i was wondering how michael jackson did a certain dance move?

He was wearing special shoes.

The secret is revealed in WIKIPEDIA!

For "Smooth Criminal", Jackson experimented with an innovative "anti-gravity lean" in his performances

''The effect in the video when Jackson and the dancers lean forward a seemingly impossible distance was achieved using special harnesses with wires and magnets. It was desired to replicate this effect for Jackson's stage show, but it would have been more obvious and cumbersome to use wire harnesses in a live performance. Jackson and his team devised an alternative way to achieve the effect on stage. The props needed for their technique were patented in the United States by Jackson in 1993,[7] and consist of pegs that rise from the stage at the appropriate moment, and special shoes with ankle supports and cutouts in the heels which can slide over the pegs and be thereby attached to the stage temporarily. These allow the performers to lean without needing to keep their centers of gravity directly over their feet. According to Patent Storm, the patent expires on June 29, 2012.''

One of my favorite songs of all time!

In the video of Smooth Criminal, wires are used allowing him to do the anti-gravity lean. But while performing live, pegs came out of the stage which clipped into custom made shoes Jackson was wearing.

Details here: http://dvice.com/archives/2009/06/michael-jackson-...

He was wearing custom made shoes, and to make sure the illusion would work, the attached some wires that would not be seen because of the dark stage backround.

it's called the anti gravity lean he has a patent for it its actually a shoe that he mad for it

http://en.wikipedia.org/wiki/Smooth_Criminal#Anti-...

hope i helped! =]