Positive Trendelenburg sign is seen in: March 2007

Ans.A: Superior gluteal nerve palsy Trendelenburg's sign is found in people with weak abductor muscles of the hip. The Trendelenburg sign is said to be positive if, when standing on one le.g., the pelvis drops on the side opposite to the stance leg. The weakness is present on the side of the stance leg. The body is not able to maintain the center of gravity on the side of the stance leg. Normally, the body shifts the weight to the stance le.g., allowing the shift of the center of gravity and consequently stabilizing or balancing the body. However, here when the patient lifts the opposing le.g., the shift is not created and the patient cannot maintain balance leading to instability. Trendelenburg sign is caused by paralysis of the gluteus medius and minimus muscles. Para!ysis may arise due to nerve damage, namely, the superior gluteal nerve.