Design and Participants: This longitudinal cohort study will have a total study population of 1,600 consenting adolescents (ages 11-15) recruited from sport-specific or junior high school settings. Exposure Measurements – A validated preseason baseline questionnaire will include questions about age, grade, sex, maturation, medical/injury history, and previous six-weeks and one-year sport participation. Anthropometric measures (e.g. body mass index), aerobic and musculoskeletal fitness, balance tests, and biomechanical screening. Outcome Measurements – The primary outcome is sport injury requiring medical attention, and/or inability to complete a sport session and/or the loss of at least one day of sporting activity. Surveillance (physiotherapist assessment & physician follow-up) has been validated in a youth population in soccer, basketball and hockey. Weekly exposure data will be self-reported or collected by a team designate in the case of soccer or basketball. Long-term outcomes are OA of the knee, annual self-reported disease-specific functional questionnaires and other specific validated measurements related to physical activity participation, neuromuscular control, program compliance, biomechanical assessment, and physiological testing.
Intervention Program – Participants will be allocated either to a 15-minute evidence-based neuromuscular warm-up intervention program or control program. Group-based warm-up components (e.g. balance, agility, jump technique, core strength) are based on effective sport-specific youth injury prevention programs. Individually targeted interventions will be based on neuromuscular rehabilitation principles.
Data Analysis – A comparison of sport injury rates (# injuries/1,000 hours) in the intervention and control groups will be examined using incidence rate ratios. Risk factors for sport injury (e.g. age, sex, injury history) and subsequent long term outcomes (i.e. levels of physical activity, OA) will be examined using incidence rate ratios to describe the association between the exposure variables and the outcomes.