Is there any assisted push up machine out there? I know they have assisted dips and pull-ups, but I've never seen anything for pushups. I know it would be a little more difficult to do (havent really thought about it much, but can't think of any great way to do it so far), but I know there are many overweight people who can hardly do 2 pushups and would definitely benefit from a machine like this. Thanks for any help.