Predicting individual risk for medial tibial stress syndrome in navy recruits

Objectives: Quantifying individual risk for medial tibial stress syndrome (MTSS) is valuable due to the high prevalence, substantial financial and service costs, and lengthy recovery time of the condition. Identification of those at risk is a key first step in prevention of the condition. This study aimed to test a suite of best evidence risk factors in a cohort of Navy recruits and to develop a predictive model for individuals at risk of MTSS. Design: Prospective cohort study of Navy recruits undergoing initial training. Methods: A prospective cohort design, this study screened recruits by assessing gender, MTSS history, years of running experience, orthotic use, BMI, navicular drop, ankle plantarflexion and hip external rotation at the beginning of basic training. Follow-up was conducted at completion of training (11 weeks). Results: Volunteers included 123 recruits (28 females and 95 males). Thirty developed MTSS (19 males and 11 females). Stepwise logistic regression of one half of the data produced a significant model (p. <. 0.001), comprising female gender (OR 4.4, 95% CI 1.0, 18.9, p = 0.05), MTSS history (OR 18.3, 95% CI 3.6, 91.5, p. <. 0.01) and increased hip ER (OR 1.1 per degree, 95% CI 1.0, 1.202, p = 0.05). Findings validated with the other half of the cohort and receiver operating characteristic curve analysis showed the model had 82% sensitivity and 84% specificity. Conclusions: This predictive model provides military institutions, clinicians and instructors with a strong and accurate calculator for predicting an individual recruit's risk of MTSS.