Which muscle prevents the pelvis from tilting during walking?

• A. Gluteus maximus
• B. Tensor fasciae latae
• C. Gluteus medius
• D. Piriformis

Answer: (C)

Keeping the pelvis level during the stance phase of walking is achieved by the hip abductors on the weight-bearing side, especially the gluteus medius. This muscle originates on the outer surface of the ilium and inserts on the greater trochanter, producing abduction of the thigh and, critically, stabilizing the pelvis so the swing side doesn’t drop. When the gluteus medius (and the gluteus minimus, its synergist) contracts, it keeps the pelvis level as you step forward with the opposite leg. Weakness here leads to a Trendelenburg pattern, where the pelvis dips on the unsupported side because the standing-leg abductor can’t hold it up.

The other muscles aren’t the primary pelvis stabilizers in this context. Gluteus maximus mainly extends and externally rotates the hip, not stabilizing pelvis height during gait. Tensor fasciae latae helps with abduction and tensing the iliotibial band but isn’t the main counterweight to pelvis tilt in walking. Piriformis is a lateral rotator and abductor when the hip is flexed, not the primary pelvic stabilizer during single-leg stance.