What does the psoas sign indicate?

The psoas sign is a clinical test used to assess for irritation of the iliopsoas muscle, which can occur due to an inflamed appendix that is located in a retrocecal position. When the psoas muscle is irritated—often due to appendicitis—the patient experiences pain when trying to flex their hip against resistance, which is the basis for the psoas sign.

In the context of retrocecal appendicitis, the appendix is positioned more towards the back (retrocecal) rather than in the right iliac fossa. This atypical position can lead to less typical presentation and can cause the irritation of the psoas muscle. The positive psoas sign indicates an underlying issue in that area, effectively pointing toward retrocecal appendicitis as the underlying cause of abdominal pain.

While conditions like gallbladder disease, pelvic inflammatory disease, and urinary tract infections can also cause abdominal or flank pain, they are not specifically associated with the psoas sign, which is most indicative of retrocecal appendicitis in the general clinical context.