 A running shoe, a person, as they're swinging and they make that rotation on the back swing and follow through, it's really easy for the weight to kind of, I guess you could say, move from the balls of your feet to the outside of your ankles. It's a very unstable base. Now, with that being said, golf shoes are fine. Tennis shoes are fine, like I said, as long as it has a nice wide base to maintain that balance.