They come in all shapes and sizes. They come in all colors and designs. But what you don’t know CAN hurt you.

From kindergarten through college, a backpack is a must for toting school work to and from school. So with something as necessary and common as a backpack, it can be hard to pay attention to the dangers that come with them.

According to studies done by physicians, a student’s backpack should weigh no more than 10 percent of his or her bodyweight. I don’t know about you, but my backpack is well over 10 percent of my body weight—filled at whopping 26.5 pounds—yes, I did weigh it.

The U.S. Consumer Product Safety Commission calculated in 2013 that about 22 thousand strains, sprains, dislocations, and fractures from backpacks were treated in emergency rooms, physician’s offices and clinics. The numbers are there. This is an extremely large amount of injuries caused by something that seems so harmless.

Yes, I know as well as anyone that it feels as if there’s not much we can do to limit the weight we put on our backs. But there are steps that we must try to take in order to ensure our health.

First of all, remove as much as you can from your class folders or binders. If you’re not using something, empty it and leave it in an extra folder at home.

Secondly, wear both straps at all time. Wearing one strap can cause weight to be distributed unevenly, leading to crookedness and back pain. According to the American Chiropractic Association, the backpack should not hang lower than four inches below your waist. The lower the backpack is, the more weight on your shoulders—throwing off the balance of your frame.

Last, you may not want to look like you’re about to climb a mountain, but additional straps on your backpack may be able to help prevent injury. Straps often are able to reposition the weight and relieve the shoulders from doing all the bulk of the carrying. It may compromise your appearance, but health should always come first.

It’s neither reasonable nor practical to give up backpacks all together, but there are ways to improve the issue of heaviness in order to prevent unnecessary back injuries.