There are seven components of force that influence the behavior of connective tissues. Let's just talk about a few of them. Good morning. Happy Monday. I have no coffee in hand and it is perfect. Very exciting. New hats arrived over the weekend. So I'm off to a great start on a Monday. We've had a bunch of discussions on IFESU. Actually, it's an ongoing discussion on IFESU University in regards to yielding and overcoming behaviors of the connective tissue. So I thought I would lean into that one a little bit and flesh out some issues. There's a lot of stuff that's capable of influencing the behavior of the connective tissues. One of the things that we want to start to recognize is that this is something that the nervous system is not involved with, and it's actually important that it's not. The nervous system is a little too slow in many of our movement behaviors, and so we have to relent the behavior of connective tissues, and so the connective tissues are viscoelastic, so they alter their stiffness and behaviors based on these seven components of force. We've got magnitude, location, direction, duration, frequency, variability, and rate, all influencing this connective tissue behavior. And so because the viscoelastic tissues behave as they do, they smooth out movement. They deform based on their inherent stiffness and how much energy is stored and release will also amplify and dampen movement. And so if you remember anything that's associated with like stretch shortening cycle, you'll get an idea of how some of the tissues behave, but we want to start thinking about all of these tissues behaving the same way. And like I said, it's going to be based on degrees of their inherent stiffness. So I got a couple of examples here. I think these are from Elite if you guys needed to get some bands. They're Elite FTS. But you can see the difference in stiffness in the two bands. And so both of them are deformable. The thicker band is going to take a lot more force to deform, but it's also going to release a lot more energy than this band. But this one actually can move quicker. So we have to look at how all of these tissues behave and we can influence them differently based on the context in which we are applying forces. Let's talk about the combined influence, if we will, about magnitude, location, and duration. So we don't talk about duration a lot. I talk about rate a lot because I think it's very easy to see. And then I've got this really cool little representation with my silly buddy that I've done a bunch of times on some videos. So when I pull on this gradually, and I get this nice little elongation, but if I pull on it very, very quickly, then of course I get it to snap.

So this behavior of this tissue is a good representation of how the stiffness can be altered. When we think about the magnitude of the load, it is going to cause more deformation of tissues. Depending on where we apply the magnitude of load, those tissues are going to respond. So it's going to be very contextual. For instance, if I need to deform bone versus fascia or a tendon, it's going to take a lot more load or force applied to get this tissue to deform. So I can actually target the skeleton under many circumstances. If I think about duration, the longer I apply a load to a connective tissue, I will get a stress relaxation response and so I can actually promote more of a yielding action. If we look at a couple of examples, if I took an overcoming static squat, we're seeing a squat where we're pushing up into the pins. The rate of loading is very quick, so I'm promoting a lot of stiffness through the system. The force application is very high because it's maximal effort up into the pins, and the duration is short due to the effort involved. So my connective tissues are behaving in a stiffer manner, which would be primarily an overcoming bias. If I change the context to a yielding static position in the squat, the initial loading rate is similar to the overcoming, but the duration is longer. I'm dealing with a little less load here, so I can do this over a number of repetitions and extend the duration of exposure to the connective tissues. I'll get more of a yielding action, teaching the connective tissues to store more energy. If you look at the tendonopathy research where they're talking about extended isometric protocols to increase the amount of load on the tendon, you'll see this stress relaxation response and how this yielding strategy will evolve. The box squat provides us another element where we can redirect the load to a specific location. If I'm doing a box squat and I'm deloading my weight onto the box, I'm actually reducing the amount of muscle activity. So I'm distributing that load now to the connective tissues, including the skeleton, which is very important, especially for big strong powerlifters or offensive linemen who need these high force components where we need to load the skeleton and release that energy for the highest forces possible. When we de-load to the box, that's how we can direct the load towards very specific elements of the connective tissue system, getting a yielding strategy through the skeleton. We have to be careful with loads as far as how we're doing this. A less qualified lifter will use a higher percentage of their 1RM in a box squat to create this yielding strategy because they need more energy to deform the skeleton. As you get stronger, that percentage drops because I only need so much load to deform the skeleton. If I increase the load too much, I deform the skeleton too much, creating too much of a yielding strategy and then I don't get any recoil off the box, losing that element of explosiveness where I can store a lot of energy but can't release it unless I use the optimal load. That's why you see percentages going down: for a less qualified lifter maybe it's 70% of 1RM on the box squat, while for a very high qualified lifter it might be 45-55% of 1RM.

