The Iliotibial Band is a dense fibrous band of tissue that originates from the pelvis and extends down the lateral (outside) portion of the thigh to below the knee. Iliotibial band syndrome (ITBS) is the result of inflammation and irritation of the distal (lower) portion of the Iliotibial tendon as it rubs against the outside of the knee, or less commonly, the greater tuberosity at the hip region.
Causes