The obturator’s sign test is defined in the academic literature as a “pain upon internal rotation of the thigh with the right hip flexed.” (Rudy, 2007, p. 116) Accordingly, the obturator’s sign is primarily relevant for its indication of possible ailments that are consistent with “contact between the internal obturator muscle and an inflammation process.” (Rudy, 2007, p. 116) This means that the obturator’s sign is relevant to help diagnosing possible appendicitis in the patient, most likely retrocecal appendix. (Rudy, 2007, p. 116)
The performance of the obturator’s sign test is carried out by the examiner, who assists the patient into a supine position. The examiner flexes the patient’s right leg at an angle of 90 degrees at the knee and hip, gripping the patient’s right ankle with his/her right hand, while rotating their right hip. (Al-Ajam & El-Bash, 2004, p. 47) If the patient experiences Right Lower Quadrant Abdominal Pain (RLQ), this means a positive obturator sign. (Al-Aljam & El-Bash, 2004, p. 47) For example, a patient suffering from appendicitis will experience pain when the test is performed because the appendix is inflamed.
However, the lack of a positive obturator sign does not discount appendicitis. (Rudy, 2007, p. 116) Accordingly, for cases where appendicitis is clearly suspected, what is usually recommended is the performance of a further test, such as the psoas maneuver. (Rudy, 2007, p. 116) This sign will be positive if it elicits pain, which is the result of the inflammation and the psoas muscle being in contact. (Rudy, 2007, p. 116)
A positive obturator sign is, however, not definitive for an appendicitis diagnosis. For example, in some women, various gynecological conditions can also yield a positive obturator sign. (Hardin, 1999) It is thus recommended that women undergo a pelvic examination, in order to gain a more definitive diagnosis. (Hardin, 1999)