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On this episode of the sports physical therapy podcast, I'm joined by our now Our Nell's a professor in the department of kinesiology at point Loma university in San Diego, where he runs their biomechanics lab. He's been publishing a ton of research related to the biomechanics of baseball pitching. In this episode, we're going to talk about the concept of energy transfer and how it relates to velocity and injury potential.
Mike:Hey, Arnell. Welcome to the podcast. Thanks for much for joining us today. How's it going?
Arnel:Good. Good. Thanks for having me.
Mike:Yeah, no, this is, um, I, you know, I feel like I say this all the time, but I'm excited for this episode. I don't, uh, I don't think there's been somebody that has made me more excited about research the last couple years or so with so many of your publications on the baseball mechanic stuff that you've been doing, I. They've really been amazing articles that I think have been really helpful to expand our knowledge. So every time I see your name pop up on my feed, when you have a new article come out or something, I get really excited. So it's, it's really awesome to, to have you on the episode today to talk about some of your research.
Arnel:Oh, thanks for having me. And you know, that's, I'm glad you say that because at the end of the day, what we wanna do in our research is provide evidence. I mean, you're, we're all in business of evidence based practice, right? Whether you're a PT, an at. A coach or trainer. Um, so I'm learning as much as everybody else. And so what I learn in our lab, I wanna be able to get the information out there so that you, uh, who are on the front lines, working with these players are able to utilize and hopefully be able to apply that for their benefit, whether it's to mitigate their injury risk, or obviously improve their performance.
Mike:That's awesome. And I, I love both of those right. Injury, risk and performance enhancement, but you know, again, going to some research, I mean, there's lots of research that gets published, but yours has a lot of clinical implications for us. And that's what us, the sports PTs and the performance coaches. That's what we really love is when we can read a study and it has an immediate impact. On us. Right. And I'm sure we'll get into it as we, we talk about some of your research, but there, you know, some of your recent stuff on the kinematic sequence of, of pitching and the flow of energy and stuff has been, uh, really, really helpful for my education and the things that I've been teaching people. So, um, I'm spreading the word, the word of our nails, Dr. A so we can get it out there. It'd be amazing. but, uh,
Arnel:let me tell you, uh, I'm still a certified athletic trainer. Um, but I haven't practiced in the training room in over 10 years. Um, but I still try to keep up with, you know, some of the evidence that's out there, not just in, in baseball pitching or hitting in particular. And because it helps me as a researcher understand, like we said, the clinical applications, the implications of what we do. So yeah, I got, I, I. I'm a nerd. I talk a lot about numbers. I try to bring all, you know, the physics, the Matics, the kinetics, and all that, a lot of coding. But at the end of the day, I, when I talk to my students, okay, how is this helpful? How is this gonna help the player? How is this gonna help the clinician who's out there? And so I gotta put my, my trainers hat on and say, can you know, is this something that. It's just a small piece of the puzzle, you know, at the end of the day, like you said, we're trying to improve the health and safety of our players and get them to perform at they're optimized, uh, a potential. And if we can find just a small piece, whether it's in the energy flow or some Matic sequence pattern that we find in a certain, you know, section of the. Population or athletic population I think is beneficial. But you know, I I've ki bringing the two perspectives from an engineer, as well as an athletic trainer. I think's helpful in making it, like you said, clinically applicable,
Mike:Right. Well it's because you know the right questions to ask, right? Isn't that what it is is you're, you're asking your research based questions from a clinician standpoint versus the researcher standpoint and, and yeah, I guess that's, that's, that's why your, your information, your publications are probably more wild. Wildly accepted is everybody's appreciative of it because we, we, we know that it came from a good starting point of what is the clinical implication and that's huge, so awesome, great stuff. All right. So let's dig in a little bit. Let's talk about some of your research. Again, some, some of my favorite stuff that's. Been published lately. Um, but in particular, talking about energy flow through the body to perform an activity. And, you know, specifically what we're both excited about is the baseball pitch. Right. But you know, the concept of looking at not just the mechanics, the, the kinetics and the, the Matics, but how that energy flow impacts things is, is really cool. What got you into starting to look at it from this perspective and, and how does it differ from some of the past stuff that's been published?
Arnel:That's actually a very good question. I've been working with baseball fishing for over 15 years, and I always hear terms like efficiency and fatigue and whatnot. And even when we're measuring things for, from a kinematic perspective or looking at the kinematic sequence, we're not measuring energy. I mean, not even metabolic energy. And I'm like, oh, how can we be talking about efficiency if we can't even talk about the basic, you know, principles of in this case, mechanical energy. So just kind of give your audience some perspective of what metabolic energy metabolic energy is like the rate of oxygen consumption. You know, if you go running, you use metabolic, there's a certain metabolic cost, right? Aerobic capacity, mechanical energy. On the other hand is the energy. Mechanics or simply the energy of movement. So you obviously, the segments are moving during a baseball pitch. So there's a certain amount of energy that's generated, absorb and transferred between segments and the degree to which a player is quote unquote efficient at what they, what they do can to a certain extent, be quantified by that exchange of energy between segment to segment. And it's such an important, um, Baseball pitching because it involves the entire kinetic chain. And I always say, and I used to be a big proponent of baseball pitching being a kinetic cane, but I would argue it's actually two kinetic chains, one for the lower half where the likes and the pelvis, the likes, the lower segment and, and the energy flow that's associated with the lower excitement, provide a stable foundation on which the pelvis can rotate. And then the upper body, which is more of a, what we call an open kinetic cane, because you got the, uh, the. Basically the distal, the distal arm, the, the, uh, the hand and ball being open to move. So those kind kind of join it together at the root, which is the pelvis, which provides that energy transfer ultimately allow a, a picture to throw it a ball. And so I spent the last few years, or along with our graduate students, try to. Understand exactly from a mechanical energy perspective, what is going on during the baseball pitch and be able to quantify that. And then more importantly, like you said earlier, be able to apply that for clinical applications.
