American Board of Internal Medicine (ABIM) Certification Practice Exam

During which test is the patient unable to maintain position if there is a subscapularis tear?

1. Neer

2. Hawkins

3. Internal rotation lag

4. Empty can

The correct answer is: Internal rotation lag

The internal rotation lag test is specifically designed to assess the integrity of the subscapularis, one of the rotator cuff muscles. In this test, the patient is asked to place their arm behind their back while the examiner lifts the arm away from the back. If the patient has a subscapularis tear, they will be unable to maintain this position, as the muscle is crucial for internal rotation and stability of the shoulder. When the subscapularis is compromised, it results in weakness or failure to hold the arm in this position, which is characteristic of the internal rotation lag test. In contrast, the Neer and Hawkins tests are more focused on identifying impingement of the shoulder rather than on a specific muscle injury like that of the subscapularis. The empty can test evaluates the supraspinatus muscle and its function, making it less relevant in the context of a subscapularis tear. Therefore, the internal rotation lag test is the one that directly assesses the condition of the subscapularis and demonstrates weakness associated with its tear.