Assuming mid propulsion falls in this propulsion phase, would mid-propulsion be in an exhalation bias, and I would say absolutely it is. So as we move through the phase of propulsion, we're going to be landing in an ER inhalation strategy, we have to move through this middle phase of propulsion where we're going to increase that IR gradient, exhalation bias gradient, and then as we leave and we go into this late propulsive phase, we're going to re-externally rotate, and we're going to move towards that inhalation bias again. Now, Slasher continues, he said, I would think that late propulsion would be a max propulsion stage of gait, and then that would be biased towards an exhalation moment, but based on the way that the propulsion is presented, it's an ER orientation. Is this correct? Or is it externally rotating from a state of internally rotating that gives me my late propulsion?

And so what we'll find is that the maximum propulsion is going to occur as the calcaneus breaks from the ground. So if I have my foot, my reposition of the foot, so I landed early, I've got a high arch, I'm externally rotated, I've got a plantar flexed first ray, and as I moved the tibia over the foot through this middle phase, The belief is that that is going to be the late stage of propulsion. Now it's late in regards to how we designate the segmentation of propulsion but it's not the highest force. The highest force actually comes right as I break the calcaneus from the ground because this is the point where from a traditional standpoint maximum pronation actually occurs. So here's what we want to do. We want to think about this from an evolutionary standpoint. So we were swimmers before we were walkers and so our biases towards inhalation to float and external rotation because we didn't have to produce force against a fixed point and so we used a lot of external rotation as swimmers. So just watch the frog swim and you'll get the idea. When we come up on land and we have to deal with gravity, this is where we started to learn how to internally rotate and produce force. So the point of maximum internal rotation is actually the point of maximum force production. And this occurs at the very end of this middle propulsive phase where traditional pronation is at a maximum. Where else will we see this? Well, we're going to see this in any rotational sport where we have to stop our turn to create some sort of forward momentum and do an implement. So if I'm throwing a baseball, if I'm swinging a golf club, if I'm swinging a tennis racket, All of these sports will demonstrate the same element where I will have a maximum propulsion where actually have to stop motion and I translate that into the implement and that is the point of max propulsion during those activities. So if we think about a baseball pitcher, it's when the lead leg that's stepping towards home plate hits its point of maximum propulsion is as they're landing through the heel and because they never get towards this end propulsive phase except through follow-through, which is actually an external rotation moment, which is actually a re-inhalation, if you will, as they're following through. So again, maximum propulsion is not in this late phase of the propulsive continuum, regardless of what activity that we're talking about, whether we're talking about gait, whether we're talking about sport. It's actually at the point of the maximum pronation that is an internal rotation strategy that is an exhalation bias. So, Slasher, I hope this helps you. I hope it helps all of you because it's gonna help you make some really good decisions in regards to how you're gonna rehab some of these people.

