Grandmaster Wong explains the importance of waist rotation

First people fought haphazardly. Then those who fought frequently devised favorable ways of fighting, which over the centuries crystallized into patterns. Patterns are linked together in some meaningful ways to form sequences. Our first four sequences which we use, amongst other things, to train combat skills are "Black Tiger Steals Heart", "Poisonous Snake Shoots Venom", "Precious Duck Swims through Lotus" and "Hang a Golden Star at a Corner".