The ‘vicious circle’ of sports injuries: an analysis of 165 athletics (track and field) athletes over a 39-week follow-up using Markov chains

Abstract

Objective To explore (1) the risk of injury according to the number of previous injuries, and (2) the risk of progression of the athletes’ health status according to the impact on athletics participation (ie, no injury/healthy (H), injury with full athletics participation (IF), injury with partial athletics participation (IP) or injury with no athletics participation (IN)).Methods We performed a secondary analysis of injury data weekly collected using an online self-reported questionnaire from 165 athletics (track-and-field) athletes during 39 weeks. Using Markov chains, we determined the probabilities of (1) sustaining an injury with participation restriction (ICPR=IP+IN) depending on the number of previous ICPR and (2) transitioning from any one injury state to any other (ie, H, IF, IP, IN). Comparisons were made by calculating the ratio and 95% CIs between two probabilities using a bias-corrected accelerated bootstrap method.Results Compared with the risk of the first ICPR, the risk of a second, third and fourth ICPRs increased on average by 1.9 (1.33 to 2.73), 2.2 (1.43 to 3.56) and 2.42 (1.37 to 4.41) times, respectively. Compared with having no injury (H), experiencing an IF at a given week had a five times higher risk of transitioning to an IP or IN the following week.Conclusions Subsequent injuries show a higher risk than the first injury. Worse health states at a given week had a higher risk of worsening the following week. Our results highlighted a ‘vicious circle’ of injuries in athletics.