Muscles of Pectoral Girdle & Arm

Biceps branchii

Flexes elbow joint and supinates forearm; weak flex of arm at shoulder

Brachialis

Major flexor of forearm/ forearm

Brachioradialis

Flexes elbow; stablizes elbow

Triceps Brachii

Prime mover elbow extension; powerful; medial head pm, long and lateral extend against resistance

Pronator Teres

pronation

Flexor Carpi Radialis

Powerful flexor of wrist; abducts hand; weak synergist of elbow flexion

Palmaris Longus

Tenses skin and fascia of palm during hand movements; weak wrist flexor; weak synergist for elbow flexion

Flexor Carpi Ulnaris

Powerful flexor of wrist; also adducts hand

Flexor Digitorum Superficialis

Flexes wrist & middle phalanges of finger 2-5; important finger flexor for speed & flexion against resistance

Flexor Digitorum Profundus

Flexes distal interphalangeal joints; slow-acting flexor of any/all fingers; helps flex wrist

Extensor Carpi Radialis Longus

Extends and abducts wrist; extends with extensor carpi ulnaris & abducts with flexor carpi radialis

Extensor Carpi Radialis Brevis

Extends and abducts wrist; synergist with extensor carpi radialis longus to steady wrist during finger flexion

Extensor Digitorum

Prime mover of finger extension; extends wrist; abduct (flare) fingers; extensor digiti minimi extends little finger

Extensor Carpi Ulnaris

Extends and adducts wrist; extends with extensor carpi radialis & adducts with flexor carpi ulnaris

Supinator

Assists biceps brachii forcibly supinate forearm; works alone in slow supination; antagonist of pronator muscles

Extensor Indicis

Extends index finger and assists in extending wrist