 The iliotibial band is a thick band of fascia on the lateral aspect of the knee, extending from the outside of the pelvis, over the hip and knee, and inserting just below the knee.The band is crucial to stabilizing the knee during running, as it moves from behind the femur to the front of the femur during activity.The continual rubbing of the band over the lateral femoral epicondyle, combined with the repeated flexion and extension of the knee during running may cause the area to become inflamed.