As a Vancouver Chiropractor I believe if you are parents of grade schoolers starting school, it is extremely vital to be aware of the impact that a bad backpack can have on the spine of your young children. Always look for the right size and correct support in a back pack. There are many good ones out there, however not one is right for all.
Never allow the child to overload his/her backpack. This may cause irreparable strain to their developing necks and backs.
Have your child checked by a chiropractor that has training in pediatric chiropractic care. This can give you baseline information of his/her musculo-skeletal health.