I think we'll call this one kettlebell swing diagnosis. Good morning. Happy Monday. I have neural coffee in hand and it is perfect. Wow, okay. Looking forward to a great week. We got a pretty good Q&A for this morning. If those of you who like to swing the kettlebell and never have any questions or concerns about some technical issues, we've got one that's a little bit more specific to address and this question comes from Annie. And Annie says, I've noticed many of my clients, even the very mobile and symmetrical folks, tend to lose right side midfoot contact during kettlebell swings in the midway point of the hinge on the descent of the kettlebell swing. I'm wondering if this is a problem with the right hip missing some internal rotation. I'm thinking if the right hip is missing the kind of IR it needs for a deep squat or something further down the knee in the ankle complex and perhaps a bit of in range right hip extension too. However, extension looks, and Annie puts looks in quotation marks, looks normal left and right. What are the common causes and systems to properly address it? Is it even a problem? And thanks for all you do. I never stopped learning from your content. Thanks, Annie. I appreciate it. Hey, this is a really good question because I think it's really, really common. And so what Annie did is she actually sent me a video representation of what she's asking about. And she didn't know the rights to it. So she did send it to me though. And so what I did is I actually duplicated it. And so it looks something like that. And so I'm just going to let this run for a second so you can kind of see it. Put it in slow-mo to make it a little bit easier to see. And so there's some interesting findings here that are not all that uncommon. But first, let's consider what we really need to execute this kettlebell swing effectively. So there's two points in a kettlebell swing where motion has to actually stop and change direction. So what that means is that we have two propulsive efforts in every kettlebell swing. Now propulsion is an internal rotation bias and so what internal rotation means is that we actually have to produce force into the ground at those two points otherwise we don't really get a turnaround in this kettlebell swing. So we have to consider the key elements of our propulsive phase which means that we want to start from the ground up. So we have to have a middle propulsive foot and so let's go back through our foot contact here.

So if I consider an early propulsive foot, I have a tibia that is externally rotated and the tibia is actually behind the malleolus here. What I have to be able to do though is I have to bring this tibia towards internal rotation and I have to have an arch that will go downward, but I also have to maintain contact with my first metatarsal head here and my big toe here. So that's our middle propulsive foot. And so if we lose that contact, then we really don't have a strong middle propulsion from the ground up. And so if we see, in the representation of any question, what we actually see is we see an ER position of the foot. So we actually lose that medial heel contact. We lose the first metatarsal head. And so in this case, it looks like we're actually producing force into the ground in external rotation, which really isn't possible because external rotation actually moves us away from the ground. It's an expansive strategy, which actually lifts us up and reduces—this is a weird one—it reduces your total density, which is kind of interesting. So we're not really producing force in external rotation. So to stop the motion, that means that we have to have a compensatory strategy somewhere. And so if we don't have hip internal rotation, if we don't have a middle propulsive foot, then what we have to do is compensate with what is traditionally referred to as spinal extension. And what this actually is, it's a substitution for the distribution of internal rotation bias through the system. And so we're going to see the spine extend in multiple places, which is typically going to be a diagnosis of a posterior lower compressive strategy in the thorax and in the pelvis. So what you're going to see is a concentric orientation below the level of the trochanter. You can see concentric orientation below the level of the scapula in the thorax. You're also going to see it up into the cervical spine, which you'll also be able to identify by head position as people are swinging their kettlebell. Now, how does this happen? Well, so people will present with these strategies because this is just a gravitational management strategy. So they may actually walk in the door with it or it's a coaching error. And so this is really, really common. It's a concept that gets coached inappropriately in my mind with say a deadlift or any kind of hingey kind of stuff where they're trying to hit the end range rather aggressively, like a glute bridge and then like a bilateral hip thrust—really common in a bilateral hip thrust. And so what happens is as you're coaching this hard end range hip extension, you're actually moving the pelvis between the femurs, you're moving it forward between the femurs, and to get into that position I actually have to re-ER the hip. So instead of driving forces into the ground through this middle propulsive foot, what we end up with is this ER position throughout the system and then we have to promote some form of substitution.

