There's been a study in America showing that ''352,698 children under the age of six were injured on slides in the US between 2002 and 2015''.
Apparently the most common injury is the lower leg being fractured and the most common cause is children going down the slide on an adult's lap.
(I found this in a local paper then searched for the story in the big paper so people wouldn't know my local area)
www.independent.co.uk/life-style/health-and-families/children-slides-parents-laps-increase-ride-risk-injury-study-playgrounds-areas-a7947941.html
I just thought it was an interesting read, something people don't tend to think about.