(Image source from: New Straits Times)

Scientists have indicated that school children who use backpacks should avoid loads more than 10 percent of their body weight and if it is a trolley it shouldn’t be more than 20 percent of children’s body weight.

Thus far the weight recommendations have been established for ordinary backpacks since they are the ones which are used for the most part.

For the study, the researchers assessed 49 primary school children. A kinematic analysis of the children (posture of the trunk and lower limbs) was conducted while (i) they walked freely, carrying no weight, (ii) carrying a traditional backpack, and finally (iii) pulling a backpack trolley with different loads (10 percent, 15 percent, and 20 percent of their respective body weights).

For the analysis, a three-dimensional optical motion capture system was used, similar to those used in animation films and video games. In collaboration with researchers from Liverpool John Moore University, scientists from the University of Granada in Spain used statistical techniques to analyze the full kinematics curves, based on tracing point trajectories.

The findings of the study, published in the Applied Ergonomics journal, indicate that the greatest alterations when using backpacks or trolleys are produced in the proximal extremities (trunk and hip), while there is little difference in the kinematics of the distal extremities (knee and ankle).

Ultimately the study confirms that schoolchildren who use backpacks should avoid carrying loads greater than 10 percent of their body weight and in case of backpack trolley, the child should avoid any load above 20 percent of their body weight, according to the study.

By Sowmya Sangam