Mike:Which is such a great way of thinking of it too, because, you know, I joke about this all the time. Right. But, uh, you and I know a lot about baseball pitching mechanics, right? That's fair to say that we both know a decent amount. Uh, why
Arnel:talked together on this.
Mike:Why exactly why can't we throw a hundred mile per hour fastball. If there's very few people in the world that know more about this than us, why can't we do it right? Is it just that we don't have the neuromuscular control? Is it, you know, you know, obviously you and I aren't six foot 4, 240 pound beast. But, um, but even if we were. Still think we wouldn't have the capacity to do it be. And it's probably because of that, that energy flow it's, it's the ability to, to neuro Musk and control that flow. Right. So, you know, for, for me, that's what, that's, what really, you know, really puzzles me sometimes is that, you know, the people that can do it seem to not know why and the people that know how to do it. Can't so I don't know.
Arnel:that's.
Mike:I
Arnel:That's exactly it. You know, I, I, I hate to kind of diverge a little bit here, but I went to a talk at the, uh, north, north American and car of biomechanics on it was on footwear, you know, looking at those carbon carbon fiber plated shoes. And you heard about, I Kip Cho who broke a two hour marathon? Uh, what was it? A two hour barrier in a marathon? Was that a couple years ago or. Two three years ago wearing these carbon fiber play shoes. I think they're called vapor flies, apple flies. You might have heard of'em before. And it's like, wow, cool. You know, these shoes return energy 4%, et cetera, can allow someone to bring to our marathon. I like, dude, I could put those shoes on. There is no way I'm gonna fit to our marathon because I'm not built for that. Exactly. And so I think, you know, when we bring it by mechanics and we, you know, we find what, you know, a guy like DMA is doing, who is able to throw a, you know, a hundred plus, you know, Quote unquote efficiently. And there's no way that a high school or a college guy can do that. It's because they've got certain aspects of their anthropometrics like you talked about earlier and what they do from a mechanical perspective in order to allow'em to throw at such a high velocity and which such high efficiency, but like you said, they, they don't know why. Right. They don't know the. Potentially the interactions between muscular attraction and gravity 9.81 meters per second square. And so the biome is kind of, you know, we as biomechanists and the PTs and, and the ATS come together to kind of look under the hood of what's going on and understand it better and potentially find ways that it can help a guy like Theron or potentially as some other who who's coming up. And he also throwing high nineties, low 100 S and beginning to say, okay, What patterns are similar and what can be optimized from a, a mechanical energy perspective?
Mike:That's awesome. So, so getting back to your research a little bit, what is it again, like what, what did you bring to the table with your research versus some of the traditional Obama Cannel stuff out that's out there. How how'd you go about this differently?
Arnel:So we have to start from the drawing board. And so again, going back to the efficiency of pitching has to have some kind of component of energy, whether it does metabolic or mechanical in this case mechanical. Now here's the great thing, mechanical energy or the energy flow analysis. That's actually been around for years, for decades in. Fact, if you look at some of the early work in the sixties on walking, some of the Kao's work where they measure the mechanical work of locomotion, I mean that pioneered, uh, clinical GA analysis, and then moving, you know, fast forward into the eighties, uh, with Robertson and winter, where you looked at, uh, you know, pedaling and look at ready, and then more recently soccer cake. And it surprised there wasn't a whole lot of, uh, Specifically on the energy flow, uh, baseball pitching. And there may be a couple studies out of, uh, Japan, um, you know, a few years ago, but just maybe within the last five, six years, have we seen, uh, you know, more work that's being done in this area? So when I say earlier, what, I don't wanna go back to the drawing bars, say, okay, we've got all this Matic and kinetic data. Can we use those same principles that was done? Gate analysis and running and applying to pitching. And it turns out you can, because at the end of the day, it's all Newtonian mechanics, it's all classical physics. And so we're just simply expanding our inverse dynamics model to, to measure torque. And then by extent you can measure what's called the joint torque power, which is the rate of either, um, energy generation or energy absorption at a particular joint, as well as a transfer of energy from segment to segment as being done by that joint. And as you know, we can look at the entire. Uh, especially now that you we've got these instrumented pitching mounts that allow us to measure round reaction for us during the baseball pitch, combined that with our motion captured data, we get a nice full body energy flow analysis. So the first part of my research is simply understanding, okay, what's going on? What are the patterns that we're seeing? And can we confirm the hypotheses or theories that we think were hap that what was happening based on work that's been done? Can connects baseball pitch for the last 20, 30 years. And some confirm others like the drive, like for example, we know that's propulsion and you know, everything that we've done, we looked at so far confirmed that, uh, whereas the stride phase or the stride, like, which is the front leg, we're seeing something com I don't say complete, but slightly different from what, what we thought was happening. Before. So putting that paradigm into baseball pitching in terms of energy flow, I think has opened up a whole can of worm to you're talking about research question. I thought we answered one, two and three that opened up, you know, five through 10 in terms of research question, uh, which is exciting. And I've got students involved. And the great thing about doing energy flow analysis that you've got. If you've got a data, if you've got data already, if you got motion, capture data and ground reaction force data, you can retrospectively look back into your database and say, Hey, let's do this EFA. Let's, let's do an induced power analysis on more closely with Dr. Chris Nicholson at wake forest university. And we've been just looking back into. You know, she's got hundreds and hundreds of players, high school and collegiate players and, and pros and just understanding, you know, what, how does energy flow look through the pelvis of your trunk, uh, and, and potentially compare between different groups, different samples, um, in baseball.
