Significance of Carnett's sign

The idea of Carnett's sign is that (acute) abdominal pain remains unchanged or increases when the muscles of the abdominal wall are tensed.So, if Pain source is Intra-Abdominal (Negative Carnett's Sign),Abdominal Pain decreases with tensing abdomen.
And in Abdominal Muscle Wall Pain (Positive Carnett's Sign), Pain increases or remains unchanged

Technique

A- Patient lies supine
B- Patient tenses abdominal wall by
-asking the patient  to lift the head and shoulders from the examination table to tense the abdominal muscles
-An alternative is to ask the patient to raise both legs with straight knees.

Carnett's sign for patients with pelvic pain. The examiner places his or her finger on the tender area of the patient's abdomen and asks the patient to raise both legs off the table. An increase in the patient's pain during this maneuver is considered a positive test.