Effect of School Backpack Weight on Shape of Children's Feet

BACKGROUND The human foot, being the load-bearing element of the musculoskeletal system, located at the lowest point in the kinematic chain, takes on the greatest loads, and its efficiency determines a person's motor skills. The aim of this study was to assess the weight of school backpacks, foot structure, and the effect of school backpacks weight load on foot shape in 10-year-old children. MATERIAL AND METHODS We studied 119 students aged 10 years (61 girls and 58 boys). Research tools included: WLC 60/C2/K RADWAG precision scale (Uniwag, Cracow, PL), medical column scale with a telescopic height gauge MS 4971 (Charder, Taichung, Taiwan), and a CQ-ST podoscope (Electronic System, Czernica, PL). RESULTS In both sexes, backpack weight values relative to body mass were correlated negatively with differences in the values of the Clarke's angle of the right (R=-0.70; P<0.001) and left foot (R=-0.75; P<0.001), and in girls backpack weight was positively correlated with differences in the width of the right foot (r=0.34; P=0.008) and left foot (r=0.41; P=0.001), with differences in the values of the heel angle of the right (R=0.34; P=0.007) and left foot (R=0.39; P=0.002) and with differences in the values of the hallux valgus angle of the left foot (R=0.30; P=0.017). CONCLUSIONS The weight of a school backpack, especially for girls, causes a decrease in the longitudinal and transverse arch, which may be an expression of their weakness in coping with this load. Girls require special care in the form of implementing countermeasures, such as monitoring the contents of school backpacks and searching for solutions aimed at reducing accessories and items that need to be carried in school backpacks, to prevent foot deformations and biomechanical disorders of the musculoskeletal system.