Stop the car: an expert says kids should be carrying those heavy backpacks to school.

For years we’ve been hearing how bad it is for kids to carry heavy backpacks to school.

We’ve worried that they could be doing permanent damage to their backs. Some parents have even taken to driving their kids to school to prevent them walking with that heavy weight across their shoulders.

But now, an expert is suggesting maybe we’ve got it wrong. In fact, she’s saying kids should be encouraged to walk to school carrying their backpacks, even if they are heavy.

Assistant Professor Sara Dockrell has carried out an extensive study into the impact of children carrying schoolbags in Ireland. She says the research linking schoolbags to back pain is inconsistent. But there's pretty clear evidence that not doing enough exercise leads to obesity.

“Walking to and from school while carrying a schoolbag could count as moderate activity and therefore it should be encouraged, and not discouraged,” Dr Dockrell says.

“Not carrying a schoolbag could be seen to be a barrier to physical activity and may deny children the benefits of daily resistance exercise as they travel to and from school.”

For years, the rule of thumb has been that children shouldn't carry more than 10 per cent of their body weight on their backs. But according to Dr Dockrell, there's plenty of research suggesting it's okay to carry more than that.

Listen: This Glorious Mess discusses everything about the return to school. (Post continues after audio.)

“I’m not suggesting for a minute that we should expect children to carry excessively heavy loads,” she says, “but carrying a weight on your back is not necessarily a problem.”

She says the latest research doesn't prove a link between heavy bags and back pain in adolescents, only an association. Back pain can also be caused by habits such as slumping in front of the TV.

Meanwhile, an Australian expert backs up a lot of what Dr Dockrell is saying.

Julianne Pegler, the chair of the Australian Physiotherapy Association's paediatric group, says walking to and from school while carrying a schoolbag should be encouraged.

Overly enthusiastic kids with backpacks. Photo via iStock.

"Parents think they're doing their kids a favour by saying, 'You can't walk to school because of the heavy backpack,'" Pegler tells Mamamia. "There's been a decrease in the number of kids actively commuting to school in the last 20 years."

But she thinks parents still need to be careful that their kids aren't carrying too much.

"With a young primary school child who might weigh 20 kilos, how much do you want them to be carrying? Half of their body weight? No. Whereas a secondary school child, whose weight may vary from 50 to 70 kilos, maybe they could carry 10 kilos."

Pegler says students should try to minimise the weight in their backpacks. They should also make sure they're carrying the backpack properly - over both shoulders - and that it's properly fitted.

Wrong, wrong, wrong. These teens are carrying their backpacks on only one shoulder. Photo via iStock.

The straps should be the right tension, the waist strap should be used, and if there are little straps to adjust the depth of the backpack, they should also be tightened.

"The load should be carried close to the back," she says.

Pegler says if kids have back pain, parents shouldn't jump to the conclusion that it's due to their heavy backpacks.

"You can't just say there's one cause for someone's back pain."