The iliotibial band (ITB) is a tendon that runs along the outside of your leg. It connects from the top of your pelvic bone to just below your knee. A tendon is thick elastic tissue that connects muscle to bone.
Iliotibial band syndrome occurs when the ITB becomes swollen and irritated from rubbing against the bone on the outside of your hip or knee.
This injury often affects runners and cyclists. Bending the knee over and over during these activities can create irritation and swelling of the tendon.
Other causes include:
- Being in poor physical condition
- Having a tight ITB
- Poor form with your activities
- Not warming up before exercising
- Having bowed legs
- Changes in activity levels
There is a water-filled sac, called a bursa, between the bone and the tendon on the outside part of your leg. The rubbing of the tendon can cause pain and swelling of the bursa, the tendon, or both.
If you have ITB syndrome you may notice:
- Mild pain on the outside of your knee or hip when you begin to exercise, which goes away as you warm up
- Over time the pain feels worse and doesn’t go away during exercise
- Running down hills or sitting for a long time with your knee bent may make pain worse
Your doctor will examine your knee and move your leg in different positions to see if your ITB is tight. Usually, ITB syndrome can be diagnosed from the exam and your description of the symptoms.
If imaging tests are needed, they may include any of the following:
If you have ITB syndrome, treatment may involve any of the following:
- Medicines or applying ice to relieve pain
- Stretching and strengthening exercises
- A shot of medicine called cortisone in the painful area to relieve pain and swelling
Most people do not need surgery. But if other treatments do not work, surgery may be recommended. During surgery, part of your ITB, the bursa, or both will be removed. Or, the ITB will be lengthened. This prevents the ITB from rubbing against the bone at the side of your knee.