Which muscle group is primarily responsible for flexing the elbow?

The primary muscles responsible for flexing the elbow are the biceps brachii and the brachialis. The biceps brachii, a well-known muscle located in the upper arm, functions to flex the elbow and also assists with supination of the forearm. The brachialis lies deeper and is a powerful flexor of the elbow, working effectively regardless of forearm position.

Together, these two muscles create a significant contribution to elbow flexion during various activities and movements, making them the main muscle group for this action. Understanding the specific roles of biceps brachii and brachialis is essential in both anatomical and physiological contexts, as they work synergistically during tasks such as lifting or pulling.

Other muscle groups listed, such as the triceps, forearm extensors, and rotator cuff muscles, primarily engage in different functions such as extending the elbow, extending the wrist, and stabilizing the shoulder or assisting in shoulder movements, thus not playing a significant role in elbow flexion.