Chances are if you’ve found this website you’re a pretty active person and/or someone that loves the outdoors. You might be a runner, a hiker or a cyclist and your knee has begun to hurt “on the outside”. What could be the cause of this frustrating pain which doesn’t seem to be going away? Whilst there are other causes of knee pain, most knee pain in runners is one of these two suspects, iliotibial band syndrome (ITBS) and patellofemoral pain syndrome (PFPS) aka Runner’s Knee.
ITBS is a frustrating running injury and yet it is actually still a mysterious condition despite a plethora of “information” available at the click of a finger thanks to the mighty Google.  It is often confused with the most common running injury, PFPS.  Both kinds of injuries are repetitive strain injuries.
Your IT band (or tract) runs from hip to knee and is more properly referred to as a thickening of the fascia lata in the thigh if you want to nerd out a little. It is a dense fibrous connective tissue that connects to most of the tendon of the gluteus maximus, your main hip extensor, and the tensor fasciae latae (TFL), a hip stabilizer and abductor, to the top of the tibia, just below the knee on Gerdy’s tubercle. It also helps stabilize and control the knee joint in addition to the hip. Most relevant for runners, it seems to stabilize the hip and knee at footstrike.
By definition, with ITBS, the intense well-defined pain only happens on the outside of the knee at the area of your femur known as the lateral epicondyle. It is caused by an irritation of tissues around this structure, and it has been argued that it is not the IT band itself but something underneath it. Several etiologies have been proposed: friction of the IT band against the lateral epicondyle, compression of the fat and connective tissue underneath the IT band, and chronic inflammation of the IT band bursa (a small fluid-filled sac found at points where friction would otherwise occur, although other research has failed to demonstrate a bursa between the epicondyle and IT band). 
The pain is particularly acute when the knee is at 30° of flexion  and often worse after activity, especially descending stairs/hills as knee flexion increases during downhill running (noticeably less painful ascending). Of course, pain in other locations may occur with ITBS but will not be ITBS – hip and thigh pain are common. Tight hip muscles (the previously mentioned TFL & gluteus maximus) control the tension on the IT band and so can be implicated in ITBS. Many patients will report hip pain in addition to their IT band pain.
Interestingly, some people with ITBS don’t even have tight IT bands, as previously thought. In their study, Devan et al. found “all the athletes with iliotibial band friction syndrome had a negative bilateral Ober test.”  This means their IT bands were not tight.
So what is causing your pain?
Research by Fairclough et al. showed that the IT band is so firmly attached to the femur near the epicondyle by thick, fibrous issue that it is not anatomically possible for it to “slide” over the epicondyle. They propose instead that the fatty tissue between the lateral epicondyle and IT band is compressed by the IT band during running, particularly when the knee is at 20-30 degrees of flexion. This tissue is rich in blood vessels and pressure-sensitive nerve endings, known as Pacinian corpuscles, and may actually be implicated in the pain associated with ITBS. 
So how do we fix it?
Evidence appeared to overwhelmingly point to a biomechanical fault in the abductor muscles of the hip as the cause for ITBS.  Weak or misfiring gluteus medius or TFL muscles are unable to control the adduction of the hip and internal rotation of the knee, leading to abnormal stress and compression on the IT band. This muscular dysfunction leads to excessive hip adduction and knee internal rotation, both of which would then increase strain on the IT band and compress it against the fatty tissue between the lateral femoral epicondyle and the IT band. But, although the pain is coming from the lateral knee, the the problem was believed to be coming from the hip muscles.
However, other research has suggested hip abductors are not to blame for for ITBS.  Wait? What? Furthermore, Foch et al. found “Hip abductor strength was less in runners with previous ITBS but not current ITBS compared to controls”. 
One assumption is that an increase in range of motion at the hip joint, stretching of the hip abductors, as well as stretching the hamstrings, calf muscles and hip flexors will help treat ITBS. 
Whereas Devan states, “When the hamstrings tire, the duration of the swing phase of gait increases, placing the hamstrings in this weakened position for a longer period of time. Interestingly, the iliotibial band is most active during the swing phase of gait. ” She deduces that diminished hamstring muscle endurance and strength relative to quadriceps endurance and strength are predisposing factors. Thus correcting hamstring muscle imbalances through strength training and conditioning may be key.
What most research does seem to agree on is that the kinetics and kinematics of the hip, knee and/or ankle/foot appear to be considerably different in runners with ITBS to those without.  This is also a condition that appears to affect females more than males. 
So should I stretch my IT band?
As previously mentioned, IT band tightness is not necessarily even a problem in those with ITBS. Not to mention that the IT band is an incredibly difficult structure to stretch. A common theme with ITBS is knee flexion  so surely for an effective stretch you would have to include knee flexion?
Let’s assume you master the perfect stretch. Then what? Researchers tested different IT band stretching methods on a series of cadavers. They carefully measured the mechanical effect of a basic IT band stretch and a more advanced stretch. They found that even ideal IT band stretching resulted in only about 2 millimeters of elongation, which is less than half a percent. The recommendation was that research should focus on the stretching and lengthening the muscular component of the IT band/TFL complex. 
So if I’m not sure of what I’m stretching or strengthening, can I at least foam roll my IT band?
It would appear that the fault here lies in the intent of the foam roller. If you’re trying to “release a tight IT band” with it, then the intent is incorrect. Know the anatomy and the fact that you are not only contacting the IT band, but all the structures in the layers from the skin to the bone. Endlessly foam rolling the IT band will likely do nothing more than only irritate the fat pad and compresses Vastus Lateralis. Focussed soft tissue release should be directed at tissue around the IT band, such as TFL and Gluteus Medius.  There is quite a bit of evidence to show the undeniable benefits of foam rolling correctly, to improve mobility and flexibility. 
What else can I do?
ITBS is a repetitive strain injury, so any repeated knee flexion at all could be creating further issues. Resting for rehabilitation is not as easy or simple as it sounds. However, you can still exercise effectively as long as you don’t irritate the knee further: strength training can be one way, perhaps with high load, low repetitions.
Icing the area may also provide relief as well as anti-inflammatories 
There is no foolproof system for beating iliotibial band syndrome. When I personally suffered from it back in 2004, a few weeks out from a half marathon, I did glute strengthening exercises, ice and ultrasound. That worked for me and I came away with a 3rd place medal.
I suspect however that everyone is different. A thorough assessment by your therapist of choice (RMT/Physiotherapist/Chiropractor) to figure out what your areas of dysfunction are from that discussed above will likely form the best treatment plan for you.
As a friend and colleague stated, “As long as it feels good and you are seeing affects that improve your quality of life, meaningful movements, keep doing it. Once you start to get affects that go in the opposite direction, then it’s time to utilize a new strategy.” (R. Libbey, personal communication, June 2016)
Side note: PFPS causes pain mostly at the front of the knee, around or under the kneecap. The pain tends to be worse when ascending stairs or hills, but may be painful both ascending and descending.
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Image: Photo taken 13th October 2016. Netter, F. Muscles of Hip and Thigh: Lateral View. Plate 482. Atlas of Human Anatomy. 5th Ed.