What does the Appley scratch test indicate?

The Apley Scratch Test: Diagnostic Utility in Shoulder Assessment

The Apley scratch test is a clinical examination maneuver that evaluates shoulder range of motion and helps identify potential restrictions in shoulder mobility. The Apley scratch test specifically assesses combined movements of the shoulder including internal/external rotation, adduction/abduction, and extension/flexion, which can help diagnose rotational cuff pathology, adhesive capsulitis, and other shoulder mobility disorders.

Test Execution and Interpretation

The Apley scratch test consists of two main components:

1. Apley Superior Scratch Test (Test 1)

• Patient raises the arm and reaches behind the head to touch the opposite shoulder blade
• This movement tests:
  • External rotation
  • Abduction
  • Flexion of the shoulder

2. Apley Inferior Scratch Test (Test 2)

• Patient places the hand behind the back and reaches upward to touch the opposite shoulder blade
• This movement tests:
  • Internal rotation
  • Adduction
  • Extension of the shoulder

Diagnostic Value

The Apley scratch test has limitations in its diagnostic accuracy when used alone. Research on similar clinical shoulder tests shows that physical examination tests generally have moderate sensitivity and specificity:

• Like other orthopedic tests such as the McMurray's test and joint line tenderness test, the Apley scratch test has diagnostic accuracy around 54-59% when used by clinicians 1
• Similar clinical tests show sensitivity ranging from 62-83% and specificity from 39-78% 2

Clinical Applications

The test is particularly useful for:

1. Screening for shoulder mobility restrictions

   • Quickly identifies limitations in combined shoulder movements
   • Helps determine which specific movements are restricted

2. Evaluating specific shoulder conditions

   • Rotator cuff pathology
   • Adhesive capsulitis (frozen shoulder)
   • Glenohumeral arthritis
   • Acromioclavicular joint disorders

3. Monitoring rehabilitation progress

   • Provides a simple method to track improvement in shoulder mobility over time

Limitations and Considerations

Several important caveats should be considered when using the Apley scratch test:

• The test evaluates combined movements rather than isolated ones, making it difficult to pinpoint specific pathologies
• Results can be affected by individual anatomical variations in shoulder flexibility
• A positive test indicates mobility restriction but doesn't definitively diagnose the underlying cause
• The test should be performed bilaterally to compare with the unaffected side
• Pain during the test should be noted but interpreted cautiously as it may originate from various structures

Integration into Clinical Practice

For optimal diagnostic utility, the Apley scratch test should be:

1. Performed as part of a comprehensive shoulder examination
2. Interpreted alongside other specific tests (e.g., Neer test, Hawkins-Kennedy test, empty can test)
3. Correlated with the patient's history and symptoms
4. Used to guide the need for further diagnostic imaging when appropriate

When clinical examination findings are equivocal or when precise diagnosis is needed for treatment planning, advanced imaging such as MRI may be necessary, though clinicians should be aware that MRI findings must be correlated with clinical presentation to avoid overdiagnosis.