Obturator sign

The obturator sign or Cope's obturator test is an indicator of irritation to the obturator internus muscle.

The technique for detecting the obturator sign, called the obturator test, is carried out on each leg in succession. The patient lies on her/his back with the hip and knee both flexed at ninety degrees. The examiner holds the patient's ankle with one hand and knee with the other hand. The examiner rotates the hip by moving the patient's ankle away from the patient's body while allowing the knee to move only inward. This is flexion and internal rotation of the hip.