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Lying Leg Curl vs. Seated Curl

So I’ve noticed that lying leg curls are really uncomfortable to perform. My hammys never feel great during and the ligaments behind my knee always hurt afterwards.
Seated leg curls are not only easier to move more weight, but 100% pain free.

Is this due to having everything more stretched out while lying down? Or could this be an issue with technique? Or possibly some stuff that’s too tight muscle/ligament wise?

I just figured the lying version of this was for people who wanted to best display their yoga pants and the seated version was a terrible joke.

I find both feel like dogshit once it gets anywhere near heavy. So I wouldn’t worry. To combat this, I do them two legged but I do a single leg eccentric, that makes it better.

I do look good in spandex.

I have a lying leg curl in my home gym. Real gym has seated. 50lbs will destroy my knees/hams in less than 10 reps on lying. Seated I can hit 20 at 100lbs, I’m pumped and can’t walk or stand, but there’s no pain. Just seems like such a huge jump in weight and pain level, makes me wonder.

Experiencing pain while squatting, or lunging, or raising your arm is one thing. But pain when you’re in a machine that locks you into a position and has fixed motion, I wouldn’t be so concerned if you otherwise don’t experience any pain, just avoid that machine

@j4gga2 might be able to give his thoughts.


Appreciate the tag man

OP, here is my theory (this is just a narrative that makes sense to me, based on my very incomplete knowledge).

In a lying leg curl, your hip is placed into more extension (i.e. your hip is straighter). However, many of us have limited hip extension due to varying reasons (which include getting stronger). To get around this, the body may dump into anterior pelvic tilt, which can lead to neurologically “shut off” hamstrings. In a seated leg curl, your body does not need to produce APT, and therefore you can effectively drive hamstrings.

Another factor that could be contributing is something called “active insuffiency” which basically describes a situation where a muscle is too contracted to contract any more. In a lying leg curl, the hamstrings are shorter because the hip is in more extension, and therefore have less potential to contract any further. This could also explain the massive weight drop and why you feel the exercise less in your hamstrings.

In terms of actually applying this information, it doesn’t really matter which one you choose. If you can get a great pump with seated leg curls without needing to think much, then I would do seated leg curls.

If you really really really want to do lying leg curls, you’ll probably be well-served to learn how to “stack” your pelvis and ribcage, and feel your hamstrings in greater and greater hip extension. I would start with the 90/90 hip lift (video below) and progress the drill by moving my body further and further away from wherever my feet are, basically letting my hips and knees become straight over time. Remember the goal of this activity is to feel your body in good positions, and feel your abs and hamstrings working (but not dying).


Also, I’d love to hear @FlatsFarmer 's ideas on what’s going on here

Great reply man! Thank you!

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Are your knees pressed into the pad or hanging off?

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I find your experience with these machines strange. To me lying leg curls are far better confortable and don¨t experience any problem with it. On the seated one if you have some problem with your lower back it might be a challenge.

I would say it could probably be an issue with technique or the weight you are using (too much?).

There is also the standing leg curl machine and that I also prefere it to the seated one, just give it a try!

Since you indicated the weight used for seated VS lying, i’m willing to guess that the lying is with your home gym machine? 99% of the time those are trash (plate loaded leg extension/curl type of machine?), it may be the reason why it bothers your knees (support, pad, rotation point, strength curve really bad, etc etc). Do you have any issue with a “real” lying curl machine?

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I use both, but prioritize GHR’s, RDL’s, Reverse Hyper among everything else for hams/posterior chain. Back to the subject at hand:

When using the lying hamstring curl, where do you adjust the pad? If it is anywhere below parallel to the floor upon full extension, it’s going to apply unnecessary pressure to the knees and other joints/ligaments.

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I pretty much agree with what everyone is saying.

Seated leg curls are awesome. Comfortable, easy and they kill my hamstrings. I don’t have one at the gym I go to now, but sometimes I sit up on a high bench so my feet can swing and do them against a band.

Laying Leg curls can totally feel terrible, but like other guys have mentioned, where you put your knees matters. They feel better if you can get your knee joint even with the hinge or pivot of the machine. This might mean hanging your knees off the pad, or sliding your body up or down the bench, or whatever you need to do to get that alignment. If your knees are above or (behind?) the pivot there’s a lot of torque on your tendons.

A agree with Jagga about keeping your abs tight and your pelvis neutral. Or staying stacked and not going into anterior pelvic tilt, trying to use lower back instead of hamstrings in the move. adark is right too, some machines suck and makes getting into a good position way harder.

A lot of laying machines have a bench with bend or angle or something on the pad you lay on. If you can, line your hip bones up with the bend.


My home lying leg curl machine is a commercial one. Came out of a high school football gym and weighs like 200lbs lol. It could still be a total piece of shit that’s built wrong, but it’s a lot less likely than one someone bought from Walmart.

Knee position, ankle position, and foot angle do not effect the way it feels on either machine.

Weight also doesn’t change the way it feels on either machine. I can do 15lbs on the lying and it hurts just the same.

I have only tried the seated version once when I trained at a buddy’s gym, as mine only has the lying version. I liked the seated version much better, and could move the whole weight stack, whereas with the other version I can lift much less weight.

If I have to speculate on the reason why that is, I think it has to do with the length-force production correlation there is when it comes to muscle, i.e. a muscle can produce more force when it’s slightly elongated and much less when it’s close to full shortening.

When you’re seated, your hips are in a flexed position, hence your hamstrings (the part that crosses the hip that is) are pre-stretched, and that might the reason why you can produce more force, as opposed to when you’re lying down and your hams are partly shortened, already.

As a side note, one reason why I don’t particularly like the lying leg curl is that it’s very hard, at least for me, to keep the lower back out of the movement. I always tend to compensate a little when I’m fatigued, no matter how much I try to brace my abs to counteract that.

Bottom line is, if I had a seated leg curl at my gym, I’d totally use that.


Yea that makes sense. I much prefer seated as well. My lying leg curl has handles I can hold onto that for some reason take my lower back out of the equation, if I don’t use them I can definitely feel it in the lower back though

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Here is the turd in question.

edit looks really short in this picture but it’s quite long and has plenty of room to move around.

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For a minute there I couldn’t figure out where you loaded the plates, then I found it. I feel like such an idiot lmao.

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If it doesn’t feel right, I wouldn’t try to force it. How well does the leg extension work for you?

Yea I’m not gonna do them anymore. I’ve wondered this before but kinda forgot about it as I wasn’t working out. My recent stint back into home gym and commercial gym reignited my quest for answers.

As to the leg extensions, love them. This machine and others feel equally good. I need to redo the foam soon but other than that, it’s fine. The flat surface on some machines is a little more favorable for me vs the round, but it’s a wash.

Edit- I will say a cable machine is a bit more consistent. Plate loaded isn’t quite the same load all the way through, but it’s not too noticeable and I doubt it matters.

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Have you tried a standing Hamstring Curl machine?

Maybe hack saw off the “arm” that the roller pad for hamstring curls is on. Then stand up and do single leg curls that way.

When I’m at home I do laying Hamstring curls against a mini band wrapped around a table leg. Or laying curls with my Old Lady three pound ankle weights. Or standing leg curls with the ankle weights.

I like to rig up a band on the leg extension machine for that smooth cable feel.