A properly fitted backpack is an essential tool for students at any age, and the right one can last for many years such as a backpack from The North Face or REI. However, many students struggle every day under backpacks that are awkward and ill-fitting, or simply too heavy for them to carry safely. Although you'll find dozens of options when school reopens each fall, some of the best backpacks are available through until graduation and beyond.

The Right Fit

You'll know you found a good fit when the bulk of the backpack's weight is resting in the curve of your child's lower back and no more than 4 inches below the waistline. This is important, because it prevents wear and tear that can lead to chronic back pain, numbness in the arms and hands and poor posture. Look for a backpack that also has wide, padded straps and a padded back wall for keeping bumps and bruises at a minimum. Thin shoulder straps can chafe and cut into nerves and blood vessels in the shoulders or even break with extended use. The best fit is to adjust strap anchor points so they rest roughly 1 to 2 inches below the top of the shoulders.

Eliminate Extra Weight

Even the best backpack can be detrimental to your child's health if he or she is packing too many books, papers and supplies inside. Make sure your child only brings home and carries to class what is absolutely necessary for completing assignments. A good rule of thumb is to carry no more than 15% to 20% of the child's body weight. That means a 100 lb. child shouldn't carry more than 15 to 20 lbs. In addition, teach your child to always use both straps, so the weight of the backpack is evenly distributed. Wearing the backpack on one shoulder for an extended period of time can throw off the child's balance, causing back pain and poor posture.

Quality Construction

A backpack will last a lot longer if it's made well in the first place. Check the stitching. Is it strong, even when you put pressure on the bottom of the backpack? Are there loose threads or is the fabric frayed? Now, check the zippers and other closures. The stitching should be strong there, as well and a covered zipper will help block rain and snow. Also, look for a lightweight fabric that is machine washable.

Ready to Roll

Many parents buy a backpack with wheels, thinking that will eliminate potential problems altogether. However, before you buy, check with your child's teacher to be sure the backpack will fit in narrow, crowded school hallways. If you're still determined to get a backpack that rolls, try one that also has traditional shoulder straps. That way, your child will be able to wear the backpack in tight environments and pull it behind him or her during the walk home or to and from the bus.