Thursday, August 6, 2015

Iliotibial Band Friction Syndrome: A Common Cause of Lateral Knee Pain


Iliotibial Band with Highlighted Area of Pain.
From An Atlas of Human Anatomy by,
Carl Toldt, M.D.
Iliotibial band friction syndrome is one of the most common cause of lateral knee pain and is especially prevalent with runners. In iliotibial band friction syndrome the iliotibial band (ITB), which is a thick connective tissue structure on the outside (lateral) portion of the thigh, rubs up against the expanded end of the femur (thigh bone). This rubbing occurs at about 30o of knee flexion. Over time, the ITB becomes irritated and can become a cause of pain when running; this can even become chronic, causing pain at rest.

Understanding the mechanism of injury helps when determining how to treat this common cause of knee pain. Many people will state that a ‘tight’ ITB is the cause; actually, this is somewhat incorrect. First, the ITB is not a muscle and is not contractible, at least compared to a muscle. Second, it is most often the case that the ITB is taut in ITB friction syndrome. What I mean by this is that the ITB is often pulled into an overlengthened position.

To understand this, it is important to understand the role of the gluteus medius and minimus in pelvic stability. During the weight bearing phase of the gait cycle, these muscles fire to prevent an excessive rising of the ilium. If you were to place your hands on your waist and press down until you feel bone, you would be on the ilium. When walking (or running), during the weight bearing portion, this bone should not rise too much. The gluteus medius and minimus are the muscles most responsible for creating this stability. If these muscles become inhibited and lose the ability to stabilize the pelvis, it then will rise excessively and structures such as the ITB will be pulled long with each step. To help visualize this, you can consider that women naturally have more pelvic movement and some women (Marilyn Monroe, historically, and many runway models) actually practice exaggerating this movement for aesthetic reasons.

In the majority of the cases, the side where ITB friction syndrome occurs is also the side where the greatest degree of inhibition of the gluteus medius and minimus occurs. This can be assessed with manual muscle tests which challenge these muscles. In addition, most patients presenting with ITB friction syndrome will have a raised ilium when assessing standing posture, and this raised ilium will be on the side of the lateral knee pain.

Treatment of ITB friction syndrome needs to include some work to strengthen the gluteus medius and minimus for optimum results. Things like foam rolling the ITB might help to soften it, but most often work needs to be on the short and tight adductors on the inside of the leg, and strengthening corrective exercises should be applied to the abductors such as the gluteus medius and minimus.

Acupuncture can be extremely helpful as part of the therapy. Acupuncture to motor points (approximately in the region of the entry site of the motor nerve into the muscle) can help turn on inhibited muscles, which is shown by the muscles strengthening after treatment when testing with manual muscle tests. In addition, acupuncture to motor points of the overactive antagonistic muscles (adductors in this case) will help reduce tension in these muscles. This helps strengthen the effects of corrective exercises and allows quicker recovery time so you can get back out and hit the trails.


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