To the connective tissues, including the skeleton, which is very, very important, especially for your big strong power lifters or your offensive linemen, etc., that need these high force components where we need to load the skeleton and release that energy for the highest forces possible. And so when we de-load to the box, that's how we can direct the load towards very specific elements of the connective tissue system. And so we get a yielding strategy through the skeleton. Now we got to really be careful with loads as far as how we're doing this. And so this is one of the reasons why you might see the difference in the loading strategies for box squats depending on the qualification of a lifter. And so a less qualified lifter will use a higher percentage of their 1RM in a box squat to create this yielding strategy because they need more energy, a certain amount of energy I should say, to deform the skeleton. And so it's just a higher percentage of their one rep max. And as you get stronger and stronger and stronger that percentage drops because I only need so much load to deform the skeleton. If I load too much, I deform the skeleton too much, I create too much of a yielding strategy and then don't get any recoil off the box and so I lose that element of explosiveness where I can store a lot of energy but I can't release it unless I use the optimal load. That's why you see the percentages going down. So again, for a less qualified lifter maybe it's 70% of one rep max on the box squat. For a very high qualified lifter it might be 45 to 55 percent of 1RM. I would go to Louis Simmons' West Side articles on this, because again, a brilliant strategy. They did it through observation. But I think that we can actually look at this through the connective tissue behaviors as far as strategy is concerned. So I hope that gives you a little bit of information or a little bit of an understanding about this yielding and overcoming action in regards to the connective tissues.

He says, more specifically, I'm curious if you suspect that powerlifters find benefit in the reverse hyperextension exercise because it attempts to create some of the mechanisms that I've described from being able to deep squat such as counterneutation, posterior expansion, stimulating blood flow from the bone above and below the spinal disc in more favorable cellular adaptations as far as maintaining disc health. So this is actually a really, really good question because, again, there's certainly some elements of powerlifting that are going to challenge maintaining some elements of health because we're dealing with, if we made a problems list, you got high levels of compressive strategy to lift heavy things, which again, we want to minimize the expansion strategies because the minute that we release any of our concentric orientation, we're going to accelerate potentially in the wrong direction, which would be downward under most cases. We don't have an effective yielding strategy because we want high levels of stiffness in the tissues. And this is obviously just a byproduct of magnitude of load. You're going to get some spinal compression that's associated with this. So we have compressive strategies throughout. But because of the loss of range of motion that's going to be associated with lifting heavy things, we have to create orientations that are going to allow us to, one, access motions to execute the exercises. And number two, we have to create propulsive strategies into the ground. So we have to produce IR to the ground. So that's going to require some orientation issues, especially with the pelvis. And then we get a lot of that spinal compression. This, in turn, reduces blood flow to the disc, so the disc is dependent on blood flow from the bone above and below. If we compress the bone, we can actually reduce that blood flow, and then we start to get the degenerative changes in the disc. What we have is this one big giant compressive exhalation strategy that is very, very useful for lifting heavy things. It's fun to do. But there are secondary consequences. And so what we may want to do to restore some measure of health, some measure of movement capability, comfort, such as pain reduction, et cetera, is we want to try to restore some of these inhalation mechanics that will provide some yielding strategy, improve our ability to turn So we're not relying on on compensatory strategies just to produce normal movement throughout the day So what we want to look at then is what do these inhalation mechanics look like? So I've got a little representation of a video. It's very subtle But hopefully you can actually see this and so what I did is I put Eric prone on the table in the purple room And I just had to breathe a little bit.

