Look at this crazy looking club with the hinge on the shaft. It's one of those Medicus swing trainers and yes, it works.

It takes a little patience because the first time you swing this thing you are going to look pretty foolish. The club shaft has a dual hinge ...

You've seen the infomercials on the golf channel. Up late, can't sleep, so you flip on the boob tube and there's Mark O'Meara swinging that Medicus golf club. You are thinking, "Hmmm I wonder if that thing works?" and "I betcha I could swing that club without the hinge breaking!" ...