A new research describes the optimal weight that children must transport on their way to school. Researchers from the University of Granada (UGR) (Spain) and Liverpool John Moores University (United Kingdom) showed that children who use backpacks must avoid loads greater than 10% of their body weight; and those who use wheeled bags cannot carry more than 20% of their body weight.
In an article published in the Applied Ergonomics, the team of scientists established for the first time global recommendations of the appropriate weight to be carried by primary school children when they use a wheeled bag. To date, weight recommendations have only been established for school backpacks, the most used in the world school environment, but in Spain the use of school wheeled bags is more than 40% and there were no studies that established weight recommendations for their use.
In this study, 49 Primary School students were evaluated, who were analyzed for kinematics (posture of the trunk and lower limb) while walking without weight, with a school backpack or wheeled bag, with different loads (10, 15 and 20% of the kid’s body weight).
For the analysis, a three-dimensional optical motion capture system was used, similar to those used in animation films and video games. In addition, in collaboration with the Liverpool experts, the researchers used statistical techniques to analyze the curves of complete kinematics, that is, point-to-point.
Advantages of the wheeled bag in front of the backpack
The main conclusions establish that the greatest adaptations when using cart or backpack are produced in the proximal extremities (hip and trunk), without having much difference in the kinematics of the distal extremities (knee and ankle).
However, the use of the school wheeled bag produces fewer changes in the kinematics. Therefore, it is more similar to the locomotion of the child without load compared to the use of a backpack, even with little weight transported.
Source: Agencia ID