That's Annasophia Robb as Violet Beauregarde in the Johnny Depp version of Willy Wonka...after she turned into a blueberry and got squeezed, she was really skinny and agile and kept doing those freaky looking back somersaults...LOL
I did that once, but it was before all these video camera's and such, and never mind that I was falling down a hill after falling off a bike. My friends said I looked like a gymnast so I had that going for me which was nice ;)
I have a friend who is way more of a weeaboo than I will ever be, he the reason I got into anime, plus I like the Pokémon anime as a kid and still watch it today.