School bag weight relative to body weight in primary school children: Nursing assessment and preventive implications in Khartoum state, Sudan.

Abstract

BackgroundSchool bag load is a school-health concern, but weight percentage alone does not represent a complete ergonomic assessment. This study characterized school bag load relative to body weight and examined unadjusted associations with grade and anthropometric characteristics among primary school students in Khartoum State, Sudan.MethodsA descriptive cross-sectional study included 380 students aged 6-13 years from four randomly selected government schools between January and March 2025. Demographic data, body weight, height, BMI, and loaded school bag weight were recorded. A paired t-test, one-way ANOVA, Pearson correlation, and chi-square tests were used. Carrying method, trolley use, duration, distance, stairs, and musculoskeletal outcomes were not measured.ResultsMean school bag weight was 4.87 ± 1.88 kg and was significantly above the individualized 10%-of-body-weight reference value (<i>t</i> = 22.142, p < 0.001). Bag weight differed across grade, BMI, height, and weight categories (all <i>p</i> < 0.001) and correlated with height (<i>r</i> = 0.623), age (<i>r</i> = 0.587), body weight (<i>r</i> = 0.518), and BMI (<i>r</i> = 0.291). Overall, 62.1% of students carried bags weighing at least 10% of body weight.ConclusionA majority of participants exceeded the study-defined 10% relative-load reference. The associations with age, grade, height, and weight are descriptive and may reflect curricular progression and confounding among developmental variables. Because carriage conditions and clinical outcomes were not assessed, the findings characterize load exposure rather than ergonomic risk or musculoskeletal harm. Future studies should incorporate carriage duration and method, environmental demands, symptoms, posture, and multivariable analysis.