between the femurs, you're moving it forward between the femurs and to get into that position I actually have to re-ER the hip and so instead of driving forces into the ground through this middle propulsive foot what we end up with is this ER position throughout the system and then we have to promote some form of substitution. So if you were to do like a glute bridge or hip thrust or something like that you see somebody's knees going out rather aggressively at this end range of hip extension, understand that you're actually promoting this concentric orientation in this posterior lower. Now, if that's what you desire, then more power to you. I just want you to understand that what you're actually doing. So, now how do we manage this thing? Okay, so go back to last week. Look at the narrow ISA end game video. There's a series of strategies that will help you alleviate some of this concentric orientation that you're dealing with in the posterior lower pelvis and thorax. Now, we can also use some of our split squat variations. So if you use a contralaterally loaded split squat, so contralateral to the front leg side, what this is actually going to allow you to do, it's actually going to allow you to more easily move that lead hip into internal rotation. Now, when you come out of this, because of the loading strategy, you're actually going to overload the extra rotation moment as you come out, which is concentric orientation. But if you hang on to the middle propulsive foot, so big toe, first met head, medial heel on the ground, you're actually gonna teach them how to maintain the IR bias under load. So you're actually gonna teach them how to capture this middle propulsive strategy. Once you can do that, then you want to superimpose some velocity on top of it because we're talking about a very dynamic explosive type of propulsive exercise like a kettlebell swing. And so we have to superimpose velocity. Otherwise, they're going to fall back into the old strategy of trying to substitute with spinal extension. We don't really want that. And so what you can do is use a split variation of your kettlebell swing. So this is a swing that's on a diagonal from the split stance. And so again, we're using the same strategy we just used in the split squat to capture the IR and then maintain the propulsive, the middle propulsive foot on the ER.

Mentorship calls this morning, big clinic day coming up, so we're going to dive right in at the Q&A, and this one comes from Jimmy. So Jimmy watched the three impingements, three strategies, three solutions video. And at the end of that, if you watch it all the way through, shame on you for not watching it all the way through, there's a little bonus comment about the fourth impingement. And so that's what Jimmy's question is about. He says, I watched your latest video on children impingement. I was wondering if you could go into more detail about the posterior internal impingement. and how this presentation usually occur in regards to the architects. And so it can present itself in both architects. It's going to be a little bit more of a bias towards one for reasons that you'll see. Excuse me. But the thing that we want to recognize that is in common with this is that this is a down pump handle sternum problem in all circumstances. And so basically we just have to look at the archetypes and what their biases may be and we'll kind of see this. So the easiest one to see is to look at the narrow and we've kind of looked at this before. Well we start with some sort of normal representation and then the narrow archetype is going to initiate the compensatory strategies with more of a down pump handle situation so we get a lot of anterior compression through the sternum. What that does is it creates a posterior expansion relatively speaking. I'm going to grab my shoulder model here for a second. And so we got the backside of the shoulder here. And so what we'll see then is this would be where the dorsal rospital area is. We'll see a turn this way and we get a compressive strategy right here on the backside of the shoulder. And so that again, that's why people reach over their shoulder and they point to that area probably the most accurate test that you'll get. So it's this angulation of the scapula relative to the tumor. So anytime we have that situation, we have the potential for this type of a compressive strategy. For the wide, it's a little bit different because they have to get there with one prior step. So with the wide, when we look at the compensatory strategies, we're typically going to see a dorsal rostral compression first. Under those circumstances, we don't get that angulation of the scapula relative to the humerus, so the internal impingement doesn't really show up too often. If we get the next layer of compensatory strategy where we get an anterior compression that follows, and this is a center of gravity issue, so we're trying to maintain center of gravity, so we push back against the sternum, we compress that downward, now we bring the lateral aspect of that scapula forward to compress against the thorax, and now we can pick up this angulation that we're talking about between the scapula and the humerus that would cause this internal impingement. There's a little bit of a difference here because when we talk about the the the Y's this will typically show up in some somebody that still has the posterior lower expansion the root cage so this is not typically going to show up in an end game presentation and so where we are talking about the narrow where we have this kind of anagulation with the with the wide They pulled this part of the scapula back forward to the thorax, and then there's a little tilt this way. So this is the posterior lower expansion that tilts this on a little bit of an anterior orientation. And then we get the compressive strategy a little bit more superiorly than posteriorly as we would see in the narrow. Now, in an asymmetrical presentation, we can still get this situation as well. It's going to be very similar to what the narrow kind of looks like because the term that's associated with the asymmetrical ISA presentation, we get the posterior expansion on the side, we get the same kind of an angulation as we would see in the narrow.

