Anatomy: Shoulders
Posterior Shoulder
| Muscle | Attachement | Nerve Supply | Actions |
| Deltoid | O: Lateral 3rd of clavicle, acromion and spine of scapula I: Deltoid tuberosity of humerus | Axillary Nerve | – Flexes shoulder – Abducts shoulder – Extends shoulder |
| Supraspinatus | O: Supraspinous fossa of scapula I: Greater tubercle of humerus | Suprascapular Nerve | – Lateral rotation of shoulder -Shoulder abdution |
| Infraspinatus | O: Infraspinous fossa of scapula I: Greater tubercle of humerus | Suprascapular Nerve | – Lateral rotation of arm |
| Teres Minor | O: Middle part of lateral border of scapula I: Greater tubercle of humerus | Axillary Nerve | – Lateral rotation of arm |
| 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 |
| Subscapularis | O: Subscapular fossa I: Lesser tubercle of humerus | Upper and Lower Subscapular Nerve | – Medial rotation of arm -Adducts arm |
Anterior Shoulder
| Muscle | Attachments | Nerve Supply | Actions |
| Pectoralis Major | O: Anterior surface of medial half of clavicle, anterior surface of sternum, superior six costal cartilages I: lateral lip of intertubercular groove of humerus | Lateral and Medial Pectoral Nerves | – Adduct humerus – Medial rotation of humerus |
| Pectoralis Minor | O: 3rd– 5th ribs near their costal cartilages I: Medial border and superior surface of coracoid process of scapula | Medial Pectoral Nerve | – Stabilizes scapula |
| Subclavius | O: Junction of 1st rib and costal cartilage I: Inferior surface of middle third of clavicle | Subclavian Nerve | – Anchors clavicle – Depresses clavicle |
