Moderate-to-vigorous physical activity is associated with lower odds of backache in children and adolescents: A multinational analysis over 19 years.

This study examines the association between moderate-to-vigorous physical activity (MVPA) frequency and backache occurrence in a large multinational sample of children and adolescents. This cross-sectional study utilized data from the Health Behavior in School-aged Children (HBSC) study, including surveys waves 2001/2002, 2005/2006, 2009/2010, 2013/2014, and 2017/2018 across 48 countries. A total of 767,647 children and adolescents (mean age = 13.7 years, standard deviation [SD] = 1.6; 51% girls) were included. Self-reported MVPA frequency was reported as days per week with ≥ 60 min of MVPA. Self-reported backache frequency was assessed on a five-point scale from "rarely or never" to "about every day." An ordinal logistic regression model was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for sex, body mass index, socioeconomic status, and survey year. Of the participants included, a 19% engaged in daily MVPA, whereas 4.5% reported no MVPA. Regarding backache, 61% reported "rarely or never" experiencing it, while 5.7% reported it "about every day". Ordinal logistic regression models suggested that older age and female sex were associated with higher odds of frequent backache, and participants with excess weight reported slightly higher odds compared with their counterparts. At the country level, higher levels of MVPA tended to report slightly lower proportions of daily back pain, although substantial heterogeneity was observed across countries. At the individual level, analysis showed that compared with participants reporting no MVPA, those with 1 day/week had 11% lower odds of more frequent backache (OR = 0.89, 95% CI 0.85 to 0.93), while those with 5 days/week had 19% lower odds (OR = 0.81, 95% CI: 0.79-0.84). At 6 and 7 days per week, the odds of backache were slightly higher than those observed at 5 days. Stratified analyses by survey wave showed that in earlier waves this pattern was less consistent, whereas in later waves the association appeared more linear and inverse.

conclusionRegular MVPA may be modestly associated with lower odds of backache in children and adolescents, with evidence of a non-linear pattern in which the lowest odds were observed around five days per week, followed by slightly higher odds at the highest activity levels. These findings suggest that some physical activity could be better than none for spinal health in this age phase and highlight the importance of promoting regular MVPA in youth populations. WHAT IS KNOWN: • Engaging in regular physical activity during childhood is broadly acknowledged as a crucial element for both physical and mental health. • Back pain is a prevalent musculoskeletal disorder among children and adolescents that hinder daily activities, restricts participation in sports, and poses difficulties in educational environments. WHAT IS NEW: • In this multinational study of 767,647 children and adolescents, modest but consistent non-linear associations were observed between moderate-to-vigorous physical activity and backache occurrence across most countries and survey periods. • Children and adolescents reporting 5 days/week of ≥ 60 min of moderate-to-vigorous physical activity showed the lowest odds of backache (19% lower than inactive peers), while those with 6 or 7 days/week displayed slightly higher odds, suggesting a non-linear association between activity frequency and backache.