A backpack with individualized compartments will help in positioning the contents most effectively. When packing the backpack, make sure that pointy or bulky objects are packed away from the area that will rest on your child's back. An uneven surface rubbing against your child's back could cause painful blisters. It is important that your child wear both shoulder straps. Lugging the backpack around by one shoulder strap can cause the disproportionate shift of weight to one side, leading to neck and muscle spasms as well as low-back pain.
Padded straps are very important.
Non-padded straps are uncomfortable, and usually dig into your child's shoulders. The shoulder straps should also be adjustable, so the backpack can be fitted to your child's body. Shoulder straps that are too loose can cause the backpack to dangle uncomfortably and cause spinal misalignment and pain. If the backpack is still too heavy, talk to your child's teacher. It might be possible for your child to leave the heaviest books at school, and bring home only lighter hand-out materials or workbooks.