Mike:I love it. So your, your research has been able to show us a little bit about how the different components of the kinetic chain contribute things to, uh, contribute to things. The velocity of your pitch, right? So ball velocity, but even torque at various points like throughout the motion, like, so obviously the elbow, various torque is a, is, is a common one that we look at because of the injury rates with Tommy Johns and stuff like that. So by being able to do this, you can determine the exact components throughout the kinetic chain that contributed to both ball velocity and potential torque, right. In, in the, the development of that. So, so what would you say let's go through some of these and say, what were some of your biggest findings then? So, uh, if you had to summarize this, your elevator pitch of your energy flow is, how, how does the energy flow and you know, where does the velocity of the ball come from? What contributes the most to pitch velocity and Tor development throughout the arm?
Arnel:Well, the, the data that we have so far. I think more than suggest. It actually indicates that the, the majority of the contribution to let's just say the induced velocity of the throwing arm, because if we're talking about the throwing arm, we're talking about acceleration at the elbow, which is obviously torque Val torque, as well as the, the baseball page itself. And the common thing we see so far is at the core at the pelvis and trunk, those have, they make up more than half in fact, you know, close to, to 80. Uh, the contribution total contribution to the induced acceleration, um, at the throwing arm. And what we find is terms of energy flow, all that goes to the root segment of the body, which is the pelvis. And so what we did in our energy flow analysis. Okay. Let's just concentrate first on what the pelvis is doing. How does energy flow, um, on the backside? What we like, what we call the stride leg, or I'm sorry, the drive leg, right? This is the. The leg is on that's on the rubber and propelling, the, the center of mass forward. And then the stride stride side, which is the front side. Um, that's obviously the front leg, the what some coach call the lead leg and then of L five S one. So those three joints make up the joints of the pelvis, the roots side, through which energy flows from the lower half of the etic chain and the upper half the chain. And really, again, it's in my opinion, it's too, too. Kinetic chains. There's a closed kinetic chain of the lower half. And the open kinetic chain of the upper half and energy flow is, is both generated and absorbed by the two hip joints, as well as the L five S one. And then there's also transfers. So if the segments are moving in the same rotational direction, even at different speeds, there's gonna be a certain amount of transfer. The best analogy I like to use is try doing a Cartwheel or Summeral. And by the way, I, I don't do that. I'm too old for that. So I can't do a Cartwheel, but if you do a. Will right. You would feel that what your left leg, if you leave it to left, would, would transfer energy to your back leg without little effort from, from your muscles, right? Your muscles can contribute, right? They'll they'll contract, but really you're just transferring into another are doing the Somerset, for example. Well, to a certain extent, your, your segments of your kinetic chain do that. Um, during baseball pitching and the degree to how. Well, you can transfer energy from one segment to the next will determine how efficient, because at the end, as you know this, whenever you contract the muscle. Cost energy. Right? And so you're, if you, you, I don't wanna say minimize that cost, but I, I cuz you still obviously need these contractions to occur, but you could change the degrees of generation and absorption as well as, um, the transfer of energy from one segment to next, in this case, from the front leg to, to the pelvis or from the back leg to the pelvis and then ultimately up the trunk, then that can allow us to determine how efficient a player moves from segment to segment. So our, in a nutshell, We find that, that transferred energy through to pelvis and ultimately trunk that's where has happened. That's the, the core power. And as you know, it kind of confirms a lot of what we knew, at least anecdotally coming in, or at least coming from a Cana kinematic perspective. It really confirmed the importance of pelvis and trunk rotation during the baseball pitch, because once it gets to the arm, that energy right there, the arm represents less than 10% of body mass. So it it's. It's not capable of generating the same amount of ankle and momentum as the, the, the core, the propel within trunk without a significant amount of bang or velocity. Right. The why we measure we clock shoulder rotation, velocity at close to 6,000 degrees per second. That's a lot, that's a lot from zero 6,000. That's a lot of GS. That's a lot of acceleration and we're trying to minimize that and the way we can minimize that it's okay. Where does that momentum energy need to come from? From the core, right? From the Peston trunk and all our energy flow analysis seems to confirm all that.
