Iliotibial Band Syndrome (ITBS or ITBFS, for Iliotibial Band Friction Syndrome) is a common thigh injury generally associated with running. Additionally it can also be caused by biking, hiking or weight-lifting (especially squats). Iliotibial Band Syndrome is one of the leading causes of lateral knee pain in runners. The iliotibial band is a superficial thickening of tissue on the outside of the thigh, 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, moving from behind the femur to the front during the gait cycle. 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, or the band itself may suffer irritation.