Heavy, Poorly Positioned Backpacks Hard on Kids

NEW YORK (Reuters Health) - The average backpack load of a typical U.S. middle-schooler is too heavy and should be reduced for comfort and safety, a University of California, San Diego School of Medicine-based team concludes in a report released today.

The researchers warn that excessive pressure on the shoulder from weighty backpacks may lead to shoulder pain, and an uneven backpack load may lead to low back pain.

Brandon Macias, a principal investigator for the study, told Reuters Health: "Based on this study and recent unpublished data, we have four recommendations -- backpacks should be positioned high on the back, backpack straps should be over both shoulders, weight in the backpacks should be minimized, and backpacks should have wide straps."

The Consumer Product Safety Commission estimates that nearly 7,500 school children are seen in emergency rooms each year due to injuries related to backpacks or book bags, the team reports in the Archives of Pediatrics and Adolescent Medicine.

With the help of ten 13-year-old students (five girls and five boys), Macias and his colleagues looked at backpack weight and how it is distributed with regard to shoulder and back pain. They fitted each child's backpack with pressure sensors on the shoulder straps. The children wore standard identical backpacks first carrying 10 percent of their body weight, then 20 percent and finally 30 percent of their body weight.

The researchers noted an increase in pain levels with an increase in backpack weight. Specifically, pressures exerted on the shoulder at backpack loads of 20 percent body weight were enough to reduce normal skin and muscle blood flow in that area. Children commonly carry backpack loads equal to 22 percent of their body weight.

"The concern of heavy backpacks and back and shoulder pain to parents is not new," co-principal investigator Gita Murthy said in a university statement. "However, the objective data that we have published is new and important. The more objective data that the public has, the more educated they become, and perhaps the more inclined to change the way children carry backpacks."

The researchers also hope that their findings will encourage backpack designers and engineers to build better backpacks with wider straps to help spread the load.

SOURCE: Archives of Pediatrics and Adolescent Medicine, December 2005.