We actually created a little bit of a compressive strategy on the anterior aspect of the abdomen and pelvis so you can actually see the expansion posteriorly. And so what we're getting, we're getting a little bit of sacral counterneutation, which is our yielding strategy on that posterior side. So we might be able to acquire this in the reverse hyperextension exercise because of this initial starting position that provides us with an anterior compression that may promote the posterior expansion. And so our mechanics here would be similar to what we might see in the initiation of a toe touch, where we want to see that sacral counter-neutation and posterior expansion. So again, we're moving somebody from this strong, compressive strategy that's going to be in that middle-delete, propulsive element of propulsion, and we want to move them backwards to early. And this might be a way for us to do this. Now we've got some issues with this. So the position is favorable. Yes. But we also have to deal with load based issues. So too much load is going to promote a compressive strategy because I need that to lift heavy things. And so I may not be able to access the yielding strategy under those circumstances. So we're going to start with a lighter load for sure to make sure that we can capture the strategy that we're actually shooting for. The second thing is, is a technical issue. And so when we do these things bilaterally, so anything that's bilateral symmetrical, one's going to create a little bit more of a compressive strategy, it's going to limit our ability to turn. And so one of the things you'll see with the execution of reverse hyper is the fact that people will sort of exceed the motion capabilities of the hip and they will start to drive this anterior orientation of the pelvis even in prone. And so you can actually overcome the benefit of the yield length strategy by taking this way too far. And so one of the things you're going to want to try to do is limit the motion to the hip excursion because by driving the motion through the hip, primarily, you're going to promote a little bit of that push to your lower compression, but you might actually capture your sacral mutation of those circumstances. If you drive it farther, you're going to create that anterior orientation. We get the compression of the sacral base, and that's exactly what we don't want to do because that's what got us here in the first place. The other issue might be velocity. And so you'll see reverse hypers performed in any number of ways. If we use high velocity, remember that as we apply velocity to viscoelastic tissues, we have a rate dependent change that might make them stiffer. And again, we won't be able to utilize our yielding strategy, which is the goal under these circumstances.

So we're not talking about a performance-related adaptation that we're chasing here. We're talking about recapturing elements of the yielding strategy, which will hopefully promote health, reduce pain, et cetera. An alternative that you might want to consider then is to use a single leg variation of this. We take advantage of the prone position, but by driving through a single leg, we can actually maintain a yielding strategy on one side. We create a little bit more of a compressive strategy on the other side, and now we're actually creating a little bit of a turning relationship between the sacrum and so we can actually capture some of that yielding strategy one side at a time. This is actually one of my favorite ways to do this, especially with your bigger, stronger human beings because it's just a lot easier to drive compression on one side because they're already compressed on both. We magnify that compression just a little bit and we actually get the benefit of the yielding strategy on the opposing side. So we'll do this in any number of supine exercises. So we've used supine cross connects and things like that in a couple other videos previously. But when we're talking about the reverse hyper, we're using basically the same strategy by doing it unilaterally. So Charlie, thank you so much for the question. If I didn't answer your question effectively, go to askbillhartman at gmail.com, askbillhartman at gmail.com, and post another question. I will see you guys tomorrow.

