In gravity-minimized testing of shoulder internal rotation, which position is used?

In gravity-minimized testing of shoulder internal rotation, which position is used?

• A. Seated with the arm by the side and elbow at 90 degrees, stabilized by trunk.
• B. Prone with tested arm hanging freely over the edge of the table, palm facing the table; head rotated to tested side.
• C. Supine with arm at side and elbow extended.
• D. Standing with arm at side and elbow flexed.

Answer: (B)

The main idea is to test shoulder internal rotation without the weight of the arm adding resistance or aiding the movement. Placing the patient prone with the tested arm hanging freely over the edge of the table lets gravity act on the arm in a way that doesn’t torque the shoulder through internal rotation, so you can gauge the strength of the internal rotator muscles themselves rather than the effect of gravity. Keeping the palm toward the table helps maintain a consistent forearm orientation, and turning the head to the tested side helps stabilize the neck and keep the shoulder in proper alignment so the movement comes from the shoulder muscles. In other positions, the arm’s weight would either resist or assist the rotation, making it harder to isolate the true muscle strength.

The main idea is to test shoulder internal rotation without the weight of the arm adding resistance or aiding the movement. Placing the patient prone with the tested arm hanging freely over the edge of the table lets gravity act on the arm in a way that doesn’t torque the shoulder through internal rotation, so you can gauge the strength of the internal rotator muscles themselves rather than the effect of gravity. Keeping the palm toward the table helps maintain a consistent forearm orientation, and turning the head to the tested side helps stabilize the neck and keep the shoulder in proper alignment so the movement comes from the shoulder muscles. In other positions, the arm’s weight would either resist or assist the rotation, making it harder to isolate the true muscle strength.