DELTOIDS

• Origin

Anterior fibers: lateral third of clavicle

Medial fibers: acromion process of scapula

Posterior fibers: spine of scapula

• Insertion

Deltoid tuberosity of humerus

• Agonist(s)

- Supraspinatus

- Infraspinatus

- Teres minor, and

- Subscapularis

• Antagonist(s)

- Pectoralis major

- Latissimus dorsi, and

- Teres major

• Function

Abducts arm at shoulder joint, assists in flexion, extension, and rotation of arm, stabilizes shoulder joint