More than 400 Whanganui students and 20 teachers report being injured on school grounds every year - costing our accident compensation scheme hundreds of thousands of dollars.
The head of a principals' group believes some claims may be from over-protective and anxious parents.
More than 2000 ACC claims were made by students for accidents that took place on school grounds or in school buildings between 2010 and 2014, according to ACC figures.
The number and total cost of claims was highest in 2011, at 691 claims for $206,315.
Meanwhile, more than 100 claims were made by teachers over the five year period. The number of claims was highest in 2011 and 2012, at 32 claims a year, while total cost of claims was highest in 2011, at $29,856.
Fractures, dislocations and soft tissue injuries were behind most claims.
Upokongaro School principal Warren Brown said skinned knees and bruises occurred on a regular basis but there had not been any children seriously injured at his school.
"Sports fields and playgrounds are busy places but there certainly hasn't been anything in the way of broken bones," he said. "We don't wrap the kids in cotton wool.
"We allow them to climb trees, swing on ropes and engage in a lot of imaginative play. Being active is an important part of the kids' development. You can't expect them to sit through a 45 minute class and not allow them to then burn some energy."
The school did several things to encourage active play, he said. "We brought bikes in because there was some kids that didn't know how to ride. Sure they had skinned knees but that's just a part of it.
"I'm even thinking about building a BMX track in the paddock over the back."
As in any workplace, the occasional accident by staff was inevitable, he said. "We try to minimise safety risks for staff as we do for the kids. They use ladders to staple things to the wall, rather than standing on a desk or chair, but the odd mishap can occur."
Nationally, 361,450 ACC claims were made by students in the past five years. The claims cost ACC more than $100 million.
The number of claims increased each year to 79,622 in 2014. The total cost of claims was higher in 2013, at $19.4 million.
The national figures for teacher claims were not available.
New Zealand Principals' Federation president Denise Torrey was surprised the number of claims had increased.
"Are our kids being nice and active like we want them to be, are we covering our kids in too much cotton wool or is it just that we're getting better at reporting these things?
"I certainly don't think our school grounds are becoming more dangerous but we're definitely becoming more protective of our kids and that could be reflected in those figures."
Standards of playground safety had improved greatly, she said. "There's certainly more of a culture around protecting kids. What we might have hobbled home on and put ice on when I was a kid is now becoming something major that turns up in the doctor's office - perhaps it's that parents are more anxious or schools are more anxious."
ACC spokeswoman Stephanie Melville said the figures were not specific to school hours or terms, and could include people using school grounds for weekend sport or other activities.
More than one injury could occur in one accident and only the primary injury was used in the data.
Students included five to 17-year-olds in primary or secondary education. Teachers included primary, secondary and special school educators.