Sorry, but every now & then I feel the need to respond to someone's sig.
Mav: Back a few years ago, I saw one of those sports page photos that really sez it all. It was of one of our beloved Syracuse (basketball) Orangemen - current National Champs, btw, thank you very much... - jamming home a game winning dunk at the end of the game.
The photo was one of those dunks where the guy, after jamming home the ball, was in a position where his legs were drawn up towards his torso such that both the hips and knees were bent at a 90 degree angle. In short, his lower body looked as if he were sitting down.
I remarked on this photo to one of my colleagues, and he christened it the "dumpster dunk", explaining that the player looked as if he were sitting on the can, experiencing one of these dumps that you spoke of.
Interesting...