Which muscles are responsible for elbow flexion?

• A. Biceps
• B. Deltoid
• C. Triceps
• D. Latissimus dorsi

Answer: (A)

Elbow flexion means bending the elbow to bring the forearm toward the upper arm. The primary muscle responsible is the biceps brachii, because it crosses the front of the elbow and, when it contracts, pulls the forearm upward. It also helps rotate the forearm, which is an additional function you might notice when you perform curls or supination moves.

Behind the scenes, the brachialis lies underneath the biceps and is actually a very strong elbow flexor in its own right, contributing to bending the elbow regardless of forearm position. The brachioradialis, running along the forearm, also helps flex the elbow especially when the forearm is held in a neutral (thumbs-up) position.

The other muscles listed don’t bend the elbow. The triceps extends the elbow, opposite of flexion. The deltoid mainly moves the shoulder, and the latissimus dorsi acts on the shoulder as well, not at the elbow joint.

So, the muscle most directly responsible for elbow flexion is the biceps brachii.