Yergason's Test: Purpose, Performance, and Clinical Significance

What is Yergason's Test Used For?

Yergason's test is an orthopedic special test primarily used to assess the integrity of the transverse humeral ligament and to identify pathology of the long head of the biceps brachii tendon, such as bicipital tendinopathy or subluxation.

Introduction to Yergason's Test

Yergason's test is a valuable component of a comprehensive shoulder physical examination. Developed by Dr. Robert M. Yergason in 1931, this specific diagnostic maneuver is designed to provoke symptoms related to the long head of the biceps brachii tendon and its stabilizing structures within the shoulder joint. Its primary utility lies in helping clinicians differentiate the source of anterior shoulder pain, particularly when considering issues with the biceps tendon or the ligament that secures it in place.

Anatomy Involved

To understand Yergason's test, it's crucial to grasp the key anatomical structures it targets:

• Long Head of the Biceps Brachii Tendon: This tendon originates from the supraglenoid tubercle of the scapula, passes over the head of the humerus, and descends within the bicipital groove (intertubercular sulcus) on the anterior aspect of the humerus.
• Bicipital Groove (Intertubercular Sulcus): A deep groove between the greater and lesser tuberosities of the humerus, serving as a pathway for the long head of the biceps tendon.
• Transverse Humeral Ligament: This strong fibrous band spans across the bicipital groove, acting as a retinaculum to hold the long head of the biceps tendon securely within the groove, preventing its displacement.

The test's mechanism relies on placing mechanical stress on these structures, particularly the tendon and the ligament, to elicit pain or a physical sign indicative of pathology.

How Yergason's Test is Performed

The proper execution of Yergason's test is critical for accurate interpretation:

1. Patient Positioning: The patient can be seated or standing, with their elbow flexed to 90 degrees and the forearm pronated (palm facing down). The shoulder should be in a neutral position or slightly adducted.
2. Examiner Positioning: The examiner stands beside the patient, placing one hand on the patient's distal forearm/wrist to provide resistance and the thumb of the other hand over the bicipital groove (located just lateral to the coracoid process, anterior to the shoulder joint).
3. Action: The examiner instructs the patient to actively supinate their forearm (turn the palm upwards) against the examiner's resistance. Simultaneously, the patient is asked to externally rotate their shoulder against resistance.
4. Observation and Palpation: During this combined resisted supination and external rotation, the examiner observes the patient's reaction and palpates the bicipital groove for any tenderness, clicking, or subluxation of the tendon.

Interpreting the Results

The interpretation of Yergason's test relies on the symptoms elicited and physical findings:

• Positive Test for Bicipital Tendinopathy/Tendinitis: The test is considered positive for bicipital tendinopathy if the patient experiences pain localized to the bicipital groove during the resisted supination and external rotation, without any audible or palpable click/snap. This suggests inflammation or degeneration of the long head of the biceps tendon.
• Positive Test for Biceps Tendon Subluxation/Dislocation: The test is considered positive for subluxation or dislocation of the biceps tendon if the examiner feels a palpable or audible click/snap within the bicipital groove, often accompanied by pain. This indicates that the long head of the biceps tendon is popping out of its groove, typically due to a torn or lax transverse humeral ligament.

It's important to note that pain alone, without a click, is more indicative of tendinopathy, while a click/snap strongly suggests ligamentous laxity or rupture allowing tendon instability.

Limitations and Considerations

While Yergason's test is a useful clinical tool, it has limitations:

• Specificity and Sensitivity: Its specificity and sensitivity are moderate at best, meaning it can sometimes produce false positives (pain from other shoulder pathologies) or false negatives.
• Co-existing Pathologies: Anterior shoulder pain can arise from various sources, including rotator cuff pathology (especially subscapularis tears), shoulder impingement, or labral tears. Yergason's test alone cannot definitively rule out these conditions.
• Subjectivity: Pain is a subjective symptom. The examiner's skill in palpation and the patient's ability to localize pain are crucial.
• Combination with Other Tests: For a more accurate diagnosis, Yergason's test should always be performed in conjunction with other special orthopedic tests for the shoulder (e.g., Speed's Test, Bear Hug Test, Empty Can Test) and a thorough physical examination. Imaging studies (MRI, ultrasound) may also be necessary to confirm findings.

Clinical Significance

Despite its limitations, Yergason's test holds significant clinical value as part of a comprehensive diagnostic battery for shoulder pain. It helps clinicians:

• Differentiate Causes of Anterior Shoulder Pain: It aids in distinguishing between biceps-specific pathology and other common shoulder conditions that can cause pain in a similar region.
• Guide Treatment Strategies: Identifying biceps tendinopathy or instability can direct conservative management (rest, ice, anti-inflammatories, physical therapy) or surgical intervention (biceps tenodesis or tenotomy) if conservative measures fail.
• Assess Ligamentous Integrity: The ability to detect subluxation provides direct insight into the integrity of the transverse humeral ligament, which is crucial for shoulder stability.

Conclusion

In summary, Yergason's test is a foundational orthopedic maneuver used to evaluate the long head of the biceps brachii tendon and the transverse humeral ligament. By assessing pain and stability during resisted supination and external rotation, clinicians can gain valuable insights into potential bicipital tendinopathy or tendon subluxation. While not a standalone diagnostic tool, its strategic application within a comprehensive clinical assessment significantly contributes to the accurate diagnosis and effective management of anterior shoulder pain.