“During the online Resistance Exercise Conference, there was a short segment where a trainer (Skyler Tanner) did a demo showing how you could use a Medex leg extension machine to do hip thrusts. He suggested that the fall off cam on the leg extension addressed the issue that Bill DeSimone had with the hip thrust exercise, namely that when done with a barbell, the resistance curve is all wrong.”
Just to clarify, since my name was attached to this: I do not encourage using the Medx LX this way. Single exercise stations are designed to be stable when used only that way. Use a Vertical Chest Press seat for step ups, or a curl station for pec stretches, and if it tips or the user gets injured, that is ALL on you.
The torque mismatch is only one of my issues with the Barbell Hip Thrust. Forcing hyperextension at the top, forcing loaded lumbar flexion at the end of the set at the bottom, and putting the load directly over the hip joint (creating zero moment arm for the hip extensors).
A low tech alternative: The Joint-Friendly Fitness Project by Bill DeSimone » Barbell Hip Thrust v. Reverse Lunge: the Biomechanics — Kickstarter
If Nautilus continued their station, both legs at one time, approximately 90 degrees of movement, from 90 degrees flexion at the hip to 0 degrees (full hip extension), with the cam widest (or resistance leverage greatist if plate loading) at 70 degrees flexion, probably requiring a seat belt… this combination would load the joint angle for peak muscle torque without risking forced hyperextension, twisting of the spine, or forcing the lumbar spine in flexion, i.e. all the benefits with none of the risks.