Hollowback

There are many different variations of this move; it is basically a
bridge with your feet not touching the floor. It can be done from a
handstand, headstand, or on your elbows. Once your balanced vertically
with your feet straight up, you begin to arch your back and lower your
feet down as if you were doing a bridge, putting your chin to your chest
will help with balance. The more your back is arched the better it will
look.