Mike:Right. Which, which makes you, makes you kind of take a big step back when you think about a lot of the things that we do with our athletes. Right. And I I've been using this quote from one of your recent publications, uh, quite a bit lately. So, uh, I've been, I've been quoting you, I've been referencing you here, but, but you know, we talk about give or take. You know, depending on, on what we're, what we're looking at is about 85% of the force that, that goes to the pitch comes from the body, not the arm. Right. And you know, we talk about this when we talk about kids and we talk about where they need to develop to get better at pitching or to increase their velocity. A lot of'em want to do things like long tos programs or weight ball programs, or even specific like pitching drills. That, that will take out the lower half and take out the core and just focus specifically on our movements. And when we kinda, you know, we kind of chuckle sometimes thinking about that and we say like, you know, that's super backwards. I mean, if you really try to wanna maximize this energy flow, you get, understand where it comes from and how to transport it. And if you're focusing on the arm, you're focusing on the, the wrong 10%, right. Is that, am, am I saying that well, or am I taking your, your data and completely hacking it up and
Arnel:No, no, that I, I think that's on point. That's definitely a, a, a fair assessment is that the, the throwing arm I've seen some terms that the throwing arm is along for the ride. That meant that may be an oversimplification in terms of that analogy. The, the throwing arm really is the guidance system, right. That ultimately determines where that ball's gonna go in the strike zone if you're throwing a curve ball or breaking ball, whatnot. Um, but the power of the pitch has to come. Proximal to the shoulder or, you know, what we call the trunk? The, the PLP is the lower half and all our data suggest. Training strategies, any interventions that are designed to, you know, mitigate injury risk at the throwing shoulder and elbow, uh, as well as increase, uh, below need to concentrate on that core need to concent on the hips. I mean, there's some great emerging research out of, uh, Auburn university ion Oliver's lab that look the hit mobility. Hip strength, um, both on the drive and stride side, and that kind of vibes with some of the stuff we're doing on energy flow is that, you know, those, those players who are at a higher risk that have higher kinetics at the shoulder and elbow tend to have limited flexibility on the stride side and hips on a Dr. On the drive and stride side, hip joints, as well as strength. And so, and, you know, pelvic rotation is all about rotation, about those hip joints. And so those muscles that are involved in, you know, pelvic rotation and, and then also made through trunk all revolve starts off with those hips, those two hip joints. And so if we could concentrate with the hips, you know, the core stabilization, there's some, some great research on core stabilization exercises they're used on in, you know, in other sports that we could borrow and. For for pitching, I think the arm quote unquote will take care of itself. If we concentrate on the, on the quote unquote core from there.
Mike:And are, are you saying that if, if I'm, if I'm hearing that information well, are you saying if we have two players that are, let's say everything's the same, so there's six foot 4, 2 40. They both throw 95 miles per hour. Right. But one of'em. Let's say their mobility, their hip, their core, their mobility's poor. You're saying that their, their outcomes may be the same, but their, their energy flow and their transfer of energy, it could be creating higher torque with the same output of velocity, which may put that person at injury risk. Is that what you're saying?
Arnel:Correct. Right. And, and. You can also even look at something, something as simple as angular velocity of the shoulder. Let's just say, so during arm acceleration, during the baseball pitch, um, I, I mentioned earlier the, uh, the shoulder, the Glen Humel joint rotates up to 6,000 degrees per second. What we found is in. The more efficient players. Let's say you get two players who throw 95 about the same, build the one who is more efficient in energy transfer, you know, has, you know, late trunk rotation, all that timing actually we'd have we have lower. Angular velocity of the linear humor joint than the less efficient person yet they're throwing the same ball speed, the same VLO. And that leads us to believe where's that where's that momentum coming from again, that's from the core and you see this a lot of younger players, there's actually some research on, on high school players and comparing to some, you know, some college age guys. Throwing around, you know, lower eighties around there, same, same Belos. But the arm speeds of the, uh, of the, uh, the high school, the younger players are actually a lot higher about a thousand degrees per second higher than their collegiate, uh, counterparts, because what are they trying to do if they, you know, you've seen, uh, a high school player scored up too early, were trunk rotation. They tend to whip their arms. Right. They're trying to try to catch up and compensate. And what do you need either? Fire everything you need, probably rotator cuff muscles, you know, biceps and triceps all need to contract. And sure. The, the player may be able to reach their, their targeted Velo, but they do so at a cost at increased torque at the shoulder. And.
Mike:Wow. Yeah. That's a great way of thinking about it when you put it all together like that. Uh, that, and that kinda leads me to what I was gonna ask you next a little bit. I, what are the differences you're seeing from the various levels of play? So from little league to high school, to college, to pro, or even just amateurs verse pros, how are you seeing that energy flow differ between that? What makes an. Athlete elite. And, and how do those young kids look differently? So we can help work with them now to try to create that better efficient energy.
