Risk factors for knee injuries among recreational runners: a prospective cohort study in the Netherlands

Abstract

Background: Running is a well-known form of physical activity and is becoming increasingly popular among recreational sports participants in recent years. Nevertheless, running can result in injuries and physical impairments. The most reported running injuries are knee injuries. Risk factors for obtaining a knee injury in recreational runners have not yet been reported. Aim: The aim of this study was to determine the risk factors for running-related knee injuries and to develop a prediction rule that estimates the probability for knee injuries in recreational runners. Methods: This study is an observational prospective cohort study and included 3,768 participants. Possible risk factors were obtained one month before the start of a running event. Information on injuries were obtained using a post-race questionnaire one week after the event. The association between potential risk factors and knee injuries was determined using multivariate logistic regression analysis. Results: In total 2,736 (73.3%) participants responded to the post-race questionnaire of which 163 participants reported a knee injury. The risk model contained four factors. A history of injuries in the previous twelve months (OR=3.29) and a long-distance run during a running event (OR=1.53) increased the risk of a knee injury. Older age (OR=0.97) and more training kilometers per week (OR=0.98) were protective factors. The explained variance of the risk model was 8.6% and the area under the curve was moderate (0.64). We derived a prediction rule from the risk model that calculates the predicted probability that recreational runners can suffer a knee injury. Conclusion: This study indicates that a previous injury in the past twelve months and a long-distance run during a running event were significantly associated with knee injuries (p<0.05) and were therefore risk factors for obtaining a running-related knee injury. The prediction rule can be used to estimate the probability of obtaining a running-related knee injury in recreational runners. Other variables should be evaluated to improve predictive capacity of the model and it should be externally validated. Implication of key findings: Recreational runners, (para)medical professionals, coaches and trainers could use the present findings to potentially reduce the risk of running-related knee injuries.