Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

What structure is evaluated with Yergeson's test?

1. Ligament of the humerus

2. AC joint

3. Rotator cuff

4. Biceps tendon

The correct answer is: AC joint

Yergason's test is specifically designed to evaluate the biceps tendon, particularly its stability in the bicipital groove. When performing Yergason's test, the clinician instructs the patient to flex the elbow while the examiner resists supination and lateral rotation of the arm. A positive test typically indicates a problem with the biceps tendon, often involving tendonitis or a rupture. Although the acromioclavicular (AC) joint, rotator cuff, and ligament of the humerus can all be significant in shoulder pathology, they are not the primary focus of Yergason's test. The test's naming derives from its association with the biceps tendon, which is crucial for understanding potential shoulder and arm injuries related to this specific structure. Recognizing how Yergason’s test centers on the biceps tendon helps to clarify its role in diagnosing conditions affecting this particular area, thus underscoring why the correct answer pertains to the biceps tendon rather than other shoulder components.