Lol, my legs do the same thing though while dropping. So a small variation on it :D

An other variation would be to keep your feet in a 45° and then keep doing and landing on every stair edge

Never seen someone else doing that, it's insanely fast if you can master it :D

Did that in my childhood on wooden stairs in my parents house. Rounded edges, kid of hazardous in general but great to slide down like this. Kind of want to try this again, but I also value the integrity of my bones.

Stair surfing - I've still done it as a middle aged guy.

I would like to learn to do it hands free, one foot in front of the other (forward and down to the next step). I can surf a bit without grabbing the rails, but only rarely make it to the bottom. Definitely needs the perfect wooden stairs to get maximum flight time!

I only do it when i can place both of my hands for support and if my hands can slide on it.

It's not dangerous i think though, wooden stairs works best indeed :p