One of the more common causes of knee pain, especially in those who tend to run a lot, is Iliotibial band syndrome. This is a condition that limits range of movement, and it causes sufferers quite a bit of pain. The Iliotibial band is a thick band of fibrous tissue. This tissue goes down the outside of the leg, starting at the hip and ending at the outside of the shin bone. The IT band works with the quadriceps muscle and other thigh muscles to ensure that there is stability for the knee, which can easily be injured, even just by repetitive movements.

Usually, the irritation is noticed on the outside of the knee, at the lower end of the thigh bone (the femur). This is where the Iliotibial band crosses paths with bone and muscle, and the motion is supposed to be a smooth one. When a person has Iliotibial band syndrome, the motion is far from smooth because the area is inflamed. This inflammation is usually accompanied by pain, which can range from mild to severe, depending on the severity of the Iliotibial band syndrome. This pain often increases the more the person moves around, and decreases when the person is stationary.