Kids are almost back to school, but if you're doing some last minute shopping -- you might want to keep this in mind: It's important you pick the right backpack.

Experts say the first concern should be your kid's back.

"Children can end up having neck pain and lower back pain," said Sharon McRae, an occupational therapist for Doctor's Hospital.

She says that's easy to avoid -- first of all by finding the right fit.

"It sits snug on his shoulders, resting one to two inches below shoulders and 4 inches below his natural waistline," she demonstrated.

"It feels nice," said Justin Smith, trying the bag on.

Another important consideration: buy the right bag.

Messenger bags might be in style -- but McRae says they are not a good idea.

"Messenger bags don't evenly distribute weight," she said.
"I don't know if I'd want to carry it around, it's heavier," Smith said.

Finally, make sure you load the bag right -- and make sure your kid puts it on right.

"Ensure your heavier books are closer to the child's back," McRae said. "Squat and pull the bookbag up, then put it on your shoulders."

There is another option: McRae is a big fan of rolling bags -- to take the weight off your kids back . . but she says the best thing to do is talk to your child.

"Parents don't realize how heavy a bag is until they start seeing red marks on the shoulders or a change in posture," she said.

When it comes to rolling bags -- not all schools allow them, so be sure to check your school's policy.

McRae also recommends you look for a bag with hip and chest straps -- that helps take even more weight off your child's shoulders.