Arnel:You know, we are seeing a lot of similarities than we are differences. Um, I could tell you what's really, I wanna say surprising. It was someone. Expected in this way. I mentioned about the stride joint, right? The, this is the front side, the lead leg, and the, the old adage that energy moves quote unquote up the chain is, comes with a caveat because what we're seeing in that front side, that, that stride phase in terms of energy flow is that the energy transfer actually goes into distal direction. So that meaning in, if you're looking at the pelvis, that means the energy is flowing from the PEL. To that front side, hip to the stride phase, not the other way around, not the hip J and the, what we're seeing is that because the pelvis is actually decelerating after front foot contact, that energy has to go somewhere. So the front side, hip joint, you know, absorbs it, but it also transferred over to that front side. So it's almost like a shock absorption mechanism by which that front side as stride leg. To provide a stable foundation on which the pelvis can continue rotation. We see that in high school players, uh, collegiate players and the pros, the only differences is degree to which that rate of energy transfer and is actually statist significant. I just presented some with this work over the summer. Um, but the pattern is still the same. It's still in that distal direction and it's from proximal of this. So it's going down. I guess if you were talking about from the pelvis down, it'd be down the chain as opposed to up to chain. Um, so is essentially going away from the pelvis as opposed to the old adage legs, pelvis and trunk, you know, I guess you, if you do, maybe back leg, pelvis, and trunk, that would make sense. But with the pelvis on the front side, what you're seeing is you've got the pelvis and you've got energy. That's moving distally. That means distal up the L five S one joint, as well as, uh, these, the hip. The, uh, uh, on the stride side and it's, I's consistent from, from play to play regardless of the levels. So in terms of differences, we see more mainly the magnitudes, the changes in which the, uh, the rate of, of energy transfer and energy or generation absorption occur. The difference that we see is, um, the degree to which each one of these factors play a role in generating Velo or valgus torque. Um, These are slight difference in what the drive side is doing in terms of hip, hip, energy generation absorption and transfer. And I apologize, I should have clarified the differences for between generation absorption and transfer. And, you know, I, I try to simplify this for the audience. So just think of the muscle contraction. There are two types of, or three types. So there's, um, concentric, eccentric and isometric. So concentric contraction is when the muscle is essentially a shortening and it's, and it is. Accelerating the segments to which, uh, it spans, right. Eccentric is the other way around. It's length limiting. And so when it, when a muscle is concentric contracting, it's generating energy to the segments. Hence they're accelerating. If it's eccentrically firing, that means it's absorbing energy because you know, the, the segments are moving. It's slowing it down. At the same time, if those segments are also moving in the same direction, even at different angular velocities, it would also transfer one en energy from one segment to the next. And what we're seeing for, for the, the, the stride side hip and the drive side hip and L five S one, if we're just costing an Apel is, as the rates are very similar, but, uh, between, uh, different, uh, levels of, of pitchers. But the degree to which that occur is is, is significant different. And this is normalized by the way, this is normalized by their body mass. So we can't really chalk it up to skeleton, mass and whatnot. Um, so that, that's interesting so far, uh, we have done some machine learning modeling just to understand a little bit of what are the, uh, the relationship between all of these energetic factors and ground reaction force factors on VLO as well as joint kinetics. And we do find some differences on what those. Particular, what we call features of energy flow occur between high school and, and pros, but we're still learning, man. I mean, this is a great thing about this is that there's so much rich data that, especially with the advent and market list technology that we're, we're trying to understand a little bit more, uh, you know, what are the similarities between players, but, and what separates, like to answer your question, what separates an elite player from, um, you know, a player who's just starting out or is just kind of just learning the roles that be less efficient. Um, we're still trying to tease that out, man. You know, I, you know, it's not, I don't, I'm not afraid to say, I don't know because I, you know, I'm still learning myself. Um, but you know, but what we've learned so far is, you know, that, that stride phase, that stride hit joint that, um, that changes the paradigm slightly and start is we need to start getting away from, okay. Energy moves up the chain, everything's up the chain. It's not as simple as that.
Mike:Right. And you can almost argue that if the front side can't break and the front side can't stabilize, then you, it stops the flow. Right. So you actually have the ability to either stop the flow of energy or maybe even catapult it. Right. Is that, is that a good way of thinking of it?
Arnel:Fair assessment. But the thing is when you slow down or stop that flow, I'm just a, you know, to a lack of a better term. Something has to be made up elsewhere. And that's where we seeing, you know, some of these players. Okay. Again, they, they obviously don't know that, oh, you know, I'm, I'm transferring energy and efficiently or so I gotta make up. They just naturally do it. right. It's not conscious. Exactly. And so they just naturally do. That's why you see that whipping arm just saying if they, and what you can see with the naked eye, or at least with, you know, with high speed camera is that they're scoring up too early, right. They score up too early or they're dropping their glove. You know, all of that are telltale signs. That energy transfer and generation absorption is not E. We, we can confront that. We see that when you see that between high school and some of these minor league players in our sample, um, so they have to make up that, that energy loss, if you will, somewhere else. And so they could technically do that and shoulder an elbow, but they use that at a cost. And so what we're trying to do is minimize that, just keep everything else efficient so that everything this doesn't have to make up or any, or compensate for whatever's lost earlier.
