A positive Roos test indicates involvement of which syndrome?

• A. Thoracic outlet syndrome
• B. Cubital tunnel syndrome
• C. Pronator syndrome
• D. Median nerve compression at carpal tunnel

Answer: (A)

The Roos test is used to provoke symptoms by placing the arms in a position that narrow the thoracic outlet, where the neurovascular bundle passes between the clavicle, first rib, and surrounding muscles. A positive result—reproduction of numbness, tingling, fatigue, or even changes in color or strength in the arm—points to thoracic outlet syndrome, indicating compression in that space. This distinguishes it from other entrapments: cubital tunnel syndrome involves the elbow ulnar nerve, pronator syndrome affects the median nerve near the pronator teres, and carpal tunnel syndrome involves the median nerve at the wrist. Because the test specifically stresses the thoracic outlet region, it best indicates thoracic outlet syndrome.