Muscles of the Forearm and Hand

Flexor carpi radialis

-Origin medial epicondyle of humerus (common flexor tendon) -Insertion Bases of second and third metacarpal bones -Nerve *Median nerve* -*Actions* Flexion and abduction at wrist - wrist flexion (abducts hand with extensor carpi radialis)

pronator teres

-Origin: humeral (medial epicondyle) and ulna (coronoid process) -Insertion Middle of the lateral surface of the body of the radius -*Actions* pronation of forearm, flexes elbow

flexor carpi ulnaris

Humerus (medial epicondyle) and ulna (olecranon process) Insertion: metacarpals V, carpals Action: flexes wrist; adduction of hand with extensor carpi ulnaris

flexor digitorum superficialis

Origin *medial epicondyle of the humerus* (common flexor tendon) as well as parts of the radius and ulna. Insertion: middle phalanges II-V Action: flexes wrist and middle phalanges of the fingers

flexor pollicis longus

Origin The middle 2/4 of the anterior surface of the radius and the medial epicondyle of the humerus Insertion The base of the distal phalanx of the thumb Nerve Anterior interosseous nerve (branch of median nerve) (C8, T1) Actions Flexion of the thumb. Antagonist Extensor pollicis longus muscle, Extensor pollicis brevis muscle

Brachioradialis

Origin: Humerus Insertion: Radius (styloid process) action: flexes forearm

Posterior Superficial Forearm Muscles

brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor carpi ulnaris,

Anterior Deep Forearm Muscles

flexor digitorum profundus, flexor pollicis longus, pronator quadratus

extensor carpi ulnaris

humerus (lateral epicondyle) insertion: metacarpal V Action: extends (adducts with help of flexor carpi ulnaris

extensor digitorum

origin: humerus (lateral epicondyle) insertion: distal phalanges II-V action: finger and wrist extension and finger abduction

Supinator

origin: humerus (lateral epicondyle) and proximal ulna insertion: proximal radius action: supinates forearm

palmaris longus

origin: humerus (medial epicondyle) insertion: palm action: weak wrist flexion

extensor carpi radialis longus

origin: humerus above lateral condyle insertion: metacarpal II action: extends and abducts wrist

flexor digitorum profundus

origin: ulna insertion: distal phalanges II-V action: flexes distal joints of fingers and wrist

pronator quadratus

origin: ulna (anterodistal) insertion: radius (anterior distal) action: pronates forearm and hand

extensor carpi radialis brevis

origin:humerus (lateral epicondyle) insertion:metacarpal III action: extends and abducts wrist

Anterior Superficial Forearm Muscles

pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis

posterior deep forearm muscles

supinator

Pronation

turning the palm downward