School is back in session and students are already packing on the pounds...on their backs.
"Many of the backpacks are loaded with books that weigh 15 to 20 pounds and if you're talking about a 50 pound child or a 70 pound child - that's a significant portion of their body weight," warned Dr. John Nobel of the Center for Orthopedics.
Dr. Noble says the weight of a backpack should not be more than 10 percent of the child's body weight.
"You don't want the backpack to be so heavy that the child has a forward posture," said Dr. Noble, "because that tends to cause a lot of strain in the muscles that help support the spine."
The Consumer Product Safety Commission reports more than 7,300 injuries were treated in U.S emergency rooms in 2006 because of backpacks, particularly in areas of the spine.
"This is the vulnerable area in children," said Noble, "it is a thin bone and fairly week in children, so it tends to be the weak link in the back."
Dr. Noble says strained muscles because of heavy backpacks combined with a child that is active in sports can make for a dangerous injury.
"What we're worried about in children is a area of the spine that is prone to stress fractures," he explained.
To lighten the load and prevent injuries, rolling backpacks are a great option, but check your student's school handbook to find out if they are allowed.
If you're sticking to a traditional backpack, distribute the weight more evenly by using both shoulder straps.
How you pack your bag can make a big difference.
Pack the heavier books closest to your back and even carry one or two heavy books in your arms.