American Board of Internal Medicine (ABIM) Certification Practice Exam

What condition is indicated by a failure to maintain the position of full external rotation of the arm?

1. Labral tear

2. Rotator cuff tear

3. Shoulder impingement

4. Subacromial bursitis

The correct answer is: Rotator cuff tear

The condition indicated by a failure to maintain full external rotation of the arm is associated with a rotator cuff tear. The rotator cuff is a group of muscles and tendons that stabilize the shoulder and allow for a wide range of motion, including external rotation. When a tear occurs within one of the rotator cuff tendons, particularly the supraspinatus or infraspinatus, it can lead to difficulty in holding the arm in external rotation. Patients with a rotator cuff tear often exhibit weakness in external rotation and may struggle to position their arm properly. Additionally, there may be pain and decreased range of motion, leading to an inability to maintain a fully externally rotated position. This symptom is particularly evident in functional activities requiring shoulder stability and strength. Other conditions such as labral tears, shoulder impingement, and subacromial bursitis may provide some overlap in symptoms relating to shoulder pain and mobility, but they do not typically present with the same specific failure to maintain external rotation as seen in a rotator cuff tear.