The test performed to evaluate thoracic outlet that is named after a clinician with the initials A.S. is which test?

• A. Allen's test
• B. Military Brace test
• C. Yergason's test
• D. Adson's test

Answer: (D)

Thoracic outlet evaluation relies on provocative maneuvers that momentarily compress the structures passing through the thoracic outlet. The maneuver named for a clinician with initials A.S. is Adson's test. In this test, the patient sits or stands while the examiner palpates the radial pulse on the tested side. The patient then extends the neck, turns the head toward the tested side, and takes a deep breath and holds it. If the radial pulse diminishes or disappears, or if there is reproduced symptoms, it suggests compression of the subclavian artery in the thoracic outlet, usually by the anterior scalene muscle or surrounding structures. This distinguishes it from other common tests: Allen's test is about hand blood supply via the radial and ulnar arteries, Yergason's test checks the biceps tendon, and the Military Brace test is another thoracic outlet maneuver but not named after a clinician with the initials A.S.