The Trendelenburg test is a simple maneuver to evaluate the strength of the gluteus medius and gluteus minimus muscle. It is performed by having the patient stand unassisted on one leg while the other leg is raised off the ground. The examiner places their fingers on the posterior ilaic spine. If there is a significant drop of the hip on the side of the raised leg, their is weakness in the gluteus medius and minimus muscle.
The gluteus medius and mimus muscle are responsible for rotating the hip inward and extending it outward(abduction).
They are critical in stabilizing the trunk and keeping it in an upright position when one’s foot is raised while walking.
If there is weakness in the glueus medius and minimus there is structural instability with disproportionate forces placed on the hip and knee. These forces can ultimately result in excessive wear of the joint cartilage and pain. 
At the Centeno-Schultz Clinic we emphasis structural integrity. If a patient has a positive Trendelenburg, they will be scheduled for therapy to restore gluteal strength which typically is in the form of intramuscular stimulation (IMS). If there has been hip or cartilage damage, a novel technique using your own stem cells can used to assist in the regeneration the cartilage.