More than a fifth of parents believe their child has been hurt carrying their school bag, a survey has found.
The National Parents Council Primary said 22% of mothers and fathers reported that one of their children experienced injury or pain because of the weight of books on their back.
The research also found that more than half of children get a lift to school and 38% of parents are extremely concerned about the weight of their child's school bag.
The findings were revealed at the Oireachtas Committee on Children and Youth Affairs as it examined options on how to limit the amount of books children are being asked to carry to and from schools.
Aine Lynch, chief executive of the National Parents Council Primary, said 3,009 parents gave their input on the issue over four days when they were notified of the committee's work.
"It's very hard to look at weight without looking at other issues as well. It's been mentioned a few times already around the homework issue," she said.
"We are clearly stating that we are looking for a review of how much text books are needed and relied on. That's it. If we muddy the waters with weights or costs or what homework should look like, around this particular issue, we keep missing the point."
Ms Lynch said primary education should be experiential and group-learning.
"Certain text books may be needed at a primary level. The question is do we need as many as we have," she said.
In some European countries and in the US, Australia and New Zealand guidelines were introduced to limit the size of a school bag to 10% of a child's weight, the committee heard.
Dr Sara Dockrell, chartered physiotherapist and assistant professor at Trinity College, told the hearing that there is evidence both for and against the regulation.
"It is a very difficult one to call," she said.
"That's why most of the recent research, including our own, would emphasise that the school bag weight limit isn't what we should hang our hats on here.
"We should really look at it in the context of all sorts of other issues."
Dr Dockrell also told the committee that having a similar weight ratio guideline in Ireland would be inappropriate due to rising levels of childhood obesity.
"I'm not suggesting for a minute that we should expect children to carry excessively heavy loads.
" Carrying a weight on your back is not necessarily a problem," she said.
Committee chairman Jim Daly also questioned if schools were taking initiatives to deal with the issue.
"That thing you see every time you walk on a plane, where you have to put your bag in - if there was one of those in every school with a weighing scales," he said.
"It just creates awareness."