As well as exercise selection in the gym. Have a great Monday. I will see you guys tomorrow. Good luck, Josh. Good morning. Happy Tuesday. I have neural coffee in hand and it is perfect. All right, sun is out. I'm going to walk here in a little bit. Very excited about that. And I mentioned this yesterday, but I'm going to mention it again today, Josh Limblum, Milwaukee Brewers pitching today. So very excited about that. Good luck, Josh. Hope you do exceptionally well. I have no doubt in my mind that you will. Now, apparently foot week continues. But it's going to be like foot month at this point, I suppose, we're a couple weeks into this. I do have a foot-related question, but it also involves cutting and change of direction and some curve sprinting and things like that. So it's an interesting application of what we have been talking about in relation to the foot. Questions come from Justin. I know who Justin is, so I know what he's been doing. He's working with athletes and he's got some cool stuff going on. This will be, like I said, a fun question. He breaks it up into two pieces. Justin also asked if I can clarify the rear foot position in the max propulsive foot versus the late propulsive foot. When we're talking about max propulsion, we produce force best in internal rotation. And so when we think about the maximum force that we could produce, that would be the most IR position under most circumstances. So if we talk about throwing a baseball, when we release a baseball at maximum velocity, the hand would be at maximum pronation. And in fact, the whole body is going to be relatively pronated under those circumstances. So if you look at the ground contact on the foot, it's going to be maximally internally rotated and such. Right off the bat, when we can produce our maximum force, we're going to be at the point of maximum internal rotation. In the foot, that's going to be the maximum of what would be called traditional pronation. So again, if I get my little foot model out here, so where the maximum pronation occurs is actually just as the heel breaks from the ground. And this comes from some of the shoe research where they actually stuck bone markers in feet. So it's fairly accurate as to when this actually occurs. In the later stage of propulsion where the heel is much higher off the ground and we've got that, the toes extended and we get that restoration, let me turn it this way, we get that restoration of the arch where the foot is so-called resupinating. That's an ER position of the foot and that's going to be, there's less force produced there. So I would equate that to, again, if we talk about throwing a baseball, maximum propulsion would be at the point that I release the ball. Everything after that is followed through, which is a re-extra rotation of the body to create the appropriate deceleration. And that's where arm velocity can be demonstrated. So again, hopefully that clarifies where this max propulsion actually is. It doesn't mean that we're always going to hit the optimum maximum propulsion. And so now we're going to talk about that in regards to some cutting and some curve running if you will. So actually running on a curve, which you'll see wide receivers will do these kinds of curved runs or you're going to see it in track and field obviously when they have to run the 200 or 400 meters where they're going to run on a curve. And under those circumstances, the inside foot of the curve and the outside foot of the curve are not doing the same thing, but we can relate it to other things that we do see in agility. So let me go to Justin's second question here. He says, I've been interested in the curve sprinting. He came across some information. And he says that they found a more lateral center of pressure relative to the second ray at push-off. And he's talking about the inside foot of the curve. So if you're running a curve to the left, as you would in track and field, we're going to talk about the left foot under these circumstances. And they suggested that one of the limiting factors in curve sprinting performance is the inside leg, because it's been shown to be more affected by the curve than the outside leg. And you want to know how this is going to affect the propulsive strategy under these circumstances, and are there any training considerations? So, inside foot. We have a couple of considerations on the inside foot. The ground contact time is going to be longer. The relative orientation of the rear foot. So they describe it as eversion in the literature. And I'm going to call it the late propulsive foot because what we have is a lack of relative motion between the talus and the calcaneus and so we're going to see a lot of that type of an action on this on this inside foot. When they're talking about pushing off the lateral aspect we're going to push off the the second third fourth and fifth metatarsal relative to the to the first and the second so the outside foot is going to push off of these two as they're running the curve. The inside of the foot is going to push off of these two. We have a stronger medial to lateral force through the foot on the inside foot because we have to maintain a centripetal force towards the center of the curve. Otherwise we don't run a curve. We run in a straight line. Now, having said that, we don't actually run in curves anyway. Humans run in straight lines. So you think about the fact that you've got a flight phase in running where you're actually not touching the ground, which means you cannot reorient yourself relative to ground. So only during ground contact do we have the ability to create the turns. So one of my feet is on the ground, I have to create a centripetal force towards the center to maintain the curve. So again, the left foot has to behave a little bit differently than the right foot under those circumstances. But the cool thing is, because we don't run curves, all we're doing is performing repetitive cuts. So we can use some of the cutting research to help us understand what's going on when we're running these curve runs. Now we go back to two strategies, one plane. And you've probably heard me say that before. Do you follow any of this stuff that I do here? On the Instagram or on YouTube, we're going to have two different approaches to how we run these curves or how we run a predictable cutting maneuver. So if we're in an environment that is predictable, like say running on a rain track where you're running between the two white lines or you're performing an agility drill where you know where you're going to be making the cut, there's going to be two strategies that show up. There's going to be one strategy where you have people that can actually reposition the pelvis and the hip over the foot before they make the cut. And so let's just say that they're narrow, infraternal angle people that can actually create a yielding strategy on the inside leg of the cut or the inside leg of the curve. So what they do is before they make their plant with the outside foot, is they've already oriented the pelvis so that the left side hip, if we're running on a running track, the left side hip is positioned into internal rotation. So they have this capability to create the delay on the left side. It allows the right side to land in a little bit more of an early position of the foot, so an early propulsive foot on the outside foot and then that allows them to make the turn or the cut in a predictable environment. The other strategy is someone that cannot make this repositioning prior to the outside foot landing. And so they have to use a totally different strategy. So they use more of a rear foot contact, which is actually a later stage of propulsion. And then they use the hip musculature to make the turn. This is a lot less efficient. It's much more energy intensive. But again, it's going to be a structural thing or a behavioral thing that's going to result in one of these two strategies because on the first strategy where I have the person that can reposition themselves as they go into the curve, they have this capability. It's going to turn out to be a structural or a trained capability where you have more internal rotation on the inside leg. Whereas, again, the people that don't turn as well, they're going to tend to be your wider ISAs. They're going to tend to be more of your nutated people. They're going to have to rely on the plant from the outside foot and then make the hip turn there. So right away, you can start to see where these strategies for training may lie. So if I can improve someone's capability to capture internal rotation on this inside leg, I may actually improve their ability to make these cuts or these curve runs more efficiently. But keep in mind that you're going to run into some limitations with structure. So for my say an offensive lineman per se, his ability to make this anticipatory orientation into the cut is going to be less or so than my wide receivers, but their physical structures are also different. So this is why wide receivers look a certain way and offensive lineman look a certain way because again, their body types put them in those positions and make them more ideal for those situations. So Justin, I hope this gives you a couple of ideas about how to address these things and it helps you represent the differences. But always keep in mind, it's like when I'm doing a curve run, all it is is a series of cuts. So if I can understand how the cutting works, then I understand how the curve runs work. So again, two strategies, one plane.

