RESUMO
There is a little information about weight excess of school materials in Ulaanbaatar, Mongolia. The aim of this study was to study of the weight of backback and the ergonomic effects of backpack carriage on school students in Ulaanbaatar. This cross-sectional study was performed in the city of Ulaanbaatar in 2015. Two hundred fourteen school students participated in study. Nordic Musculoskeletal Questionnaire was used, asking about complaints of neck, shoulders, upper and lower back. Length and weight of the children were determined. Backpacks were weighed and the relative weight of the backpack was calculated.In this study, first and second grades students carried proportionately heavier backpacks than older students and more than 10% of their weight. Musculoskeletal complaints were reported by about 79% of school students. The (relative) weight of backpacks was not related to complaints of neck, shoulders, upper and lower back.