Backpack overload sends tens of thousands of kids a year to emergency rooms, physicians’ offices and clinics from sprains, strains, dislocations and fractures.
Check out these tips from an ER physician, Dr. Matt Bush to prevent heavy pack injuries! http://www.childrensmedicalclinics.net/blog.html
https://lifesignsblog.com/2016/08/04/how-to-prevent-heavy-packs-from-injuring-little-backs/