Which muscle is primarily responsible for elbow extension?

The triceps brachii is the muscle primarily responsible for elbow extension. This muscle comprises three heads – long, lateral, and medial – and is located at the back of the upper arm. When the triceps contracts, it pulls on the olecranon process of the ulna, which results in the straightening of the elbow joint. This action is crucial for various activities, such as pushing or throwing, where extending the arm is essential.

Other muscles listed, such as the biceps brachii and brachialis, are primarily involved in elbow flexion, which is the opposite action of extension. The coracobrachialis assists with shoulder flexion and adduction but does not contribute significantly to elbow movement. Understanding the specific functions of these muscles helps clarify their roles in arm movements and enhances comprehension of human anatomy and physiology.