Prevalence of low Back pain among adolescents in relation to the weight of school bags

BACKGROUND: The association between the weight of school bag and Low Back Pain (LBP) amongst students remains under intense debate worldwide. This study aimed to estimate the prevalence of LBP amongst public high school students (14 to 19 years) in Kuwait and to investigate the association between LBP and the weight of school bags. METHODS: An analytical cross-sectional study using multistage cluster random sampling with probability proportional to size was conducted on a total of 950 public high school students from all governorates. Data on LBP were collected through face-to-face interviews using a structured questionnaire. A 0–10 Numeric Pain Rating Scale was used to rate the intensity of LBP. The students’ height and weight in addition to the weight of their school bags were measured using appropriate weight and height scales. Logistic regression was used to investigate the association between the weight of school bags and LBP while adjusting for potential confounders. RESULTS: The estimated lifetime, 6-month, and 1-month prevalence of LBP were 70.3% (95% CI: 67.30–73.21%), 49.1% (95% CI: 45.83–52.28%), and 30.8% (95% CI: 27.81–33.78%) respectively, with significantly higher prevalence amongst females compared to males (p < 0.001). The absolute weight of school bag was not significantly associated with LBP neither in univariable nor multivariable analysis. The relative weight of school bag (as a percentage of the body weight) was significantly associated with LBP in univariable analysis but not in multivariable analysis. The perceived heaviness of school bag, however, was found to be significantly associated with LBP throughout the analysis (p < 0.001). CONCLUSION: In conclusion, LBP amongst high school students in Kuwait seems to be very common with a prevalence resembling that of high-income countries. Our data suggest that the perceived heaviness of school bag is far more important than the actual bag weight. Current recommendations about the weight of school bags, which are not supported by evidence, should be revised to take into account the students’ perceived heaviness of school bag.