The brachioradialis is best tested during elbow flexion with the forearm in which position?

• A. Neutral (thumbs up)
• B. Supination
• C. Pronation
• D. Extended

Answer: (A)

The main idea is to position the forearm so the brachioradialis contributes most to elbow flexion while other elbow flexors are least involved. The brachioradialis is most effective as an elbow flexor when the forearm is in neutral, which is the thumbs-up position. In this neutral stance, the muscle’s line of pull provides a strong flexion moment without the biceps taking over (as it does more in supination) or the brachialis dominating (as it does more in pronation). Extending the elbow reduces the ability to perform meaningful elbow flexion for testing. So, testing with the forearm in neutral (thumbs up) best isolates and reflects brachioradialis strength.