WTF.. I don't think its possible to move the single muscles of the abdomen like that (my GF is a dancer and she says the same).. Could it be its rather the other way around and he uses the electrodes to contract the muscles? Or maybe its just video fx...? Anyway, funny as heck xD
You and your GF are right. Terry is partially animated here (watch the clip again and look at his face, then you'll see).
There are some more videos on youtube where Terry does the weirdest thing with his "power"