The pain could be a harbinger of longstanding back problems or even permanent injury, said Dr. David Siambanes (pronounced SIGH-am-BAN-ess), chief investigator for the study, published recently in the Journal of Pediatric Orthopedics.
"This is truly alarming," said Siambanes, a physician and partner in the spine center, in Riverside. "Research has shown that adults with severe back problems often had pain as kids. You can suffer all your life from this kind of injury."
The UCR study focused on 3,498 middle school students in Riverside and San Bernardino counties. Also on the research team were UC Riverside sociologists Jason W. Martinez and emeritus Professor Edgar W. Butler and spine center founder Thomas Haider (pronounced HY-der), a UCR donor who also is an assistant clinical professor in the university's biomedical sciences program. Haider concluded that rolling backpacks might be one possible way to deal with the substantial weight of school textbooks, since students don't really have a choice about whether to carry them or not.
Funding for the research came from the Children's Spine Foundation, Siambanes said.
Studying local 11- through 15-year-olds and their backpack habits, the team found that the main predictor of pain was how much a backpack weighed compared with the student carrying it. Long-term effects have not been assessed, Siambanes said, but the team plans to follow up on its research to learn more. Plans for doing a study took shape as the number of young patients at the spine center increased, he said.
"We got calls from families," he said. "Kids were complaining about pain, about their backpacks. Kids complain all the time and nobody pays much attention, but this seemed like too much of the same thing. We decided to get a real study, and not just blow the kids off."
The team weighed the students and their backpacks and asked the students how they used their packs and how much pain they had, if any. Sixty-four percent of the students surveyed by the UCR team reported pain, and 21 percent reported pain that lasted more than six months.
The team found an increase in reports of pain as the weight of backpacks rose compared with their owners' body weights. The increase was so gradual that the team was unable to specify a "safe" relative backpack weight for protecting students. It found that a student whose backpack weighed five percent of what he or she weighed was much less likely to report back pain than a student whose pack weighed 20 percent of what he or she weighed.
One concern researchers cited is that most schools have removed lockers because of vandalism and concerns about safety, so many students carry a whole day's worth of books and supplies at all times.
Four middle schools were included in the study. At two, a majority of students came from lower-income families, based on the percentage of students participating in a free lunch program. Two of the schools made some use of extra sets of textbooks -- one for the classroom and one for students' use at home -- so students did not have to carry all their books home. None of the schools had lockers for book storage.
The researchers calculated the relative weights of the students' packs as a percentage of their body weights. They also assessed the influence of how the students carried their packs -- in the hands, over one shoulder or over both shoulders -- and for how long they carried the packs.
More than 64 percent of the middle school students surveyed reported pain, and more than 41 percent said they felt pain while carrying their packs. Almost all said they were relieved when they could take their packs off. Of those with pain, more than 12 percent called it "not bad," more than 75 percent called it "bad" and more than 12 percent called it "very bad."
The backpacks weighed from half a pound to 37 pounds, with a mean average weight of 10.6 pounds. The ratio of backpack weight to student weight, expressed as a percentage, ranged from less than 1 percent to 43 percent. Over forty percent of the students walked to and from school carrying their packs. The team found a significant link between that and pain. How the students carried their packs did not seem significant, the team concluded.
Some Tips to Lighten the Load
These are general guidelines for school backpacks, gleaned from a variety of sources:
- Encourage use of rolling backpacks.
- Don't just choose a color -- try the backpack on your child. The backpack should end above the waist. Choose one with padded shoulder straps and a belt to distribute the weight evenly.
- Wear the backpack on both shoulders, not slung over one.
- Pull the shoulder straps snug, so the weight is on the upper back, not hanging down.
- Load the heaviest books closest to the back.
- Lift the backpack from the ground by bending at the knees, not at the waist.
- Encourage school officials to provide classroom sets of textbooks so students can keep their copies at home.
- Keep the backpack cleaned out so your child carries only the books needed for the day. Store old assignments at home. Leave home extras such as video games and inline skates.
- Provide a ride to and from school as much as possible.
- Try to keep the weight of the loaded backpack less than 15 percent of your child's body weight.