Or at least why they might have been called that when I was a kid and would go zipping through the house. Several times they "threw" me. One time in particular I remember when I went down hit my head on the furnace register and the rug got its blood revenge. :-)  Right after mom waxed the floors and put them down were the most dangerous times.

Fortunately these days I don't move so fast so not so much of a problem.