The role of the gluteus medius is to help steady the pelvis so it does not rotate downwards or sag when the opposing side is lifted or not supported with the other leg. It also assists with lateral movement away from the midline of the body, i.e. moving the thigh outward with hip straight. It lies on the side of the hip directly above the larger, “meatier” gluteus maximus. The gluteus medius can be somewhat neglected in the quadriceps-dominant activities of running, which primarily involves forward movement in a straight line, and in cycling. Sometimes knee pain can be caused by overusing quadriceps muscles when glute muscles are not “carrying their proper burden.”

crucial for good running posture