What is ITB Syndrome? Iliotibial Band Syndrome (ITB Syndrome) is one of the most common causes of pain on the outside of the knee and hip (NCBI), particularly in runners, cyclists, walkers and individuals who regularly participate in sport. The iliotibial band (IT band) is a thick fibrous band of connective tissue that runs from the outside of the hip, down the side of the thigh, and attaches below the knee. Its role is to help stabilise the hip and knee during walking, runn