Michael Jackson shocked his fans with an endless stream of seemingly impossible dance moves.

And now the secret behind his iconic 45-degree lean in Smooth Criminal has finally been revealed.

The pop legend can be seen leaning slowly forward in the music video, and while he is thought to have used wires for the clip, the star wanted to recreate the gravity-defying feat live on stage too.

And that's when his audience was left truly baffled, as he managed to lean to the huge angle without a wire in sight.

According to reports, Michael and his team created a one-off shoe with an extending slot at the bottom of the heel.

The slots could then extend at any given time and connect to a peg in the stage, keeping the shoe secure as Michael leaned forwards - supporting his own body as he did it.

(Image: http://patft.uspto.gov/)

These shoes were patented in 1992 under the names of Michael Jackson and Dennis Tompkins.

While the shoes almost always worked perfectly, there was one slip in September 1996 when, during a concert in Moscow, one of the heels came loose from its peg.

(Image: http://patft.uspto.gov/)

Michael went flying, but luckily managed to avoid serious injury - and the design was reportedly later reworked to avoid it happening again.

That shoe is now in the Moscow branch of the Hard Rock Cafe, after being auctioned off following Jackson's death for $600,000.