Students are hitting the books now that school is back in session. But lugging around hefty backpacks can bring on back pain.

From books and notebooks to pencils and other school supplies, it all gets toted around in a backpack.

But all that stuff can really add up in weight, says Dr. David Marshall, Medical Director of Sports Medicine at Children's Healthcare.

The weight of the backpack should never be lower than the waist line so the straps should be adjusted so that the backpack fits high up on the shoulders. The shoulder straps need to be two of them not just one and also they need to be wide and padded.

Experts recommend these bags not weigh more than about ten percent of the student's body weight. Also following these guidelines will help prevent the child from falling.