shoulder and arm orgins insertions

Pectoralis minor

ORIGIN: Ant. Surfaces of ribs 3-5 | INSERTION: Coracoid process of the scapula | ACTION: Ribs fixed: moves scapula forward and downward. Scapula fixed: draws ribcage superiorly

Serratus Anterior

ORIGIN: Ribs 1-8 | INSERTION: Ant. Surface of medial border of scapula | ACTION: Abducts & protracts scapula. Rotates scapula cranially

Subclavius

ORIGIN: Costal cartilage of 1st rib | INSERTION: Inferior surface of clavicle | ACTION: depresses clavicle & draws shoulder forward and downward

Levator Scapulae

ORIGIN: transverse processes of C1-C4 | INSERTION: superomedial border of scapula | ACTION: raises scapula. Scapula fixed: bends neck laterally

Rhomboids

ORIGIN: Spinous processes of C7, T1-T5 | INSERTION: Medial border of scapula | ACTION: Adducts, retracts, elevates and rotates scapula. Allows glenoid cavity to face downward

Trapezius

ORIGIN: Occipital bone, ligamentum nuchae, spines of C7-T12 | INSERTION: Lateral 1/3 of clavicle, acromion process and spine of scapula | ACTION: Stabilizes, raises, retracts and rotates scapula. Rotates arm. Superior fibers: elevate, Middle fibers: retract. Inferior fibers: depress scapula

Muscle

ORIGIN: Origin | INSERTION: Insertion | ACTION: Action

Pectoralis Major

ORIGIN: Sternal end of clav, sternum, cartilage of ribs 1-6 | INSERTION: Intertubercular groove of humerus | ACTION: Flexes, adducts and medially rotates arm

Coracobrachialis

ORIGIN: coracoid process of scapula | INSERTION: anteromedial surface of the humerus opposite deltoid tuberosity | ACTION: Fexion and adduction of humerus

Subscapularis

ORIGIN: Subscapular fossa of scap | INSERTION: lesser tubercule of humerus | ACTION: medial rotation, holds head of humerus in glenoid (stabilizes)

Biceps brachii

ORIGIN: long head: Supraglenoid tubercule of scap. Short head: Coracoid process of scap | INSERTION: Radial tuberosity | ACTION: flexes and supinates the forearm

Deltoid

ORIGIN: Lat 1/3 of clavicle, acromion and spine of scap | INSERTION: deltoid tuberosity of humerus | ACTION: primary abductor, flextion, extension, weak internal/eternal rotation of arm

Supraspinatus

ORIGIN: supraspinous fossa of scap | INSERTION: superior part of greater tubercle of humerus | ACTION: abducts arm, stabilize humeral head in glenoid cavity

Infraspinatus

ORIGIN: infraspinous fossa of scapula | INSERTION: greater tubercle, posterior to supraspinatus insertion | ACTION: Lateral rotation, stabilize humeral head in glenoid cavity

Teres minor

ORIGIN: lateral border of dorsal scap surface | INSERTION: greater tubercle of humerus, inf to infraspinatus | ACTION: Lateral rotation, stabilize humeral head in glenoid cavity

Latissimus dorsi

ORIGIN: indirect attachment via thoracolumbar fascia into spines of lower 6 thoracic and lumbar vertebrae, lower 3-4 ribs, iliac crest | INSERTION: Intertubercular groove of humerus | ACTION: Extends, adducts, medially rotates arm. Draws shoulder down and back

Teres major

ORIGIN: Lower 1/3 of post lat surface of scap | INSERTION: Intertubercular groove of humerus | ACTION: medially rotates and adducts arm

Triceps brachii

ORIGIN: Long head: infraglenoid tubercle. Medial head: posterior medial surface of humerus. Lat head: posterior surface of humerus | INSERTION: olecranon process of ulna | ACTION: Extends forearm, helps stabilize shoulder