During gait, the gluteus medius is primarily responsible for which function?

• A. Hip abduction and pelvic stabilization in the frontal plane.
• B. Hip flexion and knee extension.
• C. Internal rotation of the hip.
• D. Hip adduction with pelvic tilt.

Answer: (A)

The main idea is that the gluteus medius serves as the primary hip abductor and pelvis stabilizer in the frontal plane during gait. When one leg is in stance, the pelvis tends to drop on the opposite side without a stabilizer. The gluteus medius on the stance leg contracts to abduct the thigh and keep the pelvis level, preventing contralateral pelvic drop and providing smooth, efficient walking. This stabilization in the frontal plane is what maintains a level pelvis throughout the stance phase, which is essential for balanced gait. It does not primarily flex the hip, extend the knee, cause internal rotation, or drive adduction with pelvic tilt, which is why the best choice is hip abduction and pelvic stabilization in the frontal plane.