The Markle sign or jar tenderness is a clinical sign

Medical sign

A medical sign is an objective indication of some medical fact or characteristic that may be detected by a physician during a physical examination of a patient....

 in which pain in the right lower quadrant

Right lower quadrant (abdomen)

thumb|right|A Graphic showing Contents of The Right lower quadrant of the human abdomen, often abbreviated as RLQ, is used to refer to a portion of the abdomen that allows doctors to localise pain and tenderness, scars, lumps and other items of interest...

 of the abdomen

Abdomen

In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...

 is elicited by dropping from standing on the toes to the heels with a jarring landing. It is found in patients with localised peritonitis

Peritonitis

Peritonitis is an inflammation of the peritoneum, the serous membrane that lines part of the abdominal cavity and viscera. Peritonitis may be localised or generalised, and may result from infection or from a non-infectious process.-Abdominal pain and tenderness:The main manifestations of...

 due to acute appendicitis

Appendicitis

Appendicitis is a condition characterized by inflammation of the appendix. It is classified as a medical emergency and many cases require removal of the inflamed appendix, either by laparotomy or laparoscopy. Untreated, mortality is high, mainly because of the risk of rupture leading to...

. It is similar to rebound tenderness

Rebound tenderness

Rebound tenderness is a clinical sign that a doctor or other health care provider may detect in physical examination of a patient's abdomen. It refers to pain upon removal of pressure rather than application of pressure to the abdomen...

, but may be easier to elicit when the patient has firm abdominal wall muscles. Abdominal pain on walking or running is an equivalent sign.