Which statement best describes the obturator sign?

The obturator sign is a clinical test used to assess for irritation of the obturator internus muscle and is often associated with conditions such as appendicitis, particularly when the appendix is located in a retrocecal position. The correct statement describing the obturator sign involves flexing the hip and knee while internally rotating the hip, which typically elicits pain in the right hypogastric region if there is irritation present.

This response aligns with the anatomical structures involved and the action being tested. When the hip and knee are flexed and the hip is internally rotated, the obturator internus is stretched and can cause significant pain if there is underlying pathology such as inflammation or infection.

The other descriptions provided do not accurately reflect the obturator sign or the mechanism of testing. Descriptions that mention extension of the thigh or distant pain do not pertain to the specific muscle and motion involved in the obturator sign. Additionally, pain during inhalation in the right upper quadrant describes a different clinical sign, likely associated with diaphragmatic irritation or other upper abdominal issues, rather than the obturator sign itself.