Muscle Breakdown: Triceps Brachii
Table of Contents
What Is the Triceps Brachii
The Triceps Brachii, also known as the triceps, is a key muscle in the back of the upper arm. This skeletal muscle has three heads and its shape is considered to be a fusiform muscle. This means that the body of the muscle is surrounded by two tendons, and the muscles fibers run parallel to one another.
The Triceps Brachii an antagonist muscle to the Biceps Brachii. This means that as the Triceps Brachii contracts, the Biceps Brachii relaxes, and when the Triceps Brachii relaxes, the Biceps Brachii contracts.
Triceps Brachii Function
The Triceps Brachii plays an integral role in the extension of the forearm. Each head contributes to different movements of the arm and forearm. For example, the long head of the Triceps Brachii influences the glenohumeral joint and can help produce extension and shoulder adduction of the arm. The medial head helps to extend the forearm and the lateral head extends the elbow.
Triceps Brachii Origin and Insertion
Triceps Brachii Origin
The Triceps Brachii has multiple origins due to the three heads. The origins of the Triceps Brachii include:
Long Head: Infra-glenoid Tubercle of Scapula
Lateral Head: Upper half Posterior Humerus (Above Radial Groove)
Medial Head: Lower half Posterior Humerus (Below Radial Groove)
Triceps Brachii Insertion
The insertion of the Triceps Brachii includes,
Olecranon Process on Ulna
Triceps Brachii Innervation
The Triceps Brachii is innervated by the Radial Nerve.
Triceps Brachii Heads
As previously mentioned, the Triceps Brachii has three heads. This means that the Triceps Brachii has 3 points of origin. The Triceps Brachii has a long head, a lateral head and a medial head. Each head allows the Triceps Brachii to perform specific functions.
Long Head: Contributes more to elbow extension, extension and adduction of the arm
Lateral Head: Contributes to elbow extension
Medial Head: Contributes to shoulder elevation
Ultimately, each head of the Triceps Brachii works together to make the Triceps the main extensor of the forearm.
Triceps Brachii Exercises
Many exercises can engage the Triceps Brachii. See below to learn about a few Triceps Brachii Exercises:
Triceps Pulldown
Triceps Pulldown
Using a cable machine, secure a rope attachment. Stand with your feet hip-width apart and have a slight bend in your knees. Begin holding each end of the rope in your hands with your elbows bent at 90-degrees. Slowly begin to extend your elbow down, pulling the rope with your hands. Keep your wrists tight to the body, once you reach about hip height, and your elbows are extended, return to the starting position with your elbows bent.
Overhead Triceps Extension
Stand with your feet hip-width apart and your knees slightly bent. Using both hands, raise one dumbbell over your head, so your arms are fully extended towards the sky. Slowly lower the dumbbell behind your head by bending at the elbow. When the forearms reach 90-degrees to the elbow, use your Triceps to extend the arms back towards the sky.
