TRAIL RUNNERS SUFFER A HIGH INCIDENCE OF LOWER LIMB RUNNING RELATED INJURIES IN THE 12 MONTH PERIOD BEFORE RACE PARTICIPATION

C.T. Viljoen^1,2,3, D.C. Janse van Rensburg^3,2, A. Jansen van Rensburg³, E. Booysen¹, S. Chauke¹, P. Coetzee¹, A. Hurlimann¹, M. Jooste¹, Y. Nibe¹, C. Schulenburg¹, E. Korkie^1,2, D. Ramagole³, C.C. Grant³, T. Cronje⁴

Background: Trail runners participate in remote regions, on uneven running surfaces while being exposed to environmental hazards. Medical support in remote regions is challenging, emphasising the need to optimally prepare and train for a trail run race. More research regarding the epidemiology of running related injuries (RRIs) during training towards a trail running race is needed to guide injury prevention strategies.  

Purpose: To determine the epidemiology (retrospective annual incidence, point prevalence) and clinical characteristics (anatomical region, body area, tissue type, pathology type, severity) of RRIs among trail runners entered for the 38km, 65km, and 100km distances of the 2019 SkyRun (Drakensberg Mountain Range, South Africa).

Methods: A retrospective descriptive cross-sectional study was performed using self-reported injury data collected from a pre-race medical screening questionnaire two weeks prior to the race. Of the 412 race entrants, 305 (74.0%) gave consent for their data to be analysed in this study. The questionnaire collected data on injury history of participants during the 12 months before the race. Outcome variables included the retrospective annual incidence (injuries per 1000 hours), point prevalence (% participants), frequency (%) of injury characteristics (anatomical region, body area, tissue type, pathology type) and injury severity based on how RRI resulted in modification of training and symptoms experienced (mean OSTRC-H severity score; 95% CI).

Results: Of the 305 consenting race entrants, 28.2% reported at least one injury during the 12 months before the race and 5.2% reported multiple injuries. In total 102 injuries were reported with a retrospective annual incidence of 49.5 RRIs per 1000 hours. Only 4 consenting race entrants suffered from a RRI during pre-race medical screening, indicating a point prevalence of 1.3%. Most injuries occurred in the lower limb (88.2%), with the most commonly injured body areas the knee (26.5%), followed by the ankle (21.6%), and foot (16.7%). Muscle/tendon tissue type injuries accounted for 44.1% of injuries. Tendinopathy (27.5%), joint sprain (ligament tear/acute instability episode) (19.6%), and muscle injury (15.7%) was the most common pathology types reported. The mean injury severity score out of 100 was 31.62 (27.92-35.31).

Conclusion(s): Trail runners preparing for the 2019 SkyRun reported a high incidence of RRI that mostly affected the lower limb specifically the knee, ankle and foot. This emphasise the need to establish injury risk factors with the intention to design specific injury prevention strategies, as the recurrence of injury during a trail run race may have dire consequences.

Implications: This study highlighted the lower limb as a high risk area for injury among trail runners. Physical therapists need to consider increasing the tissue loading capacities and neuromuscular control specifically around the knee, ankle and foot when implementing prevention strategies among trail runners training towards a high-altitude trail run race. The results of this study necessitate physical therapists to educate trail runners on the importance of the rehabilitation of RRIs sustained in the 12 months prior to a race, to prevent the recurrence of an injury that may impact optimal training, and their preparation for safe participation during a race.

Funding, acknowledgements: No funding

Keywords: Trail running, Running related injuries

Topic: Sport & sports injuries

Did this work require ethics approval? Yes

Institution: University of Pretoria

Committee: Faculty of Health Sciences Research Ethics Committee

Ethics number: REC 747/2019