Anatomy - Triceps brachii muscle

Triceps brachii - Action

All heads- extension of the elbow, Long head- extension, adduction, and horizontal abduction of the shoulder joint

Triceps brachii - Origin

Long head- infraglenoid tubercle below inferior lip of glenoid fossa of the scapula, Lateral head- upper half of the posterior surface of the humerus, Medial head- distal two-thirds of the posterior surface of the humerus

Triceps brachii - Insertion

Olecranon process of the ulna

Triceps brachii - Innervation

Radial nerve (C7, C8)