Which test assesses pain at the AC joint when performing a specific maneuver where the arm is brought across the body?

• A. Cross body adduction
• B. AC shear test
• C. Adson's test
• D. Allen's test

Answer: (A)

Stressing the acromioclavicular joint by bringing the arm across the chest places compressive and shear forces directly through the AC joint. If there’s pathology there—such as arthritis, sprain, or other AC joint injury—this horizontal adduction maneuver typically reproduces localized pain at the AC joint. That makes this test specifically useful for identifying AC joint involvement, because it isolates the joint’s pain generation more than other shoulder tests. The other tests assess different structures or problems: some evaluate AC joint instability through direct shear, while others test vascular or neurogenic issues in the thoracic outlet. So pain reproduced at the AC joint with the arm crossed over the body is the hallmark indicating AC joint pathology, which is why this test is the best choice.