American Board of Internal Medicine (ABIM) Certification Practice Exam

What does a positive drop-arm test indicate?

1. Impingement syndrome

2. Supraspinatus tear

3. Adhesive capsulitis

4. Shoulder dislocation

The correct answer is: Supraspinatus tear

A positive drop-arm test is a clinical examination finding that is particularly indicative of a supraspinatus tear, which is a common injury of the rotator cuff. In this test, a patient is asked to abduct their arm to shoulder level and then slowly lower it back down. If the patient experiences pain or is unable to control the descent of the arm, resulting in the arm dropping suddenly, it suggests a failure of the supraspinatus muscle to function properly, typically due to a tear. The supraspinatus tendon plays a crucial role in initiating arm abduction and stabilizing the shoulder joint. When there is a tear, it compromises this stability and mobility, leading to the characteristic positive result of the drop-arm test. This is why a positive result is closely associated with rotator cuff injuries, and specifically with a tear of the supraspinatus muscle. In contrast, other conditions listed may present with different signs and symptoms. For instance, impingement syndrome usually involves pain during overhead activities but does not typically produce a positive drop-arm test. Adhesive capsulitis, or frozen shoulder, involves a stiffness and decreased range of motion rather than a positive drop-arm reaction. Shoulder dislocation may cause arm weakness and deformity but