Slavic Cossack dancing known as Hopak
Warning: Do not try this at home unless you were born with super Slavic knee strength
THE GUY AT THE END
Ahahah it’s not just knee strength you need, friend. It’s thighs, ass, ankles, calves, you need everything from your waist down to be horrifyingly fit and toned for this.
Also core strength. So include the waist. Everything from the nipples down.
Don’t forget absurd back flexibility