Dazaifoo, that's excellent you posted that. I've been using a slinky as a tool, especially in the areas of footwork and stepping. The slinky perfectly demonstrates the physics of the single arch contained in the feet and legs. On the body, it's most easily demonstrated in shiko-dachi - aka "horse stance"
Notice in those pictures of people in a horse stance, and how those postures "tunes" the entire skin on the body - as a single piece of skin, as on a drum. I outline some of this in the Talking Drum topic I started here. http://www.aikiweb.com/forums/showthread.php?t=22306
And watch this slinky video. https://www.youtube.com/watch?v=EZL6RGkPjws
Notice how the "steps" are not taken by actually putting weight in the front, but rather by "releasing" the back. It's the same in Kyudo (Zen archery). The arrow is "released" or "loosed." Same with a gun. The hammer, which is already back, is released.
But crucially important, before we attempt any kind of movement, is to get the drum "skin" tuned up. This applies the correct "tension" - which creates the structure. The skin of the body - acting as a single piece of skin - when it's tuned - creates the structure in internal arts.
And that spiraling structure is the same as a Slinky. And we can understand that the physics of the movement of the Slinky is also contained in the structure.