Scarf Test (Cross-Body Adduction Test)
- Fysiobasen
- Oct 4
- 2 min read
The Scarf Test, also known as the Cross-Body Adduction Test, is used to evaluate the integrity of the acromioclavicular (AC) joint. The test is particularly useful for assessing conditions such as AC joint osteoarthritis, ligament injuries, or AC joint separation.
Performance
The test is performed as follows:
The patient sits or stands with the arm in 90 degrees of shoulder flexion and 90 degrees of elbow flexion.
The examiner supports the patient’s elbow and passively moves the arm across the chest toward the contralateral shoulder in a horizontal adduction movement.
This position causes compression of the medial acromial facet against the distal clavicle, which may provoke pain if the AC joint is affected[1].
Interpretation of Test Results
The test is considered positive if the patient experiences reproduction of pain localized to the AC joint during the maneuver[1].
A positive test may indicate:
AC joint osteoarthritis (degenerative changes of the AC joint)
Ligament injury (sprain or rupture of the AC ligaments)
AC joint separation (injury causing instability of the AC joint)
Differential Diagnoses
Pain during the Scarf Test may also occur in other conditions, such as:
Posterior capsular tightness, which restricts shoulder movement and causes discomfort during adduction.
Subacromial impingement, where compression of subacromial structures may lead to pain during the test[3].
Adhesive capsulitis (frozen shoulder) or glenohumeral osteoarthritis, where pain and reduced range of motion are more characteristic of the glenohumeral joint rather than the AC joint[3].
Diagnostic Accuracy
The Scarf Test has demonstrated the following diagnostic accuracy for AC joint pathology[2]:
Sensitivity: 0.77 – 1.00 (high ability to detect the condition when present).
Specificity: 0.79 (good ability to rule out the condition when the test is negative).
Positive likelihood ratio (+LR): 3.67 (moderate increase in likelihood of AC joint pathology when the test is positive).
Negative likelihood ratio (–LR): 0.29 (reduced likelihood of AC joint pathology when the test is negative).
Evidence and Clinical Use
To increase diagnostic accuracy, the Scarf Test should be used in combination with other clinical tests[2]:
To rule out painful AC joint pathology:
Negative Scarf Test
No tenderness on palpation of the AC joint
Negative Paxinos Sign
To confirm AC joint pathology:
Positive Scarf Test
Positive Active Compression Test
Positive AC Resisted Extension Test
References
Park HB, Yokota A, Gill HS, El Rassi G, McFarland EG. Diagnostic accuracy of clinical tests for the different degrees of subacromial impingement syndrome. JBJS. 2005 Jul 1;87(7):1446-55.
Huijbregts PA. Concurrent Criterion-Related Validity of Acromioclavicular Joint Physical Examination Tests: A Systematic Review.
Owens BD. Acromioclavicular joint injury [Internet]. Medscape; 2018 [cited 2020 Dec07]. Available from: https://emedicine.medscape.com/article/92337-clinical#b3
