A seven-count pushup, basically a squat thrust with a pushup thrown in when you first drop into the pushup position but, you make the pushup harder by making it a flying pushup, that is, instead of pushing off hard and fast as if to do a clapping pushup where your feet stay on the floor, you go totally airborne and you are parallel to the floor.
So the count would be:
1.Stand and squat down with hands in front of your feet.
2.Shoot legs out so you are in the top of the pushup position.
3.Lower yourself to the bottom of the pushup position.
4.Explosively push up so you go totally airborne with your body like a board parallel to the floor and when you come down, use your arms like shock absorbers so you wind up at the bottom of the pushup position.
5.Push up like a normal pushup.
6.Pull your feet in to the squat position.
7.Stand up.
Not only good power development and explosiveness development, but a hell of a cardio workout if you do these in Tabata intervals.
Yep, I can do it, and I can do it strictly, feet together and back straight. One thing that helps is placing your hands directly under your shoulders (instead of slightly wider than shoulders like usual), this will give you more arm length to launch yourself.