O'Brien's test result interpretation.

• A. Pain greater in external rotation than internal rotation; pain inside shoulder indicates labrum, pain on top AC joint
• B. Pain greater in internal rotation than external rotation; rotator cuff
• C. Pain only with resisted abduction
• D. No pain

Answer: (C)

O'Brien's test pattern is used to sort out shoulder pathologies by how pain is produced during a rotation and resisted force. When this test is interpreted as the patient experiencing pain only with resisted abduction, that pattern points toward rotator cuff involvement, particularly the supraspinatus, rather than a labral tear or AC joint problem. A labral tear would typically show pain with internal rotation that changes when the forearm is externally rotated, and AC joint issues tend to produce pain localized at the top of the shoulder or specifically at the AC joint. If there’s no pain at all, that would argue against a pathological issue being detected by this test. So, the finding of pain only with resisted abduction best fits rotator cuff pathology in this context.