Markle's sign, or jar tenderness, is a clinical sign in which pain in the right lower quadrant of the abdomen is elicited by the heel-drop test (dropping to the heels, from standing on the toes, with a jarring landing).

It is found in patients with localised peritonitis due to acute appendicitis.^[1] It is similar to rebound tenderness, but may be easier to elicit when the patient has firm abdominal wall muscles. Abdominal pain on walking or running is an equivalent sign.^[2]

It was first described by the George Bushar Markle IV (1921–1999), an American surgeon, in 1985.^[3]