Which sign is positive when internal rotation of the right leg causes abdominal pain, indicating appendicitis?

• A. Psoas sign
• B. Obturator sign
• C. Rovsing's sign
• D. Murphy's sign

Answer: (B)

The sign being tested is the obturator sign. When the right leg is flexed at the hip and knee to about 90 degrees and the hip is internally rotated, the obturator internus muscle is stretched and the obturator nerve is put under tension. If an inflamed appendix lies in contact with or near the obturator internus (such as a pelvic appendix), this maneuver irritates the structures and causes pain in the right lower quadrant. That focal pain during internal rotation points to appendicitis, especially with a pelvic location.

If you compare with the others: the psoas sign involves pain when the hip is extended (or when the patient actively flexes the thigh against resistance), reflecting irritation of the iliopsoas muscle—often with a retrocecal appendix. Rovsing’s sign is pain in the RLQ with palpation of the LLQ, a general peritoneal irritation test. Murphy’s sign is inspiratory arrest with gallbladder palpation, used for cholecystitis. None of these specifically rely on internal rotation of the leg, so they don’t fit as well for this scenario.