Everything after that is followed through, which is a re-extra rotation of the body to create the appropriate deceleration. And that's where arm velocity can be demonstrated. So again, hopefully that clarifies where this max propulsion actually is. It doesn't mean that we're always gonna hit the optimum maximum propulsion. And so now we're gonna talk about that in regards to some cutting and some curved running if you will so so actually running on a curve which you'll see wide receivers will do these curved runs or you're going to see it in track and field obviously when they have to run to 200 or 400 meters where they're going to run on a curve. And under those circumstances, the inside foot of the curve and the outside foot of the curve are not doing the same thing, but we can relate it to other things that we do see in agility. So let me go to Justin's second question here. He says, I've been interested in the curve sprinting. He came across some information. And he says that they found a more lateral center of pressure relative to the second ray at push-off. And he's talking about the inside foot of the curve. So if you're running a curve to the left, as you would in track and field, we're going to talk about the left foot under these circumstances. And they suggested that one of the limiting factors in curve sprinting performance is the inside leg, because it's been shown to be more affected by the curve than the outside leg. And you want to know how this is going to affect the propulsive strategy under these circumstances, and are there any training considerations? Okay, so inside foot. We have a couple of considerations on the inside foot. The ground contact time is going to be longer. The relative orientation of the rear foot. So they describe it as eversion in the literature. And I'm going to call it the late propulsive foot because what we have is a lack of relative motion between the talus and the calcaneus and so we're going to see a lot of that type of an action on this inside foot. When they're talking about pushing off the lateral aspect, we're going to push off the second, third, fourth and fifth metatarsal relative to the first and the second. So the outside foot is going to push off of these two as they're running the curve. The inside of the foot is going to push off of these two. We have a stronger medial to lateral force through the foot on the inside foot because we have to maintain a centripetal force towards the center of the curve. Otherwise we don't run a curve. We run in a straight line.