If we get the next layer of compensatory strategy where we get an anterior compression that follows, and this is a center of gravity issue, so we're trying to maintain center of gravity, so we push back against the sternum, we compress that downward, now we bring the lateral aspect of that scapula forward to compress against the thorax, and now we can pick up this angulation that we're talking about between the scapula and the humerus that would cause this internal impingement. There's a little bit of a difference here because when we talk about the archetypes this will typically show up in somebody that still has the posterior lower expansion, the rib cage, so this is not typically going to show up in an end game presentation. And so where we are talking about the narrow where we have this kind of angulation with the wide, they pull this part of the scapula back forward to the thorax, and then there's a little tilt this way. So this is the posterior lower expansion that tilts this on a little bit of an anterior orientation. And then we get the compressive strategy a little more superiorly than posteriorly as we would see in the narrow. Now, in an asymmetrical presentation, we can still get this situation as well. It's going to be very similar to what the narrow kind of looks like because the term that's associated with the asymmetrical ISA presentation, we get the posterior expansion on the side, we get the same kind of an angulation as we would see in the narrow.

And what this is going to do is start to apply a stronger posterior compressive strategy and again drive that volume forward anteriorly into the pump handle. So your key performance indicators in this situation are going to be a restoration of shoulder internal rotation as the external rotation will gradually decrease. At this point we can start to move the shoulder back into external rotation positions and a posterior compressive strategy. So this is where your T's, Y's, and I's fall into play. Your PNF patterns are going to show up here. And then face pulls as well. I'm still a big fan of doing these activities laterally rather than bilaterally because I just don't want to create a pure compressive strategy under most circumstances. There are situations where we may do that. Like if we're working with somebody that has to perform a lot of pressing activities, we might utilize that. But again, we also might be sacrificing some other things as a trade-off.

Now, yes, it's a solution from a pain standpoint, but I also may be sacrificing shoulder range of motion. So you're going to have to make a choice there as to if you want to use that strategy or not. Under some circumstances, it may not be a problem. If I'm a powerlifter and I'm concerned about pushing my numbers up on the bench press, this actually might be performance enhancing to a degree and alleviate some shoulder discomfort because I'm not really concerned about maximizing shoulder range of motion from an athletic standpoint or a gen pop standpoint. For a general population, it might not be the strategy we want to go with, but I just wanted to throw that out there because it does happen, but I don't want everybody to think that it is the solution for every circumstance because it can cause secondary consequences. Jimmy, great question. Thank you for following up on that video. I really appreciate you for doing that. If I didn't answer your question, please ask me another one at askbillharman at gmail.com.

And each one of those is represented in the human body by internal and external rotation. And so all movements are based off of those two rotations, which fall into the transverse plane. So again, two strategies, one plane. I put together the archetypes as the wides and the narrows. What I did is I was constructing the archetypes to represent the two extremes. So one is this massive compressor, one is this massive expander. And so that's why they have these biases towards certain strategies. The thing that you want to recognize, regardless of the archetype, is that as we apply forces into the ground, we are superimposing internal rotation on top of external rotation. And so one of the limitations that I think most people have because of the way that they've been educated and because of the way the information is presented is that there's certain areas of your body that internally and externally rotate and there's certain areas that don't or they do the opposing and the thing we're going to recognize is that internal and external rotation is systemic. So it's the entire system that is moving into and out of internal and external rotation. It's supported by the breathing mechanism as we internally and externally rotate. And so when we run into compensatory strategies or other limitations that are superimposed upon us, that's where we might have problems that arise because now we have to strategize how to maintain our two strategies under some certain circumstance or limitation or some other context. Again, if we want to look at this thing as how we distribute these things, we can look at the foot, and David mentioned this, is that, okay, so what I want to be able to do to alleviate the pressure on the knees, I need to be able to acquire this middle propulsive strategy where this arch goes down and I get the tibial internal rotation. If I can't do that, so if I have an orientation or I have a strategy that I have to use where I'm trying to maintain a supinated foot, I have just eliminated my ability to distribute internal rotation throughout the system, and now I might get a focal load. So maybe that shows up as a knee compensatory strategy. And now I have too much internal rotation force that's applied locally, and then that might result in a pain experience. So structure and strategy are going to help us determine how we're going to produce these forces. And once again, if we don't distribute them well, we're going to find a way. You're going to find a way to internally rotate. What I want you to start to recognize is that anytime you use the words extension, adduction, or internal rotation, we're talking about the exact same thing. This is a force that goes into the ground. So we will find a way to apply force into the ground.

