Anatomy: Shoulders

Posterior Shoulder

Muscle	Attachement	Nerve Supply	Actions	Special Tests
Deltoid	O: Lateral 3rd of clavicle, acromion and spine of scapula I: Deltoid tuberosity of humerus	Axillary Nerve	– Flexes shoulder – Abducts shoulder – Extends shoulder	Deltoids Strength and Length Tests
Supraspinatus	O: Supraspinous fossa of scapula I: Greater tubercle of humerus	Suprascapular Nerve	– Lateral rotation of shoulder -Shoulder abdution	Empty Can Test, Drop Arm Test, Hawkin’s Kennedy Impingement Test, Neer’s Impingement Test, Painful Arc Test
Infraspinatus	O: Infraspinous fossa of scapula I: Greater tubercle of humerus	Suprascapular Nerve	– Lateral rotation of arm	Infraspinatus Strength Test
Teres Minor	O: Middle part of lateral border of scapula I: Greater tubercle of humerus	Axillary Nerve	– Lateral rotation of arm	Infraspinatus Strength Test
Teres Major	O: Posterior surface of inferior angle of scapula I: Medial lip of intertubercular groove of humerus	Lower Subscapular Nerve	– Adducts arm – Medial rotation of arm	Shoulder Adductors Length Test
Subscapularis	O: Subscapular fossa I: Lesser tubercle of humerus	Upper and Lower Subscapular Nerve	– Medial rotation of arm -Adducts arm	Subscapularis Strength Test

Muscle	Attachments	Nerve Supply	Actions	Special Tests
Pectoralis Major	O: Anterior surface of medial half of clavicle, anterior surface of sternum, superior 6 costal cartilages I: Lateral lip of intertubercular groove of humerus	Lateral and Medial Pectoral Nerves	– Adduct humerus – Medial rotation of humerus	Pectoralis Major Length Test
Pectoralis Minor	O: 3^rd– 5^thribs near their costal cartilages I: Medial border and superior surface of coracoid process of scapula	Medial Pectoral Nerve	– Stabilizes scapula	Pectoralis Minor Length Test, Wright’s Hyperabduction Test
Subclavius	O: Junction of 1^st rib and costal cartilage I: Inferior surface of middle third of clavicle	Subclavian Nerve	– Anchors clavicle – Depresses clavicle	Adson’s Test