So you think about the fact that you've got a flight phase in running where you're actually not touching the ground, which means you cannot reorient yourself relative to ground. So only during ground contact do we have the ability to create the turns. So one of my feet is on the ground, I have to create a centripetal force towards the center to maintain the curve. So again, the left foot has to behave a little bit differently than the right foot under those circumstances. But the cool thing is, because we don't run curves, all we're doing is performing repetitive cuts. So we can use some of the cutting research to help us understand what's going on when we're running these curve runs. Now we go back to two strategies, one plane. And you've probably heard me say that before. Do you follow any of this stuff that I do here? on the Instagram or on YouTube, we're going to have two different approaches to how we run these curves or how we run a predictable cutting maneuver. So if we're in an environment that is predictable, like say running on a running track where you're running between the two white lines or you're performing an agility drill where you know where you're going to be making the cut, There's going to be two strategies that show up. There's going to be one strategy where you have people that can actually reposition the pelvis and the hip over the foot before they make the cut. And so let's just say that they're narrow, infraternal angle people that can actually create a yielding strategy on the inside leg of the cut or the inside leg of the curve. So what they do is before they make their plant with the outside foot is they've already oriented the pelvis so that the left side hip, if we're running on a running track, the left side hip is positioned into internal rotation. So they have this capability to create the delay on the left side. It allows the right side to land in a little bit more of an early position of the foot so an early propulsive foot on the outside foot and then that allows them to make the turn or the cut in a predictable environment. The other strategy is someone that cannot make this repositioning prior to the outside foot landing. And so they have to use a totally different strategy. So they use more of a rear foot contact, which is actually a later stage of propulsion. And then they use the hip musculature to make the turn. This is a lot less efficient. It's much more energy intensive. But again, it's going to be a structural thing or a behavioral thing that's going to

They're going to result in one of these two strategies because on the first strategy where I have the person that can reposition themselves as they go into the curve, they have this capability. It's going to turn out to be a structural or a trained capability where you have more internal rotation on the inside leg. Whereas, again, the people that don't turn as well, they're going to tend to be your wider ISAs. They're going to tend to be more of your nutated people. they're going to have to rely on the plant from the outside foot and then make the hip turn there. So right away, you can start to see where these strategies for training may lie. So if I can improve someone's capability to capture internal rotation on this inside leg, I may actually improve their ability to make these cuts or these curve runs more efficiently. But keep in mind that you're going to run into some limitations with structure. So for my say an offensive lineman per se, his ability to make this anticipatory orientation into the cut is going to be less or so than my wide receivers, but their physical structures are also different. So this is why wide receivers look a certain way and offensive lineman look a certain way because again, their body types put them in those positions and make them more ideal for those situations.

Now, he had a lot of internal rotation on the left side as well. And so now, if he's on the table and I tip him up on this oblique axis, and you take him through the hip flexion, what's going to happen is he's actually going to roll on the oblique axis. And so what he ends up with is what was 130 degrees of hip flexion on one side, and then only 90 on the other. And so the thing that we have to recognize is that we get this oblique shift of the pelvis as you're moving through the range of motion. It's very, very difficult to see, but the leg can cause this weight shift through the pelvis as you're moving through the range of motion. So it's one of those reasons why you might get like a crazy straight leg raise where the pelvis actually rolls away from the straight leg raise. It's the same kind of thing that we saw here with the hip flexion. So it's just something that has to be appreciated in regards to when you're taking your measurements on the table. So this will happen with shoulder range of motion. This will happen with hip range of motion. in any number of different ways. Some of the other things that you might see is if you have somebody in sideline and you're doing hip abduction, abduction measures, you'll see all kinds of orientations in three dimensions as well. You have to be able to appreciate those measures or those adjustments as part of your measurement because some of them are not true. So maybe you're abducting or abducting out of plane, if you will, and you're getting a rotation or reorientation of the pelvis that skews your measurement. So again, it's just a really important thing for people to recognize and appreciate that there's a lot of movement going on underneath your measures.

Okay.

Curious about your thoughts on it. Speed breeds efficiency.

Sure.

Speed breeds efficiency.

Speed breeds efficiency. Yes. This is in reference to what?

pitching mechanics and arm speed.

I understand what they're probably trying to get at.

I do, but knowing what I know now, I'm having a hard time accepting that.

Well, I think let's reverse it. I think that would be a much more profound statement is that efficiency breeds speed. I don't think it goes the other way. I don't think that doing something faster necessarily produces the desired outcome. I think that if you, when you think about just the sequence of events that it has to occur to produce a major league of basketball, if there's not an element of efficiency in that, I don't know how it even remotely occurs in some form of control.

That's exactly.

I don't think it goes the other way. I don't think that doing something faster necessarily produces the desired outcome. I think that if you think about just the sequence of events that has to occur to produce a major league basketball player, if there's not an element of efficiency in that, I don't know how it even remotely occurs in some form of control.

