Trendelenburg test is positive due to injury to which of the following nerve

TRENDELENBURG SIGN:- Normally, when the body weight is suppoed on one limb, the glutei of the suppoed side raise the opposite and unsuppoed side of the pelvis.However, if the abductor mechanism is defective, the unsuppoed side of the pelvis drops- Trendelenburg sign +ve. Sign is positive in defects of power- paralysis of the glutei medius and minimus ( supplied by superior gluteal nerve), defects of the fulcrum (congenital or pathological dislocation of hip), defects of weight. {Reference : BDC 6E pg no.70}