Abstract:
BACKGROUND: There are limited data on factors that predict an increased risk of multiple injuries among distance runners. The objective of this
study was to determine risk factors that are predictive of individual runners with a high annual multiple injury risk (MIR). METHODS: A retrospective, cross-sectional study at 4 annual (2012 2015) Two Oceans 21.1 km and 56.0 km races in South Africa with 75,401
consenting race entrants. Running-related injury data were collected retrospectively through an online pre-race medical screening questionnaire.
The average number of injuries for each runner every year was calculated by taking a runner’s race entry history and injury history into account
and categorizing entrants into 4 MIR categories (high, intermediate, low, and very low (reference)). Multiple logistic regression modeling (odds
ratios) was used to determine whether the following factors were predictive of a high MIR (average > 1 injury/year): demographics, training and
racing, chronic-disease history (composite chronic disease score (CCDS)), and history of allergies. RESULTS: Of all entrants, 9.2% reported at least 1 injury, and 0.4% of entrants were in the high MIR category; the incidence rate was 2.5 injuries
per 10 runner-years (95% confidence interval (95%CI): 2.4 2.7). Significant factors predictive of runners in the high MIR category were: running for > 20 years: OR = 2.0 (95%CI: 1.3 3.1; p = 0.0010); a higher CCDS: OR = 2.2 (95%CI: 2.0 2.4; p < 0.0001); and a history of allergies:
OR = 2.8 (95%CI: 2.0 3.8; p < 0.0001). CONCLUSION: Runners who have been running recreationally for > 20 years and those with multiple chronic diseases or a history of allergies were at
higher risk of multiple running-related injuries. This high-risk group can be targeted for further study and possible injury-prevention interventions.