I agree 100%.

I was just thinking about the importance of sleep. We definitely talk about the importance of sleep for athletes and people on weight loss, but have you experienced patients or clients in rehab recovering better with more sleep or less sleep? Is that something you even talk about?

Sleep comes up every once in a while. This may sound like a cheesy statement, but have you read my book? The whole section in my book addresses this. I'm not a sleep expert, so I tend not to get too deep about it. However, as I said, it does come up on occasion. The execution of the things I have to have them do and the acute element within the appointment remains my priority. But obviously sleep is important. From a stress response standpoint, actually I had somebody come in yesterday, and we did mention it. So we'll talk about it from a recovery standpoint with our athletes who might be dealing with some issues. Every time I do a mentorship call, I talk about it at every call because I want everyone to understand that when you're trying to be productive, energy is everything. Sleep is foundational; if you don't get enough, everything gets worse. I think you just try to get the big rocks under most circumstances. Make sure people hit a sleep time, wake time kind of thing—probably one of the biggest things is just the regularity of sleep. If anything, I might emphasize that.

Right.

It's like, make sure that people hit like a, a sleep time, wake time kind of thing is probably one of the biggest, just the regularity of sleep. So if anything, I might emphasize that.

We do talk about the importance of sleep, especially with the group of people who are losing weight. That's one of the big rocks we focus on, especially if they're feeling frustrated that they're not losing weight. And we kind of look back at their stress management and go into how they're sleeping. Are they getting adequate sleep? But I just didn't know if you're seeing people who are in pain and if they're getting adequate sleep, do they actually go through rehab a little bit faster than people who are getting less sleep? And how, I guess, would sleep impact your side of the spectrum?

Well, here's how it impacts everything. And we can talk about your context as well. So think about the behaviors that you're trying to influence. You're trying to get people to actually change the way that they behave, right? And so that requires a little bit of output from your brain because you're making decisions all day long. So if you put a piece of chocolate chip cheesecake down in front of somebody that's restricting their food intake, that takes energy to say, 'I'm not going to eat that.' And so the foundation then is: do I even have the energy to make that decision? Because every decision that you make during the day, even the smallest ones, requires energy. And have you heard about concepts like decision fatigue and things like that? Is it David Rock? I think he has the book 'Your Brain at Work' or something like that? He talks about that type of concept. So you have to appreciate that. So if they're starting from a deficit, if you're trying to lose weight and you don't have some other factor that's going to influence your behavior favorably towards the goal, you're going to be in trouble. So I think, you know, from your standpoint, obviously it's very, very impactful. It is impactful from my standpoint because pain is a decision. It's just a decision that they don't make consciously, right? And so if they are defensive, a lot of people will come to me and their physical behavior, their motor output is a defensive behavior. And again, if they don't have enough energy, then they're going to default to the easiest thing, which is the negative. Everybody defaults towards the negative. It's one of our little protective elements that we're born with. So if you're dealing with a painful situation and I don't have enough energy and I default to the closest thing, yeah, they're going to feel crappier.

Because I may talk about baseball, pitching and stuff because I know throwing pitching mechanics, there's definitely some similarities there with Serbs. I guess I was just curious if that's something you work with ever frequently. kind of how that relates.

I haven't worked extensively with tennis players, though I have treated one who was older. I've seen my fair share of athletes in similar sports. While there are some obvious differences between these sports, the strategies are fundamentally the same. Anytime you're producing force into an implement, especially when using rotational force to generate power, there will be similarities in how and when that force is produced. The specifics differ with implements like tennis rackets versus golf clubs, but the underlying concepts remain the same. The challenge is that people's perception of what's happening differs significantly from the actual mechanics. When we see a racket moving quickly, we focus on that visible velocity, but that's not where maximum force is actually produced. Maximum force occurs earlier in the movement, just before the racket accelerates, which creates deception about how these athletes need to be trained to generate force.

Could you go over the mechanics in the pelvis? So you said, for instance, the first one was the compression in the dorsal rostral area, typically, to push their center of gravity forward. Would the mechanics for that in the pelvis be above the trochanter?

Correct.

Would the iteration for that in the pelvis be above the trochanter?