Could you guess the trick?

http://www.youtube.com/watch_popup?v=6HfDeTVpinU&vq=medium

Just a detail or maybe a hint: when they sit they do it very carefully.

 

What the heck are they just dancing around and playing music for when it looks like there is some weird space version of a Dalek on the screen just spinning around looking like its getting ready to attack?

 

At 1.01 they anchor their left foot on the floor. Must be some kind of armor or bendable structure around/behind their left leg, something strong enough to sit on.

 

Yeah, looks like they hook into the floor or something, they are all looking down to make sure the foot is aligned correctly, then rotate the heel....

 

There being supported by some sort of mechanical locking mechanism that allows them to sit by moving a certain way, and get up and stand by moving a certain way. They do it slowly so they don't mess up.