Weak hip abductors?
It would be logical to correlate the presence of weak hip abductors with iliotibial band friction syndrome, since weak abductors might lead to increased hip adduction during the stance phase of gait with a consequent increase strain of the iliotibial band and a greater tendency for it to compress the tissues underneath.
MacMahon and colleagues, Noehren et al., and Fredericson et al. all reported that ITBFS sufferers had abductor weakness or increased hip adduction during the stance phase of gait, a finding which could be interpreted as being due to abductor weakness [4, 16, 17].
On the other hand, Grau et al., using a dynamometer that was mechanically stabilized instead of hand-held, did not find hip abductor weakness in their study of 10 runners with ITBFS as compared to healthy matched controls [18].
Thus, we may have more to learn about the relationship of iliotibial band friction syndrome to hip abductor weakness or to the related issues of the timing and magnitude of hip abductor activation during the gait cycle and the amount of hip adduction that occurs during the stance phase of gait.
Tight iliotibial band?
It is also logical to link tightness of the ITB with iliotibial band friction syndrome, since presumably a tighter band would lead to greater compression of the underlying tissues with each gait cycle.
The Ober test is most commonly used to assess tightness of the iliotibial band. As described by Gajdoski et al. [19], the Ober test is performed with the examiner standing behind the side-lying patient. The examiner stabilizes the pelvis with one hand, flexes the uppermost thigh, and then moves it into maximal abduction. He or she then maintains the abduction while moving the thigh into extension. The examiner then lowers the limb into adduction until it stops, or until the pelvis starts to tilt. The angle of hip joint adduction (or abduction, if the thigh cannot adduct even to neutral) is considered to be a measurement of ITB length or distensibility. Gajdoski’s article also describes variations of the Ober test that call for the knee of the side being tested to be either flexed or extended.
However, no study to date has actually correlated the findings of the Ober test (or any other test for ITB distensibility) with iliotibial band friction syndrome. Moreover, Devan and others did not find a correlation between a positive Ober test and the occurrence of ITBFS in female college athletes [8].
On the other hand, Fredericson [20] believes that most athletes with ITBFS exhibit a tight iliotibial band, though the Ober test and other clinical examination methods, as they are used in common clinical practice, may not be sensitive enough to detect it.
In 2007, Hamill, Miller, Noehren, and David published findings that showed that runners with ITBFS had a “looser” iliotibial band, exhibiting increased strain (it elongated more when subject to an external load) and, to a statistically significant degree, an increased strain rate (it elongated more rapidly) during running [21].
These findings seem to contradict the commonly asserted link between a tight iliotibial band and ITBFS. Furthermore, they would imply that stretching the ITB—insofar as the purpose of stretching would be to increase the distensibility of the band—could accentuate the symptoms of ITBFS.
Angle of knee flexion during stance phase?
The portion of the knee range of motion at which the ITB is most likely to rub against or compress the underlying structures is with the knee flexed about 20°–30°. Perhaps differences in the degree of knee flexion between individual runners play a role in the onset of ITBFS. The commonly held association of ITBFS with running downhill [22, 23] may be due to the fact that downhill running results in a higher degree of knee flexion at heel strike, thus increasing the friction of the ITB with the lateral epicondyle or the pressure the ITB places on the underlying soft-tissues.
However, Orchard et al. found no difference in the angle of knee flexion between runners with or without ITBFS when running on a treadmill [22]. This finding was echoed by Noehren et al. [17].
An additional subtlety was studied by Miller and others in 2006 [24]. Hypothesizing that a runner’s biomechanics might deteriorate adversely with fatigue, they tested runners’ biomechanics at the end of an exhaustive run. Indeed, runners with a history of ITBFS exhibited an increased angle of flexion of the knee at heel strike.
Rearfoot eversion?
Busseuil et al. found a higher incidence of ITBFS and other lower extremity injuries in athletes who over-pronated [25].
However, Messier et al. and Noehren’s group reached the opposite conclusion, that runners with ITBFS had reduced rearfoot pronation as compared to controls [3, 17].
Other biomechanical factors
Other biomechanical factors that have been linked with iliotibial band friction syndrome include: increased landing forces, increased knee internal rotation, low hamstring strength as compared to the quadriceps strength on the same side, and genu recurvatum [3, 8, 17, 25].