From elementary school through college, kids carry their whole lives around on their backs. After you pile school supplies, a lunch, binders and textbooks (which can weigh approximately 3.5lbs each) into your child’s backpack, the load he or she is bearing can actually be dangerous.

According to the American Occupational Therapy Association (AOTA), about 55% of students carry a backpack that is heavier than the recommended guideline. In one study of American students ages 11 to 15 years, 64% reported back pain related to heavy backpacks, with 21% reporting the pain as lasting more than 6 months.

And approximately 85% of university students self-report discomfort and pain associated with backpack usage. So not only does the incidence of pain increase as our child ages, but the 2,000 or so backpack-related injuries that were treated in 2007 has increased more than seven fold since that statistic was recorded.

Improperly used backpacks can do more than just cause back pain, however. Injured muscles and joints can also lead to severe neck, shoulder, hip and knee pain, tingling in the joints, and posture problems. How to spot if the load your child is carrying may be too much for them?

If your child grunts when putting on or taking off the backpack or has red marks on his shoulders from the straps, it may be time to reassess his backpack situation. The same goes for any child complaining of her arms or fingers “falling asleep.”

As much as your child may prioritize fashion over function, the following tips will arm parents with the information they need to give their kids the gift of good posture for years to come.

Know Where to Look

Your best bet when going back-to-school shopping for a backpack is to hit a sporting goods store, because employees will know how to properly fit a backpack to your child’s frame. Children’s backpacks tend to be made of lighter weight material, and an educated employee can point you in the right direction to begin your search.

Size Matters

It is recommended that a loaded backpack should never weigh more than 10% of a student’s weight, so go for as small a backpack as possible, because your child will likely over pack it. The general guideline for backpack length is to closely match the length of the torso, ending approximately two inches below the waist, with the bottom of the pack resting in the curve of the lower back.

Never let the bottom rest more than four inches below the child’s waist; an argument against buying a bigger backpack with the goal being for your child to “grow into” it.

Straps Are Everything

Shoulder straps should be wide (at least three finger widths) and S-shaped, meaning they curve out away from the neck and then back along the chest. Straps that run straight up and down are uncomfortable and not remotely ergonomic.

Look for a padded nylon material that won’t cause too much sweating, and be sure to impress upon your child the importance of using both straps at all times.

If your child’s pack still runs on the heavy side, you can find backpacks that distribute weight against the hips with hip pads, belt-like waist straps, and sometimes even a sternum strap. Similar to hiking backpacks, these packs place far less strain on a child’s shoulders.

After all, “shoulders are not designed to hang things from,” says Dr. Elise G. Hewitt, president of the American Chiropractic Association’s (ACA) Pediatrics Council, who points out that this is the reason indigenous people carry things on their heads.

Pack It Properly

Your best bet is to go with a pack that has a variety of pockets, helping to keep heavier items on the bottom and closer to the body. Sharp or odd shaped items can go in middle pockets away from the body, and lightweight items are perfect for the smaller compartments on the exterior.

Start Now With Proper Lifting Techniques

As adults, we’ve all been taught the proper way to lift a heavy box—by bending at and lifting from the knees, rather than by bending at the waist. This is the same way your child should lift his or her backpack, so it’s never to soon to start teaching this important lesson.

To ensure the backpack you’ve purchased is a good fit for your child, call In8Love at 310-477-3335 and make an appointment for a complimentary consultation and fitting.

Just leave the tags on your purchase until I can assess its appropriateness for your child’s frame, and together we can help your child stand tall for years to come.