They used to be for carrying books and lunches. When you add portable video games, gym clothes, and designer school supplies, though, backpacks are just too heavy for most kids.

Nancy Gold does a test when she fits a child for a backpack. She takes three phone books—no small item in Schenectady, NY—and puts them in the pack. Most children tell her that's just about how much weight they carry in their backpacks every school day.

Many backpacks that appeal to children are ill-designed for the task at hand—carrying a day's worth of school books, supplies, gym clothes, and myriad kid treasures. They may have the right movie character, but none of the proper padding and support to keep children from developing chronic problems with their backs.

Weighing the Pack

The American Academy of Orthopaedic Surgeons (AAOS) surveyed orthopedists about back problems related to backpacks. More than 70% of those surveyed said the extra weight can lead to medical problems for kids, with muscle fatigue and strain at the top of the list. They also concluded that a backpack could injure a child if the weight of its contents add up to more than 20% of his or her body weight.

Also, researchers from the University of California, San Diego School of Medicine concluded that most children do carry backpacks that are too heavy, which can lead to should and back pain.

Most doctors recommend that a pack does not exceed 10%-15% of the child's body weight.

Having Chronic Back Pain

"The numbers of kids with back pain is becoming staggering," says Dr. Scott Bautch, president of the American Chiropractic Association's Council on Occupational Health. "Backpacks are not the only reason, but we need to be very conscious. We're seeing so much more chronic ]]>back pain]]> in young people. It's the number one disability in this country. I see more people between 18 and 30 than any other age group with back pain."

"When I first started here five years ago, I thought a lot of what I would see would be sports-related, short-term injuries," says Hester Bourne, chief physical therapist at the University Health Center at the University of Georgia, who sees primarily 18- to 22-year-olds. "I never imagined I'd see as much chronic, ongoing low back pain."

Physicians are quick to point out a lack of scientific study linking back pain in children to overstuffed backpacks, but "anecdotally, I see an awful lot of children with back pain with a negative or normal work-up," says Dr. Robert Bruce, assistant professor and chief of pediatric orthopedic surgery at Emory University in Atlanta, Georgia. That means there's no disease or physical abnormality to account for the pain.

Creating a Better Backpack

Dr. Bruce looks at the way kids lift and carry their backpacks, and in extreme cases, even writes prescriptions for a second set of books to keep at home so they don't have to be toted back and forth.

"It's a good idea to have a pack that's supportive, with padding and support in the back portion," he says. "If you're carrying a load, a frame adds to the weight distribution. I recommend kids look at using rolling bags, and even backpacks with wheels on them."

Identifying the Problem

"There's more homework at a younger age, and there's a tendency to carry every single book from class to class," Bourne explains. "Children are carrying book bags at the age of six or seven."

To understand the problem, we went to the people who do research for some of the most serious backpacks in the world—the US Army Research Institute for Environmental Science. With soldiers carrying packs weighing up to110 pounds for miles at a time, back pain is a critical issue. The Army uses high-speed filming and force transducers to determine the postural effects of equipment.

"It's always hard to carry that kind of weight," says Everett Harmon, a research physiologist and head of the institute's biomechanics lab. "If you carry a pack on one shoulder, you have to tilt your body, which puts stress on the spine and the torso," Harmon explains. "You develop muscle imbalances, and…you're more likely to develop problems. We tell soldiers to shift the load frequently. When you walk with a heavy load, move the straps around. Don't keep them over the same place all the time."

"Keep the straps as light as possible, and hook them over both shoulders," says Kim Azbell, a physical therapist from St. Mary's Hospital in Athens, Georgia. "It may look geeky, but it's better for your back."

In a study of children in middle school, researchers found that 37% reported back pain. A third of the students said that the pain limited them from doing some activities. Researchers also found that two factors were associated with back pain: having school lockers available and using a lighter backpack. If your child doesn't have a locker at school, lightening the load might help.

Lightening the Load

Orthopedic surgeons and chiropractors recommend these guidelines when using back packs:

Students

  • Use both of the backpack's straps, firmly tightened, to hold the pack two inches above your waist.
  • Tighten the straps so the top is just below the base of the head. When packs are carried low on the back, near the buttocks, it weighs down the spine.
  • Use the correct lifting techniques. Bend with both knees when picking up a heavy back pack.
  • Place the heaviest items close to your back.
  • Neatly pack your backpack, and try to keep items in place.
  • Try to make frequent trips to your locker, between classes, to replace books.

Parents

  • Remember that a backpack's weight should not exceed 20% of your child's body weight, and even less for a young child.
  • Select a backpack with padded, wide straps and a padded back.
  • Use a hip strap for heavier weights.
  • Consider purchasing a backpack with wheels, or a pack with an internal frame.
  • Consider purchasing a second set of books for home.
  • Buy the smallest backpack possible.
  • Clean out your child's backpack once a week.
  • Talk to your child's teacher about sending home only what is absolutely necessary.