Washington Master Esthetics Practice Exam

Which muscle is responsible for flexion of the elbow?

1. Triceps brachii

2. Biceps brachii

3. Brachialis

4. Coracobrachialis

The correct answer is: Brachialis

The muscle primarily responsible for flexion of the elbow is the brachialis. This muscle lies underneath the biceps brachii and plays a significant role in bending the elbow, particularly when the forearm is in a pronated position. The brachialis allows for efficient flexion by attaching to the humerus and the ulna, providing a powerful pulling action when flexing the elbow joint. While the biceps brachii does contribute to elbow flexion, it is more prominent when the arm is in a supinated position, such as during a bicep curl. The triceps brachii, on the other hand, is responsible for extending the elbow and thus opposes the motion of flexion. The coracobrachialis is more involved in flexing the shoulder rather than the elbow. Understanding the functions of these muscles helps clarify their different roles in arm movement.