Iliotibial Band Syndrome
(IT Band Syndrome)
What Is Iliotibial Band Syndrome?
The iliotibial band (IT band) is a thick band of fibers that begins at the iliac crest (the border of the most prominent bone of the pelvis) in the pelvis and runs on the lateral or outside part of the thigh until it attaches into the tibia (shinbone). The gluteal or buttock muscle fibers and the tensor fascia latae (muscles of the hip joint) attach to it, and the band acts to coordinate muscle function and stabilize the knee during running.
Iliotibial band syndrome describes the pain caused by inflammation of the band as it crosses the lateral condyle of the femur. When the leg is in a straight (known as extended) position, the band fibers are anterior to, or in front of, the condyle (a bony projection on the outer surface of the femur, or thigh bone). As the knee flexes, the fibers move across the lateral condyle and are positioned behind or posterior to it. A bursa or sac in this area allows the iliotibial band to glide over the end of the femur.
When the band becomes irritated, friction may occur with walking or running, causing knee pain due to inflammation on the lateral part of the knee joint.
If symptoms are ignored, further inflammation and scarring may occur in the bursa, causing progressive pain with decreased activity.
Picture of Iliotibial (IT) Band Syndrome
What Causes Iliotibial Band Syndrome?
Inflammation of the iliotibial band occurs because of overuse and is most often seen in marathon or other long-distance runners. Commonly, mechanical issues with poor flexibility and decreased strength in the quadriceps muscles of the thigh lead to the inflammation.
Factors such as leg length discrepancy, an abnormal pelvic tilt, and "bowlegs" (genu varum: genu=knee + varum=angles in) may cause iliotibial band syndrome because of excess stretching of the IT band across the femoral condyle.
Training errors in long-distance runners (for example, running on one side of the road only) may also cause symptoms. Since most roads are higher in the center and slope toward the edge, running on only one side will cause one leg to always be downhill from the other. Runners who fail to recognize this issue are at risk to develop inflammation of the iliotibial band.
Because of the mechanics of running, in contrast to long-distance runners, sprinters tend not to develop this syndrome, but tennis players and bicyclists may.
Medically Reviewed by a Doctor on 10/21/2016