Feel and Physics

Gina Pongetti: Welcome to the MedGym podcast. I'm Gina Pongetti Angeletti, physical therapist, and someone who has spent a career in the gap between what an athlete's body can do and what it's being asked to do. The show is about health in the sport across three pillars: mental, physical, and training. As we have watched at World Gymnastics Championships in Rotterdam and will continue to see in the lead up to the LA Olympics in 2028. Athletes compete on various styles, variations, and brands of floor and bars and land on many variations of matting. If you were a former gymnast, you had a favorite beam or floor and probably have reasons why. As a coach, you may have a favorite manufacturer based on feel or consensus at your gym. As a parent, you just hope that your gymnast can hit her routines in spite of different environments, competition venues, and feel. We are going to talk today about how this equipment comes to be, from thought to creation, from design to manufacturing and testing. How bouncy is the floor and why? How much give can a high bar truly take? How does a beam in the Netherlands feel just as close to the same as one in China? Today we welcome Tiago Bessa, mechanical engineer and product engineer for Speeth. He represented Portugal for a decade at both European and World Championships as an elite men's artistic gymnast. Combining experience and knowledge, he bridges the gap between what the athletes ask for and what the sport demands. Welcome to the MedGym Podcast, Tiago. Tiago Bessa: Thank you. It's a pleasure to be here. Thank you for the invitation. Yeah. Gina Pongetti: Thank you. Of course, coming to us live from Germany. talk to us just a little bit about your journey with 20 years in the sport of gymnastics and how it has brought you to this place working with equipment from schooling to your process from retirement to entering into the workforce. Tiago Bessa: So to give a little context, my whole family comes from gymnastics since my grandfather. I have different cousins, mom, aunt, uncle, dads, all related to gymnastics from rhythmic to artistic to acrobatic, trampoline. So it was natural that I would end up Gina Pongetti: Fantastic. Tiago Bessa: in a gym hall sooner or later. And gymnastics has been since four I was four. has become a part of my life and it's become the major part of my life up until recently as an athlete. Now it's it's still part of my life, but from an engineer side. I was I was not always focused on working in gymnastics. I never wanted to be a coach or a judge. And the idea to actually work in this area came fairly late in my studying life. I was already in university and I remember having this this breakthrough moment on a science materials class. We were studying very specific thing called stress strain diagram, Gina Pongetti: Mm-hmm. Tiago Bessa: and we were talking about something that it's called elastic behavior of metals. And I had a breakthrough moment where I looked at a graph. throughout an explanation from the teacher and and I realized like the high bar is a spring. Yeah, it's like it it's a Gina Pongetti: Yes. Tiago Bessa: spring. It it compresses and releases. And when it releases, it gives a huge amount of energy. And as a gymnast, you learn how to control this energy from an early age and to develop and work with this energy. And from that moment just a wave of emotions and thoughts and ideas just started to flooding. And and I at the end of the day I was completely sure, okay, I know what I want to do from from now on. And that's with a bit of luck and opportunity, I ended up moving to Germany a couple of years later and to work for Spitz as an engineer. And yeah. Gina Pongetti: I love it. As we talked to Jan and Jeanette in a previous episode where they had explained the rigorous hiring and team that they build to make sure that front-facing from a sales perspective to an engineering perspective, they not only have the best in the business, but they're lucky to have you as someone that was a former gymnast as well, and can bridge that gap between understanding what the equipment feels like and what an athlete's response to it would be. as well. When you were a gymnast, Tiago, did the coaches respond pretty well to your choice for what equipment that you wanted to train on? If you felt like there the floor needed to be changed or the pommel was getting too slippery. How how was your experience with either personal coaches and or even at meets and that difference in how things feel? Tiago Bessa: Yeah. from the coaches side not much. I've I had a coach that used to say good gymnasts can perform regardless of the equipment, which I found it to be half true to to some extent. But it it's fairly difficult to to approach this with with people when people are not so deeply involved in gymnastics previously as gymnasts. not not to say That they people lack of knowledge, but it's difficult to understand something if you haven't gone through it in a certain way. there's certain things Gina Pongetti: Of course. Tiago Bessa: that you cannot learn from the books. So there is there's a hard line between what you think and what you feel, and what you can make people understand. And this became mainly my motivation to to pursue this career choice to say. I have the knowledge and and I can make the translation from both worlds to say, Okay, I can help this and I can improve the communication between these two worlds to come together so that there's an understanding and how things can develop from here. Gina Pongetti: I hear you. I had a similar experience. a s very similar experience with that. I was sitting in a class when we were transitioning to from anatomy, basic memorization, if you will, to the application of anatomy, which is kinesiology. And we are talking about lever arms and physics and all I could think about was flipping and particularly how much easier it would be to do a hollow hold if I would have understood, you know, lumbar. Lordosis and then how to do how a free hip is is really just moving your arms up and how a cast handstand should be easy if you're if you're tighter. and that really triggered you know, my desire to go into physical therapy and the mechanics side of sport, as opposed to being a surgeon or someone that fixes, which is incredibly respectful and knowledgeable. But I think that this, as you had said, the understanding of the translation and the putting together of and I I would say knowing both languages, if you will, the language of the athlete and the language of science and being able to put that together and listen to when an athlete says, I'm not, I'm sliding on vault and you think, okay, sliding, friction coefficient, is it worn out? Is it tested well? Are you hitting at the wrong angle? Do you, you know, and and you just kind of all of a sudden, all of a sudden go. Tiago Bessa: So so it wasn't always obvious to you that you would end up doing what you do? Or is Gina Pongetti: It was not always obvious to me. I was I was very blessed to have coaches that I really did love and