O’Brien’s Test (Active Compression Test)

The O’Brien’s Test, also known as the Active Compression Test, is commonly used to evaluate shoulder pain originating from either SLAP lesions (Superior Labrum Anterior to Posterior) or acromioclavicular (AC) joint pathology. While the test is not diagnostic on its own, it can serve as a valuable clinical indicator of intra-articular labral injury or AC joint problems¹ ².

Technique

Execution

• The patient stands or sits with the arm in 90° flexion and 10–15° horizontal adduction.

• The shoulder is placed in full internal rotation and the forearm in pronation.

• The examiner applies a downward force distally while the patient resists upward.

• The maneuver is repeated with the arm in supination (neutral rotation).

Interpretation of Results

• Positive test:

  • Pain or a clicking sensation during the pronated position.

  • Symptoms reduce or disappear in supination.

  • Deep pain: Suggests a SLAP lesion.

  • Superficial pain: Suggests AC joint pathology.

• Pain in both positions may indicate other conditions, such as rotator cuff tendinopathy or glenohumeral instability.

Diagnostic Accuracy

Positive test:

• Pain or a clicking sensation during the pronated position.

• Symptoms reduce or disappear in supination.

• Deep pain: Suggests a SLAP lesion.

• Superficial pain: Suggests AC joint pathology.

• Pain in both positions may indicate other conditions, such as rotator cuff tendinopathy or glenohumeral instability.

Diagnostic Accuracy

Condition	Sensitivity	Specificity	+LR	–LR
SLAP lesion ⁵ ⁶ ⁹	0.63–1.00	0.73–0.98	2.3–50.0	0.00–0.51
AC joint ⁸	0.41–1.00	0.95–0.97	8.2–33.3	0.00–0.62

• The test demonstrates high specificity for AC joint pathology, meaning a positive result strongly indicates AC involvement.

• For SLAP lesions, diagnostic accuracy varies widely, reinforcing the need for additional tests.

Test Clusters and Combinations

When evaluating suspected SLAP lesions, O’Brien’s Test is best used in combination with other maneuvers⁷:

• Crank Test

• Apprehension Test

• Biceps Load II, Speed’s, or Yergason’s Test

➡ A combination of positive findings increases diagnostic certainty (sensitivity ~75%, specificity ~90%).

Clinical Relevance

• SLAP lesions: O’Brien’s Test can indicate labral pathology but should not be used in isolation due to variable accuracy. It is best combined with other special tests or MR arthrography for confirmation.

• AC joint pathology: High specificity makes the test particularly useful when AC joint injury is suspected.

• Overhead athletes: Especially relevant for throwers, tennis players, and other sports with repetitive overhead activity.

Clinical recommendation:O’Brien’s Test should always be interpreted as part of a test battery. If positive but diagnostic uncertainty remains, further imaging such as MR arthrography should be considered.

References

1. O'Brien SJ, Pagnani MJ, Fealy S, McGlynn SR, Wilson JB. The active compression test: A new and effective test for diagnosing labral tears and acromioclavicular joint abnormality. Am J Sports Med. 1998;26:610-613.

2. Owen JM, Boulter T, Walton M, Funk L, Mackenzie TA. Reinterpretation of O'Brien test in posterior labral tears of the shoulder. Int J Shoulder Surg. 2015 Jan-Mar;9(1):6-8.

3. everydayPT. O'Brien's Shoulder Special Test. Available from: https://www.youtube.com/watch?v=v_EL9XqTJQQ [last accessed 21/8/2024]

4. Parentis, Michael Andrew et al. “An evaluation of the provocative tests for superior labral anterior posterior lesions.” The American Journal of Sports Medicine 34.2 (2006): 265-8.

5. Ebinger, Nina et al. “A new SLAP test: the supine flexion resistance test.” Arthroscopy: The Journal of Arthroscopic Related Surgery: Official Publication of the Arthroscopy Association of North America and the International Arthroscopy Association 24.5 (2008): 500-5.

6. Guanche, Carlos A, and Donald C Jones. “Clinical testing for tears of the glenoid labrum.” Arthroscopy: The Journal of Arthroscopic Related Surgery: Official Publication of the Arthroscopy Association of North America and the International Arthroscopy Association 19.5: 517-23.

7. Oh, Joo Han et al. “The evaluation of various physical examinations for the diagnosis of type II superior labrum anterior and posterior lesion.” The American journal of sports medicine 36.2 (2008): 353-9.

8. Flynn, T.W., Cleland, J.A., Whitman, J.M. (2008). User's guide to the musculoskeletal examination: Fundamentals for the evidence-based clinician. Buckner, Kentucky: Evidence in Motion

9. Flynn, T.W., Cleland, J.A., Whitman, J.M. (2008). User's guide to the musculoskeletal examination: Fundamentals for the evidence-based clinician. Buckner, Kentucky: Evidence in Motion