When inhaling at the start to get tight counter-nutated sacrum, which isn't ideal for overcoming at the bottom, how would you coach that at the pelvis? And she wants me to use the pelvis to demonstrate, so that's going to be kind of easy. But the thing that we need to understand here is that, so Sandy, your interpretation is actually not correct. So you don't have a clear understanding of what we're talking about with the yielding and overcoming because you're looking at yielding as this overarching kind of position thing where you're including the counterneutation and the the the ilium public floor and guts etc in this. So what I want you to understand about yielding and overcoming is the yielding and overcoming actions are the distribution of the forces through the connective tissues. We don't want to include the contractile element, the musculature in that because that's what's actually going to alter the rate at which the connective tissues are loaded which determines whether we have a yielding or an overcoming strategy. So when I load connective tissues very, very quickly they become very, very stiff and overcoming when I when I load them very, very slowly. They actually yield and that's where we start to see the expansive capabilities even with situations of concentric orientation of musculature. So a concentric yielding strategy is a concentric orientation, so a muscle that is moving into a shorter position, but the connective tissues are allowing the expansion to occur at the same time. And that's how we distribute some of these forces. So right away we have a little misunderstanding that hopefully that explanation is going to help. Now, let's compare two squats. So you mentioned what we would consider traditional, maybe like a body weight squat or something like that. So as we start at the top we would be in a relatively inhaled sort of a counter-nutated position at the top. So we're going to start bias towards an inhale as we move through this middle area of the of the squat. So plus or minus 30 degrees of your sticking point. What we're going to see is we're going to see movement towards a more concentric orientation of pelvic diaphragm, internal rotation of the hip joint, and nutation of the sacrum. To get below that level, we're going to have to re-counter-nutate. So we're actually going to see more movement at the ilium in this case to achieve this deeper hip flexion position. To get into that depth, we have to have eccentric orientation of the pelvic diaphragm to get there. If we don't have that expansion downward, you're never going to get into that deep squat. Now let's take this over to powerlifting. Under most circumstances there are exceptions to the rule but under most circumstances when we're talking about a powerlifting style squat we don't want as much eccentric orientation. In fact, we hardly want any at all. We want just enough to get competition depth and then get back up. So the power of the squat is all about staying as close to this maximum concentric orientation as possible. We're going to use a compensatory breathing strategy throughout the entire lift. Because if you think about where you're going to position the bar in a back squat, you're going to try to retract the scapula to a degree. That's going to create upper back compression. So dorsal kyphosis is going to be compressed. Upper dorsal kyphosis is going to be compressed. You're going to engage the lower posterior rib cage musculatures like lats and things like that. So we're going to try to compress that. You're going to compress everything that you can across the backside of the pelvis to make a very, very stable structure. You're going to use your final compensatory strategy in the lower part of the pelvis where you're going to drive the extra rotation moment. You're going to try to compress this apex of the sacrum. So we want the minimum amount of eccentric orientation to allow us to get into that position, because the minute that you release the concentric orientation to any significant degree, you are going to accelerate towards the ground under maximum loads, which is really not effective, especially in competition, because you tend to not get your white lights under those circumstances. So again, so we're gonna actually limit this. So we don't wanna go past this concept of orientation. So your setup that you're talking about at the very beginning of the squat, yes, you're gonna charge your thorax with air, and then you're gonna squeeze the bejesus out of it, cut it off at the throat with a valsalva, right? Because we wanna create this incompressible body that we can stack a bunch of weight on top of. And I cannot release that at any significant degree during the lift otherwise I am going to lose my position rather rather readily and again I'm going to miss my lift so the breathing that you're talking about in the the competition squat is a compensatory strategy all day every day it's it's concentric on concentric and and so we're not going to follow the normal mechanics that we would under a normal circumstance when we're talking about a regular if you will or a body weight squat where we have this transition from expansion to compression to expansion again. The power lifting squat is compression on compression on compression with the most minimum of eccentric orientation. That's why the box squat so popular with power lifters is because it does allow them to capture eccentric orientation at a depth. But it's the minimum allowed, and then they learn how to yield throughout the entire system. So all of their connective tissues are providing the yielding strategy to even get into position, which is why we tend to see connective tissue issues with a lot of power lifters. We see a lot of bony changes with a lot of power lifters over time because of the dramatic, compressive strategies that they're utilizing. That affects blood flow to the joints, affects blood flow to the connective tissues, We got a whole world of hurt in our futures if we don't take care of ourselves. So I hope that clarifies a little bit of the yielding and overcoming strategy. If we're looking at the power lifting style squat at the bottom, you're going to be as nutated as you can, but also compressed underneath. So I can't even create the position with my pelvis model because you're going to probably bend the sacrum underneath you to a significant degree. So, you know, from a health standpoint, from a power living standpoint, it would behoove you to work on both styles of squat, one squat, obviously for your maximum effort, for competition purposes, and the other one to help you maintain some health and mobility. So again, I hope that helps you, Sandy.