respect. And I didn't want to go into medicine to change things because I wasn't treated well. although I was injured, many knee injuries, multiple ankle sprains, two back fractures, which ultimat ultimately ended everything. I wanted to go into understanding how to teach athletes and their coaches how. To teach gymnastics better, if that kind of makes sense. So I had to learn all the science and climb the mountain in order to come back down the mountain and put into lay terms where the missing puzzle pieces are. for instance, you take something simple like a free hip and you turn that into a f a freehipped kotchav or a hindorf, and understanding that you have to wait until a certain point in time to start. the rotation, you have to feel the rebound of the bar in order to do that instead of forcing it to happen. The best bar workers in the in the in the world that we'll see on the in the next couple of years work with the equipment. and and I think Tiago Bessa: Exactly. And Gina Pongetti: that that's really what I wanted. I felt like I had just a an interesting knowledge or a gift to understand science and the sport and the ability to teach. And so Tiago Bessa: Match them together, yeah. Gina Pongetti: To match them together, which I think is is exactly where you where you were, and and turning that into going into having this your own way of seeing things as an engineer from from your work eyes now. So I want you to go back into when you were a gymnast and think about landing your biggest tumbling passes on the floor, and you are welcome to walk us through what those were and how now that you understand. spring and and reboundability and oscillations, how would you have changed your training to maybe work better on conditioning and absorption and everything else? What what sort of trigger moments now do you think about reflecting back into the sport for yourself? Tiago Bessa: I would I would start with load management for one. it's the easiest way to mismanage something is the the loan management and this can cause so much issues that are recurrent and they happen on the long term and then become the most problematic to solve. Gina Pongetti: Yeah, the chronic chronic injuries with overtime Tiago Bessa: Yeah. Gina Pongetti: landings, which obviously Spieth and every equipment company have amazing levels of Tiago Bessa: Good time. Gina Pongetti: matting that can help to manage that if you are indeed doing skills on hard floor landings with with 10 centimeter mats, 20 centimeters, et cetera, loose foam pits, absorptive landings, that all goes into load management. Tiago Bessa: Yeah, correct. This is this is one. The second would be to have an a physics understanding of the actual things I was doing. And this came much, much later in my in my career as a gymnast. when I understood how physics played a role in gymnastics, I immediately started to see gymnastics with a different angle and to understand the biomechanics and the mechanics of not only from the apparatus. from the body and to actively see okay this is where I need to get so how do I get there? Okay I need to push a little back on this direction. I had to hold on for half a second or and this this self-improvement this data collection on one's mind Gina Pongetti: Yes. Tiago Bessa: this this builds up and until you actually achieve something and when you achieve it it's no longer I did it because I was lucky. It becomes a database for you and you can build and you can improve on this much faster and much more reliable than just be pushing point forward sides, and by feel exactly. Yeah. Gina Pongetti: Right? By feel and and yeah, by feel. Now as we are looking into triple backs on floor and we are we move on to Simone's amazing vault, you know, and if you slide, if your hand moves a little bit, and we'll show the audience as well the vault testing pictures. From the IAT, and that's very interesting because as the vault actually has an angle to it, so do the testing. So it's not that a ball very simply, people ask me all the time: do they just drop a bowling ball on a vault? They don't just drop it vertically on all the surfaces, they drop it vertically where vertical is necessary in case somebody hits in that way. But the vault is tested in in angles of where impact would be from pre-flight onto vault. For instance, So if someone is doing a very difficult skill and they feel that the friction coefficient or what they feel is the slide of the top surface is a little bit too slick, they might not feel that they are going to get as much height out of it and then thus therefore pull back to maybe a different vault that's less difficult because of the risk. And like you had said, once you get to know that the science behind it says, as long as I don't feel my hands slip, I think I'm high enough to flip this. That those data sets in the mind give you all of the confidence and knowledge that this is doable. and I think the harder that our skills are becoming, the more reliant our athletes need to be on their feel of height and proprioception. and I would love to hear what your thoughts are on that, both from a former athlete's perspective and an engineer. Tiago Bessa: It's again, it's not it's not a straightforward question because it depends a lot on the feeling for each an individual athlete. But the the the feeling that you get from a piece of equipment, it does play a part and influentiate decisions and sometimes last-minute decisions, whether you go for a skill or not, and you just simply change your routine. I had I met a Brazilian gymnast, Diegi Polit, well-known Gina Pongetti: Yes. Tiago Bessa: Brazilian gymnast. He was good friend of the Portuguese team. And one time we were at a World Cup event and he was sitting on the sides during a finals, he was the last one, and he was sitting on the sides watching everybody. It's like, are you not competing? I said, yeah, yeah, I am, but should you be warming up? Yeah no I just want to see what everybody's doing so that I can decide what what I'm gonna do. So this this comes to the level Of such small things can influentiate your decision, let alone the the equipment. When you have fresh out-of-the-box equipment, the pommel horse, the ladder is slippery, the vault, the ladder is slippery, the carpet on the floor, it's slippery. And you have to make Gina Pongetti: In that you're saying when it doesn't have sweat and it doesn't have friction that's happened is not used, right? Right. Tiago Bessa: When it's not wearing out when it's not worn out, usually when they're worn out they're more grippier. You have a more safety feeling than when the apparatus is new. for example, spring boards when they are new, they are slightly stiffer than used boards. So you have to play with these feelings and you have to play with the information that you retrieve from from the from the piece of equipment, and then you make the adjustments as you go. Obviously, the majority of the situations you still go along with it because are marginal differences, but at times they can play a difference to say, okay, I