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Lying Leg Extension Machine


Is there such a thing as a lying "leg extension" machine? Basically the same thing as the lying leg curl machine, but the resistance goes the other way (so you actually do a leg "extension", not a curl).

I'm asking this b/c I'm looking for a way to isolate quads throughout their FULL ROM (I mean, literally starting from my heel touching the back of my legs...)
(with weights, of course...)


I've never seen anything like that, and that's after being at some really legit gyms,

If you're looking for something interesting for quad rape, watch this:

Keep in mind DOH is pretty effing big and strong - so note the weights he's using here.


Definitely give somersault squats a try (video above)! They're very interesting. For me, I feet them primarily in my outer quad (vastus lateralis).
The craziest part about them is that I don't feel particularly fatigued during a set, but when I rack the bar...I can barely stand.


Somersault squats are awesome, definitely give them a try.

Another good option would be Sissy Squats (free weight or on a machine Hack Squat). Those are essentially the same motion you are describing, but you must keep your hips extended with your Glutes the whole time. Be a little conservative with the weights when you start though if you've never done any similar movements as they can place a bit of pressure on the knee and could cause issues if your connective tissues aren't ready for/accustomed to them.


Not that I've ever seen, nope. Some kind of band setup would be the closest to it. But...

The quads weren't meant to be isolated through that extreme range of motion. That is, the knee isn't structurally designed to support the stress induced by that much ROM.

"Regular" leg extensions have a high amount of knee stress at the bottom position, further increasing that ROM would increase the knee stress without significantly increasing the muscular stress. The knee joint needs the support of the hams, glutes, and quads working in coordination.

Stick with "standard" leg extensions, deep front squats, the hack machine, sissy squats, or maybe those somersault squats posted above.

Those somersault squats, BTW, sort of remind me of a Smith machine Pierre Roy Squat (used for different purposes though). The Roy squat is less continuous tension and more hamstrings.


Agree with Mr. Colucci above. Also, it's worth remembering that the quads span the hip joint as well, and that supine-quad extensions would place the proximal (hip-related) quad attachment in a mechanically vulnerable position for the initiation of a hard quad contraction. To put it in perspective, the biceps equivalent would be to start a heavy preacher curl from the bottom, with the arms fully extended. I think most of us can recognize that such a movement would be unwise.


If you can find a LifeFitness leg extension/leg curl combo unit, you can perform the leg extensions with the seat folded down. There won’t be a pin spot where you need the seat, so it’s up to your lumbar to control the extension in your back… But it gets as much rom out of the quads as you’ll want, while targeting those hard to hit muscles in the quads