Muscles That Move The Arm And Forearm

Front 1

Pectoralis Major

Back 1

Origin: clavicle, sternum cartilage of the 2nd to 6th ribs

Insertion: greater tubercle and intertubercle sulcus of humerus

Action: flexes, adducts and rotates arm medially

Front 2

Lastissimus Dorsi

Back 2

Origin: spines of inferior 6 thoracic vertebrae, lumbar vertebrae, crests of sacrum and ilium, inferior 4 ribs

Insertion: intertubercular sulcus of humerus

Action: extends, adducts and rotates arm medially. Draws arm inferiorly and posteriorly

Front 3

Deltoid

Back 3

Origin: acromial extremity of clavicle and acromion and spine of clavicle

Insertion: deltoid tubercle of humerus

Action: rotates arm medially abducts at shoulder joint

Front 4

Biceps brachii

Back 4

Origin: long head-tubercle superior to glenoid cavity; short head of corticoid process of scapula

Insertion: radial tuberosity and bicipital aponeurosis

Action: flexes and supinates forearm; flexes arm

Front 5

Brachialis

Back 5

Origin: distal anterior surface of humerus

Insertion: owner tuberosity and corticoid process of ulna

Action: flexes forearm

Front 6

Tricep brachii

Back 6

Origin: long head projection inferior to glenoid cavity of scapula; lateral head; lateral and posterior surface of humerus Superior to radial groove; medial head-entire posterior surface of humerus inferior to the groove for the radial nerve

Insertion: olecranon of ulna

Action: extends forearm, extends arm