Reverse Leg Presses How is the motion? CFTS

I’m looking at the picture in the CFTS about reverse leg presses and I can’t figure out exactly what to do. I am stoping leg curl so I really need to know exactly what the motion is.

Thank you

The reverse leg press was done on an old universal leg press with the athlete holding onto the dip attachment facing away from the leg press. The athlete then placed their foot on the foot peg and pressed against the peg this caused the hip to extend and the glutes to contract. It is the same as triple extension. Their is a machine called a power runner that can do the same thing.