blumberg test/rebound tenderness: Hold your hand 90 degrees, or perpendicular, to the abdomen. Push down slowly and deeply, then lift up quickly, This makes structures that are indented by palpation rebound suddenly.
o A normal, or negative, response - no pain on release of pressure.
o Abnormal response - Pain on release of pressure confirms rebound tenderness, which is a reliable sign of peritoneal inflammation