In this article https://d9e86ad9-1b1f-47af-a542-bc654e577aa4.filesusr.com/ugd/d9fb91_bd4e0b77f69940d8a85366a4573f0af6.pdf
Arthur Jones describes duo squat as revolutionary. However he never developed one with MedX and Nautilus stopped production. I just acquired a duo leg press which is same but with different seat. Any particular reason why this idea appears to have been abandoned. Have I made a good acquisition? Please and Thanks! 
Your time and help are greatly appreciated!
I think the machine is great and still an excellent exercise tool.
I believe that Nautilus found that once the Duo Leg Press came along , demand for the Duo Squat diminished quite substantially.
The main complaint about the Duo Squat I found was the discomfort on the shoulders once you starting increasing the weights. The Duo leg press never had this problem.
In summary, both are great machines , but in my opinion. the Duo Squat is a better “overall” machine for the lower body , but the Leg Press is more user friendly and thus commercially was the better option.
Mark
Yes, Mark is correct in his observation. The duo leg press is an awesome machine.
Thanks, gentlemen. Still wondering why MedX never produced?
I’m guessing combination of commercial and Arthur’s intense focus on optimization of lumbar exercise.
I’ve only just put together my duo leg press and am only just trying out. The feeling of increasing resistance as you approach lock out is very different and although I haven’t hurt myself, it feels as though I’m subjecting my pelvis (sacro iliac?) to quite a load. Should I be considering a different seat setting or not pushing out as far? (Not locking out now). Also anyone share Ken Hutchins’ concerns about unilateral loading and whether that would apply here when alternating legs? Please and Thanks!
One more question: how to apply 301030 to duo leg press if alternating legs? Or if using legs together? Please and Thanks!
I could be wrong, but it seems like that’d make it really hard to put the same amount of effort in on your second leg. If you had to do it, I’d say do your weak leg - if you have one - first, but overall, I’d just do both legs.
You can prevent some of the force on the duo leg press by placing the seat mechanism a notch or two back. I would not recommend doing 30-10-30 on the duo leg press or any unilateral machine.
MedX made a squat machine that was equal or better than the duo squat or leg press. It was in their plate-loading line and was called the Avenger Squat.
I thought this was the entire purpose of these types of machines?
It’s like accommodating resistance except that instead of using bands or chains, the cam increases the force required to complete the rep at approximately the same curve as the body gains a mechanical advantage through a given range of motion, right?
That is the idea, yes.
Is the cam able to be rotated so that the increase occurs at a different point?
Cams work from a fixed position - think of the way pistons work in a V8 engine. The piston goes straight up and down but the compression force varies because the end is fixed to a cam (on a shaft). The cam rotates somewhat around its fixed position as the camshaft moves but it is really the shape of the cam that dictates how much load is transferred.
Thank you. I get that. I’m talking about rotating its original position so that it changes the loading curve instead of reducing the range of the exercise by moving the seat back.
If you mean does it move longitudinally or transversely - no
The compression force on your neck and shoulders from the Duo Squat was huge (and always left bruises on my shoulders). Moving the seat back a notch reduced that compression. The Duo Leg Press is the same machine but with a different seat. In the Duo Leg Press that same compression force ended up on your lower back.
No.
I mean that if it’s positioned at top dead center 12:00 and loads as you move it counter clockwise, can you rotate it (the point which would be TDC) forward to 1:00 (or ccw, to say, 11:00)to change the point at which the maximum load occurs?
I get that. Like a compound bow.
Pretty sure we’re talking about two different things at this point.
Thanks. The picture is worth a thousand words.
I think the answer to your question on this machine is no. I have seen where the cam can rotate and lock into different positions to change the load vs distance curve. I don’t think these machines do that.
Yeah. Once I saw how it mounts its pretty clear. 
Communicating about mechanics is tough! (with my vocabulary)
Ok… if it’s what mnben has pictured - then no. It didn’t do that 
I had a similar experience to yourself with the Duo Squat many years ago. The compression and pain in the shoulders often meant it was difficult to push the exercise as hard as possible!
I have never used a Duo Leg Press however would not like to have that level of compression on my lower back either!
