The Triceps Brachii, commonly known as the tricep, is the large muscle on the posterior, or back, side of the upper arm. This muscle is significantly larger than the biceps and forms the majority of the muscle mass in the upper arm’s dorsal compartment. Its main responsibility is to generate the force necessary for pushing movements.
Anatomy and Location
The name “Triceps Brachii” literally translates to “three-headed muscle of the arm,” which describes its unique anatomical structure. These three heads are the long head, the lateral head, and the medial head.
The long head is unique because its origin point is on the scapula, or shoulder blade, specifically the infraglenoid tubercle. This attachment means the long head crosses both the shoulder and elbow joints, giving it a role in both movements. The lateral head originates from the posterior surface of the humerus, the upper arm bone, in an area superior to the radial groove. This head is typically the most visible on the side of the arm.
The medial head is the deepest of the three, originating from the posterior surface of the humerus, inferior to the radial groove. This head lies closer to the bone and is partially covered by the other two heads. All three muscle bellies taper down the arm and merge into a single, thick tendon. This final tendon then inserts onto the olecranon process of the ulna.
The Role of Elbow Extension
The primary and most powerful function of the tricep muscle is the extension of the forearm at the elbow joint. This action is simply the straightening of the arm from a bent position, such as when pushing a door open or performing a push-up. The tricep acts as the antagonist to the biceps brachii, which is the muscle primarily responsible for bending the arm.
Beyond this primary role, the long head has secondary actions due to its attachment on the scapula. It assists in extending the arm backward at the shoulder joint and in moving the arm toward the body’s midline, a motion known as adduction. This head also contributes to the overall stability of the shoulder joint, especially when the arm is held close to the body. For fine motor control and low-force tasks, the medial head is often continuously active, while the lateral head is recruited during movements that require high-intensity force.
Practical Ways to Strengthen the Tricep
Strengthening the tricep muscle is important for upper body function and can be achieved through a variety of exercises that work the muscle heads from different angles. Exercises where the arm is positioned overhead, such as overhead tricep extensions, place a greater stretch and emphasis on the long head. This focus is due to the long head’s attachment at the shoulder, which makes it fully elongated when the arm is raised above the head.
Other movements, like tricep pushdowns performed on a cable machine, effectively target all three heads but are particularly beneficial for the lateral and medial heads. Performing dips, either on parallel bars or a bench, is another highly effective compound exercise that engages the entire tricep complex. For those preferring free weights, the close-grip bench press or lying tricep extensions, sometimes called skull crushers, use a heavier load to build strength across the muscle.
When performing any tricep exercise, maintaining proper form is important to maximize muscle engagement and reduce the possibility of joint stress. For example, keeping the elbows relatively stationary and close to the body during pushdowns or extensions helps isolate the work to the tricep muscle. Consistent training that incorporates a mix of these movements helps ensure balanced development across all three heads of the Triceps Brachii.