Incidence of injuries and associated factors in treadmill runners: a prospective cohort study

ABSTRACT

Abstract Aims: To determine the incidence of injuries in exclusive treadmill runners and the main associated factors in 24 weeks. Methods: The incidence of injuries was investigated every two weeks by an electronic form. To analyze the associated factors, muscle force output, range of motion, and flexibility were investigated. To perform a descriptive analysis (baseline) and injury predictive factors (regression), we divided runners into two groups, injured and uninjured. Comparisons between groups were assessed evaluated by Student's t-test, Mann-Whitney, or Chi-square test. The relationship between associated factors and incidence of injuries was estimated by Logistic regression analysis. The model's accuracy was assessed by the receiver-operating characteristic curve (ROC). Thirty-seven runners completed the study. Results: The incidence of injuries was 6.8 per 1,000 hours of exposure. Among the associated factors, we highlight that runners with higher hip flexor force output were 4 times more likely not to injure (OR 4.0; CI 95% 1.03 -16.23) and lower knee extensor force output was related to a greater chance of injury (OR .24; 95% CI .65 - .93). The area under the ROC curve was 0.84. Conclusion: The incidence of injuries in treadmill runners was high. The factors associated with the injuries were the output of the flexor strength of the hip and the extensor force of the knee.