We want just enough to get competition depth and then get back up. So the power of the squat is all about staying as close to this maximum concentric orientation as possible. We're going to use a compensatory breathing strategy throughout the entire lift. Because if you think about where you're going to position the bar in a back squat, you're going to try to retract the scapula to a degree. That's going to create upper back compression. So dorsal rostrum is going to be compressed. Upper dorsal rostrum is going to be compressed. You're going to engage the lower posterior rib cage musculatures like lats and things like that. So we're going to try to compress that. You're going to compress everything that you can across the backside of the pelvis to make a very, very stable structure. You're going to use your final compensatory strategy in the lower part of the pelvis where you're going to drive the extra rotation moment. You're going to try to compress this apex of the sacrum. So we want the minimum amount of eccentric orientation to allow us to get into that position, because the minute that you release the concentric orientation to any significant degree, you are going to accelerate towards the ground under maximum loads, which is really not effective, especially in competition, because you tend to not get your white lights under those circumstances. So again, so we're gonna actually limit this. So we don't wanna go past this concept of orientation. So your setup that you're talking about at the very beginning of the squat, yes, you're gonna charge your thorax with air, and then you're gonna squeeze the bejesus out of it, cut it off at the throat with a vasalva, right? Because we wanna create this incompressible body that we can stack a bunch of weight on top of. And I cannot release that at any significant degree during the lift otherwise I am going to lose my position rather rather readily and again I'm going to miss my lift so the breathing that you're talking about in the the competition squat is a compensatory strategy all day every day it's it's concentric on concentric and and so we're not going to follow the normal mechanics that we would under a normal circumstance when we're talking about a regular if you will or a body weight squat where we have this transition from expansion to compression to expansion again. The power lifting squat is compression on compression on compression with the most minimum of eccentric orientation. That's why the box squat so popular with power lifters is because it does allow them to capture eccentric orientation at a depth But it's the minimum allowed, and then they learn how to yield throughout the entire system.

So all of their connective tissues are providing a yielding strategy to even get into position, which is why we tend to see connective tissue issues with a lot of power lifters. We see a lot of bony changes with a lot of power lifters over time because of the dramatic compressive strategies that they're utilizing. That affects blood flow to the joints, affects blood flow to the connective tissues. We got a whole world of hurt in our futures if we don't take care of ourselves. So I hope that clarifies a little bit of the yielding and overcoming strategy. If we're looking at the powerlifting style squat at the bottom, you're going to be as nutated as you can, but also compressed underneath. So I can't even create the position with my pelvis model because you're going to probably bend the sacrum underneath you to a significant degree. So from a health standpoint, from a power living standpoint, it would behoove you to work on both styles of squat, one squat obviously for your maximum effort, for competition purposes, and the other one to help you maintain some health and mobility. So again, I hope that helps you, Sandy. Biggest, small A, small hand, big D. I will see you guys tomorrow, have a great Wednesday, and then coach is called tomorrow, and then it's chips and salsa day too, so I'll see you.

I understand it's very foundational for evals and stuff for just movement.

It's just a starting point. Just keep that in mind. It's just a starting point.

Going off that, if the goal is to get movement, you know, from narrow to wide or wide to narrow. And let's say you get that change. I'm assuming if it does change, and you can get movement, the longer that change lasts, the better. And with that assumption, do you find anything particularly helpful with having a longer change?

Don't say wide to narrow or narrow to wide, because you're not going to change that. What I would say is, can you get one to move? Okay. Because you're not trying to change somebody. You're not trying to change a wide to a narrow or a narrow to a wide. Okay. So I just want to interrupt you. So, change your thought process a little bit. Okay. Go ahead.

I'm assuming that if there is change and movement, the longer that change lasts, the better. And with that assumption, do you find anything particularly helpful with having a longer change?

The longer the change, obviously that represents the potential adaptability, right? And so just give you a for instance, so we got a guy that's a, you know, six foot, 3,300 pound football player. He hasn't changed much, right? Because when we don't want him to change all that much. And so because it's a performance related adaptation that we kind of know is going to be somewhat restrictive on certain elements of movement. When you're talking about, say, the rehab mode where adaptability is the primary concern. So we're trying to get as much adaptability into the system as possible because we never do know what's wrong. And so we're trying to get as much adaptability. And so we do want that to be maintained for a much longer period of time because again, that represents the adaptability until it's time for them to do whatever it is that they do that would reduce their adaptability. So if they go back into some training process where they're trying to recapture some element of performance, then we know that that kind of thing is going to change. And so under that circumstance, we would always want the ISA to be mobile, right? Because again, it is that foundation. It represents the first compensatory strategy. If we look at the two extreme archetypes, it represents the first compensatory strategy. So that's what stops the ISA from moving is when the diaphragm has a limited excursion. And if I can't move that, then I know that the rest of the stuff isn't going to move with full relative capabilities.

