Assessment of the elementary school students' schoolbag weight in the urban environment in Poland: A cross-sectional study carried out as a part of the 'Lightweight Schoolbag' and 'Let's Get the Kids Moving' projects.

Background: Carrying a properly weighted schoolbag is an important factor in preventing the occurrence of muscular skeletal disorder in early school age children.

Objective: The purpose of this cross- sectional observational study was to examine the schoolbag weight and to determine the percentage of children were carrying overloaded schoolbag.

Methods: The study group included pupils from five primary public schools in Wrocław, Poland. Anthropometrical measurements such body weight (BW) and height were conducted on 650 children (51.1% of boys). Children's age, gender, Cole's Index was juxtaposed with schoolbag weight. The mean age of the examined students was 8.7±0.8 years (range 7 to 10 years).

Results: The mean schoolbags weight was 3.7±0.92 kg, which represented 13.0±3.8% of pupils' BW. The percentage of pupils carry the schoolbags weighing more than 10% of their BW was 77.9%. More than a quarter of Polish children carry school backpack above 15% of their BW. The majority (96.8%) had schoolbags which may be carried on both shoulders. A significant negative correlation was observed between relative schoolbag weight and Cole's Index (rho = -0.44, p < 0.05).

Conclusions: The problem of overloaded schoolbags among elementary school children was frequent. Pupils ought to be educated in the proper packing of their school backpacks. Additionally, parents and teachers should pay attention regarding the contents carried by children in their respective schoolbags.