In elbow flexion MMT performed in anti-gravity, which forearm positions correspond to testing the biceps brachii, brachialis, and brachioradialis?

• A. Biceps Brachii tested with forearm supinated; Brachialis with pronated; Brachioradialis with neutral.
• B. Biceps brachii with pronated; brachialis with supinated; brachioradialis with neutral.
• C. Biceps with neutral; brachialis with supinated; brachioradialis with pronated.
• D. Biceps with supinated; brachialis with neutral; brachioradialis with pronated.

Answer: (A)

The main idea is that forearm position changes which elbow flexor can work most effectively, helping you isolate specific muscles during anti-gravity elbow flexion MMT.

Biceps brachii is best tested with the forearm in a supinated position because this muscle’s strength and line of pull are greatest when the forearm is supinated, and its primary action includes supination. Keeping the forearm supinated minimizes other muscles’ contribution and allows the biceps to show its strength clearly.

Brachialis is best tested with the forearm in pronation. Pronating the forearm reduces the influence of the biceps (which is weaker when the forearm is pronated) and lets the brachialis, a pure elbow flexor that operates effectively regardless of forearm position, contribute more, making its action easier to assess.

Brachioradialis is best tested with the forearm in neutral (mid-position). In this position, brachioradialis is most active as an elbow flexor, while its contribution decreases if the forearm is fully pronated or fully supinated.

So, the forearm positions align with isolating the biceps brachii in supination, brachialis in pronation, and brachioradialis in neutral during anti-gravity elbow flexion MMT.