CLEVELAND -- Eighty percent of people are plagued with back pain.

Adults may think of it as the unfortunate process of aging, but new studies suggest that it could start in grade school.

In Connecting With Kids, NewsChannel5's Tonya Strong reported on what many believe is the main culprit.

Heavy school loads are weighing in on the backs of many children.

"My back feels like it just wants to lay down and rest," Kathryn, 12, said.

"We have a lot of kids, particularly high-schoolers or junior high-schoolers, who are going through fairly rapid growth phases (and) don't know a lot about back care and are carrying heavy backpacks," said Dr. Carla Neal-Haley, a pediatrician.

Pediatricians strongly discourage a child toting around more than 15 percent of his or her body weight or carrying a backpack on one shoulder. Doctors said that children with poor posture and improper back care are much more likely to feel the effects of a heavy backpack.

"It feels like it's cracked over, like bent," one child said.

"It feels like I have, like, broken bones in my back," said another.

Sitting up straight, holding the shoulders back and keeping fit will naturally strengthen the muscles along the back.

A straight, strong and resilient back will take a less painful curve for the worse when faced with carrying heavy loads for extended periods of time.

Doctors said that taking care of a child's back in the early years could be an insurance policy for the future.

According to doctors, the key is keeping your body physically fit. By doing so, a person keeps the muscles and ligaments in tone, which will hold the spine into its natural curvature.

Check out NewsNet5's Connecting With Kids page for more information and helpful tips.