Trendelenburg test is positive on right side. Nerve injured is

Superior gluteal nerve, if injured, paralyses the 3 muscles: gluteus medius, gluteus minimus and tensor fascia latae and hence lead to Trendelenberg test positive, which is evident on the contralateral side. Pelvis sags on the unsuppoed lower limb. In Trendelenberg test the action of gluteus medius (superior pelvic tilt of contralateral hip) is absent and we actually observe that there is a downward drop of the unsuppoed hip -due to unopposed action of gravity. This leads to Lurching gait in the patient.