The Influence of the Weight of the Backpack on the Biomechanics of the Child and Adolescent: A Systematic Review and Meta-analysis With a Meta-Regression

Abstract

Purpose: To evaluate and explore the influence of the weight of a backpack on standing posture and gait in children and adolescents. Methods: We conducted a search of MEDLINE (PubMed), Cochrane Library, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science, with the last search in July 2021. Standardized mean differences (SMD) and 95% confidence intervals were calculated for relevant outcomes and were pooled in a meta-analysis using the random-effects model. The participants were healthy children or adolescents. The outcomes were postural variables, spatiotemporal gait variables, gait kinematics, and muscle activity. We analyzed the influence of a loaded backpack on posture while standing and spatiotemporal and kinematic variables while walking. We used GRADE, Risk of Bias 2, ROBINS-I, MINORS, and PEDro scales to rate the quality, certainty, and applicability of the evidence. Results: Wearing a loaded backpack induces a significant increase of the craniohorizontal angle while standing and a decrease of walking speed and stride length while walking. Only the craniovertebral angle had a significant relationship with the weight of the backpack. Conclusions: Wearing a backpack induces postural changes while standing and affects gait in children and adolescents; however, almost all the changes are not related to the backpack weight.