Should you take sides on the debate about whether children should or should not carry their backpacks on (or mostly on) just one shoulder? This study adds fuel to one or another side of the debate:
“Effects of Carrying a Backpack in an Asymmetrical Manner on the Asymmetries of the Trunk and Parameters Defining Lateral Flexion of the Spine,” Justyna Drzał-Grabiec, Sławomir Snela, Maciej Rachwał, Justyna Podgórska, Justyna Rykała, Human Factors, epub August 8, 2014. (Thanks to investigator Neil Martin for bringing this to our attention.) The authors, at Rzeszow University, Rzeszow, Poland, report:
The aim of this study was to examine changes in the body posture parameters defining asymmetry of the trunk and lateral flexion of the spine in children while carrying a backpack weighing 10% of a child’s weight…
Results: Trunk inclination shifted significantly in the opposite direction to the shoulder the backpack was carried on, and an increase in shoulder asymmetry was also found. We also observed a more pronounced right-side lateral flexion of the spine when the backpack was carried on the right shoulder and an analogous relationship for the left side.
Conclusion: The results of this study show that carrying a backpack in an asymmetrical manner negatively affects spine, even if the backpack weight constitutes 10% of the child’s weight, which has been previously recommended as a safe load for a child’s shoulders.
Here is a video of an older student carrying a backpack on one shoulder: