Hawkins-Kennedy Impingement Test: Procedure, Interpretation, and Clinical Significance

What is the Hawkins Test for Pain?

The Hawkins-Kennedy Impingement Test is a common orthopedic assessment used to identify potential subacromial impingement syndrome in the shoulder, a condition where soft tissues become compressed during arm elevation, leading to pain.

Understanding Shoulder Impingement

Shoulder impingement syndrome is a prevalent cause of shoulder pain, particularly in athletes and individuals performing repetitive overhead activities. It occurs when the rotator cuff tendons (most commonly the supraspinatus) and/or the subacromial bursa become compressed between the head of the humerus and the acromion (part of the shoulder blade) during specific arm movements. This compression can lead to inflammation, pain, and, if left unaddressed, potential tears in the rotator cuff. Clinical tests, such as the Hawkins-Kennedy test, are crucial tools for clinicians to help diagnose this condition.

What is the Hawkins-Kennedy Impingement Test?

The Hawkins-Kennedy test is a provocative maneuver designed to reproduce pain by mechanically compressing the structures within the subacromial space. It is considered one of the more sensitive tests for detecting subacromial impingement, meaning it is good at identifying individuals who do have the condition.

How the Test is Performed

The test is typically performed by a healthcare professional (e.g., physician, physical therapist, chiropractor) and involves specific positioning of the patient's arm:

• Patient Position: The patient can be seated or standing.
• Arm Position: The examiner passively flexes the patient's shoulder to 90 degrees. The elbow is also flexed to 90 degrees.
• Forearm Position: The examiner then internally rotates the patient's shoulder by rotating the forearm downwards.
• Movement: The internal rotation of the humerus brings the greater tuberosity (a bony prominence on the humerus) closer to the coracoacromial ligament and the anterior aspect of the acromion, effectively narrowing the subacromial space.
• Positive Sign: The test is considered positive if this maneuver reproduces the patient's typical shoulder pain, particularly in the anterior or lateral aspect of the shoulder.

The Biomechanics Behind the Test

The rationale for the Hawkins-Kennedy test lies in its ability to narrow the subacromial space, thereby compressing the soft tissues within it.

• Structures Involved: The primary structures at risk of compression include:
  • Supraspinatus tendon: This rotator cuff muscle passes directly through the subacromial space.
  • Long head of the biceps tendon: This tendon also traverses the subacromial area.
  • Subacromial bursa: A fluid-filled sac that reduces friction, located beneath the acromion and above the rotator cuff tendons.
• Mechanism of Compression: When the shoulder is flexed to 90 degrees and then internally rotated, the greater tuberosity of the humerus, where the supraspinatus tendon inserts, is driven anteriorly and superiorly. This movement causes the supraspinatus tendon and/or the subacromial bursa to be "impinged" or squeezed against the undersurface of the acromion and the coracoacromial ligament. If these structures are inflamed, degenerated, or swollen, this compression will elicit pain.

Interpreting the Results

A positive Hawkins-Kennedy test suggests the presence of subacromial impingement syndrome. However, it's crucial to understand that:

• Not Definitive: A positive test alone is not diagnostic. It indicates a high probability of impingement but must be considered alongside the patient's medical history, other clinical findings, and potentially imaging studies.
• Differential Diagnosis: Pain during the test could also be influenced by other shoulder pathologies, such as:
  • Rotator cuff tendinopathy or tear
  • Bicipital tendinopathy
  • Subacromial bursitis
  • Acromioclavicular (AC) joint pathology (less common but possible)
• Negative Test: A negative test (no pain produced) makes impingement less likely but does not entirely rule it out, as other factors or specific pain triggers might not be replicated.

Clinical Significance and Limitations

The Hawkins-Kennedy test is a valuable tool in a comprehensive shoulder examination due to its relatively high sensitivity.

• Sensitivity and Specificity: Studies have shown varying levels of sensitivity (how well it identifies true positives) and specificity (how well it identifies true negatives). It is generally considered highly sensitive (meaning a negative test makes impingement less likely) but less specific (meaning a positive test doesn't definitively rule out other conditions).
• Part of a Cluster: For improved diagnostic accuracy, the Hawkins-Kennedy test is often used in conjunction with other impingement tests (e.g., Neer's test) and rotator cuff strength tests. A cluster of positive tests significantly increases the likelihood of impingement.
• Examiner Skill: The accuracy of the test can be influenced by the examiner's technique and experience.

Next Steps After a Positive Test

If the Hawkins-Kennedy test is positive and consistent with the patient's symptoms, the next steps typically involve:

• Professional Consultation: A definitive diagnosis and treatment plan require consultation with a healthcare professional, such as an orthopedic surgeon, sports medicine physician, or physical therapist.
• Further Assessment: This may include:
  • Detailed History and Physical Examination: To gather more information about the onset, nature, and aggravating factors of the pain.
  • Imaging Studies: X-rays can rule out bony abnormalities (like spurs or acromial shape variations), while an MRI (Magnetic Resonance Imaging) can provide detailed images of soft tissues, revealing inflammation, tendinopathy, or rotator cuff tears.
• Treatment Plan: Depending on the severity and underlying cause, treatment may involve:
  • Rest and activity modification
  • Anti-inflammatory medications
  • Physical therapy (strengthening rotator cuff muscles, improving scapular stability, modifying movement patterns)
  • Corticosteroid injections
  • In some cases, surgical intervention (e.g., arthroscopic subacromial decompression)

Conclusion

The Hawkins-Kennedy Impingement Test is a fundamental clinical assessment in the evaluation of shoulder pain, particularly when subacromial impingement is suspected. By intentionally narrowing the subacromial space, it helps clinicians identify the mechanical compression of soft tissues that can lead to pain. While a positive test is a strong indicator, it is always interpreted within the context of a thorough clinical examination and, when necessary, advanced imaging, to guide appropriate diagnosis and effective treatment strategies for optimal shoulder health.