don't feel 100% there either because you're not feeling fully fit on that day, maybe you didn't sleep well enough, maybe you had lunch and was not so good. And there's Gina Pongetti: Right. Tiago Bessa: so many things that play a role in this decision, then when you put the equipment into play. you may come across this decision to do so. I've I've done a couple of decisions, those myself. but in the end Gina Pongetti: Yes. And Laurent Laurent spoke very, very candidly about that with Simone that there's always a backup vault and when she was not ready and if they didn't feel like she was safe to do it, they s some days if the press would ask her, Are you are you are you flipping today? And she'd say, We'll see how the day feels. and Tiago Bessa: Yeah. Gina Pongetti: I think that's the best, most intelligent and calculated answer to give. Tiago Bessa: It is. It is. I'm taking the the time to speak about Simone, it's interesting the the twist is case. This is something that it's I mean, almost every gymnast has gone through this and they have their own opinion on this and how they manage to deal with this. And we'll see how the day goes. This is a fairly accurate statement to to of someone who clearly understands Gina Pongetti: Yes. Tiago Bessa: what they have on their hands and how they must manage it. on their own accord. Gina Pongetti: Yes. Tiago Bessa: And this is a at the end of the day it's one's decision what to make and how to make it. Gina Pongetti: Yep. I will tell our our viewers I have two very well read articles on the twisties from Tokyo where I had the pleasure of actually being there and working the Olympics even in the midst of COVID. And also article called The Layer of Fear. And it was back in the day when we were talking about Simone's dismount but talking just about that fear layer in in some things, and and people will say, but a double back is still scary. I'm like, well, it's much less scary than a triple. And so if you just don't feel like you have the ability to do your Tanko Double pike and you can do double tuck because you need you feel like you need one inch less in the air or one nanosecond less of a set, then that's what people are making those decisions on. Now getting into the science nerd aspect of this with you and I, this leads greatly into talking about FIG or world gymnastics testing policies. obviously, neither Tiago or I work for the FIG, we do not work for the International Testing Center, we do not work for the universities. and so this is all just based on what is published and how the testing procedures go. but they test things like reboundability and they test essentially ground reaction force. And we're gonna talk about some of those terms in a moment. But one of them that they do test is that friction. And they have what they call a slider, and the slider has a certain amount of weight to it. And when that slider is Hold on to forces and when it is pushed on to different surfaces, such as the padding of a beam or the top of a palma horse or the top of a vault, there's a certain amount of friction that it has to have, and there is a top amount of friction that it can't have, and it has to sit in that realm of enough to allow someone to do a turn. but not so little that it allows you to go s do slip and slide. So Tiago, I would love for you to talk about from an engineering perspective a little bit about the materials that that you work with and some of the feedback that you get from athletes and or yourself on on the surfaces. Tiago Bessa: Yeah. So all of our equipments on FIG level, they are required to comply with FIG standard testing and procedures. And this is something that we are always actively looking for is to comply with this, not only to guarantee the performance levels that are required from our equipment, but also from a safety point of view, it's important to comply with these regulations. With this being said, there's a a a great underlying here, which is these are tests controlled in vi under controlled environment and conditions. And there is a gap between this and what actually is happening. And to mitigate this difference, to create a bridge between these two settings, if it's a an FIG standard or a reality use case, this is the job that we do here at Speed. And this is made by either research, understanding of not only the usage from the end user, what are the the framework, what are the requirements, what is the objective for using this technology in this case, whether it's a letter surface or a mat or a Moscow floor, the principle is always the same, is to take the end end use, the objective, decompose it into biomechanics, it's physics, the needs, and Gina Pongetti: Right. Tiago Bessa: then you start working from the layers from the bottom up. So you start from the core and you move up until this point of contact to that is used by the gymnast. And this is made Gina Pongetti: Which is very interesting that you say that because just as an instance for balance beam, right? Friction coefficient of a 0.35 to a point six, your slider is. Five kilograms or 11 pounds for us in America that are not using the kilogram system. And it's along a longitudinal access and a lateral or a horizontal access. So if someone's landing a fliff-up layout and they're landing a little bit low, they're not landing vertically. It's not just a straight jump that lands in the air. Their foot is landing in a different plane of motion than just vertical. And part of this friction testing is to make sure that it's stiff enough and also to protect from sideways motion as well. There is a a large, I think that's pretty large, 0.35 to 0.6 in variation. So there are some people and some equipment that feel softer on the top that might want to allow the lowest end as possible. And there are some manufacturers that want it to be as high as possible. Their reasons are very interesting. Athletes can can choose, but there there are norm value chunks of space. For a reason, in order to maybe have some athlete feedback on that as as well. Tiago, you talked earlier, and we know the honey and the sugars and the different magnesium and chalk that everyone's using, but testing a piece of equipment after it's been used in a gym for a year might lead to very different results than a piece Tiago Bessa: Yeah. Gina Pongetti: of equipment that's been used 50 times. That friction coefficient on that surface changes as not to be gross people, but dead skin and germs and bacteria and sweat and everything are ground into that material. And so tell me a little bit about your thoughts on that and how you anticipate that with design. Tiago Bessa: It's very difficult to to to do this, yeah. And the simple reason is that if I come to the balanced beam routine, I would prep the beam on my own way, on according to my own preferences, according to my own sweat, state of mind. If I feel more or less confident, maybe I can push a little on the magnesia or not. if you if you come in five minutes and you will do a beam routine, you'll do it your own way. And during a world championship