So now let's take this up to the pelvis for a second. So let's just say that I have some form of compressive-compensatory strategy that is going to take away some of my internal rotation via orientation, compression, etc. What I might see is somebody anteriorly orienting their pelvis forward. This is another attempt to get force into the ground. So this is internal rotation. That again might limit my ability to distribute. So now maybe somebody walks in with back pain. So the solutions for us as practitioners and coaches when we have limitations in movement, when we have situations where people might be becoming to us with pain experiences is we have to determine what strategies that they are using. And then as we alleviate that and we teach them how to redistribute these forces throughout the system, this is the solution in many, many cases. Not every case. Sometimes we have constraints that have changed. Sometimes we have neurologic influences that will supersede the biomechanical aspect of this. But in many, many cases, we've just failed to distribute these forces. And so I would encourage you, number one, as a solution is learn how to measure reliably. You have to create a representation of what this person is bringing to you in three dimensions, preferably four dimensions, because we do have a time constraint here under many cases. Secondly, you need to recapture external rotation. So, external rotation is a very, very broad field. Internal rotation is superimposed upon it. If I have limitations in the expansive capability, which means I've limited ER, I've immediately limited my IR capabilities, and now I have a limited capacity to distribute force and load throughout the system. Once I recapture the extra rotation, that's the time to start this superimposed internal rotation upon it in a distributed manner if my goal is to increase adaptability. When we're talking about performance, when we're talking about taking somebody into the weight room, or we're training them to produce speed and force and power, we may intentionally restrict the adaptability to create these high levels of performance because higher force output speed demands that we have limitations in movement. So we might have to do that intentionally, but we monitor them over time, keep performance indicators to make sure that we don't end up with vocal pressures, potential destructions, et cetera, et cetera. We just do the best we can. Injuries are gonna happen no matter what. So, David, thank you, thank you, thank you. I love talking about the two strategies, one playing concept. It's so simple, but it needs to be understood so it can be applied effectively so we can provide solutions to our patients and our clients. Everybody have a fabulous Wednesday. Coffee and Coaches Conference calls 6 a.m. tomorrow. I will see you guys there. Have a great day. Happy Thursday. I have neuro coffee in hand and It is perfect.

Bill kind of building off of all this. If you were dealing with one of those bodybuilders that step on stage at like 260 pounds that has pretty gnarly sciatica from it, how does your thought process and handling that change? Because now this guy's going to keep training and keep trying to push the needle forward. What's, I guess, like a result of a similar positional thing, like that posterior chain, just pushing forward? And how would you go about managing that? Cause this guy's going to want to squat heavy. He's going to want to leg press heavy. He's going to want to do all this stuff. What would be your guiding light for that?

Well, you're dealing with an adult conversation with him where you say, look, the chances of you feeling great if you're not willing to make the changes that I need you to make are slim. But something that if he can't deep squat would be a place that you might need to go as a representation of creating the posterior expansion that you're going to need. Because a lot of times, if you can get them to do that, again, if they can't already do it unless they're like those kind of guys where they're squatting like 500 pounds, 600 pounds on a regular basis, that's how they deep squat. They get pushed into it, right. They have a massive yielding strategy that allows them to get down there. But you're going to need something that is representative of them getting sufficient posterior expansion because they're losing the field of external rotation. The external rotation gets narrower and narrower and narrower and it starts to compress the internal rotation as well. So then they get kind of stuck in the middle where they don't have sufficient external rotation and then the internal rotation they do is like maxed out. And so what we always want is a broader field of external rotation than internal rotation. That's what you want to chase first.

What would be kind of like your litmus test? Would it be the ability or like what would be your kind of KPI? Would it be the ability to get down below parallel and hold it or would it be a? I would want to be able to, I need them to get as low as possible without the posterior orientation. So, here's what we don't want to see. We don't want the pelvis and the lumbar spine to move as a single segment in a posterior orientation. So you don't want that lumbar flexion moment. Okay. You got to be able to identify the difference between the posterior orientation with the lumbar spine inflection versus somebody that can deep squat into counter-neutation with the lumbar spine following as it normally would, right?

