Epidemiology, Clinical Characteristics, and Risk Factors for Running-Related Injuries among South African Trail Runners.

Trail running involves running on varying natural terrains, often including large elevation gains/losses. Trail running has a high risk of injury, and runners often participate in remote regions where medical support is challenging. The aim of this study was to determine the epidemiology, clinical characteristic, and associated injury risk factors among trail runners. A modified Oslo Sports Trauma Research Center Questionnaire for Health Problems (OSTRC-H) was used biweekly to collect running-related injury (RRI) and training history data prospectively, among 152 participants (males n = 120, females n = 32) over 30 weeks. We report an overall injury rate of 19.6 RRIs per 1000 h and an RRI mean prevalence of 12.3%. The leading anatomical site of RRIs was the lower limb (82.9%), affecting the knee (29.8%), shin/lower leg (18.0%), and the foot/toes (13.7%). A history of previous RRI in the past 12 months (p = 0.0032) and having a chronic disease (p = 0.0188) are independent risk factors for RRIs among trail runners. Two in three trail runners sustain an RRI mainly affecting the knee, shin/lower leg, and foot/toes. A history of previous RRI in the past 12 months and a having chronic disease is independently associated with RRI among trail runners. These results could be used to develop future RRI prevention strategies, combined with clinical knowledge and experience.

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

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.

Epidemiology of Injury and Illness Among Trail Runners: A Systematic Review.

BACKGROUND: Trail running is characterised by large elevation gains/losses and uneven varying running surfaces. Limited information is available on injury and illness among trail runners to help guide injury and illness prevention strategies. OBJECTIVE: The primary aim of this review was to describe the epidemiology of injury and illness among trail runners. METHODS: Eight electronic databases were systematically searched (MEDLINE Ovid, PubMed, Scopus, SportsDiscus, CINAHL, Health Source: Nursing/Academic, Health Source: Consumer Ed., and Cochrane) from inception to November 2020. The search was conducted according to the PRISMA statement and the study was registered on PROSPERO international prospective register of systematic reviews (CRD42019135933). Full-text English and French studies that investigated injury and/or illness among trail runners participating in training/racing were included. The main outcome measurements included: trail running injury (incidence, prevalence, anatomical site, tissue type, pathology-type/specific diagnosis, severity), and illness (incidence, prevalence, symptoms, specific diagnosis, organ system, severity). The methodological quality of the included studies was assessed using an adapted Downs and Black assessment tool. RESULTS: Sixteen studies with 8644 participants were included. Thirteen studies investigated race-related injury and/or illness and three studies included training-related injuries. The overall incidence range was 1.6-4285.0 injuries per 1000 h of running and 65.0-6676.6 illnesses per 1000 h of running. The foot was the most common anatomical site of trail running injury followed by the knee, lower leg, thigh, and ankle. Skin lacerations/abrasions were the most common injury diagnoses followed by skin blisters, muscle strains, muscle cramping, and ligament sprains. The most common trail running illnesses reported related to the gastro-intestinal tract (GIT), followed by the metabolic, and cardiovascular systems. Symptoms of nausea and vomiting related to GIT distress and dehydration were commonly reported. CONCLUSION: Current trail running literature consists mainly of injury and illness outcomes specifically in relation to single-day race participation events. Limited evidence is available on training-related injury and illness in trail running. Our review showed that injury and illness are common among trail runners, but certain studies included in this review only focused on dermatological injuries (e.g. large number of feet blisters) and GIT symptoms. Specific areas for future research were identified that could improve the management of trail running injury and illness.

One in four trail running race entrants sustained an injury in the 12 months training preceding the 2019 SkyRun race.

OBJECTIVE: To determine the epidemiology and clinical characteristics of RRIs among trail runners who entered the 2019 SkyRun races. DESIGN: Descriptive cross-sectional study. SETTING: 2019 SkyRun races. PARTICIPANTS: Consent for data analysis was given by 305 of 412 (74%) race entrants. MAIN OUTCOME MEASURES: Retrospective annual incidence (RRIs/1000 h), point prevalence (%), frequency (%), characteristics (anatomical region, body area, tissue type, pathology type) and injury severity (mean severity score; 95% CI) of RRIs. RESULTS: 28.2% of participants reported at least one RRI. The retrospective annual incidence was 49.5 RRIs per 1000h and the point prevalence was 1.3%. Most injuries occurred in the lower limb (87.3%), with the knee (26.5%), ankle (21.6%), and foot (16.7%) reported as the most frequently injured body areas. Muscle/tendon accounted for 44.1% of tissue type injuries. Tendinopathy (27.5%), joint sprain (19.6%), and muscle injury (15.7%) were the most common pathology types reported. The mean injury severity score was 31.6. CONCLUSIONS: One in 4 trail runners reported at least one RRI in the 12 months leading up to a race. RRIs mostly affected the lower limb specifically the knee, ankle and foot. Future research should establish injury risk factors to ultimately develop specific injury prevention strategies.