Iliotibial Band Syndrome (ITBS): Pain on the Outside of the Knee in Runners

For decades ITBS was believed to be a friction syndrome: the band was supposed to “snap” forwards and backwards over the lateral femoral epicondyle as the knee bends and straightens, causing irritation and even bursitis. That theory explained why pain appears at about 30 degrees of flexion and stood behind recommendations for foam rolling, stretching and treatments “for inflammation”. Anatomical studies, however, have undermined its foundations.

An earlier study by the same team, based on dissection of 15 cadavers and magnetic resonance imaging in healthy volunteers and in two athletes with acute ITBS, showed that the band was anchored to the distal femur by fibrous strands and that no bursa was found in any case. MRI showed that at about 30 degrees of knee flexion the band is pressed against the epicondyle as a result of internal rotation of the tibia, and that signal changes in patients with ITBS concerned the area occupied by fat under the band. This is a good explanation of why the pain is so characteristically linked to the phase of gradual knee flexion during running.

The belief that ITBS is linked to weakness of the hip abductors (mainly the gluteus medius) originates in a small but influential study from 2000. The authors compared hip abduction strength in 24 runners with ITBS and 30 healthy runners from track teams and found that the affected limb was significantly weaker both than the healthy limb of the same person and than the limbs of runners in the control group.

This is a study without a control group in the treatment phase, so we do not know how much of the improvement was due to strengthening and how much to the natural course and reduced training load. A later systematic review of studies that measured hip abduction strength in distance runners indicated that abductor weakness may be associated with ITBS (three of five studies found weakness in runners with ITBS, and two of them — those with the greatest methodological rigour — found a relationship between weakness and injury), whereas for other running injuries, such as patellofemoral pain or medial tibial stress syndrome, no such relationship was obtained. The authors noted that the result comes mainly from cross-sectional studies, and therefore does not settle whether weakness is a cause or a consequence of pain.

Note how wide the range of results is: pain reduction from 27% to 100% over a short time (2–8 weeks) means very different effects in different studies and populations, and small samples (201 people in 13 papers in total) do not allow precise comparisons. The common direction is, however, consistent: hip abductor strengthening is the most commonly used and regarded-as-effective component of conservative treatment programmes.

A second review, comparing conservative and operative treatment of ITBS (15 studies, 179 athletes treated conservatively and 200 operated on), indicated that in the conservative studies pain consistently decreased (in 6 of 6 studies), whereas follow-up was short (a mean of 2 months vs 33.5 months after operations). The rate of return to sport after surgery was 81–100%. The authors stressed, however, the low quality of evidence (level II–IV, many studies of poor or fair quality) and concluded that conservative treatment effectively reduces symptoms at follow-up of up to 6 months, and that surgery is an option for athletes who do not respond to non-operative treatment.

Since the leading element of the programmes is hip abductor strengthening, and the pain results from repeated loading in a particular phase of running, the plan rests on two pillars: temporary training modification and progressive strengthening. The outline below is general; the specific dose of exercises, their difficulty and the pace of progression are chosen with a physiotherapist on the basis of an examination.

As for the other popular methods: foam rolling, stretching the band and massage are widely used, but we do not describe randomised trials here that would show their superiority over strengthening — treat them as a possible supplement for comfort, not as the basis of treatment. Shockwave and manual therapy appear in the 2024 review as a possible add-on to exercise, but the evidence is preliminary. Steroid injections are used in clinical practice, but the reviews discussed contain no strong evidence that would allow them to be recommended as first-line treatment.

ITBS is an injury that can be annoyingly predictable: the same distance, the same point on the route, the same pain. The most sensible strategy emerging from the literature is simple, if unspectacular: temporarily drop below the pain threshold, systematically strengthen the hips and pelvis, and increase running gradually. This approach makes physiological sense, is low-risk and is consistent with the best available, albeit preliminary, data.

Patience with your own diagnosis is especially important: if the pain has a different character from classic ITBS or does not respond to the programme, do not look for further treatments for the band but review the diagnosis. The general importance of strength training for a runner’s safety is described in our knowledge-base entries on strength training and on sports recovery.