Which of the following is NOT an elbow flexor?

The triceps brachii is primarily known as an elbow extensor rather than a flexor. Its main function is to extend the elbow joint, which is essential for actions such as pushing or throwing. This muscle originates from the scapula and the humerus and inserts at the olecranon of the ulna, facilitating straightening of the arm.

In contrast, the biceps brachii, brachialis, and brachioradialis all contribute to elbow flexion. The biceps brachii, which has two heads, helps flex the elbow while also aiding in supination of the forearm. The brachialis lies underneath the biceps and is a powerful flexor of the elbow irrespective of forearm position. The brachioradialis aids in flexing the elbow as well, particularly when the forearm is in a neutral position.

Understanding the functions of these muscles helps clarify why the triceps brachii is not classified as an elbow flexor, highlighting its contrasting role in arm movement.