I am sitting outside enjoying the day. As I am sitting there my foot begins to shake back and fourth making the bottom of my shoe slap against the bottom of my foot. Making a very loud slapping noise. The sound becomes relaxing to me and I continue to do it. I switch legs and do it with the other foot also. I slap the shoes back and fourth on my feet very fast and then slow. I like the way it feels hitting the bottom of my foot.