Sand is softer than wood

Another study done by scientists who apparently have never been children, or don't have any:

Children who fall off playground equipment and land on sand may be less likely to break an arm than if they land on wood chips, Canadian researchers say...

...How badly a child is hurt depends not only on how far they fall, but also the type of surface they land on, researchers at the Hospital for Sick Children in Toronto found after some school playgrounds in the city were resurfaced.