rotation of body of crab drive robots

[michael_obrien]

I'm confused as to how a crab style robot rotates itself entirely (not just wheel modules), particularly coaxial ones in which all the wheel modules face the same angle and are powered by the same gearbox. I see on the wildstang video page that they have a little foot that comes down to pivot on, and I can see how that could work with a crab like the one i'm describing, but it seems like a large turning radius and the necessity of having to rotate the modules to a certain angle and put down a foot would kinda counteract the whole ultimate mobility thing that crab drives have going for them. But then I think wildstang won last year so it's got to work fairly well.
...
...
...
Basically what I'm asking is how crabs turn and how well it works.