In a Trendelenburg test, the iliac crest drops on which side indicating a positive result?

• A. The weight-bearing side
• B. The non-weight bearing side
• C. Both sides equally
• D. The opposite leg raises

Answer: (B)

The Trendelenburg test measures the strength of the hip abductors, mainly gluteus medius and minimus, when you stand on one leg. Those muscles should pull the pelvis up and keep it level during single-leg stance. If they’re weak, the pelvis can’t stay level and sags toward the side that isn’t bearing weight—the non-weight-bearing side. That drop of the iliac crest on the non-weight-bearing side is a positive Trendelenburg sign, signaling weakness of the stance leg’s hip abductors. If the pelvis remains level or the torso shifts to compensate toward the stance leg, that suggests normal strength or compensation rather than a positive sign.