The concern is prompted in part by a new study that showed more then 60 percent of school-aged children said they had back pain caused by book bags that were too heavy.

Backpack expert Candy Diamond-Krupitsky said there are a slew of problems that you can get from carrying a backpack.

She said backpacks can be too heavy or not have enough strapping and that can cause shoulder pain radiating down into the arm, neck, which causes lower back problems and pain extending down to the hips, knees and ankles.

"You might not think toys and backpacks can cause so many problems," said Claudia Towles of aMuse Toys. "But they really do have an impact."

Experts said start early to get kids into good habits.

The first step is to choose the correct size bag. It should fall between the shoulders and lower back, and not extend any lower. The second step is to pack smart.

"You want to pack heavier things closer to your back and the lighter things further away. You don't want things to be able to move around inside the backpack, so pack it nice and tight.

Another suggestion was to make sure your child wears the backpack on two shoulders with the straps pulled tight and close to the back.

Diamond-Krupitsky also recommended that kids put the backpack down if they are waiting for the bus.

"It gives the back a break," she said.