event you have three hundred, four hundred gymnasts. On a club, you have fifty, a hundred kids every day doing this. So it becomes to a point where you're no longer playing in the realms of FIG controlled environments. You're just in a black hole of options and scenarios that don't cannot even cross your mind. So our main focus here is to say, okay, we need A criteria for material selection that we know that comply not only with the quality of our products, safety, but again to complement inside the FIG standards. So balancing these requirements is like creating a a life puzzle. So you have all your p all your pieces put together, then you Gina Pongetti: Right. Tiago Bessa: change one piece and the whole structure around changes. So now you're gonna put back up a hole on the other corner. And this one is already moving out because you changed something on the other setting. And balancing all these features, it's sometimes very tricky and time consuming. But it's something that we do actively on all of our equipments because we need to. There's no, there's not really an end result. It's a continuous process and it's a continuous work because materials change, technologies progress, and we are like we discussed before early today. We do collect feedback from gymnasts constantly, so we are constantly improving on the information that we receive. Gina Pongetti: Now we talked with Jan and Jeanette also about matting, for instance, and how a top portion of the mat can be worn, but the inside can be replaced as well if there are spots that the athletes are particularly landing in. Can you walk me through, Tiago? And this might be great for you from an art and science perspective. If we cut a mat in half, take a twenty centimeter or ten centimeter mat, what the layers of that mat include. as we as from a from a Rehab perspective and my perspective, we are looking for some mats to have stability. Say you're coming back from an ACL or an ankle. You want something a little bit more stable and not as compliant so that the ankle doesn't have guesses, right? and then we also have matting that we want to be more absorptive from a landing perspective, but maybe create less stability. So walk me through a little bit about. the foam that is involved on the inside of any of the mats that you have that you can walk us through. Tiago Bessa: So the importance to to understand about mats, mats are a very tricky piece of equipment because they need to fulfill several several requirements. and I'm not talking about FIG, I'm talking about from the Atlas perspective, which is like you mentioned, you need stability, you need a certain compliance, and you also need stability. So right here you have three different factors that play three different roles and are controlled by three complete different settings. And To create a successful mat in all three aspects, it's very, very hard as you're playing with a triangle. And if you want to keep the triangle equal on all three sides, it's virtually impossible because Gina Pongetti: Yes. Tiago Bessa: it requires a huge amount of effort, money and and and time. But the the mechanics Gina Pongetti: Well, and if you if you want a mat that does absorb maybe a little bit more shock, you're going to now have something that is a little bit less stable. And so to Tiago Bessa: Exactly. Gina Pongetti: those to those that are looking at this the triangle that we go through in mechanics where when you give with one thing, something else has to shift and that centerpiece of perfection can never really be in the middle. Tiago Bessa: Yeah exactly. S so if you imagine the ideal layer construction of a mat, it would be composed by three layers. So first layer would be the main dispersion action action mechanics. No, from the top to the bottom. I'm thinking about from Gina Pongetti: First layer from the bottom or the top, Tiago, just for our listeners. From the top, perfect. Tiago Bessa: the movement of the gymnast landing, this is how Gina Pongetti: Yes. Tiago Bessa: the mat will behave. So the first layer will disperse all the force that will be transmitted to the rest of the of the mat. The second layer Is the responsible for the majority of the load's absorption. So first one is dispersion, so avoiding Gina Pongetti: Mm-hmm. Tiago Bessa: one point of contact, but to spread out the energy load through the most areas possible. And the second layer will be the responsible to absorb that energy. Moving on to the third layer, which is the one on the bottom, and it's in contact with the floor, would be the ideal layer for stability and rebound effect. So to avoid that you actually hit your feet on on the concrete. So this will be responsible to Gina Pongetti: Right. Tiago Bessa: kind of lift you back up a bit and say, okay, the you're safe from here. This is the basic mechanics of the mat. How do you achieve this? You have different layering, you can add more layers, you can read you can take off layers, but then you play with foam types, foam densities, looking for this perfect positioning between the triangle and This is like I said, this is like juggling. Yeah, it's it's a balancing Gina Pongetti: Right. Tiago Bessa: act and it's constantly moving because every time you change a feature, all the others will be affected and somehow you add another Gina Pongetti: Very Tiago Bessa: metaphorical layer which is costs, because you Gina Pongetti: Yes. Tiago Bessa: can you can simply develop the best Met in the world and if it costs a lot of money, then you cannot sell it. It's no longer a good product for anyone. Gina Pongetti: I also want to bring up a wonderful point of annoyance, and I'm sure this is for you as well. I travel the world as a consultant to NGBs and gyms, and sometimes people say, it's just easier, just put that four-inter in or put the the 10 centimeter mat in or put the 20 in. And because it's local and because it exists one foot from where you want to be, shouldn't be the reason that you choose that mat for that athlete. It should be with anticipation of what you want that map to do. If Tia Tiago Bessa: To do Gina Pongetti: yes, if Tiago is in the middle of a Monday through Friday and we're in leadups three weeks to an event and we need to do some hard floor landings, do we want to test and see how well he can absorb? Are we six weeks earlier and we want to do the takeoffs in the middle of a floor routine, for instance, and we really want to save bones and save that load management. Or are we coming back from an ankle surgery and we want to see how confident you are in landing your two and a half before we add a punchful out of it? All three of those should lead to very different decisions for matting. And one of my biggest pet peeves is the mats here, just bring it on over or it's local without thinking about today's goal is to accomplish air sense, but nobody cares about landing, so let's absorb as much as possible. Or today's goal is to see how stable he is, because we have a meet in a week. and there are plenty of choices for all of those goals. Tiago Bessa: