While a backpack is still one of the best ways to tote homework, an overloaded or improperly worn backpack will get a failing grade. Worn correctly and not overloaded, a backpack is supported by some of the strongest muscles in the body: the back and abdominal muscles. They work together to stabilize the trunk and hold the body in proper postural alignment.
However, improper backpack use can cause injury, especially to children with young, growing muscles and joints. The American Physical Therapy Association recommends a child’s backpack should weigh no more the about 10 percent of his or her body weight.
Injury can occur when a heavy load causes poor postures such as arching the back, leaning forward or, if only one strap is used, leaning to one side. Over time, these positions can cause compression and/or improper spinal alignment, and may damage the disks between the vertebrae that provide shock absorption. A too-heavy load can also cause muscles to work harder, leading to strain and fatigue and leaves the back more prone to injury. A heavy load may also cause stress or compression to the shoulders and arms. When nerves are compressed, the child may experience tingling or numbness in the arms.
Consider these guidelines for safe backpack use:
- Wear both straps. Using only one strap, even with backpacks that have one strap that runs across the body, causes one shoulder to bear the weight of the bag. By wearing both shoulder straps, the weight of the pack is better distributed, and balanced posture is improved.
- Make sure the backpack fits. It is important to pay close attention to the way a backpack is positioned on the back, and the size of the backpack should match the size of the child. Shoulder straps should fit comfortably on the shoulder and under the arms, so that the arms can move freely. The bottom of the pack should rest in the contour of the lower back. The pack should "sit" evenly in the middle of the back, not "sag down" toward the buttocks.
- Load heaviest items closest to your child’s back.
Look for these features when selecting a backpack:
- A padded back to reduce pressure on the back and keep the pack's contents from digging into your child's back.
- A backpack that has padded, contoured shoulder straps will also help reduce pressure on the chest and shoulders.
- A waist belt to help distribute some of the load to the pelvis.
- Compression straps on the sides or bottom of the backpack that, when tightened, compress the contents of the backpack and stabilize the articles.
- Reflective material so that the child is visible to drivers at night.
If heavier loads are truly necessary, backpacks with wheels may a good option. However, wheeled backpacks may present problems, such as getting them up and down stairs or trying to fit them into cramped locker spaces. If a wheeled backpack is chosen, be sure that the extended handle is long enough so your child is not forced to twist and bend, and that the wheels are sufficiently large so the backpack doesn't shake or topple.
So how do you make sure that your child stays injury-free? Parents should ask about and look for the following signs that the backpack is too heavy:
- Pain when wearing the backpack
- Tingling or numbness in the arms
- Red marks on the shoulders
(Jeanne DeKrey, PT, DPT, PRC, is a licensed physical therapist at CHI St. Alexius Health. She is certified by the Postural Restoration Institute which she applies to her clinical practice by focusing on spine pain and spine dysfunction.)