Iliotibial band syndrome is an overuse injury of the connective tissues that are located on the outer thigh and knee. The iliotibial band runs along the lateral or outside aspect of the thigh, from the pelvis to the tibia, crossing both the hip and knee joints. The iliotibial band is an important stabilizer of the lateral part of the knee as the joint flexes and extends.
Inflammation and irritation of the iliotibial band can occur as it travels back and forth, crossing the bony prominence of the femoral epicondyle as the knee flexes and extends. Iliotibial band syndrome is an overuse injury causing pain on the outside part of the knee especially during running when the heel strikes the ground.