The iliotibial band (ITB) is a long tendon which connects from a muscle called the tensor fascia lata in the pelvis all the way down to the tibia (lower leg bone). The ITB runs down the side of the thigh and you can feel the tendon on the outside of your thigh when you tighten your leg muscles. At the knee, the ITB crosses over a part of the femur. To protect the ITB from rubbing on the bone, there is a bursa. A bursa is a fluid-filled sac that cushions body tissues from friction. These sacs are present where muscles or tendons glide against one another.
There can be varying causes for the symptoms of ITB syndrome. The most common is overuse. When your knee bends and straightens the ITB glides over the bursa which may become irritated or inflamed with repeated use, such as with running or biking for prolonged periods, or pushing activities beyond your limit. The alignment of your lower extremities may also be a cause for ITB syndrome. For example, if you have a weak gluteus medius muscle in your hip, or the arches of your feet collapse, your lower extremities may stay turned in (bow-legged posture). This will keep the ITB pressed against the bursa and may cause irritation. Additionally, an SI dysfunction or lumbar dysfunction may lead to ITB syndrome due to altered biomechanics of your lower extremities.
Symptoms of ITB syndrome commonly begin with pain at the outside of the knee, just above the knee joint. Tenderness in this area is usually worse after activity. As the pain continues, it may radiate up the side of the thigh and down the side of the leg. Patients sometimes report a snapping or popping sensation on the outside of the knee.
Your physical therapist will work with you to differentiate the underlying cause of the ITB syndrome. Your therapist will utilize a variety of hands-on techniques to correct any biomechanical or alignment issues as well as therapeutic exercises to strengthen and stretch your lower extremities. They will also discuss a home exercise and/or training schedule as well as you may be issued custom foot orthotics.