<prompt> Which is not a cause of positive trendelenburg sign?Paralysis of gluteus maximusCongenital dislocation of hipUn-united fracture of neckCoxa vara  <response>: Ans A Paralysis of gluteus maximusRef: Maheswari Orthopaedics, 5th ed. pg. 135 When a person stands on one leg, the tendency of unsupported side to sag down is counteracted by gluteus medius and minimus. These two muscles form the abductor mechanism of hip. In case the abductor mechanism is defective, unsupported side of the pelvis drops and is called Positive Trendelenburg sign. It is seen in: Paralysis of gluteus medius and minimus Congenital dislocation of Hip Ununited fracture Coxa vara 