With regards to the performance aspect, I know we've spoken about that multiple times. My question is we're trying to evaluate these KPIs to see if that person has pain or has some sort of movement-related issue. We're trying to evaluate the whole system to see, okay, well, what do they potentially need more of, or trying to figure out why that's happening. Now, as you're saying, everyone has their individual kind of sweet spot. I find that, obviously, I think the way that I see it so far is that, because I've been playing with that in the past few years and it takes a long time to really develop that, like a lot of exposure to that person, personally at least to find, okay, this seems to be their sweet spot. This is kind of what they need. Have you found a particular way of doing this, either of like saying, okay, well, how are we going to correlate your hip range of motion with your sprinting mechanics or with in order to have an easier time figuring this out, figuring like, what are their KPIs? What's that spectrum? You know, like that path would always talk about the spectrum of like, this is where they perform well, and like outside of that, no good. So, like, how do you go about figuring this out over time to say, okay, this is what this person needs. Those are the KPIs.

Okay. You're married, right? Yes. Okay. How did you figure out that she was the one? Well, a lot of exposure. Yeah. Yeah. Or you go on The Bachelor, right? The Bachelor TV show. And that's how you find the right one, right? You just weed them out. No, it's exactly the way you describe it. And everybody wants a shortcut process. And the reality is, is that you've got to get to know this person. How do they respond to certain elements? If you're dealing with the pain issue, obviously you have to induce enough adaptability to alleviate that first. And then you just start to superimpose the performance aspects back on and then you monitor for the changes. You kind of know where they started, which is really, really good because again, now you have a comparator from a performance aspect and you say, you know what, if I get close enough to that presentation, chances are our performance is gonna go up, but that's gonna be my indicator that I'm probably getting too close to where that they start to create their own interference. But this is why it's hard. This is why we don't have great answers or predictive capability because we just don't know. So I think that you've got to date your client a little bit and find out if she's the one. I mean, seriously, it's unfortunate. It'll be really nice if we had these hard and fast rules. You know, say, oh, when you have 17 degrees of hip internal rotation, that's bad. I don't know. Is it bad? What if it makes her faster? Right? You know, but maybe, you know, 15 degrees and now you've got interference. How are you going to know? You measure a bunch of stuff. You create the adaptability to alleviate anything that is interference, and then you re-superimpose everything. You just bring them back. That's ultimately what the return to play process is. I don't think return to play is very special. I don't even think we need a concept called return to play. We usually just call that training. Right? It's just that, where's your starting point? So if somebody's coming off of a surgery or an injury, right? They're just starting at a different place than somebody else that doesn't feel pain. But if we monitor them the same way, that's gonna be the best way to figure out what is the desired outcome.

Well, a lot of exposure.

Yeah. Or you go on The Bachelor, right? The Bachelor TV show. And that's how you find the right one, right? You just weed them out. No, it's exactly the way you describe it. And everybody wants a shortcut process. And the reality is, is that you've got to get to know this person. How do they respond to certain elements? If you're dealing with the pain issue, obviously you have to induce enough adaptability to alleviate that first. And then you just start to superimpose the performance aspects back on and then you monitor for the changes. You kind of know where they started, which is really, really good because again, now you have a comparator from a performance aspect and you say, you know what, if I get close enough to that presentation, chances are our performance is gonna go up, but that's gonna be my indicator that I'm probably getting too close to where that they start to create their own interference. But this is why it's hard. This is why we don't have great answers or predictive capability because we just don't know. So I think that you've got to date your client a little bit and find out if she's the one. I mean, seriously, it's unfortunate. It'll be really nice if we had these hard and fast rules. You know, say, oh, when you have 17 degrees of hip internal rotation, that's bad. I don't know. Is it bad? What if it makes her faster? Right? You know, but maybe, you know, 15 degrees and now you've got interference. How are you going to know? You measure a bunch of stuff. You create the adaptability to alleviate anything that is interference, and then you re-superimpose everything. You just bring them back. That's ultimately what the return to play process is. I don't think return to play is very special. I don't even think we need a concept called return to play. We usually just call that training. Right? It's just that, where's your starting point? So if somebody's coming off of a surgery or an injury, right? They're just starting at a different place than somebody else that doesn't feel pain. But if we monitor them the same way, that's gonna be the best way to figure out what is the desired outcome.

