Hi~
Proper backpack wearing is a passion of mine. There are some important facts to keep in mind no matter what back pack you choose. Such as (http://www.aota.org/DocumentVault/Backpack/44404.aspx)
1) there were more than 23,000 backpack‐related injuries were treated at hospital emergency rooms, doctor’s offices, and clinics in 2007
2) It is recommended that a loaded backpack should never weigh more than 15 percent of the student’s total body weight (for a student weighing 100 pounds, this means that the backpack should weigh no more than 15 pounds).
3) The way backpacks are worn affects your health. The height of the backpack should extend from approximately 2 inches below the shoulder blades to waist level or slightly above the waist. It is recommended that individuals always wear the backpack on both shoulders so the weight is evenly distributed
Here are some tips on backpack loading and wearing (http://www.aota.org/DocumentVault/Backpack/44388.aspx) :
Loading a backpack:
1) Load heaviest items closest to the child's back (the back of the pack). Arrange books and materials so they won't slide around in the backpack
2) If the backpack is too heavy or tightly packed, your child can hand carry a book or other item outside the pack
3) if the backpack is too heavy on a regular basis, consider using a book bag on wheels if your child's school allows it
Wearing a backpack:
1) Distribute weight evenly by using both straps. Wearing a pack slung over one shoulder can cause a child to lean to one side, curving the spine and causing pain or discomfort. (* I knew someone in high school who had to get his jackets specially made because one shoulder was higher than the other)
2) Select a pack with well‐padded shoulder straps. Shoulders and necks have many blood vessels and nerves that can cause pain and tingling in the neck, arms, and hands when too much pressure is applied
3) Adjust the shoulder straps so that the pack fits snugly on the child's back. A pack that hangs loosely from the back can pull the child backwards and strain muscles.
4) Wear the waist belt if the backpack has one. This helps distribute the pack's weight more evenly
5) The bottom of the pack should rest in the curve of the lower back. It should never rest more than four inches below the child's waistline
6) School backpacks come in different sizes for different ages. Choose the right size pack for your child's back as well as one with enough room for necessary school items.
That being said LLbean has a great return policy so if you are unable to try one in the store and get one from them you should be able to exchange it if it does not fit your child. there are also several choices with waist belts. On a side note I had an LL bean back pack that has lasted me 10 years!
:) Good luck!!!