Cross-sectional Study to Assess Iliotibial Band Morphometry and Stiffness Using Ultrasound Imaging in Runners With and Without Symptoms of Iliotibial Band Syndrome: a Feasibility Study

The iliotibial band (ITB) is a complex structure in which morphometry (shape, thickness, cross-sectional area) and viscoelastic properties remain poorly understood. While some hypothesize that the pain originates from friction of the ITB on the femoral condyle during knee flexion, others affirm that it is rather a compression of the ITB on the tissue underlying fat, which is highly vascularized and innervated. Current treatments in physiotherapy are based, in part, on the theory that stiffness in the ITB may contribute to iliotibial band syndrome (ITBS), resulting in prescription of stretching exercises in most rehabilitation programs. However, the plausibility of this theory remains to be demonstrated with valid and reliable instruments. Standard-mode (B-mode) ultrasound is gaining popularity for assessing ITB morphometry. However, these data remain to be correlated with the clinical symptomatology. Sonoelastography (SWE), on the other hand, is used to assess tissue stiffness. Recent studies have attempted to assess the stiffness of ITB under different experimental conditions, but these have methodological flaws (low power) and they are carried out in an asymptomatic population. This project is a first step to fill the gaps on ITB morphometry and stiffness values and explore the potential association between these factors and the clinical profile of SBIT. The primary objective is to evaluate the study the feasibility of the protocol by documenting the variables associated with this concept. Secondary objectives are: 1) To measure the stiffness of the distal BIT in runners with and without ITBS; 2) Describe the morphometry of the distal BIT in the two groups of runners; 3) Compare ITB morphometry and stiffness between the two groups of runners and 4) Investigate the association between ultrasound variables and ITBS signs and symptoms.