PLAY equipment designed by "safety nazis" doesn't allow children to learn from risk-taking, an expert has warned.

More kids aged two to seven were getting injured in playgrounds because they didn't know how to take calculated risks.

A speaker at the Early Childhood Education Conference in Melbourne this week, early childhood specialist Prue Walsh said modern "plastic fantastic" playgrounds were too safe.

"Often playgrounds are designed by engineers who have no knowledge of children," she said.

"Children need to actively explore and discover the world around them and to do that they need to learn to take calculated risks," she said.

Playground injuries were often a result of children being poorly co-ordinated because they did not know how to negotiate risks, Ms Walsh said.

"I worry about children who don't run up slippery slides," she said.

Ms Walsh said commercial pressures, such as insurance premiums, had influenced the design of today's playgrounds.

"Parents are scared of their precious children getting injured and teachers are scared of getting sued," she said.

To improve playgrounds, Ms Walsh suggested longer and bigger slides built into embankments to eliminate falls.

Also, smooth boulders for balancing, shallow ponds for exploring and plenty of vegetation to provide nooks and crannies for children to crawl around.