Factors Contributing to Medial Tibial Stress Syndrome in Runners: A Prospective Study

PURPOSE: Medial tibial stress syndrome (MTSS) is one of the most common overuse injuries sustained by runners. Despite the prevalence of this injury, risk factors for developing MTSS remain unclear. The purpose of this study was to prospectively evaluate differences in passive range of motion, muscle strength, plantar pressure distributions, and running kinematics between runners who developed MTSS and those who did not. METHODS: Twenty-four National Collegiate Athletic Association Division 1 cross-country runners participated in this study. Participants underwent a clinical examination documenting passive range of motion and muscle strength at the hips and ankles. Plantar pressure analysis was used to quantify mediolateral pressure balances while walking and 3D motion capture was used to quantify running kinematics. Participants were followed up for a 2-yr period during which time any runners who developed MTSS were identified by the team's certified athletic trainer. RESULTS: Runners who developed MTSS demonstrated tighter iliotibial bands (P = 0.046; effect size ES = 1.07), weaker hip abductors (P = 0.008, ES = 1.51), more pressure under the medial aspect of their foot at initial foot contact (P = 0.001, ES = 1.97), foot flat (P < 0.001, ES = 3.25), and heel off (P = 0.034, ES = 1.30), greater contralateral pelvic drop (P = 0.021, ES = 1.06), and greater peak amounts (P = 0.017, ES = 1.42) and durations (P < 0.001, ES = 2.52) of rearfoot eversion during stance phase. A logistic regression (χ = 21.31, P < 0.001) indicated that every 1% increase in eversion duration increased odds of developing MTSS by 1.38 (P = 0.015). CONCLUSIONS: These findings demonstrate that the development of MTSS is multifactorial, with passive range of motion, muscle strength, plantar pressure distributions, and both proximal and distal kinematics all playing a role. We suggest that coaches or sports medicine professionals screening runners for injury risk consider adopting a comprehensive evaluation which includes all these areas.