Subscapularis, Supraspinatus, Infraspinatus, Teres Minor

Origin: Subscapular fossa of scapula

Insertion: Lesser tubercle of humerus

Action: Internal/medial rotation and adduction of humerus

Origin: Supraspinous fossa of scapula

Insertion: Greater tubercle of humerus

Action: External rotation, abduction of humerus, and stabilization of head of humerus

Origin: Infraspinous fossa of scapula

Insertion: Greater tubercle of humerus

Action: External rotation, lateral rotation, and extension of humerus

Origin: Upper 2/3 of axillary border of scapula

Insertion: Greater tubercle of humerus

Action: External rotation, lateral rotation, and extension of humerus

Origin: Thoracolumbar aponeurosis, lower 6 thoracic spinous processes, sacrum and iliac crest, lower 3 to 4 ribs, and inferior angle of scapula

Insertion: Intertubercular (bicipital) groove of humerus

Action: Extension, internal/medial rotation, and adduction of humerus

Origin: Inferior angle of scapula (dorsal surface), lower 1/3 of axillary border of scapula

Insertion: Medial lip of intertubercular (bicipital) groove of humerus

Action: Extension, internal/medial rotation, and adduction of humerus

Origin: Clavicular head - medial half of clavicle, sternal head - sternum, cartilages of upper 6 ribs

Insertion: Lateral lip of intertubercular (bicipital) groove of humerus

Action: Adduction, horizontal adduction, medial/internal rotation of humerus, flexion, and extension of humerus from a flexed position

Origin: Anterior surface of ribs 3, 4, 5 near costal cartilages

Insertion: Coracoid process of scapula on medial border of superior surface

Action: Protraction, depression, and downward rotation of scapula

Origin: External occipital protuberance, ligamentum nuchae, C7-T12 spinous processes

Insertion: Upper - lateral 1/3 of clavicle and acromion, middle - spine of scapula, lower - root of spine of scapula

Action: Upper - elevation and upward rotation of scapula, middle - retraction of scapula, lower - depression and upward rotation of scapula

Origin: C1-C4 (transverse processes)

Insertion: Vertebral border of scapula from superior angle to root of spine

Action: Elevation and downward rotation of scapula

Origin: Minor - C7 and TI, major - T2-T5

Insertion: Minor - root of spine of scapula, major - vertebral border of scapula from root of spine to inferior angle

Action: Retraction and downward rotation of scapula

Origin: Coracoid process of scapula

Insertion: Tuberosity of radius and bicipital aponeurosis

Action: Flexion of elbow, supination of forearm, and flexion of humerus

Origin: Supraglenoid tubercle of scapula

Insertion: Tuberosity of radius, bicipital aponeurosis

Action: Flexion of elbow and supination of forearm

Origin: Lateral 1/3 of clavicle

Insertion: Deltoid tuberosity of humerus

Action: Flexion, horizontal adduction, and internal/medial rotation of humerus

Origin: Lateral acromion

Insertion: Deltoid tuberosity of humerus

Action: Abduction of humerus to 90 degrees

Origin: Spine of scapula

Insertion: Deltoid tuberosity of scapula

Action: Extension, horizontal abduction, and lateral rotation of humerus