Exactly. And this is the reason why I was going to say this is the exact reason why we have so many different kinds of mats. And you can think about as simple the ten centimeter, the twenty centimeter, the parallel bar paddings. there's a a variety of purposes and applications and those varieties of applications are developed with a certain specific case and usage or need in mind to say, okay, this is developed exactly for this purpose. And This is to say not only to protect the gymist for their own safety, but also Gina Pongetti: Yes. Tiago Bessa: to improve them in the development of their skills in a in a in a safe way during this transition from a learning control and then complete mastering of this of this technique. Gina Pongetti: Well, and in my mind, from an elite gymnastics perspective, there are three reasons for microcycles and matting. The first is the learning curve. The second is where you are within season. And the third would be coming back from injury. And all three of those possibilities, where if an athlete is learning a double back, it's very different on landing than if we are doing it within a routine and we'd like to either save or stress a certain aspect of it. So that's the time continuum. microcycle. And the third would be injury. And are we coming back from something where we really are concerned about takeoffs and timing, but we need to save the ankles or or maybe someone's going through Osgoods or has a a knee issue and then absorption is is really something and we can parallel this in no pun intended to things like rings and the t and the TCS and we can talk about high bar and and where we are with with matting, but I'm just using floor as an example because I think it's the easiest way for people to see things. So as we talk about that, let's get into just a a a little bit of science nerd, science nerd talk, which is which is my favorite, which we were talking about earlier. a bunch of the different t terms and science terms that we're talking about with testing so that everyone understands the testing procedure. So there's impact velocity, which is the velocity right just prior to impact onto any surface that we're testing. There's your theoretical drop height and how high you'd like for this object that weighs whatever it weighs, depending on testing. we have what the what we call the base plane. So we would just call that ground zero. So wherever something starts, and then deflection is essentially measured in millimeters as to how far down a mat allows you to go or a floor allows you to go before oscillation. And then we talk about first oscillations and and oscillations after. We measure these in Newtons of force. We measure with accelerometers. We measure how much force is being dispersed, as you said, how much load is being absorbed, how much time it takes for that transition of the load from contact from deflection point to go to the other side. Talk to us just a little bit about throw any example you're comfortable out about any piece of equipment and what it takes for you before it goes to the IAT in your magic labs and universities that you use with testing. So there's s there's objects that are dropped, there's tension cables that are used. talk us through a little bit about equipment testing. Tiago Bessa: So the first stage would be obviously the development at the engineering department. we start usually from what we already know, from our database that we have and our knowledge that we've been building throughout these last fifty six years. And we start from this point always in the sense of to improving what we have and to rely on not only past tests, but also feedbacks that we got from from ev from gymnasts, clubs. collaborators and we build on this whether it's looking for new materials, new technologies, or even manufacturing process. We develop this through a certain final product. From this point when we are certain that we've done our homework, so to say, we then Gina Pongetti: Mm-hmm. Tiago Bessa: can submit this for if it's an FIG, we would submit our equipment to an FIG test under a certain specifications. If would be for example a school product that would be assigned to the school market, we can simply go through a local club and make a protocol with them and say, okay, we would like to help us so that you can collect some feedback from you to see what's what's the what's the feedback how we should develop this is it in the right direction it's not something that we need to pay attention for for the FIG products this becomes much more scrutinized so you have a lab environments everything is protocoled and it's documented highly technology sensors and measurements and the most important things I would say for a math, let's let's keep this simple. every every equipment has their own set of testing procedures and regulations and what to measure and what not measure. But to make this simple, we take the the math case. So in the the math case, we do a drop test. We FIG testing procedures dictate that do a drop test. This meaning they're a ball, a sphere of a given weight, which would be 20 kilos, is dropped from a given height of eighty centimeters up to nine different points. They are measured and positioned according to a set of rules. And Gina Pongetti: And and by the way, Tiago, anyone we're gonna show all of these graphics also in some of the additional things. Tiago Bessa: Okay. Okay. Gina Pongetti: But if you take a mat, they test the center points, they test the back of the mat, the front of the mat, very close to the edges to see how things work. So it's not just they're not just randomly chosen spots, they're predetermined spots on on matting. Go ahead. Tiago Bessa: Yeah. Excellent. And so when you drop this mass, could be a cylinder, could be a a sphere, you have some sensors attached to it and they measure basically three things. And these are the three main things that we are looking for. So force of impact is how how hard it hits the mat, the height of rebound, which is the recall on the actual mass, and the deflection, which was what you were talking about, the ground zero. And how far down this reference line does the material actually gives away to disperse and absorb these kinds of loads. Yeah. And this is Gina Pongetti: That's great. Tiago Bessa: this is what we are looking for. This is our this is objective data, and we rely on this data to improve and to tweak. Sometimes we need to correct something because it's either too far out or too far under. And we need to be on the optimal zone because then we know we can compromise something. later down whether it's stability, whether it's rebound or even load absorption capacity. And this is how everything comes together. We conduct several tests, several drops to say yeah, can I say drops? we we Gina Pongetti: Yes, yeah, absolutely. Tiago Bessa: can do we can duck around 12 drops for each point and we exclude the highest and the lowest level And then we observe the median from all the values that we obtained from these sensors and we record these three values. And