Gravity-defying 45 degree forward tilt during his “Smooth Criminal” performance was a clever illusion invented by the pop star, scientists have revealed.  

The "mind-boggling" dance move was first seen in the 1987 video for the song, but he also repeated the feat live. 

Several fans tried to copy the move but none have managed to emulate the entertainer's dance move. 

Led by long-time Jackson fan Nishant Yagnick, a team of three neurosurgeons set out to establish exactly how he achieved it.  

They found that most trained dancers can achieve no more than 25 to 30 degrees of forward tilt 

During the move, strain is shifted from the erector spinae muscles that support the spinal column to the Achilles tendon, they wrote in the trio from Postgraduate Institute of Medical Education and Research in India wrote in the Journal of Neurosurgery: Spine.

 "This allows for a very limited degree of forward bending from the ankle joints, while keeping a stiff straight posture - unless you are Michael Jackson," they wrote. "MJ pulled off a gravity-defying 45 degree move that seems unearthly to any witness."

So how did Jackson do it? Well now a patent registered under Jackson's name reveals how the trick was achieved.

The pop legend designed a special shoe with a triangular slot in the heel which hooked onto a metallic peg that emerged from the stage floor at just the right moment.

This allowed Jackson to lean forward at a seemingly impossible angle without collapsing in a heap.

The authors stressed that despite the illusion, Jackson's physical abilities were nonetheless impressive.

"Even with specially designed footwear and the support of the hitch member, the move is incredibly hard to pull off, requiring athletic core strength from strengthened spinal muscles and lower-limb anti-gravity muscles," they wrote. 

"Trick or not, new forms of dancing inspired by MJ have begun to challenge our understanding of the modes and mechanisms of spinal injury. Ever since MJ entertained us with his fabulous moves, throughout the world dancers have tried to jump higher, stretch farther, and turn faster than ever before."

Agencies contributed to this report