Acute Effects of Wedge Orthoses and Sex on Iliotibial Band Strain During Overground Running in Nonfatiguing Conditions

BACKGROUND: Previous research has identified that iliotibial band (ITB) syndrome is more prevalent in females than in males. It has been theorized that high ITB strain rate is a primary etiological factor for developing ITB syndrome. Orthoses are commonly used to influence gait mechanics and may reduce ITB strain rate by influencing alterations in the kinematic chain. OBJECTIVES: To identify how wedge orthoses and sex affect ITB strain and strain rate. METHODS: Thirty asymptomatic participants (15 male, 15 female) ran with 7 degrees lateral, 3 degrees lateral, 0 degrees (no wedge), 3 degrees medial, and 7 degrees medial wedges in this within-subject, repeated-measures study. Participants ran overground while data were collected with a motion-capture system and force platform. Iliotibial band strain and strain rate were estimated using a novel 6-degrees-of-freedom musculoskeletal model. A mixed-model multivariate analysis of covariance for between subject comparison of sex and within-subject comparison of wedge was used. RESULTS: There were no significant differences in ITB strain or strain rate between wedge conditions. Females had significantly higher ITB strain and strain rate compared to males. CONCLUSION: Clinicians should be aware that medial wedges may not acutely alter ITB strain or strain rate. Females exhibited greater peak ITB strain and strain rate, potentially due to increased hip internal rotation compared to males. Further research is needed to investigate longitudinal effects of the wedges.