Biomechanical comparison of sagittal vertebral column bend change induced by backpacks in school-aged children and adolescents: Systematic review and network meta-analysis

Abstract

Background: Studies have investigated the effects of backpacks and their loadings on the physiological spinal curvature changes in school-aged children and adolescents across different anatomical planes of motion. However, the dose-response relationship between varying backpack weights and changes in spinal physiological curvature remains unclear due to the uniformity of study protocols. Objective: The purpose of this systematic review is to explore the sagittal vertebral column bend change induced by backpacks in school-aged children and adolescents. Methods: Three relevant authoritative databases (PubMed, Scopus, and Web of Science) were searched. Indicators of vertebral column bend in the sagittal plane were selected as the outcomes. In the data organization phase, the extracted data were standardized and pooled together by the Aggregate Data Drug Information System. The Cochrane Risk of Bias Assessment Tool and the website of Confidence in Network Meta-Analysis were used to evaluate the risk of bias and confidence ratings of results. Results: 4 trials were included within 244 potential studies. The results indicated a potential dose-effect relationship between backpack weight and sagittal vertebral column bend change. The findings suggested a possible dose-response relationship between backpack weight and sagittal vertebral column bend change, as evidenced by a sequential reduction in the likelihood of causing the most negative effect on sagittal vertebral column bend in 4 backpack scenarios: without backpack, <10%, 10–20%, and >20% of body weight, with probabilities of 0.61, 0.25, 0.13, and 0.01, respectively. The results also indicated that there were no significant differences in the effects on the sagittal vertebral column bend between the four backpack scenarios, in pairwise comparisons. Additionally, the results from the risk of bias assessment revealed that this review suffers from a lack of inclusion of high-quality studies. Moreover, the confidence rating indicated that both direct and indirect comparisons in the network meta-analysis were rated as “Very Low” in confidence rating induced by CINeMA. Conclusion: This review suggests a potential dose-effect relationship between backpack weight and sagittal vertebral column bend, with no significant differences across each head-to-head comparison.