Michael Jackson's anti-gravity illusion shoes - GIF and patent

[old kodger]

I'm interested to note that the patent date is 1993, and as such I don't quite see how he could get a patent for it because in 1982 or thereabouts I was the fabricator for The Sydney Theater Company and we were putting on a production of Chicago wherein one of the dancers had to lean forward towards the audience, I fitted his shoes with keyhole plates in the heals that located with coach type bolts in the floor. A little more difficult to locate, but the same idea.