Yesterday's daypack has become, with some redesign and enhancement, the preferred schoolbag of today for preschoolers to varsity students.
It's the ideal and ergonomically sensible way to carry a pile of books and folders, PE gear and lunch.
But have you ever weighed your children's schoolbags? And then compared that figure with their body weight? You might be in for a shock when you find the weight they're carrying every school day. Throw in a laptop or sports gear and they could be carrying up to 15kg.
Professional opinion is that about 10 per cent of a youngster's body weight is the most that should be carried on a daily basis.
Then there's the way that they carry the load. On their back? Or in one hand or slung over one shoulder?
If not worn correctly on their back, the result can be bad posture, shoulder, neck and back pain, numbness in hands and arms and even permanent nerve damage.
Since youngsters' bones and connective tissues are still growing, the damage can be long-term, causing serious problems later in life.
And it seems it's a worldwide problem.
Italian researchers have found that lower back pain in children is fast approaching that seen in adults and that heavy schoolbags are the culprit.
In the United States the number of serious schoolbag-related injuries each year has led some states to impose an upper limit on the weight of textbooks.
An Irish politician has raised the problem with the European Commission, the Irish Health and Safety Authorities and book publishers.
A paper presented to the Indian Academy of Paediatrics discussed low back pain being a common problem in 34 per cent of students.
Closer to home, the Australian Chiropractors Association has cautioned that parents are sentencing their children to life-long health risks by selecting poorly designed schoolbags.
Specialists seem to agree that the best schoolbag is a backpack style with broad, padded, adjustable shoulder straps set so that at least 80 per cent of the weight sits squarely on the hips. It's one item you shouldn't buy with a view to your youngster growing into it.
It should be packed so that the centre of gravity is the same as the child's, with heavy gear packed close to the child's back. Any weight that pulls them backwards forces them to hunch forward or arch their back.
A padded back will help protect them from the sharp corners of heavy objects and an adjustable hip belt will keep the pack close to the body.
Most of all, the load shouldn't exceed 10-15 per cent of your child's body weight. Something to think about as the new school year gets under way.
© Ian Munro 2012. All rights reserved.