How does IT band syndrome cause knee pain?

The iliotibial (IT) band is a thick band of tissue that runs along the outside of your thigh and knee. When you move your knee, especially during activities like running, the IT band moves over the outer part of the knee. If it moves too much or too forcefully, it can rub against the bone, much like rubbing two rough surfaces together.

This constant rubbing can lead to irritation, swelling, and inflammation, which results in pain on the side of your knee. Workouts that involve a lot of repetitive bending and straightening, going up or down hills, or long periods of exercise without enough rest or stretching can worsen this condition. If you're experiencing persistent knee pain and want to understand what might be causing it, try our free symptom checker to get personalized insights in minutes. The pain comes from the body's response to the repeated stress and friction.

Doctors and therapists usually help manage this pain with exercises that stretch and strengthen the muscles around the IT band, along with rest and sometimes changes in workout routines. This helps the band move more smoothly over the knee, reducing friction and pain over time.