at the end, we see under these parameters, does it fall how far under one side or the other? If it falls out, then we have an issue and we have to go back to the drawing board and say, okay, Gina Pongetti: Yes. Tiago Bessa: for example, if we have if we had a height of rebound that it's out, and I'm talking about over the limit on a positive side. It means that our foam is too stiff. So, but too stiff, it's also good because we need stability. So, okay, I can take down the height of rebound a little, but I will have to compromise stability. And this is Gina Pongetti: Correct. Tiago Bessa: how the whole process works across the three corners of the triangle. So, like I said, it's Gina Pongetti: Right. Tiago Bessa: sometimes it's not so straightforward as yeah, okay, I just take a softer or a harder foam, I change this and it's fine. Then you add A different construction to this, whether it's layer where it's compounding, where it's a core block with different forms around on top or on the bottom. There's so many different combinations that you can play and explore. That choosing these combinations become somewhat complicated and at times impossible to say, okay, what do I do now? So we rely heavily on simulation. To to do this nowadays, it's something that has been working for us in a very, very good way. To learn also from simulation. We can program the mechanical behaviors of certain materials, and then we can play and instead go into the lab and just blindly tested combinations to see what works in our favor and whatnot. We can just simply run simulations and we can compile months of testing into a couple of weeks. on the computer and that gives us a ballpark to what we should work with before we go to testing. So by the time we go to testing we are pretty confident on what we are getting from from that point. Gina Pongetti: I love that. Your triangle, just so people can kind of understand, is force dispersion, force absorption and stability or rebound on your third? Tiago Bessa: It's rebound. Gina Pongetti: Rebound, right. So so that everyone can kind of understand that when you are let's say we're vaulting and we're twisting, You know, as an audience, I want you to think as you're listening to this, what are we trying to protect when we're landing? Well, I mean, ACLs are my first, are my first protection, ankles would be my second, and overall load management would be my third. So you don't want something that's super squishy when you're landing, and essentially you are twisting into where you are landing, you're grinding yourself into where you're landing, as opposed to and and balancing where an athlete can feel where they're landing, and it's going to help them absorb. the mass amount of force or acceleration right prior to max acceleration right prior to to hitting. but also you want it to be stiff enough where they can feel where they're where they've landed. Tiago Bessa: Correct. It's it's funny that you mentioned the vault. the vault has for me personally it has two two things here. One was the actual redesign of the vaulting table in the early two thousands, which was at the time and please correct me if I'm wrong, was one of the pieces of equipments where the most traumatic injuries occurred in gymnastics. And Gina Pongetti: Yes, back in the day I vaulted on a palm horse, essentially, that was this way. And now, right. And now, and I t I Tiago Bessa: Me too. I learned I learned how to vault on a pommel horse. And how to think that Gina Pongetti: tumbled on a wooden beam too. I mean, I'm not that old, but I did. And now I I I feel like everybody has a mattress that they can that they can that they can t vault on. Tiago Bessa: Put their feet on and just yeah. Gina Pongetti: Yeah. And although there is a sweet spot within the vault that obviously gives you the most energy if we're talking about kinetic energy energy and transfer of energy back, if you make a small mistake. You also don't miss the vault. back in the Tiago Bessa: Yeah, you have Gina Pongetti: day when it was a Palma horse, if you miss it, you're already flipping and you have all this energy and where is it going? So Tiago Bessa: Yeah, and you have plenty of YouTube videos to show this these times that you Gina Pongetti: Yes. Tiago Bessa: did not accurately place your hands on on top of the vault. Gina Pongetti: Yeah. Tiago Bessa: But but this to say that the one one level of the aspect is the actual redesign of the vaulting table was caused by this, the this movement, also to improve on the safety of the gymnastics. And on the landing sides, following up what we discussed about Matt's, it was interesting that you that you mentioned the part of the rotation and the landing because If you have a two softer mat when you land and you're landing with your feet rotating, what happens is your feet get stuck and your body still keeps on turning. And this is when you have your knees twisting with Gina Pongetti: Right. Tiago Bessa: a fixed base, which is your foot. And this also causes a problem torsion. Yeah, exactly. Gina Pongetti: And we talk about tibial torsion that that torsion, the femoral torsion. So your femur, if you're imagining this at home for people watching, your your femur and your tibia align and your knee bends, but there also is rotation and you have ligaments, your ACL, your PCL, MCL, and LCL also secondarily that help with that rotation. So as a person is rotating, their whole body should be rotating. But if their foot, if if their foot stops, their femur can continue to rotate, causing that femoral tibial torsion, which is not good. Let's just say that for for those of us that treat. And also ankle sprains if the foot is is is solid also. and no one is twisting in the air and doing a full and then falling out of the sky unless we're doing post Olympic tour things that look really cool on floor, right? Everyone is trying to get the maximum of rotations in. We're doing, you know, d the two and a half is an ominar, then there's your Chenko double and people are squeezing out that last half. And if they're two inches not so high, or again the friction on the vaults or their angle into the vault wasn't the max height that they feel like they need. They're going to be twisting into the ground instead of completing their rotations. And that's Tiago Bessa: The rotation. Yeah. Gina Pongetti: that's a concern. So let's talk a little bit about Achilles, Tiago. I did not prep you on this, but one of the biggest acute issues that I deal with as a physical therapist and someone that works obviously mat side at meets and travels. Is the acute Achilles tear. And this has nothing to do with certain equipment manufacturers or countries or NGBs. It is prevalent throughout an umbrella throughout the entire sport. Of course, my personal opinions on this are a lot related to load management and the conditioning that we're doing and prep that we're doing for the athletes, the usage of mats, micro, macro cycles, et cetera. I would love your opinion on where we are with equipment right now, with how floors are made. and