Learn about the best tricep exercises for the three heads of the triceps , and maximize your triceps muscle growth and strength gain. The triceps muscle is a main muscle of the upper arm, running from the top of the shoulder to the elbow at the back of the arm. When the triceps muscle contracts, it causes the elbow to straighten. Triceps brachii is a three-headed (tri - three, cep - head) muscle of the arm. It represents the only constituent of the posterior muscle group of the arm, spanning almost the entire length of the humerus. Triceps muscle, any muscle with three heads, or points of origin, particularly the large extensor along the back of the upper arm in humans. It originates just below the socket of the scapula (shoulder blade) and at two distinct areas of the humerus, the bone of the upper arm.