Mike:Right. That's awesome. I, I think that's a great way of saying it too. So, um, you, you mentioned the market list, motion capture, which is obviously something that is really cool. That is, that is gonna be the future of a lot of the technology we're dealing with biomechanics. Um, give us a snapshot of that. Where, where are we with marketist motion capture? Is this something that is it, is it, is it ready for prime time? Is it reliable enough? Is it valid enough? How are we looking with market list stuff?
Arnel:We're getting there. It's getting close. There are a number of different vendors out there that have various various levels. I should say of mark list tech. Um, there are in-game systems that are out there and in fact, all major league baseball has in-game cameras that can measure at higher frame rates, mark list technology. Uh, I've done some work in terms. Uh, validity and reliability studies. I, I, I, I hate to use the word validity because it assumes that there is a ground truth or slash criteria and method to which market list can be compare. Now we, yes, we use market based technology. We have been for, you know, 30 plus years, but markerless a market based technology in itself has limitations. I mean, you're basically putting markers on skin and you're trying to infer what the bones are doing. Based on what's on the surface. Right. And so I, I like to use the term equivalent. So how equivalent, for example, is there kinematic variables that are measured with a market based system, compared that with a mark list system and then. Put the data out there and then users can then make the decision on their own and say, well, I, you know, to me, market based technology is the holy grail. So anything close to that, you know, I, I, I will certainly use, um, but when I get asked, the question is, okay, how is this system? How is this market system? Um, in terms of its accuracy, I go, well, that's such a loaded question. I mean, go, what variable are you looking at? Elbow flexing extension. It is on point. I
Mike:was, yeah.
Arnel:from, yeah. So here, here to. If you're looking at, you know, trunk rotation, velocity, eh, it may not, it may be off by the close to 20%, maybe even 30% in some regards. Um, and so it, it, it, what we try to do is when. Perform these equivalents and reliable, um, types of analysis. It provides the levels of agreement between modality. So this mark list versus marker base, and then users can make a determination of whether or not they're gonna use it on the field, uh, for a full body kinematic assessment and all three planes or. Maybe just use it for elbow flexion, extension, a new flex extension, you know, something that they can rely on. Uh, what I find teams do. They'll say, you know what, we're seeing some, some weird stuff happening with children, internal on rotation and foreign pronation, super nation. We're gonna send'em to the lab to double check and the analogy that I always use. And again, if you, if you consider mark based to, to be valid and reliable and you know, again, we all with all this limitation is if you got these mark list tech, these feasible tech that's out in, in game. and consider that your field tests consider that your Lockman's and say, you know what? I, I, I suspect something's going off on. I suspect there's a red flag there. Let's go send'em to get an MRI. The MRI is the quote. Market based system in this case, right. That's the lab and it just to help confirm. Yeah, I think what he's doing in, in, during the game he's doing consistently, and we confirmed that in a lab in terms of kinetics, for example, or in, you know, these transfers place rotations such as hip, external internal rotation or at the shoulder. Uh, so. To answer your question about mark list technology. I think we're getting very close and just the, uh, the, the advantage of having, you know, mark list tech, you know, these athletes in their in-game situations, right. And quote unquote, real life, or what's some, you know, there's a quote outta Stanford is just biomechanics in the wild, which technically it is, right. They're quote unquote in the wild and, and understanding what it goes on is obviously very important. But I, I think. Some teams take that as a whole, the grail say, oh, this mark list that all the data is, there is 100% we can rely on that. Just take a step back, understand what you know, those, those systematic biases are and then make appropriate decisions from there.
Mike:Okay. So am I ever going to be able to use my iPhone to do this? Is the
Arnel:Yeah. There's some, yeah, that, that, that's a very good question. In fact, there, I know there are some applications out that you might have heard of, uh, mustard and pro play AI. They use a phone and, you know, again, great. I you've done some initial validation tests in, in our lab and found that, you know, those Saal plain motions are actually pretty good, pretty dialed in, you know,
Mike:some things are perfect. Yeah.
Arnel:Some things are perfect. And some, some are just like, wait a sec, there's something going on here. Especially when you go downstream, you know what happens? And I, I, I, you know, I don't wanna get too technical, is that your first level of kinematic stream is that angler displacement. These are things like internal on a rotate inflection extension abduction, abduction, right? The things that we know that we can measure with a go ter, for example, The next level in mathematically speaking, the next time derivative would be angle velocity. So whatever minute errors are in the, the angler displacement level will tend to propagate and magnify as you move down the stream. So once you get down to accelerations and then kinetics, those errors are now magnified at bigger scale. And at that point, Signal to noise rates are so low that it may not be useful to make any decisions on. And at the end of day, what we're, that's what we're trying to do. So with these iPhones, um, a lot of them use machine learning and you know, this very, um, sophisticated, uh, AI models to, to both learn what the body's doing in this case, during a baseball pitch, and also be able to identify what those estimated poses are during the pitch. And then compare then ultimately to, you know, a system like a market based motion capital system. Um, I think we're getting closer to that. Um, I always advise no matter where you're from is just either doing some internal testing on your own or partner up with a university that can do it for you. Uh, because at the end of the day, you're trying to make decisions on player development and, and injur your risk mitigation. And you gotta be able to trust the tools that you have.
Mike:That's great. So it sounds like the future is bright. We just, we just gotta
Arnel:It's.
