Upper Back & Shoulder: Origin & Insertion

Trapezius (Upper Fibers) - Origin

External occipital protuberance, superior nuchal line, ligamentum nuchae

Trapezius (Upper Fibers) - Insertion

Lateral third of clavicle, acromion process

Trapezius (Upper Fibers) - Action

Elevates scapula, upwardly rotates scapula, extends neck

Trapezius (Middle Fibers) - Origin

Spinous processes of C7-T3

Trapezius (Middle Fibers) - Insertion

Spine of scapula

Trapezius (Middle Fibers) - Action

Retracts (adducts) scapula

Trapezius (Lower Fibers) - Origin

Spinous processes of T4-T12

Trapezius (Lower Fibers) - Insertion

Medial end of scapular spine

Trapezius (Lower Fibers) - Action

Depresses scapula, upwardly rotates scapula

Levator Scapulae - Origin

Transverse processes of C1-C4

Levator Scapulae - Insertion

Superior angle and medial border of scapula

Levator Scapulae - Action

Elevates scapula, downward rotation of scapula

Rhomboid Major - Origin

Spinous processes of T2-T5

Rhomboid Major - Insertion

Medial border of scapula (below spine)

Rhomboid Major - Action

Retracts scapula, downward rotation, stabilizes scapula

Rhomboid Minor - Origin

Spinous processes of C7-T1

Rhomboid Minor - Insertion

Medial border of scapula (at level of spine)

Rhomboid Minor - Action

Retracts scapula, downward rotation, stabilizes scapula

Serratus Anterior - Origin

Lateral surfaces of ribs 1-8

Serratus Anterior - Insertion

Medial border of scapula (anterior surface)

Serratus Anterior - Action

Protracts scapula, upwardly rotates scapula, stabilizes scapula against thorax

Subclavius - Origin

Junction of first rib and costal cartilage

Subclavius - Insertion

Inferior surface of clavicle

Subclavius - Action

Stabilizes clavicle, depresses clavicle

Latissimus Dorsi - Origin

Spinous processes of T7-L5, thoracolumbar fascia, iliac crest, inferior 3-4 ribs

Latissimus Dorsi - Insertion

Intertubercular groove of humerus

Latissimus Dorsi - Action

Extends, adducts, and medially rotates humerus ("swimmer's muscle")

Teres Major - Origin

Inferior angle of scapula

Teres Major - Insertion

Medial lip of intertubercular groove of humerus

Teres Major - Action

Extends, adducts, and medially rotates humerus ("lat's little helper")

Deltoid (Anterior) - Origin

Lateral third of clavicle

Deltoid (Anterior) - Insertion

Deltoid tuberosity of humerus

Deltoid (Anterior) - Action

Flexes and medially rotates arm

Deltoid (Middle) - Origin

Acromion process

Deltoid (Middle) - Insertion

Deltoid tuberosity of humerus

Deltoid (Middle) - Action

Abducts arm

Deltoid (Posterior) - Origin

Spine of scapula

Deltoid (Posterior) - Insertion

Deltoid tuberosity of humerus

Deltoid (Posterior) - Action

Extends and laterally rotates arm

Supraspinatus - Origin

Supraspinous fossa of scapula

Supraspinatus - Insertion

Greater tubercle of humerus (superior facet)

Supraspinatus - Action

Initiates abduction of arm (first 15°), stabilizes GH joint

Infraspinatus - Origin

Infraspinous fossa of scapula

Infraspinatus - Insertion

Greater tubercle of humerus (middle facet)

Infraspinatus - Action

Laterally rotates arm, stabilizes GH joint

Teres Minor - Origin

Lateral border of scapula

Teres Minor - Insertion

Greater tubercle of humerus (inferior facet)

Teres Minor - Action

Laterally rotates arm, stabilizes GH joint

Subscapularis - Origin

Subscapular fossa of scapula

Subscapularis - Insertion

Lesser tubercle of humerus

Subscapularis - Action

Medially rotates arm, stabilizes GH joint

Pectoralis Major (Clavicular Head) - Origin

Medial half of clavicle

Pectoralis Major (Clavicular Head) - Insertion

Lateral lip of intertubercular groove of humerus

Pectoralis Major (Clavicular Head) - Action

Flexes and adducts arm

Pectoralis Major (Sternocostal Head) - Origin

Sternum, costal cartilages of ribs 1-6

Pectoralis Major (Sternocostal Head) - Insertion

Lateral lip of intertubercular groove of humerus

Pectoralis Major (Sternocostal Head) - Action

Extends flexed arm, adducts and medially rotates arm

Pectoralis Minor - Origin

Ribs 3-5

Pectoralis Minor - Insertion

Coracoid process of scapula

Pectoralis Minor - Action

Protracts and depresses scapula

Coracobrachialis - Origin

Coracoid process of scapula

Coracobrachialis - Insertion

Medial shaft of humerus

Coracobrachialis - Action

Flexes and adducts arm

Biceps Brachii (Long Head) - Origin

Supraglenoid tubercle of scapula

Biceps Brachii (Long Head) - Insertion

Radial tuberosity, bicipital aponeurosis

Biceps Brachii (Long Head) - Action

Flexes elbow, supinates forearm, assists in flexion of arm

Biceps Brachii (Short Head) - Origin

Coracoid process of scapula

Biceps Brachii (Short Head) - Insertion

Radial tuberosity, bicipital aponeurosis

Biceps Brachii (Short Head) - Action

Flexes elbow, supinates forearm

Triceps Brachii (Long Head) - Origin

Infraglenoid tubercle of scapula

Triceps Brachii (Long Head) - Insertion

Olecranon of ulna

Triceps Brachii (Long Head) - Action

Extends forearm, assists in extension and adduction of arm