What muscle group primarily assists with the flexion of the elbow joint?

The primary muscle group that assists with the flexion of the elbow joint includes the biceps brachii, brachialis, and to some extent, the brachioradialis. The biceps brachii is well-known for its role in flexing the elbow, especially when the forearm is in a supinated position. The brachialis lies underneath the biceps and is often considered the strongest elbow flexor because it generates force regardless of the forearm position, making it crucial in flexion without the influence of forearm rotation.

While the triceps brachii is primarily responsible for elbow extension, it is not a flexor of the elbow joint. However, it plays a stabilizing role during certain movements involving the elbow. Therefore, the answer reflecting flexibility and considering the function of multiple muscles involved in the elbow joint flexion accurately encompasses the contribution of the biceps brachii and brachialis, which are the main muscles directly responsible for this action. As such, it is acknowledged that various muscle groups can assist with elbow flexion in different ways, leading to the understanding that the simplest response would be inclusive of all relevant muscle contributions.