Psoas sign

Elicited by the iliopsoas test, the psoas sign is an indicator of irritation to the iliopsoas group of hip flexors in the abdomen.

The test is performed by having a supine patient with knees extended flex their thighs against resistance. If abdominal pain results, it is a positive psoas sign. ^*

Because the right iliopsoas muscle lies under the appendix when the patient is supine, a "positive psoas sign" may suggest appendicitis.