Independent Risk Factors Predicting Gradual Onset Injury in 2824 Trail Running Race Entrants: SAFER XVIII Study

Carel T. Viljoen*, Nicola Sewry, Martin P. Schwellnus, Dina C. Janse van Rensburg, Sonja Swanevelder, Esme Jordaan

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Introduction: Trail running is characterized by elevation changes, with uneven and varying running surfaces. Risk factors that may predict gradual-onset running-related injuries (GORRIs) in short-distance trail running have not been explored. The objective was to determine risk factors that predict GORRIs in trail running race entrants who entered mass community-based trail running events. Methods: In this descriptive cross-sectional study, data were collected prospectively from a prerace medical screening questionnaire over 4 trail run events held annually. Using a Poisson regression model, runner demographics, race distance, running training/racing variables, history of chronic diseases (number of chronic diseases reported as a cumulative “chronic disease composite score”), and allergies were investigated to determine factors predicting self-reported GORRI history in the previous 12 mo. Results: This study included 2824 race entrants (80% of entrants). The retrospective annual incidence for GORRIs was 13%. Independent risk factors predicting GORRIs were longer race distance (P<0.0001), increasing chronic disease composite score (P=0.0012), and a history of allergies (P=0.0056). The lower limb (94%) was the main anatomic region of GORRIs, and soft tissue injuries accounted for most (83%) GORRIs. Common specific GORRIs were iliotibial band syndrome (22%), Achilles tendon injury (10%), and hamstring injury (9%). Conclusions: Independent risk factors predicting GORRIs among trail running entrants included longer race distance, a higher chronic disease composite score, and a history of allergies. This study has highlighted trail running race entrants at risk for sustaining GORRIs who could be targeted for future injury prevention interventions.

Original languageEnglish
Pages (from-to)293-301
Number of pages9
JournalWilderness and Environmental Medicine
Issue number3
Early online date2021
Publication statusPublished - Sep 2021
Externally publishedYes

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