Objectives: The purpose of this study was to determine whether the iliotibial band (ITB) moves relative to the lateral femoral epicondyle (LFE) as a function of knee flexion in both non-weight-bearing and weight-bearing positions in asymptomatic recreational runners.
Methods: Five male and 15 female asymptomatic recreational runners (10-30 miles/wk) aged 18 to 40 years were examined with sonography to assess the distance between the anterior fibers of the ITB and the LFE in full extension, 30° of knee flexion, and 45° of knee flexion. Measurements were obtained on both knees in the supine (non-weight-bearing) and standing (weight-bearing) positions.
Results: The distance between the anterior fibers of the ITB and the LFE decreased significantly from full extension to 45° of knee flexion in both supine (0.38-cm average decrease; P < .001) and standing (0.71-cm average decrease; P < .001) positions. These changes reflect posterior translation of the ITB during the 0° to 45° flexion arc of motion in both the supine and standing positions.
Conclusions: Sonographic evaluation of the ITB in our study population clearly revealed anteroposterior motion of the ITB relative to the LFE during knee flexion-extension. Our results indicate that the ITB does in fact move relative to the femur during the functional ranges of knee motion. Future investigations examining ITB motion in symptomatic populations may provide further insight into the pathophysiologic mechanisms of ITB syndrome and facilitate the development of more effective treatment strategies.
Keywords: iliotibial band; iliotibial band syndrome; sonography.