strange sounding tricks / wrist concerns

hi. this is the first time I’ve ever mailed anything to mass numbers of people,
so bear with me if I sound idiotic.

I’ve been sort of having trouble visualizing the “hop standing on wheel 5 times”
trick for level 5. What exactly am I supposed to do here? Put my feet on the
wheel as if I’m about to walk the wheel and then somehow hop up and down? Stand
on top of the wheel and hold on to the seat? Or what? However it’s supposed to
be done, to me this trick sounds about ten zillion times more difficult than
just walking the wheel (a level six trick). So what’s the deal?

Another question – as a somewhat frequent computer user, I’ve become a bit
worried about messing up my wrists. I’ve noticed that when I have to hold onto
the seat to jump a lot, or (attempt to:) do stairs, they start to hurt. Does
anyone know of anyway to minimize this effect, or should I abandon my efforts at
hopping curbs and doing stairs (both very useful skills) ?