterior surface of ulna Nerve - Radial Action - Extends forearm Pronator teres Origin - Medial epicondyle and coronoid process of ulna Insertion - Middle of lateral side of radius Nerve - Median Action - Pronates and flexes forearm Flexor carpi radialis Origin - Medial epicondyle of humerus Insertion - Bases of second and third metacarpals Nerve - Median Action - Flexes forearm, flexes and abducts hand Palamaris longus Origin - Medial epicondyle of humerus Insertion - Flexor retinaculum, palmar aponeurosis Nerve - Median Action - Flexes forearm and hand Flexor carpi ulnaris Origin - Medial epicondyle (humeral head); medial olecranon, and posterior border of ulna (ulnar head) Insertion - Pisiform, hook of hamate, and base of fifth metacarpal Nerve - Ulnar Action - Flexes forearm; flexes and adducts hand Flexor digitorum superficialis Origin - Medial epicondyle, coronoid process, oblique line of radius Insertion - Middle phalanges of finger Nerve - Median Action - Flexes proximal interphalangeal joints, flexes hand and forearm Flexor digitorum profundus Origin - Anteromedial surface of ulna, interosseous membrane Insertion - Bases of distal phalanges of fingers Nerve - Ulnar and median Action - Flexes distal interphalangeal joints and hand Flexor pollicis longus Origin - Anterior surface of radius, interosseous membrane, and coronoid process Insertion - Base of distal phalanx of thumb Nerve - Median Action - Flexes thumb Pronator quadratus Origin - Anterior surface of distal ulna Insertion - Anterior surface of distal radius Nerve - Median Action - Pronates forearm Brachioradialis Origin - Lateral supracondylar ridge of humerus Insertion - Base of radial styloid process Nerve - Radial Action - Flexes forearm Extensor carpi radialis longus Origin - Lateral supracondylar ridge of humerus Insertion - Dorsum of base of second metacarpal Nerve - Radial Action - Extends and abducts hand Extensor carpi radialis brevis Origin - Lateral epicondyle of humerus Insertion - Posterior base of third metacarpal Nerve - Radial Action - Extends and abducts hands Extensor digitorium Origin - Lateral epicondyle of humerus Insertion - Extensor expansion, base of middle and digital phalanges Nerve - Radial Action - Extends fingers and hand Extensor digiti minimi Origin - Common extensor tendon and interosseous membrane Insertion - Extensor expansion, base of middle and distal phalanges Nerve - Radial Action - Extends little finger Extensor carpi ulnaris Origin - Lateral epicondyle and posterior surface of ulna Insertion - Base of fifth metacarpal Nerve - Radial Action - Extends and adducts hand Supinator Origin - Lateral epicondyle, radial collateral and annular ligaments, supinator fossa and crest of ulna Insertion - Lateral side of upper part of radius Nerve - Radial Action - Supinates forearm Abductor pollicis longus Origin - Interosseous membrane, middle third of posterior surfaces of radius and ulna Insertion - Lateral surface of base of first metacarpal Nerve - Radial Action - Abducts thumb and hand Extensor pollicis longus Origin - Interosseous membrane and middle third of posterior surface of ulna Insertion - Base of distal phalanx of thumb Nerve - Radial Action - Extends distal phalanx of thumb and abducts hand Extensor pollicis brevis Origin - Interosseous membrane and posterior surface of middle third of radius Insertion - Base of proximal phalanx of thumb Nerve - Radial Action - Extends proximal phalanx of thumb and abducts hand Extensor indicis Origin - Posterior surface of ulna and interosseous membrane Insertion - Extensor expansion of index finger Nerve - Radial Action - Extends index finger ◄.....Go back to the Gross Anatomy homepage