Mike:a little bit, but, you know, and hopefully that'll, that'll, that'll go even faster. So awesome Arnell that this was amazing. Uh, great topic. I mean, your research has been amazing. Thank you so much for that. Uh, before we go, I get our high five, five quick questions. Five quick answers for you. Just showing a little bit about what your brain's thinking right now. But, uh, love to answer, uh, love to throw these at my guest to see what they say. But first one real quick is what are you currently working on for your own professional development or your own ConEd? What are you learning right now?
Arnel:Well, I mean, again, going back to my nerd, uh, uh, speak, when I'm talking about energy flow, I wanted to expand energy flow. We've done some, some initial, uh, modeling with, you know, some really basic machine learning approaches like lasso and other types of regularly regression. So we're exploring some other avenues of predictive model, especially now that we do have access to. Such rich market based technology, right? So we have all this data points, you know, close to 70,000 data points for different pitches throughout a season. And if we can tease out, for example, those players who got her during a season, or, you know, maybe have their vs uh, decrease, you know, two or three miles per hour, we can then tease out both the intrinsic and extrinsic factors from a biomechanical perspective that's happening in game. And again, I like borrowing. You know, models or research that's done in other areas, such as that epidemiology has a very sophisticated, uh, predictive models that, you know, there's no reason why we can. Somehow, tweak it a little bit and optimize it for what we do in, in baseball and baseball by mechanics. Um, so I'm exploring ways and, you know, I, you know, I work closely with our, our, our math and information computer systems, um, our department here at the university and just trying to pick their brains and understand a little bit more of what's out there. What packages are out there that we could potentially use on RN working with the a. Working with different teams, um, see what they're doing and what they're seeing, and, you know, potentially find ways that we can collaborate and contribute. Um, so, uh, that is kind of my, um, you know, at least in baseball, biomechanic, that's where I'm exploring and I'm, you know, getting my team ready and see, find ways from them to do it. That's number one, number two. Probably gonna laugh at this, but it's actually interesting. I'm actually dabbling into dancing dance by mechanics. I've got a couple. Yeah, I've got a couple of, uh, uh, students who are, who are ballet instructors. And so I definitely I'm no ballet dancer. I'm no ballet coach. Uh, but I come in in terms of biomechanics, there's obviously a lot of, um, injury implications, right. Clinical implications that are associated with these dancers. So as a different set of research questions, You know, that area, at least in terms of biomechanics is, is, is poorly understood. You know, it's unclear. So I was telling my student, Hey, let's, let's look at this, let's have some ballet desert come in and do the, the GU Ron deja and the, the, the the Sean Jamal I'm. Yeah, yeah, exactly. I'm learning all these, uh, new, uh, ballet, uh, techniques. Um, and just begin to understand, you know, you know, like turnout little things like that. And then we talked about hip. Flexibility away. That's, that's a huge in these dancers and trying to understand the, the biomechanical effects of these, these strategies on these dancers and find ways to same thing is at the end of the day, we're trying to minimize their injury risk and optimize their performance. In this case, we're optimizing the performance on the dance floor.
Mike:That's awesome. I love it. Uh, what's one thing that you've recently changed your mind about.
Arnel:Recently changed your mind about
Mike:Right.
Arnel:let's see, that's a, that's actually a very good question. You know, I was reading this book, it just, I just finished it and it's, um, it's on energy flow, not but it's on flow and it's called here the art of impossible by Steven caller. And it's all about the flow. Right and flow state and every human being has this, um, this state in which they just get it, they just perform they're optimized, no matter what it is, whether you're, you know, a stock trader or a baseball biomechanist, like such as myself, um, and begin to understand the steps to get into that flow state. You know, whether you you're in front of your computer or you're out. Performing. And I, you know, some of the things that I've learned from this book and some of the preferences that he got out of there, I mean, that just blew my mind. You know, I didn't realize little things like being mindfulness, just turning things off in the morning, you know, emails and phones, whatnot just for a few minutes, can, can provide a clean slate for your mind to say, okay, let's take on the rest of the. Little things like that, or kicking, walking, all of the things that you know, can go way beyond what we do in research can go to any aspect of life to make the impossible possible. And I'm still trying to learn that. I mean, I'm obviously not gonna learn everything just from the book, reading a book, but hopefully during practice, uh, over practice, maybe we'll get to that flow state. It's a start for sure.
Mike:see this, this, this is why I
Arnel:that's the thing, you know, we continuously learning.
Mike:Yeah. That's why, that's why I ask these questions. It shows that you're continuously learning, but like, you know, just these great little nuggets like that. I think that's awesome. Uh, what, what's your best piece of advice that you give students? What's your favorite advice you give them?