I would want them to be able to get as low as possible without the posterior orientation. So here's what we don't want to see. We don't want the pelvis and the lumbar spine to move as a single segment in a posterior orientation.

So you don't want that lumbar flexion moment. Okay.

You got to be able to identify the difference between the posterior orientation with the lumbar spine inflection versus somebody that can deep squat into counter-neutation with the lumbar spine following as it normally would, right?

What are some long-term negative repercussions of squatting that deep with the lumbar moving posterior like that?

Take every negative side effect associated with lumbar flexion and count them up. The difficulty people have is distinguishing between the two. Once you've seen both, you'll identify the difference. The cool thing is you've probably already seen this and watched it change for the better just by watching guys add more weight to the bar. If you've ever seen a guy squat 400-500 pounds and watch him warm up with 135 lbs, it looks horrendous. By the time he reaches 400-500 pounds, he has a really pretty squat because now he can use a yielding strategy—his tissues are stiff from heavy lifting, so when he squats without load, he has to use a posterior orientation. But with weight on him, he demonstrates a yielding strategy with proper yield in the pelvis, sacrum, and lumbar spine—the way it should be in a good squat. Do you understand?

I know exactly what you mean. I know what you're trying to do. There is a difference. There is a difference. When Seth and I squat with the safety squat bar, we rig it in such a way that lets us get tremendous depth, but we definitely get some of that lumbar flexion. It's weird though, because it feels incredibly safe. It doesn't feel like we're in a position that might be compromised. It feels like we're not necessarily that heavy yet, but it feels incredibly safe. It almost feels like we're just driving a piston up and down.

So make a comparison. Get like a 10 degree heel elevation. And then do it flat footed and make the comparison. Because you'll feel the difference because the heel elevation will give you a yielding strategy more so than your heels flat under most circumstances. And that will give you even a better sense of what you're actually doing.

Yeah.

And then do it flat footed and then make the comparison. OK. Cause if you feel, cause you'll feel the difference because the, the, the heel elevation will give you a yielding strategy more so than your heels flat under most circumstances. And so that, that will give you even a better sense of, of what you're actually doing.

Can you show a representation of the two that you're discussing? Of the lumbar flexion versus I think, and I was gonna say, wouldn't a heel elevation change that?

I have to actually use a term that I never use, because I hate it with a passion. When people talk about buttwink, what that is, is the posterior orientation of the pelvis and the flexion of the lumbar spine as a single unit. And that's the negative representation of it. So when the whole pelvis posteriorly rotates, from the front you get a rounding of the lower back. That's problematic because under most of those circumstances, the sacrum is still nutated and relatively speaking, you get deflection in the lumbar spine. That's where you get everybody going, 'wow, look at the size of his erectors,' and it's like, 'no, that's the lumbar spine flexing.' Now, as you capture depth and you get below 90 degrees of deflection, if I can get the sacrum to counter-nutate a little bit, and then you'll see the indentation at the thoracolumbar junction, so T11-12 will still have its little inward curve. Then you'll see the lumbar spine come back out and there'll be a nice relationship where it's almost, I don't want to say flat, but it's not the big rounding under of the pelvis when they hit depth. Once you see it, you'll understand the difference in the two where one is a counter-nutation of the sacrum and the other is a nutation with the orientation. And the one with the nutation and the orientation is not what you're looking for. You can get away with it for a while, but it's just not recommended because chances are, under those circumstances, you're walking around with a nutated sacrum. You've got an anterior orientation of the pelvis, which creates a compressive strategy on the backside of the lumbar joints. This puts pressure on the posterior aspect of the disc. Enough pressure on the disc in that way reduces the blood flow to the bone above and below the disc that supplies the disc with its nutrition. The disc starts to break down. And then you have a flexion moment. Everybody says, 'oh, flexion causes the disc herniation,' which is like, 'yeah, it's the end result.' But it was the other stuff that you did before with the compressive strategy that promoted the degeneration of the disc, the weakening of the radial structure of the disc. So you have to have all this extension-based compression first, then you have a flexion moment. That's why we want to avoid flexion.

There, your world's changing.

