Understanding the O'Brien's Test (Active Compression Test) Assessment
To detect **Superior Labral Anterior to Posterior (SLAP) lesions** or **Acromioclavicular (AC) joint pathology**.
Watch How It's Done
How do I start?
Patient is sitting or standing. Arm is flexed to 90°, horizontally adducted 10-15°.
What happens?
**Phase 1 (SLAP/AC Joint):** Arm is internally rotated (thumb pointing down). Examiner applies a downward force that the patient resists. **Phase 2 (Control):** Arm is externally rotated (palm pointing up). Examiner applies the same downward force.
In Plain English
What Does a Positive Result Mean?
**Pain or clicking in Phase 1 that is relieved in Phase 2.** If pain is deep in the shoulder, it suggests a labral tear (SLAP). If pain is superficial at the top of the shoulder, it suggests AC joint pathology.
Helpful Tip:
Relief of pain in Phase 2 is essential for a true positive test.
Safety First
This guide is to help you understand what happens in a clinic. Do not try to diagnose yourself. If you have severe pain, swelling, or cannot put weight on your leg, please visit an urgent care center or your doctor immediately.
Other shoulder Tests
Adson's Test
To assess for Thoracic Outlet Syndrome (TOS) due to compression of the neurovascular bundle by the anterior and middle scalene muscles.
Anterior Drawer Test Of The Shoulder
To assess for anterior glenohumeral joint laxity and instability and the integrity of the anterior capsular structures.
Arm Squeeze Test
This is a new clinical test that may be useful to distinguish between Cervical radiculopathy from other shoulders related pathology. The anatomic reasoning behind this test is that because the musculocutaneous nerve (cervical root from C5 to C7), the radial nerve (from C5 to T1), the ulnar nerve (from C7 to T1), and the median nerve (from C5 to T1) are relatively superficial in the middle third of the arm and easy to elicit a painful provocation response by squeezing the arm. A moderate compression of skin, subcutis, and muscle by squeezing the middle third of the upper arm (brachial biceps and triceps area) on the side with shoulder pain elicits an intense reaction of local pain only in patients with cervical nerve root compression from C5 to T1, not when the pain arises from the shoulder.
Bear Hug Test
To assess for a tear or significant weakness in the **subscapularis tendon** (subscapularis strength).