Movement in batters box

Question
I was watching a women's college softball game recently, and noticed that a lot of lefty hitters trying to get a "running" start inside the batters box, before hitting the ball. Almost looks like a "Happy Gilmore" like swing. I'm sure the batter can't hit the ball outside of the box, but some look as if they're out with the front foot. Is it a legal hit to you or the blue behind the plate if one foot is out?

I've pitched in intermediate softball, and never had a batter try to get a running start before the hit, and not sure of the rules or reasons behind it. It just seems like an odd way of trying to hit a ball.

Answer
Aaron,

It is not an illegal hit unless both her feet are outside the batters box when she swings and hits the ball. If you were watching the Washington vs. Arizona game, you would have seen the the home plate umpire ruled a batter out because she had both feet outside the box when she hit the ball.

I hope this helps.

Jesse

P.S. I liked the "Happy Gilmore" analogy, I love that movie.