 The disc is between the vertebrae. If you twist the vertebrae, it's like ringing out a dish towel. And again, it allows it, but it's not it's not the best thing for it over time. And again, especially say in sports, you're trying to apply force, speed, repetitions. So turned-on twist is another one of these cliches. And then from manual labor, lift with your legs, not your back. Which really means hold your back fairly stiff while your bigger muscles of your legs lift the object now. These aren't just, this isn't just my idea of how the spine works. Every institution that puts out safe lifting guidelines, whether it's universities, Department of Defense, agricultural groups, industrial groups, they all say more or less the same thing. They all, they all advise about the discs. They all talk about lifting with a stiff back, letting your legs do the lifting. They all have the same breakdown of the anatomy. But somehow when we walk into a gym, we touch a kettlebell, a machine, a barbell, doesn't matter. This is, touching this stuff is going to make me invulnerable. All right, so, so getting back to the general idea of, of avoiding injury from your workout, it's really not a question about being the exercise police, you know, don't do this exercise, don't use that brand name. It's, it's a question of given your choice of the exercise you have, how likely are you to keep this posture in the back for right now? And again, rather than just blanket, not do the exercise, know what the issues are, and then you can decide, all right? So unless you're a powerlifting where you have to do those three exercises, you've got a pretty wide range of things that all, in effect, do much of the same thing. So back in the gym, and now we're going to get into the, the raw preference section here. I personally don't barbell squat anymore. Whatever magic it has, it's just not worth the aggravation to my back. If I was, I would definitely consider a Smith machine, and I would, and keep it in mind that I want to protect the curve in the lower back, probably not too much lower than this position here. And then the other thing I would do is you have to use the bottom stops, because if you descend too low, you're gonna have that big moment arm when your thigh goes vertical, and you get crushed, like the poor guy I mentioned in the first, the first slide. So really the bottom stops are probably about here, right? Not down here, they're probably about here. So you squat as low as you can go and still keep the lumbar curve intact. Richard Wynette sent me an email saying, you know, conventional muscle thinking is that the Smith machine is bad for your knees. Well, if your feet are out here, and you're trying to squat with a vertical back, and you go so low that your femur is horizontal, yeah, that would be bad for your knees, right? Or if your feet are here, but instead of, instead of sticking your butt back as your squat, you dropped your spine straight down. Yeah, that would be pretty rough on your knees. But if, basically, if you're mimicking a free barbell squat with the good form, the Smith machine will actually keep the bar from crushing you. Absent to Smith machine, hip belt squat, right? Now the curve in the back isn't as obvious, because the hip belt is, is, that's exactly what the hip belt is, all right? One of the things I like about the hip belt squat, you're still loading the hips and the thighs. The spine can keep its posture and support the weight of your head, which is what it's supposed to do, all right? One of the things I don't like about the hip belt squat is, you got to be very careful about getting out, because if you go to failure and you sit right on that 45-pound plate, you're not going to worry about hip belts, lower backs, so you have to plan for how you're going to get out of the hip belt squat, okay? Either stop short of failure and unhook, or get your knees on, hands on your knees, or use a machine that allows it. But aside from that teensy detail, this actually does a pretty good job of matching up how the spine works. From congruent exercise, various split squats, so in, in the left one, you know, it's not, it's a, it's a, long, you might hear, you see it described as a lunge, but actually you, you lunge to get into position, and then you do a squat. So in that one, the forward foot has stepped forward, and then you're squatting, trying to keep your weight on this leg. And again, your spine doesn't have to support more than what it's supposed to, much more than what it's supposed to. This is sort of like a reverse lunge, so if you have the balance, you're here, and this leg comes back. And again, the front leg is doing the work. Again, now, again, you're bending over a little bit, right? But it's ma, it's manageable that you can keep the, the curve in your spine. Not that it's perfect, but it's manageable. So a number of years ago, somebody closed some ruckus online with the squat and the leg press. Now, when I, when I said or, or gave him presentations squat or leg press, I meant this leg press, not this leg press, okay? The nitro leg press, you can adjust the seat back so you can mimic the body position of a squat. It's got curves in the seat back that you can fit into the curves of your back to support it, okay? So that's the kind of leg press I was referring to. That's kind of interesting. That's kind of interesting. Yeah, okay. All right, so now more, more conventionally, right? So now this is from an NSEA textbook from about 2000. So this is like a very old school leg press. Now, what, what, what differences do you see in the two? Well, this angle is much closer to a right angle than this one. Okay. So I'm able to open up a little bit in the hips because what happens here is first of all, her knees came so far back, you can't really see it, but it's unavoidable that her lower back flattens against the pad. So instead of having her back curved this way as the knees approach her ribs, it has to flatten. And if you're doing the leg press to minimize the stress on your lower back, you just defeated the purpose. Especially in, in like the 70s where the, the Muscle Magazine advice was, you know, let your, let your, let your knees go into your armpits for that full range of motion and push out. Well, the only way you can get your knees into your armpits is if your pelvis flips and your lower back flips. Another, another thing about this joint angle is when she gets to a right angle, when she presses this away from her and her femurs and her torso is at a right angle, the exercise is over, right, because she can lock out. But the, the joint angle for where the glutes are strongest is, is a little bit further out than that, which you can't possibly reach here. So while this is very uncomfortable, especially at the bottom position, it doesn't necessarily, it's not exactly the right kind of challenge. It's, it's only uncomfortable because of what the compression at the hips and your lower back. All right. Remember I said about not being exercise police? Now, don't do this exercise. I've, forget that. This, this, the example I mentioned, college football player doing barbell step-ups and he either stepped off at the end of the set, twisted his ankle, dropped the bar, damaged his spine, or he had the bar here, he turned around to bring it back to the rack and the thing, he lost control of it and then injured his spine. One of those, one of those is what happened. He injured his spine, came back to play and, and walk again. Okay. But since I wrote congruent exercise, another college football player stepped off backwards, injured his spine, and is paralyzed. Okay. I don't know what benefit this exercise has compared to other leg exercises and it makes for, it looks, it looks like a pretty simple picture. But other than getting off and starting exercise, other than ending and starting the exercise, it's, it's fine. So here's the problem with this. This implies that he steps up on the bench and stands up perfectly erecting his back on top of the bench, right? But if you try to stand up a bench that high and I'm perfectly standing up here and I get my foot up here, I can't get, I can't stay vertical and get on, on the platform. I and everybody else has to bend over to do it. Only now, like when you bend over in a squat, you have two feet as a base. Only now you have one foot as a base. So unless you're, unless you're using a step like a regular conventional architectural step, you can't get on top of the bench without bending over with the barbell on your back on one foot. So you have, so you have this load that's extraordinarily wide and now you're bent over on one foot. It's amazing more people don't get hurt doing this. Exercise, the best manuals and exercise I've ever written. So please let me welcome to the stage, Bill de Simone. So you'd be a champion, but it would kill you, would you take it? And methodology aside and whatever the quibble's people had aside, a lot of people said yes. So that type of thinking, it's not just CrossFit. It's been around for a while. A boxer, a tennis player. The reason why you turn, you don't twist is the disc is between the vertebrae. If you twist the vertebrae, it's like ringing out a dish towel. And again, it allows it, but it's not, it's not the best thing for it over time. Your office are a certain height. You can pretty much do it with all hip and quad action and not make it more complicated. Also, from the 2000 NSCA textbook. Same exercise, different parts of the book. Okay, and neither part of the book identified one of these as the wrong way to do it or a risky way to do it. Perfect, but if you aim for perfect, then the natural, if you fall short, you still have a lot of margin of error.