More on IT Band Syndrome
IT Band Syndrome (ITBS) is an injury most commonly caused by overuse in distance running as well as biking, hiking and other repetitive activities. The injury causes pain that is concentrated at the outer side of the knee and is described as a stinging or sharp stabbing pain that can make running unbearable even after just a short distance. The pain may extend above the knee along the IT band going up and along the outside of the leg.
The pain is a result of irritation where the IT band passes along the outer side of the knee. There is a small bony protrusion called the femoral epicondyle on the outer side of the femur bone. You can feel with your hand this bony protrusion most easily when standing.
The IT band has some movement across the femur and the bony protrusion. This movement is often describes as a sliding action but can become more of a friction, or over compression, when things go wrong. The IT band is narrower and so less strong near the knee so this area may be more prone to strain and injury. The complex movement (pulling and bending at once) of the IT band at the knee may also make it more prone to injury.
Inflammation under the IT band may occur at the site of the femoral epicondyle. Some experts describe a lubricating sac, called a bursa, between the IT band and the knee. The bursa may be the site of the irritation.
In the past, it was thought that during running and other knee bending exercise the IT Band passed back and forth across a bony outcropping on the side of the knee calls the lateral epicondyle of the femur. It was thought that repetitive movement of the IT band back and forth over the bone was the cause of IT Band Syndrome. More recently it has been proposed that the IT Band is more firmly attached to areas of the femur and other connective tissue and therefore the IT band cannot easily slide back and forth across the bone.
Fairclough et al propose that IT Band Syndrome may be associated with fat compression beneath the IT band rather than a friction from rubbing in "The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome." Click here to see the full article.