An exercise was shown to me that is called Iron Ox Ploughs the Earth (Tie Niu Geng Di).

The starting position looks like you are doing a pushup, but during the exercise you flex your body from the waist in a sort of whipping action, so that your triceps doesn't take much load. The movement is circular and is harder on ones lower back and abdominals. The hands were shoulder width apart and the elbows went out (not parallel to your body) when the movement went downwards. When you look at it from the side, then the path is shaped like a "U", but it is much more flat.

I don't own the book, but one of the photos on the cover of Xingyi Neigong, by Cartmell, Miller and Black looks like the ending of one cycle.

When typical Western push-ups use local muscle, then this style seems to try to use the whole body in the process. I have heard of an exercise with the similar objective used in Chen style taiji. I haven't seen this one, but it was supposed to teach you to apply jin through your arms.

Can anyone tell a little more about this?
Does my description fit your understanding of this exercise?