Trendelenburg gait - primary muscles involved. Which muscles are primarily involved?

• A. Gluteus medius and gluteus minimus on the stance leg.
• B. Quadriceps femoris on the stance leg.
• C. Tensor fascia latae on swing leg.
• D. Hamstrings on stance leg.

Answer: (A)

Stabilizing the pelvis in the frontal plane during single-leg stance is the key function being tested. The primary muscles doing this are the gluteus medius and gluteus minimus on the stance leg. When you step onto one leg, these hip abductors contract to lift and keep the pelvis level on the supported side as the opposite leg swings forward. If these muscles are weak, the pelvis drops toward the opposite side, producing a Trendelenburg gait. The tensor fascia latae can assist, but it isn’t the main stabilizer in this moment. The quadriceps and hamstrings aren’t primarily responsible for this pelvic stabilization, since their roles are knee extension and hip extension, not maintaining pelvis level during single-leg stance.