I think he always did a lot of that on stage, but in 2006 he modified it a lot more as he couldn't run around as much. He was carrying an injury around his lower back from memory which he was getting treatment for on tour. So I guess he was just changing his style on stage a bit as he couldn't run around as much. I remember him saying something about the dancing and different dancing he was doing in an interview I heard.
yeah thats most likely the case. lets face it, he aint in his 20s anymore and years of smoking wont have helped either.