How to perform back extensions with an animated image showing the move. This method demonstrates using your hands behind your head. Click on the picture to see the full sized animation. 
- Position your thighs on the pad on a hyperextension machine with your ankles under the braces.
- Place your hands behind your head.
- Bend your waist to lower your body.
- Raise your torso until it is in a line with your legs.
Your flexibility will determine how low you can go. Perform the movement in a slow and controlled manner; do not bounce at the top or bottom.
Also, depending upon the height of your machine and how flexible you are, watch out for knocking your head against the floor. You probably will not do it hard enough to hurt, but it can be embarassing if anybody else happens to notice. (That’s a joke, by the way; while theoretically possible I have yet to see it happen.)
Blaine, a Roman Chair and a hyper machine are two different things (that one on Amazon just happens to have both in one). Judging from your pic, that’s a straight 45 degree hyper.
Thanks; I edited it. I also took the picture off the front page since it was messing up the formatting a wee bit.