If you're referring to Grant, Raven, etc. skating a vert ramp or a pool padless, they're not trying nollie 360 heels and shit, they're just grinding and doing airs ("just"), also, it looks like they run down the tranny easily, seems like an easy out most of the time. If you got bad knees and can't run out of tricks down the wall, then yeah, pad up and kneeslide.