The iliotibial band (ITB) is not a muscle—it’s a thick, fibrous band of connective tissue that runs down the outside of the thigh. It originates from the iliac crest (top of the pelvis) and inserts into Gerdy’s tubercle on the lateral aspect of the tibia, just below the knee. It’s not just a passive strap—it acts as an extension of the tensor fasciae latae (TFL) and gluteus maximus, both of which insert into it and generate force through it. Functionally, the ITB helps stabilise the hip and knee