What is the primary function of the triceps muscle?

The primary function of the triceps muscle is the extension of the elbow. This muscle is located at the back of the upper arm and is responsible for straightening the arm. When the triceps contract, they pull on the ulna bone in the forearm, allowing the elbow joint to extend. This action is crucial for various physical activities, such as pushing, throwing, and lifting.

In contrast, the other options pertain to movements that do not involve the primary action of the triceps. Flexion of the elbow refers to the bending of the arm, which is primarily facilitated by the biceps muscle. Abduction of the shoulder involves raising the arm away from the body, which is performed by different shoulder muscles. Flexion of the shoulder, similar to elbow flexion, primarily involves muscles like the pectoralis major and anterior deltoid. Therefore, while these other movements are important in their own right, they do not describe the principal function of the triceps muscle.