American Board of Internal Medicine (ABIM) Certification Practice Exam

The cross-arm test is used to diagnose what condition?

1. Shoulder impingement

2. Supraspinatus tear

3. Acromioclavicular joint disorder

4. Shoulder instability

The correct answer is: Acromioclavicular joint disorder

The cross-arm test is primarily utilized to assess for acromioclavicular joint disorders. This test involves the patient flexing their shoulder to 90 degrees and then horizontally adducting the arm across the body. If there is pain or discomfort at the acromioclavicular joint during this maneuver, it suggests the presence of an acromioclavicular joint issue, such as arthritis, separation, or other related pathologies. In the context of diagnosing shoulder conditions, although the other options might be associated with shoulder pain, they typically involve different tests or evaluations. For example, the assessment of rotator cuff injuries, including a supraspinatus tear, often relies on different specific tests like the empty can or the drop arm test. Shoulder impingement is also assessed using distinct maneuvers, such as the Neer or Hawkins-Kennedy tests. Lastly, shoulder instability is evaluated through tests focusing on the glenohumeral joint, such as the apprehension or relocation tests. Thus, the cross-arm test distinctly points to disorders of the acromioclavicular joint, clarifying its key role in the evaluation of that specific area.