Then as this movement reverses, the foot pronates into IR but the pelvis and hips ER. Is that correct, or am I missing something? Well, this is actually really interesting. It's a pretty good question because it doesn't appear to be as clear and clean as we would like, but principles hold in regards to the inner effects of movement and as well as our transitions from inhale to exhale to inhale to ER to IR to ER states. And so let's break this down into some pieces. We'll talk about the theoretical representation first. So we have some frame of reference to work from. We'll talk about the hinge part first. And so when we talk about the difference between a hinge and a squat, if we're going to use that terminology, our hinge assumes we have full excursion of breathing available to us before we initiate the forward bend into the hinge. But the hinge is going to bias us towards a nutated position of the sacrum. And what this allows is for the pelvis to move posteriorly as we bend forward. Because otherwise, if we didn't counterbalance, we'd just face plant. So we need to have some element of posterior expansion. So we get that in that posterior lower aspect of the pelvis. This is going to move the acetabulum towards an IR position. So we get an IR position at the hip. And then if we look on down the extremity, we're going to look at the knee. The knee's going to have to unlock. So the knee's going to have to bend, and that's going to move towards internal rotation as well. So we'll have a tibia that's internally rotating on the femur, which would be the position that we need for normal knee flexion. And then if we go on down to the foot, what we'll see is we'll see a foot that will move from its initial inhaled position, which would be ER supination. It'll move towards pronation. And that's gonna happen somewhere in that general vicinity of about 90 degrees of the traditionally measured hip flexion in the imaginary sagal plane. And then obviously to come out of that, we would just simply reverse gears. So we're going to move from our IR position back to our ER position. Now that's theoretical. So let's talk about reality because the way that these things get performed in the gym tends to not be so clean.

And so what that's going to do, when we talk about the forces down into the ground, we're going to move that foot towards its position of late propulsion, right? So as I would shift my foot forward, so the center of gravity is moving forward over the foot, what should happen is like if I was walking, I would be able to pick that heel up. But because we've got this posterior weight shift, the heel is going to get stuck to the ground. So I've got a foot that's moving into an ER position, but I also have a pelvis that's moving into an ER position. So I have a constraint problem that I'm going to run into. So as I nutate this, and I start to flex forward, I get posterior expansion, but I can only expand so much in this direction. And so then what I'm going to have to do, because I'm increasing the degree of hip flexion, I'm moving towards an ER inhale position, I'm actually going to counter-nutate. I'm going to move towards counter-nutation. So I'm going to get a posterior expansion this way, which is still going to help me keep my center of gravity backwards over my foot, but I've got this foot in a late propulsive strategy. So this is where we're gonna see that ER position. Now, if everything's moving towards this ER position, even though I'm still forward bent, I still need to have an internal rotation force into the gram. And so where we're gonna see that occur is in the thoracolumbar junction. So we're gonna see that above the lumbar spine. And that's gonna give us enough downward force. So we need to have a position of the center of gravity that's towards the middle of our stance and slightly in front so we can maintain our balance. And so what we end up with in this scenario as we pass the IR element of this hinging activity is we're going to get concentric overcoming posterior lower pelvis and thorax. We'll get a concentric yielding at the sacral base and in the dorsal rostrum. And so it'll look something like that.

Now it is possible that we can get more internal rotation at the hip, but it is going to depend on stance width and the actual orientation of the thorax as to whether we can acquire some of that internal rotation at the hip, but it is possible. Now, if we add load to this, obviously we're going to get more compressive strategy. We're going to get more superficial concentric orientation, which is immediately going to limit what we're going to have available to us. So when it comes to trying to recapture that internal rotated position, it's going to be much more difficult to do. And so a lot of times what you're going to see is you're going to see that a much earlier ER compensatory strategy under these circumstances. So you'll see people separate their knees as they're trying to initiate their hinge or you'll see them have to make an adjustment in their stance width. So Mihail, I would refer you to the kettlebell swing diagnosis video for an example of what I'm just talking about, where we're seeing the extreme ER compensatory strategies. So basically, you can see that it's not as clean as we would like it to be, but the principles do hold. I'm moving from ER strategies to IR strategies to ER strategies under every circumstance. It's just a matter of where it's going to happen. That's going to be dependent on how much movement we're trying to acquire, how much load we're using, what's our stance, and any pre-existing compensatory strategies.