Jackson and the other dancers perform an "anti-gravity lean" that appears physically impossible. The dancers lean forward 45 degrees with their backs straight and feet flat on the floor, and hold the pose before returning upright. The lean moves the body's center of mass further than it can support. The illusion was achieved using cables and a harness. In October 1993, Jackson's team patented a method of performing the lean in concert using specially designed shoes that hook into pegs that rise from the stage. Even with the shoes, the move requires good athletic core strength.