Yeah, well, sometimes you gotta speak the language to make a point, right? This is really hard for me to say it out loud. Okay, when people talk about but wink, what that is, is the posterior orientation of the pelvis and the flexion of the lumbar spine as a single unit. And that's the negative representation of it. And so when the whole pelvis posteriorly rotates, and if I'll show it from the front, and I get that kind of a thing, right? So it does that. Okay, that's bad because under most of those circumstances, the sacrum is still nutated and relatively speaking. And then you get deflection in the lumbar spine. That's where you get everybody goes, wow, look at the size of his erectors. And it's like, no, that's the lumbar spine flexing. Okay, now, as you capture depth and you get below 90 degrees of deflection, if I can get the sacrum to counter-neutate a little bit, and then you'll see the indentation at the thoracolumbar junction, so T11-12 will still have its little inward curve. Then you'll see the lumbar spine come back out and there'll be this nice relationship where it's almost, I don't want to say flat, but it's not the big rounding under of the pelvis when they hit death. And like I said, once you see it, you'll understand the difference in the two where one is a counter-neutation of the sacrum and the other one is a nutation with the orientation. And the one with the nutation, the orientation is not what you're looking for. You can get away with it for a while, but it's just not recommended because chances are, under those circumstances, you're walking around with a mutated sacrum. You've got an anterior orientation of the pelvis, which creates a compressive strategy on the backside of the lumbar joints. So what that does is it puts pressure on the posterior aspect of the disc. Enough pressure on the disc in that way reduces the blood flow to the bone above and below the disc that supplies the disc with its nutrition. The disc starts to break down. And then you have a flexion moment. And everybody says, oh, flexion causes the disc herniation, which is like, yeah, it's the end result. But it was the other crap that you did before with the compressive strategy that promoted the degeneration of the disc, the weakening of the sort of the radial structure of the disc. So you have to have all this extension based compression first, then you have a flexion moment. That's why we want to avoid flexion.

Lots of really cool mentorship calls. Kind of had like once again the perfect storm of questions that came through this week. And there was a whole series of foot related stuff that came through some mentorship calls and some of the Q&A's. And so I thought I would just wrap up Friday with a little bit of perspective on the performance-related foot because I think it's still a little bit of a challenge for people because of some of the biases that have been created over time and some of the perspectives as to what constitutes a good performance foot versus one that is interference. And so I want us to look at this thing differently. Now, let me preface everything that I'm about to say is that performance is multifactorial. There are so many potential influences here. It's not just a foot thing. The foot is one part, but we're gonna talk about it in isolation to give you a little bit of perspective. So the things that you also probably need to consider is like, okay, what kind of an archetype are we dealing with? What are some of the proportional issues in physical structure? So the size of your thorax relative to the size of your pelvis is an influence in performance. Your proportions as far as you know the length of your actual skeleton to the length of the appendicular skeleton is an influence. Your force to weight ratio, etc., etc. So again, let's keep this in perspective, okay? The first thing we want to do then is we want to review a little bit about the simplified foot model. So we're going to go through the phases of this foot position. So our traditional heel rocker would represent this early propulsive phase. So as I bring the medial calcaneus to the ground and I get the forefoot to the ground and the toes are extending, the tibia is still behind the foot. So this is an ER position. So I still have an arch and I've got an ER tibia relative to the foot. And so that's my early propulsive foot. As I move through middle, this is where the arch is going to move down towards the ground. So this is your traditional pronation. This is tibial interrotation. So this is a lower arch. Now, here's the key element of this that I want you to understand is that the maximum force into the ground is that maximum pronation. And where that is, max propulsion is just as that medial calcaneus has re-bared from the ground. And so this is actually a low position of the arch because right after that I'm going to get a bunch of concentric orientation on the plantar aspect of the foot. This is what they traditionally call that windlass effect and I'm going to crank that sucker back into an externally rotated position, right?

