Muscles of the Pectoral Girdle and Shoulder

Trapezius: action

Superior fibers: elevate and superiorly rotate scapula

Middle fibers: retract scapula

Inferior fibers: depress scapula

Levator scapulae: action

Elevates and inferiorly rotates scapula

Rhomboid major: action

Elevates, retracts, and inferiorly rotates scapula

Rhomboid minor: action

Elevates, retracts, and inferiorly rotates scapula

Pectoralis minor: action

Protracts and depresses scapula

Serratus anterior: action

Protracts and superiorly rotates scapula; stabilizes scapula

Subclavius: action

Stabilizes and depresses clavicle

Trapezius: origin

Occipital bone, cervical and thoracic spinous processes

Trapezius: insertion

Clavicle, acromion and spine of scapula

Trapezius: innervation

Accessory nerve (CN XI)

Levator scapulae: origin

Upper cervical transverse processes

Levator scapulae: insertion

Superior medial border of scapula

Levator scapulae: innervation

Dorsal scapular nerve

Rhomboid major: origin

Spinous processes of T2-T5

Rhomboid major: insertion

Medial border of scapula

Rhomboid major: innervation

Dorsal scapular nerve

Rhomboid minor: origin

Spinous processes of C7-T1

Rhomboid minor: insertion

Superior medial border of scapula

Rhomboid minor: innervation

Dorsal scapular nerve

Pectoralis minor: origin

Ribs 3-5

Pectoralis minor: insertion

Coracoid process of scapula

Pectoralis minor: innervation

Medial pectoral nerve

Serratus anterior: origin

Ribs 1-8

Serratus anterior: insertion

Anterior medial border of scapula

Serratus anterior: innervation

Long thoracic nerve

Subclavius: origin

Rib 1

Subclavius: insertion

Inferior surface of clavicle

Subclavius: innervation

Nerve to subclavius

Latissimus dorsi: action

Extends, adducts, and medially rotates GH joint (“swimmer’s muscle”)

Latissimus dorsi: origin

Lower thoracic spinous processes, lower ribs and iliac crest

Latissimus dorsi: insertion

Intertubercular groove of humerus

Latissimus dorsi: innervation

Thoracodorsal nerve

Pectoralis major: action

Arm flexion; adducts and medially rotates GH joint

Pectoralis major: origin

Medial clavicle, superior ribs, and body of sternum

Pectoralis major: insertion

Intertubercular groove of humerus

Pectoralis major: innervation

Lateral pectoral and medial pectoral nerves

Deltoid: action

Anterior fibers: flex and mediall rotate GH joint

Middle fibers: GH abduction

Posterior fibers: extend and laterally rotate GH joint

Deltoid: origin

Acromial end of clavicle; acromion and spine of scapula

Deltoid: insertion

Deltoid tuberosity of humerus

Deltoid: innervation

Axillary nerve

Coracobrachialis: action

Adducts and flexes GH joint

Coracobrachialis: origin

Coracoid process

Coracobrachialis: insertion

Middle medial shaft of humerus

Coracobrachialis: innervation

Musculocutaneous nerve

Teres major: action

Extends, adducts, and medially rotates GH joint

Teres major: origin

Inferior lateral border and inferior angle of scapula

Teres major: insertion

Lesser tubercle and intertubercular groove of humerus

Teres major: innervation

Lower subscapular nerve

Triceps brachii: action

Extends GH joint, acts on elbow

Triceps brachii: origin

Infraglenoid tubercle

Triceps brachii: insertion

Olecranon process

Triceps brachii: innervation

Radial nerve

Biceps brachii: action

Flexes GH joint, acts on elbow

Biceps brachii: origin

Supraglenoid tubercle

Biceps brachii: insertion

Radial tuberosity and bicipital aponeurosis

Biceps brachii: innervation

Musculocutaneous nerve

Subscapularis: action

Medially rotates GH joint, stabilizes GH joint

Subscapularis: origin

Subscapular fossa

Subscapularis: insertion

Lesser tubercle of humerus

Subscapularis: innervation

Upper and lower subscapular nerves

Supraspinatus: action

Abducts GH joint, stabilizes GH joint

Supraspinatus: origin

Supraspinous fossa

Supraspinatus: insertion

Greater tubercle of humerus

Supraspinatus: innervation

Suprascapular nerve

Infraspinatus: action

Adducts and laterally rotates GH joint, stabilizes GH joint

Infraspinatus: origin

Infraspinous fossa

Infraspinatus: insertion

Greater tubercle of humerus

Infraspinatus: innervation

Suprascapular nerve

Teres minor: action

Adducts and laterally rotates GH joint, stabilizes GH joint

Teres minor: origin

Superior lateral border of scapula

Teres minor: insertion

Greater tubercle of humerus

Teres minor: innervation

Axillary nerve