Most of them are former martial artists and b-boys who eventually got more into powermoves and acrobatics. You can learn the basics by doing either of these (especially Taekwondo and mainly Caopeira).

dat good game slap at the end

go tricksession.com and learn basics, randoms

I'm not half as skilled as them. I have had so many injuries during my gymnastic career.

so humble

That's crazy. How anyone can do a double backflip without a trampoline is just beyond me, I can't even nearly do a single

1:09 is great btw