Iliotibial Band Syndrome, or ITBS, is a common overuse injury among runners. Although the injury occurs because of inflammation of the tendon near the outside of the knee, the problem often arises from tightness in the Tensor Fasciae Latae (TFL), a muscle of the hip that inserts into the Iliotibial band.
Causes of ITBS
As you run, hip muscles work together to stabilize the pelvis. The longer you run, the more likely these muscles are to become fatigued. Once fatigue sets in, the hip has a tendency to sag in a side-to-side motion with each stride, which can also cause the knee joint to move inward towards the midline of the body instead of staying in line with your foot.
Athletic trainer Michael Busby, who works specifically with runners, says that weak hip abductors such as the gluteus medius (smaller muscle located on the side of the hip/gluteus) can be an indirect cause of ITBS in running-related injuries. "Weak hip abductors such as the gluteus medius won't likely cause ITBS on their own," he says. "But with prolonged lower-extremity movement such as running, weak muscles become exposed, forcing your ITB and the TFL to work harder than they should. The harder they work, the tighter they'll become."
While a tight ITB does directly result in inflammation, strengthening the gluteus medius is a must in order to improve hip strength and avoid pain, particularly on long runs.
Strengthening the Gluteus Medius
One exercise that Busby recommends for gluteus medius strengthening is called clamshells. "Clamshells are a great exercise to start with. If your hip abductors are weak, start out doing them with both legs at once."