Going back to school can be a pain in the neck -- and back.
That's why choosing the right backpack is so important, says Dr. Daniel Hedequist , an orthopedic surgeon at Children's Hospital in Boston.
Hedequist, who runs a spine clinic, advises parents to make sure kids' packs not only fit right but also are not too heavy. When kids complain of back pain, he says, overloaded packs are often the culprit.
``They'll start pulling out all sorts of things, textbooks, iPod, snack, gym clothes, magazines," he says. ``It's an endless amount of stuff."
More than 40 million children carry backpacks, but more than half of them may be carrying too much weight, according to American Occupational Therapy Association.
The professional group sponsors ``Pack it Light, Wear it Right" National School Backpack Awareness Day on Sept. 20, in which volunteer schools hold ``weigh-ins" to ensure students are not carrying too much.
A backpack should never weigh more than 15 percent of a child's body weight, the group says. That means, for example, that a 100-pound child shouldn't have a pack that weighs more than 15 pounds. But it's not unusual to see young teens lugging ones that weigh 30 to 40 pounds, says Hedequist.
Children carrying overloaded or improperly worn backpacks can experience neck, shoulder, and back pain, as well as poor posture, but Hedequist says no research shows that such packs will cause spine deformities or other permanent back injuries. ``I don't think there are any long-term risks," he says.
When buying a backpack, Hedequist says, look for one with double well-padded shoulder straps and a waist belt. A bigger challenge will be getting your child to wear it that way.
Most kids still think it's cooler to carry their backpacks jauntily on one shoulder -- even if it's bad for your back.
Hedequist thinks two-strap packs are healthier than one-strap messenger bags, but if your teenager insists one of those, make sure it is worn correctly with the strap tightly over the shoulder and the bag on the side.
Fit is also important. Make sure the pack isn't too big for your child's body. It shouldn't fall any lower than 4 inches below the waistline. In addition, make sure the pack isn't too big for your child's locker.
Hedequist says you don't have to spend a lot of money to get a good backpack. L.L. Bean and Land's End sell backpacks in catalogs and online. A basic pack costs around $30, while a rolling pack is around $60.
Any store that sells children's items -- such as Gap, Children's Place, Toys `R' Us and Target, sells backpacks. At Target, for example, a basic pack costs under $20, while a Hello Kitty pack is $11.
``It's not so much where you buy it, it's the fit of the pack in relation to the torso," Hedequist says.
Hedequist, 37, has two young children and one on the way. His 3-year-old daughter already has a Strawberry Shortcake backpack for preschool and camp.
But he's not worried about its effect on her back, since the most she carries in it is her lunch, a swimsuit, and, of course, the occasional stuffed animal.