More than 80 percent of children are carrying school bags that weigh nearly a fifth of their body weight, putting more pressure on their backs, a new study conducted by charity organization BackCare reveals.
Studies show that carrying any more than a tenth of your body weight can cause spinal damage. Experts warn we are facing an epidemic of back problems in young adults when the long-term effects of this early damage starts to appear.
"We are seeing increasing numbers of young adults coming for treatment in relation to back trouble and this can often be traced back to carrying heavy bags to school," warns Peter Skew, an Essex-based expert in musculoskeletal medicine, the Daily Mail reports.
Skew, vice-president of BackCare, adds: "Children's skeletons are still developing, and having a heavy bag slung over one shoulder can exert unnatural force on the spine, muscles and attachments.
"Rather like exercising only one side of your body in the gym, you quickly get unilateral muscle-loading, which can cause the small muscles in the back to tighten and compress the spine," adds Skew.
A 2007 British study showed that 13 to 50 percent of 11-17 year olds have experienced back pain. And it's been shown that if you experience back pain as a child, you are four times more likely to have to endure back pain as an adult.
"Picking up and swinging a heavy backpack onto your shoulder multiple times a day is potentially more damaging to a growing body than having to walk a long distance with a static load," says Skew.
It's not just getting to and from school that's the problem, because most schools no longer provide lockers or desks to store books (children sit at tables), so children have no choice but to carry everything around with them all day.
Skew says young people are made even more vulnerable to back problems by their increasing inactivity - muscles don't develop properly if you spend your time playing computer games instead of running around. This is compounded by poor posture and one-size-fits-all furniture.
The weight of the bag is not the only factor to consider: the type of bag your child is carrying can contribute to pain and strain.
The ideal school bag, according to Lorna Taylor, paediatric physiotherapist, is a not-too-large backpack with wide, padded straps to spread the load, and a waist belt. Heaviest items should be closest to the spine, which is the centre of gravity, to reduce the strain.