More information about text formats
I read the article by Professor Sibert et al. I believe that all
information regarding the prevention of injury is important, it is also
important to understand the validity of the Standards that are in place.
I believe having realistic Standards would not only continue to reduce the
incidence of head injuries, they would also significantly reduce the
injuries you have studied.
There are 3 “heights” in the description of a protective surface.
The first is the critical height, which is the height at which a surface
exceeds that pass/fail of the standard. The second is the fall height of
the play structure, which is defined in each standard for each piece or
type of equipment. Interestingly the fall height for play structures with
guardrails and protective barriers is the platform. The third is the
drop height, which is the distance from the underside of the headform
containing the accelerometer and the surface being tested.
The requirement of standards for playgrounds is that the protective
surface critical height must be equal to or greater than the fall heights
for the play structures. This should be of concern for the prevention of
injury since the tops of barriers and guardrails from which children fall
are a minimum of 38” (approx 1 meter) above the point at which the pass
Your article indicates that pass/fail of 200 Gmax or 1000 HIC may not
be low enough to prevent head injuries and the types of injuries that are
now occurring and being studied. The lowering of Gmax and HIC and
maintaining the lower values over the life of the playground are
We would suggest that your recommendation for lower Gmax and HIC
values should be coupled with the realistic fall heights of tops of
guardrails and barriers.
Attached you will find some articles that might be of assistance in
your understanding of the concerns we have raised.
I look forward to your reply.
Canadian Playground Advisory Inc.,
Per: Rolf Huber,
articles that were to be attached can be found at
The articles at this location may be reprinted provided premisison is
(1) C Norton, J Nixon, and J R Sibert. Playground injuries to children. Arch. Dis. Child. 2004; 89: 103-108