And that is traditionally considered this high propulsive foot with the force application came just prior to that. And so this is the demonstration of what happens after that force production. And so when we talk about a performance related foot, this is why we're going to see lower arches on a lot of these really, really high performance feet. So people look at these feet and they go, oh, these are really crappy feet because pronation has always been described as this accommodative foot position, which is not untrue. But the highest force production also happens in maximum pronation. So that's where our max propulsion is. So when we look at feet like this, it can be a little confusing as to why we would see these low arches. But what they're actually doing is it's a time saver that allows these athletes to get to maximum propulsion much faster than what we would consider our non-athletic population. So that's what they're representing. Now, we've got some subtle differences between these low arched feet as well that we can talk about. If we have someone that is closer to maximum propulsion than, say, another athlete, what you're typically going to see under these circumstances is you'll see, if we were to make a comparison in performance, we would see a better broad jump than vertical jump. So it doesn't mean they're bad vertical jumpers, it just means that as a representation of where they perform the best, they are better at horizontal projection because they are so much closer to maximum propulsion than another athlete would be. And so they'll have the quicker first step. They'll have great acceleration. But what you're going to measure, to throw them on the table, they're going to be biased more towards external rotation. So remember, as I break that foot, I get this concentric orientation that's going to move me quicker towards the ER. So what happens is they have a reduced yielding strategy, which again, that dampens their ability to produce a vertical jump, but it also improves their horizontal projection. They're going to have limited hip flexion. They'll probably have a limited straight leg raise, et cetera, that's associated with this extra rotation bias and a reduced yielding strategy. If I move you back just slightly from max propulsion, I have now just increased the amount of time that you have between where you are as a representation of your center of gravity and maximum propulsion. So in doing so now, I've actually increased the time that you have to produce a yielding strategy. These are the people that will have a better vertical jump than broad jump as a representation. But they're going to be a little bit slower in regards to change of direction. But they're going to have better top speed because their vertical projections are better. They're going to have slightly less external rotation bias. So they're going to have a little bit more of an internal rotation capability than, say, our guys that are better horizontal projectors. And so they'll have a little bit better hip flexion, a little bit better straight leg raise.

So they're going to have a little bit more of an internal rotation capability than, say, our guys that are better horizontal projectors. And so they'll have a little bit better hip flexion, a little bit better straight leg raise. So if we look at a couple representations of feet, I'll try to show you the subtle little difference. So what we have right there is a pair of feet that can run a 4-4-40. So he is very, very good at acceleration. He is very, very good at change of direction. So this is a Division I football player. And he played four years of high level Division I football. This other representation right here looks very, very similar, but this is a better vertical jumper than a horizontal projector. And so this is actually a very, very high level basketball player. And so he's got a better vertical jump than horizontal projection. And so again, subtle differences as to how close these guys are to their maximum propulsion phase. Now, let me show you another pair of feet that don't jump very well and not very fast, but also on a very high level basketball player. So this individual has a much higher arch. He has positioned much more into an earlier phase. So he's a little bit slower. He doesn't jump as high and he's not as fast. Doesn't mean that he can't play high level basketball. It just means that he's going to rely on other things. This person also happens to be exceptionally tall. And so again, we have all of these representations. So again, everything's multifactorial from a performance perspective. There are many different different ways that these people can perform. But what we want to start to think about is like, okay, I have these different feet. They're going to be better at different things. And it is one element that supports this high level of performance. Now, let's take this into the clinic. I can take these same concepts and I can start to look at my, quote, unquote, normal people from a very, very similar perspective. When I see a pair of feet that might be more pronated, so the arch is lower to the ground, I might have this person that is struggling with gravity. And so they're in a situation where they're constantly producing a higher force into the ground because they're just not managing gravity as well. You will have the compensatory strategies that we'll typically see help a lot of concentric muscle orientation and therefore a lot of limitations in range of motion. Under those circumstances, we probably want to move him away from maximum propulsion to give him the capacity to move through his extra rotation to intro rotation strategies. And this allows him to move away from the ground to reduce the concentric orientation and then restore a lot more of the active range of motion that he's missing.

So again, it's just a matter of perspective of what we're looking at. But feet are always a great representation of this. They're very confirming as far as some of your measures that you're going to find on up the chain, so to speak. So some of your top-down influences are going to be represented in the feet. If you can't manage this from a top-down influence, then it may be time to do something about this at the foot. So maybe this is your manual therapies for the foot. Maybe this is selecting activities that are specifically designed to improve the representation of sensation from the ground up. Maybe this is the person that you put in an orthotic as a solution to give them the capacity of adaptability. Performance is an intentional reduction of adaptability to create a higher level of output. Whereas when we're trying to make people more adaptable, such as the rehab situation, now we need to take away some of that reduction in adaptability, restore it to give them the ability to reset, reduce that concentric orientation and then restore ranges of motion. So hopefully that just gives you a little bit of perspective on what we're talking about when we're talking about the performance related foot and how it might be related to what we're measuring on the table or what we're seeing on the court or on the field.