A system for allowing a shoe wearer to lean forwardly beyond his center of gravity by virtue of wearing a specially designed pair of shoes which will engage with a hitch member movably projectable through a stage surface. The shoes have a specially designed heel slot which can be detachably engaged with the hitch member by simply sliding the shoe wearer’s foot forward, thereby engaging with the hitch member.

In other words: a patent submitted by “inventor” Michael J. Jackson!

See also: origins of the moonwalk.

(via Adam Norwood)