DPT ~ Deltoid Muscles AIONS

Deltoid origin

Lateral third of clavicle; acromion and spine of scapula

Deltoid insertion

Deltoid tuberosity of humerus

Deltoid action

Clavicular (anterior) portion: Flexes and internally rotates arm.

-Acromial (middle) part: Abducts arm

-Spinal (posterior) part: Extends and externally rotates arm.

Deltoid innervation

Axillary nerve (C5,C6)

Teres Major origin

Posterior surface of inferior angle of scapula

Teres Major insertion

Medial lip of intertubercular sulcus of humerus

Teres Major action

Adducts and internally rotates arm

Teres Major innervation

Lower subscap nerve (C5, C6)

Triceps long head origin

Infraglenoid tubercle of scapula

Triceps insertion

Proximal end of olecranon of ulna and fascia of forearm

Triceps action

Chief extensor of forearm; long head resists dislocation of humerus, especially important during adduction

Triceps innervation

Radial nerve (C6,C7,C8)

Triceps lateral head origin

Posterior surface of humerus, superior to radial groove

Triceps medial head origin

Posterior surface of humerus inferior to radial groove