Educational video describing the condition Trendelenburg gate. During the stance phase of the gait cycle, the gluteus medius work to maintain both hips at the same level. Trendelenburg gait is an abnormal gait that is usually found in people with weak abductor muscle of the hip which is supplied by the superior gluteal nerve. The patient cannot abduct the affected hip due weakness of the abductor muscles on the affected side. If the patient has weakness on one side of the pelvis and when the patient stands on that side, the pelvis on the contralateral side will drop. This is called Trendelenburg sign. The gluteus medius is very important during the stance phase of the gait cycle in order to maintain both hips at the same level. The stance phase accounts for about 60% of the gait cycle. Three times the body weight is transmitted to the hip joint during the stance e phase. The hip abductor actions account for 2/3 of that body weight. We identify the weakness stance phase if the pelvis drops to the opposite side. Weakness can also occur in patients with L5 radiculopathy or avulsion of the abductor muscle tendon which occurs with increasing frequency after hip replacement surgery. The superior gluteal nerve injury is a major factor in this gait. A positive Trendelenburg sign occurs when there is dysfunction of the abductor muscles and the body is unable to maintain the center of gravity on the side of the stance leg The patient will show an excessive lateral lean to keep the center of the gravity over the stance leg. The patient will show an excessive lateral lean to keep the center of gravity over the stance leg. With bilateral weakness of the abductor muscles, the patient will have dropping of the pelvis on both sides during walking which leads to a waddling motion. This gait is seen in patients with myopathies. Become a friend on facebook: http://www.facebook.com/drebraheim Follow me on twitter: https://twitter.com/#!/DrEbraheim_UTMC