combining code of points and and the demands on the athlete and where you think the sport can go in the future, including equipment to help potentially mitigate something such as the acute Achilles takeoff tear. Tiago Bessa: interesting subject. there's a context to to be to be explained around this topic, which is if you look in the last ten to fifteen years where dynamic floors were introduced and also matching up with the evolution of the vault apparatus, then we can talk about this increase in traumatic injuries as as you say about Achilles also ACLs on a floor side. But this comes with the development of the apparatuses. So regardless of how well you develop an equipment and how beneficial it is for the progression of the sport, it comes at a cost. So and dividing this into two categories, so vault and floor, addressing the vault topic first. You've seen in the in the the last years an increase in women's difficulty in vaulting. And y this is Easily translated by the the traditional men's vaults becoming more and more present throughout the the women's coder points. They become more often and even more used by the events also on the finals. You virtually cannot tell on a on a women's level whether if it's a men's vault or a women's vault, this is bec becoming very intertwined to to to pull them apart from each other. And this means that you have Higher heights, you have harder landings, the difficulty just increases. And this increase of difficulty is paid by the body. So when you have a full control and a spatial awareness of your movement and how you control your movement throughout the landing, then obviously equipment has a a play here and how can assist the control of one's activity. This all together play play a significant role, like I said, and this is what dictates whether an an injury occurs, a traumatic injury, or a stress injury occurs throughout repetition, through training, through a heavy calendar of computing and many, many events throughout the year. So this is this is one one side of of of the coin. The other side is obviously you get an improvement, you get maybe better timbling passes, and you get Higher difficult scores, you get more wow factor, you get more double Gina Pongetti: Mm-hmm. Tiago Bessa: yourchenko double pikes on the finals at the Olympics. so that you cannot you both of them are correlated, so you cannot talk of one without talking to the other. So obviously, my understanding also as a gymnast is that equipment play a heavy part in this, but One thing is from talking as as as a gymnast, the other is talking as an engineer. As an engineer, our job and my job is to make sure that the equipment can can help the gymnast in safely develop these skills and in a controlled environment. Whether it's on a training facility or a competition on an event hall, we must be sure that we comply with the requirements to s safely support the athletes in performing those hard skills. about the floor itself. Gina Pongetti: Right. Tiago Bessa: My understanding is there's been an increase in traumatic injuries, naming ACLs and also Achilles, but mainly more from my understanding would be more ACLs. And this is this can be easily explained by if you ever have you ever seen a slow motion of a landing on on on the floors. So when the gymnast lands You see the floor is coming down, but all the area around it kind of waves through. And this is something that it was designed on purpose, which is to spread out the load evenly. So we're always coming back to the same topics, which is load dispersion, absorption, rebound. And what happens is the amount of stress that you put into the floor, there's so much that it can spread out, but the majority of the load still stays consistent under one point. So what happens when you compress it? It stores the energy, compresses, it keeps storing, comes to a point where you can no longer absorb the energy. So it only has one way, it's up. So the floor will back up Gina Pongetti: To give back. Yep. Tiago Bessa: and it will be and it will back up against your foot, your ankle, your tibia and your knee and your hip and your column and all the way up in whatever position. Gina Pongetti: In whatever position that's in. So if you're in a bent position, it will torque it, it will push up. Yep. Tiago Bessa: And I've I've seen a former colleague of mine, I did actually see him rupture an ACL because he did triple twisting and he landed a bit still bended and his his legs were not still straight and the outside knee was in a like in an angled position. So you actually saw the recoil of the floor throughout the leg and you saw his knee doing And this is unfortunately this is the the price that we are paying at the moment. But at the same time, it's something Gina Pongetti: Yes. Tiago Bessa: that we actively pursue to improve and to make safer and to say, no, okay, we know how this behaves, we can deconstruct the movement, and now we can address each specific point and the chain of reaction to say, I want to change this, I want to manipulate this or that behave in that way. Obviously, this is broadly speaking, this is very easy to say. Gina Pongetti: Yes, yes. Tiago Bessa: it it has its own challenges, not only for the athletes but also for the engineers to to say, Okay, I want it to behave it like this, but I need certain certain aspects to be controlled. Gina Pongetti: But at the same point in time, you also want someone to be able to get as much height they can out of just a simple backhandspring entry point into a double layout. So too much dispersion too quickly leads to not having that quickness of what we consider our block or our turnaround time. So as we say everything comes with a cost, you do bigger skills, you have to be stronger. everything also comes with a cost when you take that triangle and you move where your centerpiece is. And so if if a floor is designed in a way that it absorbs a little bit more, it might be designed in a way where you're not getting as much height out of your block as possible. And that is a wonderful conundrum for you, Tiago. Tiago Bessa: This is this is easily observable. If you take the floors from around 20 years ago, early 2000s, they were mainly driven by foam blocks. And foam on its own right, it's mainly absorbent. It's not Gina Pongetti: Right. Tiago Bessa: obviously today you have different composites, different materials that you can play with, and you can play a little with this with this these features, but in the end they were mainly absorbent. And from the moment that the dynamics floors were introduced. you saw an incre an exponential increase in difficulty in the coda points. You started see triple twisting, connecting with double or two and a half twisting with double somersaults, double triples, double full layouts. You start to see a toolbox of of new tumbles that are just getting harder and harder and harder and harder. And this was obviously not not possible twenty years ago. And I Gina Pongetti: Right. Tiago Bessa: remember at the Athens Olympics? Athens Olympics 2004. there was Gina