Real-time morphologic changes of the iliotibial band during therapeutic stretching; an ultrasonographic study.

The purpose of this study was to evaluate the utility of ultrasonography (US) in determining the morphological changes of the iliotibial band (ITB) with the modified Ober maneuver. Forty-four subjects (23 men and 21 women, mean age (+/- SD), 24.7+/-4.7 years) who had no previous history of lower back, gluteus, hip or knee pain and satisfied additional inclusion criteria were recruited. Twenty out of the 44 subjects were initially examined by both MRI and US for measurement confirmation. Band width of the left ITB (the measures of which were highly correlated between techniques) was then assessed for these 44 subjects by US with the modified Ober maneuver in three gradually increased hip adduction positions; neutral, adducted and adducted with weight in these 44 subjects. In addition, examiner reliability was assessed by conducting duplicate measurements in 20 randomly chosen subjects. Results demonstrated that measures of band width, but not thickness, were highly correlated between MRI and US (p<0.001, r=0.850). Significant reductions in band width were observed between the three positions with the modified Ober maneuver (p<0.001). Intratester reliability was high (intraclass correlation coefficient (ICC)=0.86-0.94). Band width changes indicated that the ITB was subjected to a significant stretching force during hip adduction. We conclude that US is a reliable means to directly assess the real-time effects of stretching exercises.