SPEAKER_00 5:56–8:55
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.
max propulsionfoot mechanicscurve sprintingcutting strategiesinternal rotation