Wow, KML you are sharp! My H did have a concussion a few years ago from skating at the park even though he was wearing a helmet.
The worst part was that the reason he bailed out of the trick and fell was because our son (who was also skating) got in his way. He did the right thing, but I think still felt resentful about that situation.
me-35 WAS-37 T-16 1/2 Son-14 (HF Aspergers) BD,ILYBINILWY,"I met my soulmate": Oct5,2013 "Letting go because I love him, holding on because I love him."