In manual muscle testing for shoulder internal rotation performed anti-gravity, which describes the correct test position?

In manual muscle testing for shoulder internal rotation performed anti-gravity, which describes the correct test position?

• A. Prone with shoulder abducted to 90 degrees and elbow flexed off the edge of the table, head rotated toward the tested side.
• B. Seated with the arm by the side and elbow at 90 degrees, with resistance applied to the forearm.
• C. Prone with the arm hanging over the edge of the table, palm facing the table.
• D. Seated with the shoulder flexed and the elbow extended.

Answer: (A)

Testing shoulder internal rotation against gravity is best done with the arm positioned so the internal rotators have to actively pull the humerus medially while the rest of the shoulder girdle is stabilized. Placing the patient prone with the shoulder at 90 degrees of abduction and the elbow flexed, with the forearm hanging off the edge of the table, sets up a clear line of rotation that isolates the internal rotators (like subscapularis, teres major, and part of pectoralis major) and makes the movement require true active effort against gravity. Having the head turned toward the tested side helps keep the neck and trunk from compensating and keeps the scapula in a stable position for a clean test. In this arrangement, resistance can be applied to the forearm to challenge the internal rotators as they work against gravity, giving a reliable measure of strength. The other positions don’t place the shoulder in the same isolating setup or require the movement against gravity in a consistent way, and they can invite compensations or involve different motions that don’t reflect pure internal rotation strength.

Testing shoulder internal rotation against gravity is best done with the arm positioned so the internal rotators have to actively pull the humerus medially while the rest of the shoulder girdle is stabilized. Placing the patient prone with the shoulder at 90 degrees of abduction and the elbow flexed, with the forearm hanging off the edge of the table, sets up a clear line of rotation that isolates the internal rotators (like subscapularis, teres major, and part of pectoralis major) and makes the movement require true active effort against gravity. Having the head turned toward the tested side helps keep the neck and trunk from compensating and keeps the scapula in a stable position for a clean test. In this arrangement, resistance can be applied to the forearm to challenge the internal rotators as they work against gravity, giving a reliable measure of strength.

The other positions don’t place the shoulder in the same isolating setup or require the movement against gravity in a consistent way, and they can invite compensations or involve different motions that don’t reflect pure internal rotation strength.