The triceps brachii is a large muscle that covers the entire back side of the upper arm. It is divided into three sections, known as the lateral (outer) head, medial (middle) head, and long (inner) head.

Origin

The medial head of the triceps originates on the lower portion of the back of the humerus over a wide space extending nearly two-thirds of the length of the bone.

Insertion

All three heads come together into a common tendon which inserts on the olecranon process of the ulna.

Function

Elbow joint extension.

Overhead Triceps Press

Triceps Push-Down

45-Degree Triceps Extension

Triceps Kickback

Bench Press

Pushup