This move is simple and somewhat less contrived than most: imagine you are a firefighter chopping down a door.
I call it the fireman rather than the firefighter, not because I am a sexist brute, but because this is the most testosterone laden of moves and I wanted to emphasize that fact.
Middle-earth fans may prefer to think of it as "smite the orc," an image which suggests the movement admirably.
Interesting aside: while I can't claim they do shovelglove, many fire departments do use sledgehammers in their training programs.
Note: I've stopped doing this movement regularly because I think it might perhaps unduly strain the back. This may just be my imagination, but I prefer to be cautious.