Arnel:Uh, well, obviously they're, they're here to learn, but just, you know, I like to remind student that we're also learning from that, you know, I, I like to get their perspectives and the reason me is that yeah, we can teach them. The fundamentals, um, in this case say biomechanics, or, you know, I teach research methods how to perform research in the lab or on the field. But, you know, we also get questions, uh, about, you know, what we do in research from our students who have practical experience as an athlete or as a dancer, as a Pilates instructor, we've got all kinds of, uh, a lot of our, our, our students. You know, they either go into PT, athletic training, OT, or by. And one of the major reasons why they chose that specific field, they saw applied health or allied health fields is because they were a patient themselves. You know, some of them may had a, may had CP as a kid, or they, they injured their ACL in high school and they went to PT for how many weeks. And it's like, man, this is something I wanna do. And so when they come in, I'm work. We're learning as faculty, we're learning from their experiences, from their anecdotes and say, you know what, we could probably do that. And alive, we can probably research this new technique is flywheel training or this, you know, di the plant based diet, whatever it is that they come in. So, so. When they come in. Yeah. You wanna learn from faculty, but also know that, you know, we, as faculty are also learning from our students, so don't be afraid to, to open up, to be transparent and, and show them that you're you have something to offer you as a student has something to teach as well. Another piece of advice too, and this is the flip side of that is absorb. Choose an advisor that you can get personal lid and remind our personal levels that you could talk to him or her. Any other thing, besides research, any other thing about the content? Because at the end of the can spend countless hours trying to complete your work, trying to complete your research and your, your academics. You gotta be able to trust your instructor, your, your professors. Uh, so if, you know, if you can find a school that has a good faculty student ratio, that's even better because. Typically, well, we we're on a first name basis with all my students. We know all our students, I don't, I don't have 150 plus students in my, my lecture. All they have maybe 30 max. Right. And even then sometimes in my old age, I forget names, but you know, but I'd make it a point to try to remember their names and, and, and get to know them on both their professional and personal level, because then the, it sets them up. It sets them up nicely for. Uh, for graduation and ultimately to PD school and, you know, you know, I have no problems writing them letters of recommendation, um, because I know I've known how that I know their work ethic, I know their, their rapport. Um, and that's what I think here at, at point Loma Nazare university. We're all about. The whole student, you know, and then that's mind, body, and spirit, and trying to under and try to develop all the major parts of what makes a good human being and all our, if all of our students are gonna be clinicians, they're gonna be working with patients. Yeah. They gotta know their anatomy, they gotta know their phase. They gotta know how, how to do these various special tests. And. We get that we can test that, but you also gotta be connect with your patients. Your patient has to trust you as a clinician and you have to have those personal skills to do that. Right.
Mike:that I
Arnel:so that's one thing you just absorb it. Nothing.
Mike:That's hu. That's huge. I love the perspective. That's great. Uh, well, what's coming up next for you, Dr. A what do we get on the, uh, docket from you?
Arnel:Uh, well, quite a bit, you know, we, uh, we have this new pitching lab, uh, that we just opened up or over the summer. It's, uh, I'll send you some pictures. It's really cool. Uh, and we've had a few teams that actually come out all our Southern California teams. Pods and Dodgers and angels all already came out and visited. We just had Dodgers over the weekend, um, while they're in town. And, um, we want to continue in developing and we've just got a new cohort of graduate students. So we had one guy just came from the red Sox. Actually, he did an in internship, um, the last six months. Um, so we're gonna continue some of these. This research lines, I've got all these research questions and you probably know this. Whenever you finish a research study, you come up with more research questions than you do answers
Mike:It's endless.
Arnel:it's endless. So, you know, it's a, I don't wanna say it's a vicious cycle, but it's a good cycle to have, right. We're continuously learning in that regard. So we're gonna continue that route. Um, I've got a number of players, our number of students who are interested in hitting. And we wanna, we've already done some energy flow of hitting. Um, I had one student who presented this work at ISBs over the summer. So we wanna continue that obviously the injury potential is not as high. It is for pitch, but there's obviously very important hitting performance implications of ER. So understanding that from an energy. Energy flow perspective is huge, uh, golf swing. We wanna do the same paradigm. There's no reason why we can't apply some of these same techniques to other activities that we see in sports.
Mike:I love it. Yeah. Awesome. Well, how, how do we learn more about you? If we enter to find some of your research and stuff like that, do you have a, a place of social media? Where do you want everybody to go to learn more about you?
Arnel:probably the biggest one would be, uh, Twitter, uh, twitter.com/arnell_ado. Cuz I, I put, I post up a lot of research, um, related content there, along with my dad jokes. And you probably could just ignore the dad jokes. So my kids always ignore my dad jokes. But I try to post those up. Um, uh, also I'm on LinkedIn. I also post those stuff on there and some job openings as well. So those are probably my, to just look up Arnell, canal them both on LinkedIn, as well as Twitter. I got some and YouTube. I forgot my YouTube as well. So all three of those are a good, good sources for content.
Mike:and I'll put up some links. So, so people can from head from this podcast episode to them, it'd be awesome, but, but Arnold, thanks so much for taking the time out. That was a great, uh, podcast, uh, obviously, uh, wealth of information from you. So thanks for sharing all that stuff. And, and again, keep up the great research it's been.
Arnel:No, thank you for having me and you too. Keep up, uh, what you're doing over there. I'm actually a fan. I mean, you, you were talking about my summer art. I'm a fan of your, I, I quote a lot of your research, especially just recently on, on weighted balls, right? Plys and look at stuff like that. So, You know, thanks for having me, you know, you're, hopefully we'll able to do a few talks together again in the near future.
Mike:Sounds good. Look forward to it. Thanks again. Take care.