HEALTHYTRAILSBR: PREVALENCE OF RUNNING-RELATED INJURIES IN BRAZILIAN TRAIL RUNNERS: AN OBSERVATIONAL CROSS-SECTIONAL STUDY

Trail running is a growing sport worldwide. However, the prevalence of running-related injuries (RRI) in trail runners is not well established.

The aims of this study were: (1) to investigate the point prevalence of RRIs; and (2) to describe the most frequently reported RRIs in Brazilian trail runners.

This was an observational cross-sectional study embedded in the HealthyTrailsBR research project. After consenting to participate, 1068 trail runners were included in this study. The participants were over 18 years and with at least six months of trail running experience. The data were collected between April 2019 and February 2020 through an online survey. The self-reported questionnaire was composed of four sections regarding: (1) personal data; (2) training characteristics; (3) current RRIs and (4) history of RRIs. Numeric parametric data were described using mean, standard deviation (SD) and/or 95% confidence interval (95% CI). Dichotomous and categorical data were described through counts and percentages. The point prevalence of RRIs was presented as percentage and 95% CI. Data analyses were performed using Python version 3.7.7.

The mean age of the participants was 39.5 (SD 8.29) years. A total of 65.4% (n=699) of the sample was man and 34.6% (n=369) was woman. A total of 544 RRIs were reported by 419 injured trail runners. The point prevalence of RRIs was 39.2% (95% CI 36.3 to 42.2; n=419). The anatomical regions with the highest point prevalence were the knees (13.4%; 95% CI 11.5 to 15.6; n=143); lower legs (11.0%; 95% CI 9.3 to 13.1; n=118); ankles (10.3%; 95% CI 8.6 to 12.3; n=110); feet (8.9%; 95% CI 7.3 to 10.8; n=95); and hips (7.3%; 95% CI 5.9 to 9.0; n=78). The health conditions with the highest point prevalence were ankle sprain (5.7%; 95% CI 4.5 to 7.3; n=61); patellofemoral pain syndrome/chondral injury (5.7%; 95% CI 4.5 to 7.3; n=61); plantar fasciitis (5.0%; 95% CI 3.8 to 6.4; n=53); calf muscle strain (2.9%; 95% CI 2.0 to 4.1; n=31) and medial tibial stress syndrome, known as shin splint (2.5%; 95% CI 1.7 to 3.7; n=27).

The point prevalence of RRIs in Brazilian trail runners was 39.2% (95% CI 36.3% to 42.2%), that is, approximately 2 out of 5 trail runners (⅖) reported being injured at the time of data collection in this study. The most prevalent injured anatomical region was the knee (13.4%; 95% CI 11.5 to 15.6). The most prevalent conditions were ankle sprain and patellofemoral pain syndrome/chondral injury, both with 5.7% (95% CI 4.5 to 7.3). 

The findings of this study may directly contribute to the estimation of the health burden associated with RRIs as a result of trail running participation. Understanding the health burden of RRIs may foster further research on RRI prevention. In addition, the results of this study may assist physiotherapists, coaches and sport professionals in planning strategic intervention programmes in order to manage the most frequent RRIs that could be reported by trail runners during, but not limited to, trail running events.

Luiz Hespanhol was granted with a Young Investigator Grant from the São Paulo Research Foundation (FAPESP), grant 2016/09220-1.