Purpose: This study aims to conduct a systematic review of injury prevention programs on muscle flexibility in children and adolescents.
Methods: Relevant articles were searched in two electronic databases, PubMed and Scopus. An electronic search was conducted on December 1, 2022, without applying any year constraints. Studies that investigated the effect of injury prevention programs on muscle flexibility in subjects under 17 years of age were included. The study method was evaluated using the PEDro scale. 
Results: A total of 3563 studies were initially retrieved from databases, and data from 5 randomized controlled trials (RCTs) were used in this systematic review. Injury prevention programs (three out of five articles) can improve the muscle flexibility of children and adolescents (before and after the intervention).
Conclusion: Injury prevention programs can improve the muscle flexibility of children and adolescents in the intervention group (before and after the intervention); although no improvement was observed in the control group. Therefore, factors, such as duration, frequency and intensity of the program, gender, activity level, type of sport, and sample size are decisive in muscle flexibility.