Deltoid – Essentials

Actions

• Abducts humerus (all fibers)
• Flexes humerus TIP 320 (anterior fibers)
• Medially rotates humerus (anterior fibers)
• Horizontally adducts humerus (anterior fibers)
• Extends humerus (posterior fibers)
• Laterally rotates humerus (posterior fibers)
• Horizontally abducts humerus (posterior fibers)

Origins

• Lateral 1/3 clavicle
• Acromion process of scapula
• Spine of scapula

Insertion

• Deltoid tuberosity of humerus