Background: The relationship between physical activity and low back pain (LBP) in adolescents is complex, with conflicting evidence on whether activity is protective or a risk factor. The COVID-19 pandemic has introduced new challenges, increasing sedentary behaviors among adolescents. This systematic review updates the evidence on the association between physical activity and LBP in this population, focusing on the impact of the pandemic. Methods: A systematic search of PubMed, Cochrane Library, Web of Science, Medline, and SCOPUS identified observational studies published between January 2011 and December 2023. This review focused on adolescents aged 10 to 19 years, examining the effects of various physical activity levels and types on LBP incidence. Quality assessment was conducted using the ROBINS-I tool. Results: Twelve studies were included, with a total of 78,850 adolescents. The findings suggest a U-shaped relationship between physical activity and LBP, where low and high activity levels increase LBP risk, while moderate activity appears protective. The pandemic exacerbated LBP prevalence, likely due to increased sedentary behavior. Gender differences were noted, with females more likely to report LBP, particularly related to sports participation. Conclusions: Moderate physical activity may protect against LBP in adolescents, whereas both inactivity and excessive activity heighten risk. The pandemic's impact highlights the need for balanced physical activity to prevent LBP. Further research should explore the long-term effects of these changes.
Keywords: adolescent health; low back pain; physical activity; prevention strategies; sedentary behavior; sport.