Many athletes with running injuries present with poor gluteus medius function and it is viewed by many health professionals that the strength and function of this muscle is the most important active component in the achievement of a biomechanically efficient running technique.
During the stance phase of running the normal role of this muscle is to stabilise the pelvis on the hip. So, when landing on the right leg this muscle contracts to stop the pelvis from tilting too far on the left. Given that when we run we land on the stance leg with many times our body weight, this muscle must be strong enough to withstand that force.
If the gluteus muscle is not functioning well to control the pelvis on the hip it may produce a waddling motion at the hip or a compensatory body tilt. This type of running style is known as a Trendelenburg gait.
This lack of stability around the pelvis can result in all sorts of injury from back pain to foot pain and all areas in between because of the stress it places on other tissues. It can cause stress reactions in the pelvis, overuse strain in the groin or hamstring muscles, pain around the knee, shin splints, and pain around the foot and ankle. Improving strength and function of the gluteus medius muscle not only prevents these types of injuries occurring but also increases the efficiency of running.