Have u ever been on swing? Yea i bet u wre but never on this one ;) or similar one .. I had some strange fealing in my body while watching this so good luck u to :) and dont try this at home .....
They used to (30 years ago) have a similar thing at carnivals except as riders you stood in a pivoting cage so you never inverted but you could make it swing and get it to go over the top by "pumping", by shifting your body weight from side to side.