During the Roos stress test, which description best matches the procedure?

• A. Abduct both arms to 90 degrees, externally rotate, elbows at 90 degrees, and open/close fists for 3 minutes
• B. Arms abducted to 180 degrees with fists clenched
• C. Arms placed at sides and squeezed fists
• D. Shoulders shrugged and arms extended forward

Answer: (A)

The Roos stress test checks for thoracic outlet syndrome by stressing the neurovascular structures as the arms are placed in a provocative position and the hands are moved repetitively. In this test, the arms are raised to about shoulder height with the elbows flexed at 90 degrees and the arms abducted to 90 degrees with the hands externally rotated, and the patient repeatedly opens and closes the fists for about 3 minutes. If symptoms such as numbness, tingling, fatigue, weakness, or pallor occur during the maneuver, it suggests compression in the thoracic outlet area.

This option matches the exact position and action of the test: 90-degree abduction, external rotation, elbows at 90 degrees, and repetitive fist opening/closing for several minutes. The other described postures do not place the limb in this provocative configuration or involve the same sustained hand activity, so they aren’t testing the same mechanism.