You can do that at home too.
I've done them by using my downstairs sofa to pin the bottom of my feet down. I actualy call this exercise "Hamstring Push Ups"; go figure. All I do is pin the bottom of me feet(not my heels)down with a light leather sofa; slight bend in the knees for the pivot point. And by being in push up position, you can assist your raises by pushing up and prolonging the TUT. You can also do reverse hypers from this position, just start from the verticle position.