Uncovering Factors Associated With Lower Extremity Injury Rates in Youth Ice Hockey Players

<b>OBJECTIVES:</b> To (1) examine the incidence of game- and practice-related knee, ankle, and combined lower extremity injuries in under-13 (ages 11-12 years), under-15 (ages 13-14 years), and under-18 (ages 15-17 years) youth ice hockey players and (2) explore factors associated with game- and practice-related lower extremity injury rates in these players. <b>DESIGN:</b> Prospective cohort study. <b>METHODS:</b> Youth ice hockey players were studied over 5 seasons. Validated injury surveillance methodology was used, which included conducting annual baseline measures, collecting playing exposure, and identifying lower extremity injuries. Crude rates of game- and practice-related knee, ankle, and combined lower extremity injuries were estimated for each age group. Multilevel Poisson regression adjusted for clustering effects by team and multiple imputation of missing covariates were used to estimate incidence rate ratios (IRRs). Models were adjusted for age group, sex, body-checking policy, level of play, weight, previous injury within 12 months, lifetime concussion history, and position. <b>RESULTS:</b> The cohort included 4418 male and female players (representing 6584 player-seasons). The rate of game-related lower extremity injury was highest for under-18 players (1.01/1000 game hours; 95% confidence interval [CI]: 0.75, 1.35), followed by under-15 players (0.64/1000 game hours; 95% CI: 0.49, 0.83) and under-13 players (0.33/1000 game hours; 95% CI: 0.20, 0.55). Rates of practice-related lower extremity injury were lower than the game-related rates for each age group. The factors significantly associated with game-related injury were policy permitting body checking in games (IRR = 1.88; 95% CI: 1.09, 3.24), female sex (IRR = 1.92; 95% CI: 1.02, 3.62), and previous 12-month injury (IRR = 1.43; 95% CI: 1.01, 2.01). <b>CONCLUSION:</b> The rates of knee, ankle, and combined lower extremity injuries were substantially higher in games than in practices. Playing in a body-checking league, female sex, and having a history of injury within the previous 12 months were associated with higher rates of injury. <i>J Orthop Sports Phys Ther 2025;55(10):1-10. Epub 18 August 2025. doi:10.2519/jospt.2025.13106</i>.