More on the IT band
The IT band (iliotibial band) is a thick fibrous strip of connective tissue that runs along the outside of the thigh. Fascia, also known as connective tissue, are similar to tendons (connect bone to muscle) and ligaments (connect bone to bone). The IT band is anchored at the "iliac" crest of the pelvis and down at the "tibia" shin bone just below the outside of the knee. These traits give the name iliotibial band. The IT band is also affixed to the thigh muscles along the leg so the IT band does not move freely under the skin. The IT band stabilizes the knee during running and keeps the knee from bending outward. The buttock muscles and the hip joint muscles engage and tighten the IT band to help control the leg and knee movement. The IT band is extremely tough and strong.
In his article titled, "Iliotibial Tract," Tim Taylor describes the iliotibial band in more detail. Click here to see the full article.