Blumberg sign (or Rebound tenderness positive sign) is elicited by palpating slowly and deeply over a viscus and then suddenly releasing the palpating hand. If rebound tenderness is positive then the patient experiences pain. The sign is explained by the fact that gradual stretching of the abdominal wall by deep palpation followed by sudden release of this pressure stimulates the parietal peritoneum which, if inflamed, produces pain. Rebound tenderness is not always a reliable sign and should be interpreted with caution, particularly in those patients with a low pain threshold.
Rebound tenderness is commonly done as part of physical examination of a patient of appendicitis. Rebound tenderness is also named positive Blumberg’s sign.
Blumberg Sign inccorect on Wikipedia
While reading about appendicitis on wikipedia.com i found out that the definition of Blumberg’s sign is given wrong over there. According to wikipedia (on 7th May, 2010) Blumberg’s sign due to inflammed vermiform appendix is:
Palpation of the left iliac fossa, followed by sudden release causes contralateral (right iliac fossa) rebound tenderness.
Which is obviously not so. It is even technically incorrect as rebound phenomenon occurs on the ipsilateral side and not the contralateral.I have submitted the correction in the wikipedia article regarding Blumberg’s sign mistake. Hopefully they will approve it.
Image demonstrating blumberg sign / rebound tenderness
Note that the doctor is examining the right iliac fossa of the patient. This way to press is not appropriate however, first try using the palm resting on the right iliac fossa and then pressing in to elicit blumberg sign / rebound tenderness. . Also always approach the patient from the right side.
What is a positive rebound tenderness sign?
As said above, Blumberg’s sign is same as rebound tenderness sign. A positive rebound tenderness sign means that rebound tenderness was successfully elicited.
How is rebound tenderness checked? The patient is asked to lie down flat with a pillow if possible and knees bent a bit to relax the muscles of the abdomen. Once in this position, the doctor examining the patient pushes the right iliac fossa inside using the fingers (or altering the method, depending on their expertise). While pressing the hand into the fossa gently, the patient is distracted like by asking his personal profile, name, symptoms etc, and then the hand is held in the pressed position for a few seconds, so that the patient forgets about the pain. Remember patient has to be distracted. And while he is talking, he is asked to keep his eyes open and then suddenly the hand is removed, releasing the compressed right iliac fossa. If this release elicits a sign of pain in the patient this is called positive rebound tenderness sign or blumbergs sign.
Blumberg’s sign significance
The positive blumberg’s sign or rebound tenderness is indicative of peritonitis (inflammation of peritoneum). Which means that blumberg sign can be positive for any disease condition inside the abdominal cavity which leads to peritonitis such as appendicitis (inflammation of appendix). In appendicitis the blumber’s sign or rebound tenderness will be positive in right iliac fossa of the patient (and on the left in case of citus inversus).
Blumberg sign vs Rovsing sign
As noticed in comments, there is some confusion among people regarding Blumberg sign and Rovsing sign.
Rovsing sign is very much different from Blumberg sign. The blumberg sign is the direct rebound tenderness test. However, Rovsing’s sign is when you press the left iliac fossa and as a result the pain aggravates in the right iliac fossa, due to the overall increase in pressure on the appendix for example, due to the push and shift of the viscera towards the opposite side.
Hopefully now it’s clear what blumberg sign and rebound tenderness is and how it’s different from rovsing sign.