There are actually two actors.  The first is a man with no legs.  He is placed on top of a man who is a contortionist.

The presence of the small/little person in the act is a clue: there's a small person inside the torso with his legs folded up in front of him. The hands are not real; they're "hand-stilts" being held by the small person. This is to make up for a small person's shorter arms. The legs by themselves are not real legs. They're padded stilts that the small person shoves his legs into when lying down. When one of the legs moves early on in the trick, it's just by string or whatever commons means a magician would use for a trick like that. We've all seen those. That's my take on it.

Could be that the subject was a double amputee... the "legs" they attached could have been a prosthesis... notice the magician never showed us that it WASN'T a prosthesis - another explanation?  he could have been a stunt man who can bind up his legs... again, we were not shown any details in order to judge.  The subject was in full costume and nothing showing... for all we know could have been that lady we have seen on Discovery channel in the show, "Half a woman"

I just did a search on a possible explanation and the term "hemicorporectomy" popped up; it seems that there actually is only a half man there, but how does that explain the legs?  Bionic?  A person without a top half?  A mutant who can divide himself?

This is a really interesting, well-performed illusion.  The show would be even better if they did not have the unintelligent "sexy, bimbo nurse" routine. It's an insult to **real** nurses--well-educated professionals of both genders who do not need to be "sexy" to do their jobs of saving lives well.