Backpacks are the leading cause of back and shoulder pain for millions of children and adolescents each year, according to the American Chiropractic Association. And children are suffering from back pain much earlier than previous generations, the group says.

The American Academy of Orthopedic Surgeons also warns parents that bags that are too heavy or are worn incorrectly could injure a child’s bones, muscles and joints.

According to the U.S. Consumer Product Safety Commission, about 10,000 children ages 19 and under were treated at hospital emergency rooms, doctors’ offices and clinics for backpack-related injuries in 2005, the most recent year for which figures are available. Injuries caused by tripping and falling or getting hit by a backpack are common. A large number of these injuries, particularly chronic complaints such as those seen by orthopedic surgeons, include strains to the shoulder, neck and back from carrying a backpack.

“Injury can occur when a child who is trying to adapt to a heavy load uses faulty posture such as arching the back, bending forward or leaning to one side,” said James H. Beaty, M.D., first vice president of the AAOS, on the organization’s Web site.

“A backpack load that is too heavy also causes muscles and soft tissues to work harder, leaving the neck, shoulders and back more vulnerable to injury.”

Usually the backpack itself is not the problem. Children simply haven’t been shown proper methods of packing, lifting and carrying their backpacks.

Overloading seems to be the chief culprit in backpack-related injuries. The ACA says a child’s book bag should weigh no more than 10 percent of his or her body weight, and parents should aim for only 5 percent.

The way a child wears his backpack can also be detrimental to his physical well-being. The carry-all should never hang more than 4 inches below the waistline. Wearing it too low can cause a child to lean forward when walking.

Packing the child’s tote properly is important. Where you put the heavy stuff does make a difference. Doctors suggest placing heavy items in the big compartment close to the body, where the weight won’t cause as much of a shift to the center of the body mass. Remember to place pointed objects or those with sharp corners facing away from the back.

Another way to keep the load even on the body is to make sure the child uses both straps. This is one of the biggest mistakes children make, according to the ACA. Slinging the bag over one shoulder puts more strain on one side of the body, which leads to neck and low-back pain. If a parent notices a child using one strap constantly, the parent should consider purchasing a sling bag, designed to be carried across the body.

To address the growing trend of injuries in young children from backpacks, doctors of chiropractic have created Backpack Safety America/International, an eight-step prevention program to train parents, students and teachers in the correct way to use backpacks. Visit www.backpacksafe.com

ADVICE FOR PARENTS

The American Chiropractic Association offers the following checklist to help parents select the best possible backpack for their children:

– Is the backpack the correct size for your child? The backpack should never be wider or longer than your child’s torso, and the pack should not hang more than 4 inches below the waistline. A backpack that hangs too low increases the weight on the shoulders, causing your child to lean forward when walking.

– Does the backpack have two wide, padded shoulder straps? Non-padded straps are not only uncomfortable, but they can place unnecessary pressure on the neck and shoulder muscles.

– Does your child use both straps? Lugging a heavy backpack by one strap can cause a disproportionate shift of weight to one side, leading to neck and muscle spasms, lower-back pain and poor posture.

– Are the shoulder straps adjustable? The shoulder straps should be adjustable so the backpack can be fitted to your child’s body. The backpack should be evenly centered in the middle of your child’s back.

– Does the backpack have a padded back? A padded back not only provides increased comfort, but it also protects your child from being poked by sharp edges on school supplies (pencils, rulers, notebooks, etc.) inside the pack.

– Does the pack have several compartments? A backpack with individualized compartments helps position the contents most effectively. Make sure that pointed or bulky objects are packed away from the area that will rest on your child’s back, and try to place the heaviest items closest to the body.