Which muscle acts as antagonist to the brachialis during elbow flexion?

Which muscle acts as antagonist to the brachialis during elbow flexion?

• A. Anconeus
• B. Biceps brachii
• C. Triceps brachii
• D. Brachioradialis

Answer: (A)

The main idea here is which muscle provides the opposite action to elbow flexion. The brachialis is a primary elbow flexor, pulling the forearm toward the upper arm. To oppose that flexion, an elbow extensor is needed. The anconeus sits at the back of the elbow and its main role is to extend and stabilize the joint, especially as the elbow moves toward extension or when the movement is fast or resisted. Because it directly produces elbow extension and helps control the joint during flexion, it serves as the functional antagonist to the brachialis in elbow flexion. The other options either produce elbow flexion themselves or aren’t the primary extensor opposing brachial flexion in this context.

The main idea here is which muscle provides the opposite action to elbow flexion. The brachialis is a primary elbow flexor, pulling the forearm toward the upper arm. To oppose that flexion, an elbow extensor is needed. The anconeus sits at the back of the elbow and its main role is to extend and stabilize the joint, especially as the elbow moves toward extension or when the movement is fast or resisted. Because it directly produces elbow extension and helps control the joint during flexion, it serves as the functional antagonist to the brachialis in elbow flexion. The other options either produce elbow flexion themselves or aren’t the primary extensor opposing brachial flexion in this context.