IT Band Syndrome (ITBS) – Fact Vs Fiction

IT Band Syndrome (ITBS) – Fact Vs Fiction 1

This expert article comes from our friends and partners at UESCA, the leading provider of Endurance Sports Education.
UESCA’s running coach and ultrarunning coach certifications are considered industry-leading, with a science-backed, zero-bias approach.

If you’ve been a runner for even just a day or two, you’ve likely heard of the term IT Band Syndrome, or ITBS, and it being synonymous with pain at the side of the knee.

But before we go any further, let’s define what the IT Band is.

The IT band stands for the Iliotibial band.

It is a thick band (tract) of connective tissue that originates at the top of the pelvic crest and inserts on the lateral head (lateral condyle) of the tibia, right below the knee. It runs down the lateral side of the thigh.

With respect to running, the primary role of the ITB is to stabilize the knee.

Now, let’s get into what the IT Band Syndrome actually is.

The IT Band.

What Is Friction Syndrome?

Due to where the ITB inserts on the tibia, pain at the side of the knee while running has traditionally been thought to be caused by the ITB rubbing against the protrusion on the lateral side of the femur where it meets the knee, essentially a shearing-type movement.

This bony protrusion is called the lateral femoral epicondyle. This is why ITBS is also commonly termed ‘IT Band Friction Syndrome (ITBFS).’

The ITBFS theory largely assumes that there is a bursa sac between the ITB and the lateral femoral epicondyle.

A bursa sac is a fluid-filled sac whose purpose is to reduce friction between surfaces. ITBFS is therefore theorized to be the result of inflammation of the bursa sac (bursitis).

However, research by Fairclough et al. found no presence of a bursa sac between the ITB and lateral femoral epicondyle. What was found was a layer of high innervated fat (i.e., lots of nerves) below the ITB… more on this later.

A runner holding their knee.

The Causes Of ITBS: The Fact Vs Fiction

Movement of the IT Band

ITBFS is thought to be caused by the ITB passing or rolling over the lateral femoral condyle in a front-to-back motion when the knee bends… therefore causing friction.

The same study by Fairclough et al. also found that the ITB is firmly anchored to the femur and is also part of the tensor fascia lata (TFL), and thus, the theory that it ‘passes over’ the lateral femoral epicondyle is incorrect.


In the Fairclough study, two runners that presented with ITBS showed no changes in the ITB based on magnetic resonance scans in relation to asymptomatic runners, but changes in the fatty layer under the ITB were identified.

It was also discovered in the study that the ITB compressed against the lateral femoral epicondyle at 30 degrees of knee flexion. This was largely due to internal rotation of the tibia.

Therefore, ITB pain is most likely due to compression of the fat layer beneath the ITB versus friction caused by the ITB ‘rolling over’ the lateral femoral epicondyle.

In other words, the ITB or bursa sac (which is not present) is not what is irritated; it’s the fat layer underneath it.

A person holding his knee.

Training Implication

Like most running-related pain, the common advice and treatment options for ITBS typically revolve around stretching and foam rolling.

Let’s first address stretching.

The ITB is a very tough structure. In fact, in a 2010 study by Falvey et al., a strain gauge was used to test various stretches on the ITB, and the result was that the ITB was unaffected.

Therefore, it is highly unlikely that stretching will have any effect on the ‘tightness’ of the ITB.

Now let’s discuss foam rolling. This is pretty simple. Stop doing it!

Anyone that has ever performed foam rolling on their ITB will tell you that it is insanely painful. The erroneous and commonly held belief is that if it’s painful, it must be tight, and therefore more foam rolling is the answer.

However, let’s refer back to what is likely the cause of ITB pain – compression.

Assuming this is true, or at least a very strong contributing factor, common sense would dictate that adding compression via foam rolling will only exacerbate the issue.

A person foam rolling.

Why ITBS Occurs and Recommended Course of Action

So, what should one do if they have pain at the side of the knee?

As ITBS is largely an overuse injury, the first logical step would be to rest or, at the very least, reduce training volume.

Like a lot of other pain-related issues, the localized area of ITBS pain is likely the result of dysfunction in one or more areas. In the case of ITBS, according to Fairclough et al., it is likely that hip dysfunction may be a leading cause.

Therefore, seeking out a trained clinician is likely the correct course of action.

With respect to hip dysfunction, a lot of runners do not strength train or do any movement in the frontal plane (left to right).

As a result, the hip muscles (gluteus medius) that act to stabilize the pelvis while running and thus control how much hip drop a runner has are often weak. This weakness can likely contribute to ITBS due to a lack of stability in the pelvis. 

A physical therapist checking out someone's knee.

It also should be noted that with respect to running, asymmetries can also influence the tension on the ITB. For example, if an individual has either a structural or functional leg length discrepancy, this would place more stress on one leg than the other.

In the same content, running a lot of volume on a banked surface such as an indoor track or a road that slopes will also affect the symmetry of a runner and, thus, the tension on the ITB.

When encountering pain, a lot of athletes go straight to their medicine cabinet and take pain relievers such as ibuprofen and/or start icing the painful area.

While these two things were considered the ‘go to’ pain remedy for a long time, that is no longer the recommended course of action – or at least it shouldn’t be.

Not only are these two things largely a band-aid for the actual cause of the pain, but they can actually make the situation worse.

Therefore and as noted previously, stopping running for a while or reducing volume is the recommended first step, and if that does not solve the issue, seeking out a trained clinician, such as a physical therapist that has a background in treating runners is recommended.

For more expert guides on running ailments, check out Rick Prince’s guide to the DOMS here!

A physical therapist checking out someone's knee.


John Fairclough, Koji Hayashi, Hechmi Toumi, Kathleen Lyons, Graeme Bydder, Nicola Phillips,5 Thomas M Best, and Mike Benjamin.The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome.” J Anat. 2006 Mar; 208(3): 309–316. doi: 10.1111/j.1469-7580.2006.00531.x. PMCID: PMC2100245. PMID: 16533314

Falvey EC, Clark RA, Franklyn-Miller A, et alIliotibial band syndrome: an examination of the evidence behind a number of treatment options.” Scand J Med Sci Sports. 2010 Aug;20(4):580–7. PubMed #19706004

Fairclough J, Hayashi K, Toumi H, et al. Is iliotibial band syndrome really a friction syndrome? J Sci Med Sport. 2007;10(2):74-78. doi:10.1016/j.jsams.2006.05.017

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Rick Prince is the founder and director of UESCA, the leading provider of Endurance Sports Education. UESCA's running coach and ultrarunning coach certifications are considered industry-leading, with a science-backed, zero bias approach. Rick holds a BS in Kinesiology from Springfield College and is a certified corrective exercise specialist through the National Academy of Sports Medicine (NASM), as well as a certified UESCA running and triathlon coach. Rick is a competitive runner and cyclist, having raced bikes nationally and internationally and run collegiate track and cross-country. Rick competes in running races and tries in vain to keep up with his 4-year old son.

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