The iliotibial band is a strong band of connective tissue running from the pelvis to the tibia, just below the knee. Iliotibial Band Friction Syndrome (ITBFS) is an overuse injury caused by excessive rubbing of the band against a bony bump along the outside of the knee when the band is tight. Pain is generally felt along the outside of the knee and is aggravated by activities that involve repeated bending and straightening of the knee, such as running. ITBFS generally does not get better on its own if the cause is not addressed and you continue to exercise. The best course of action is to get assessed by a sports physiotherapist.