The main purpose of the triceps is to extend the elbow and straighten the arm. The triceps is located on the back of the arm and attaches to the upper arm around the shoulder and then again to the elbow, but it originates at the shoulder blade. The muscle works opposite to the bicep that is located on the opposite side of the arm.
The name triceps means "three head" in Latin, and the triceps muscles are often referred to by this term. There are three sections to the triceps muscles which are the long head, medial head and the lateral head. The long head runs along the inside back of the arm. The long head also serves to extend the shoulder, which assists in the overall movement of the arm. The medial head is underneath both the long and lateral heads, but runs along the entire back of the upper arm. The lateral head is located on the outside edge of the back of the arm. Each of these muscles has its own corresponding connection to the spine and motor controls. The triceps muscles contain the radial nerve and the axillary nerve. These muscles take specific types of exercises to work them out, including triceps extensions, push ups and bench presses.