Definitely practice in the mirror before you attempt it. You have to use your body in the upright position, you can use your knees for support and that's the only way you can twerk.
I don't really like knees.
I am not crazy about my knees.
Inner-thigh strength is important, and not just for appearance sake. If you enjoy - or have always wanted to try - ice skating or roller blading, strong inner thighs will come in handy.
Real twerkers can use their knees for support.
I dislocated my patella on the court - that's what the pain was coming from - and I ruptured my patella tendon.
The human knee is complex and prone to failure in a variety of ways; there's a lot of muscle mass low down in the legs which makes moving them fairly inefficient.
The Moto Knee shows people what's possible. It's about guys getting back in action in a sport they love.