Effect of Injury Prevention Programs on Lower Extremity Performance in Youth Athletes: A Systematic Review

BACKGROUND: Understanding how existing youth injury prevention programs affect specific modifiable injury risk factors will inform future program development for youth athletes. OBJECTIVE: To comprehensively evaluate the effects of injury prevention programs on the modifiable intrinsic risk factors associated with lower extremity performance in youth athletes. DATA SOURCES: This systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A systematic search of the literature was performed using multiple databases (PubMed, EBSCOhost including CINAHL, Medline, and SPORTDiscus, and PEDro). Secondary references were appraised for relevant articles. Article types included randomized or cluster randomized controlled trials and randomized cohort designs with youth athletes engaged in organized sports, along with outcomes that included at least 1 physical performance outcome measure. STUDY SELECTION: Eight studies met inclusion and exclusion criteria and were reviewed by 2 independent reviewers, with a third consulted in the case of disagreement, which was not needed. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 3. DATA EXTRACTION: Included studies underwent review of methodological quality using the Physiotherapy Evidence Database scale. RESULTS: Studies included mixed-sex samples of youth athletes who predominantly participated in soccer at different skill levels. The FIFA 11+ series was the most commonly used injury prevention program. Among studies, the mean percentage of improvement identified was 11.3% for force generation, 5.7% for coordination, 5.2% for posture, and 5.2% for balance. The lowest mean percentage improvement was in speed (2.2%). Endurance was not significantly affected by any of the programs. CONCLUSION: This systematic review shows that injury prevention programs improve several modifiable intrinsic risk factors of lower extremity performance among youth athletes, particularly force generation. However, several intrinsic risk factors were either not significantly affected or specifically addressed by existing programs.