Open-source Modeling & Simulation of Iliotibial Band Mechanics

Iliotibial band syndrome (ITBS) is the second most commonly reported overuse running injury [1]. The iliotibial band is a thickened lateral component of the tensor fasciae latae [2]. This band of dense fibrous connective tissue traverses down the lateral thigh and passes over the lateral femoral epicondyle before inserting onto the anterolateral aspect of the tibia [2]. Until recently, it was believed that the iliotibial band rolled over the lateral femoral epicondyle during activities involving repeated knee joint flexion and extension which caused fricition [3]. This friction force was thought to lead to inflammation of the iliotibial band [3]. However, based on cadaveric experiments, anterior-posterior glide of the iliotibial band over the lateral femoral epicondyle may not be possible [2]. Instead, it has been proposed that medio-lateral motion of the iliotibial band compresses adipose tissue containing free nerve endings lying beneath the band, thus, causing pain during activity [2]. An increase in hip adduction angle may be one mechanism that increases medio-lateral motion of the iliotibial band. Results from previous studies examining running kinematics supports the premise that increased hip adduction but not knee flexion angle differences are exhibited in runners with ITBS compared to controls [4, 5]. In addition to increased hip adduction angle, the results from modeling investigations suggest that increased strain magnitude [6] and strain rate [7] may also be biomechanical risk factors associated with ITBS. However, it has yet to be determined if runners with increased iliotibial band strain also exhibit increased iliotibial band force. Therefore, the purpose of this investigation was to determine if differences in iliotibial band force exist between female runners with and without a history of ITBS. We also sought to determine if iliotibial band strain and strain rate differences exist between groups during running. It was hypothesized that iliotibial band force, strain, and strain rate would be greater in runners with a history of ITBS compared to controls. METHODS