Pongetti: Yes. Tiago Bessa: a male gymnast from Korea. He made the first double back somersault with triple twisting. Gina Pongetti: Yes. Tiago Bessa: And we I was I don't know, I was fourteen at the time, fifteen. I was still like going through my ranks to through the national team as a junior. And and I was I felt so far off from that moment, like this is this is not possible. Like it it's not even the realms of imaginability, like this cannot Gina Pongetti: Right. Tiago Bessa: be. And today a a double triple twisting seems so I I don't want to say normal, but but it does not come with the same understanding that it came twenty years ago on a different construction floor. Gina Pongetti: Well, and I love how you said possible. Possible and sustainable are also in my mind. So as a scientist that does physical therapy, which is a mix of art and sport, obviously, as you know, possibility of doing something and the possibility of being good at that for two full years and maintaining that skill for two full years until the next Olympics or until the next world, allowing your body to survive. Not getting femoral and tibial stress fractures, not having OCD in your ankles from landing too short, making sure that you're using matting and doing everything, that's where we come in and we say, is this skill worth it? Well, I can do it. I'm happy you can do it once. I'm happy you can do it, but can you do it and maintain it? And now we're looking at people doing two to three Olympic cycles and they're made I mean, getting to a lead is one thing. Maintaining a lead enough to get to an Olympics is another thing, but doing three Olympic cycles over the course of of an i it's it's eight years if you bookend is really difficult. Yeah and and that Tiago Bessa: Yeah, book and yeah. Yeah. How do you do you I'm sorry for interrupting, is Gina Pongetti: Go. Tiago Bessa: there a way where you can when you when you follow up with development of a skill and you obviously you have the ability to look at the skill and say, Okay, this is a stress point in this joint that is not so critical in the movement, what are the risks, what are the benefits? Do you do you have this active thought of decomposing biomechanically to decompose an element and to say, okay, I need to reinforce this kind of work. I need to apply this preparation or this conditioning specifically throughout a a cycle or a microcycle, or depending on the planning that you have, to say, okay, we need to address this because this will become an issue after six months. Gina Pongetti: Yes. So I have three of my main things that we always talk about, which I think are important, but also a little scary for people that don't do them. So I don't know if you're aware, but I have the world's first gymnastic sports medicine course. It's 28 hours in educating people on everything from load management to diagnostics to best practices in films with x-rays, how to get people back, sports psychology, nutrition, et cetera. We touch on mechanics to a point where it's probably a one out of ten of Tiago level knowledge. but for PTs, it's it's it's pretty high level. So I think there are three main things. My my first is two years before you want to do a skill, you have to think that you want to do it and you have to start preparing the body for doing it. And what that just means is if you want to do Tikachevs, you have to have shoulder flexibility that isn't just to 180 that goes way past. Otherwise, we're gonna rip our shoulders. So it does you can't just decide in June, school's out, let's start to do new skills. second, you have to assume that every level seven is gonna be a level eight or a nine someday. And if they're going to need to load more, a double back is a heck of a lot more load than a standing back tuck. And then we need to load them more in eccentric ways in strength to to prep them for those skills. I think a big frustration on my point is in my third level is you have to keep record of everything, absolutely everything. And coaches that think that their job is just walking into a gym and saying, today we're going to bars, let's just do things, does not work. So how many routines are you doing? How many individual skills? For Tiago, it might be that you need 10 double tuck timers before doing a full in. I might only need two. And so our load, even though our end game is that we're doing the same skill, is very, very different. And if I'm ever looking at your tibial fracture or a labral tear or maybe a patellar tendinosis or a thickening, I should look and see how many reps you're doing. Can we then say, I need you to half that for the next four weeks instead of going down to zero and see if that gets better? And I would say, 90% of coaches don't have a diary, don't keep track of macro and micro cyc microcycles. And therefore I can't figure out how to change what's not working if I don't know what you're doing in the first place. I can prep your Achilles for understanding how if we're going from our base plane and you're going into a deflection point that you can't just do heel raises from neutral. And you don't just need heel raises. We're always so focused on going up and That's mostly in pliometric capacities in women's gymnastics and in men's, we're not doing it. No one is focusing on that eccentric load and that load into the negative. If you picture someone doing a normal squat and they're in perfect position and they're squatting back to a chair, their tibia still advances in front of a vertical plane, which still puts their Achilles past 90 degrees. When you land a skill, often that tibial inclination, if you will, goes to 45 degrees, if not 65 degrees. So are we strengthening? Well, Tiago Bessa: Or sometimes even more in case of compression fractures. Gina Pongetti: yeah, then we're talking about talus fractures and Achilles tears and people all are focused on flexibility. I'm really happy that you're flexible. But when you land, there's a point in time when your talus cannot take it. You Tiago Bessa: You need a structure to hold it. Gina Pongetti: absolutely do. And why are we focusing so much on a calf when we aren't working on Glutes and hamstrings and that eccentric posterior chain. So just in the simplest, and Tiago, this is physics lessons by Gina and Tiago today. If you're if you're standing, this is your tibia, this is your foot, right? Now you're standing on a floor and it's soft, your heel actually dips down five degrees just with weight bearing because no one stands on the front of their foot. Now we're gonna go into a squat and your tibia actually moves forward. You're landing a back tuck to 45 degrees, a double back to 65, and maybe you're landing poorly and you're getting all the way into 60, 70 degrees. Most of the kids we test passively can't even get to 36 degrees. That's our average with our med gym testing. So if you can't get there passively, actively, things are just going to go forward. So again, load management, proper conditioning. No one is doing tendon structure conditioning with isometric and isotonic load in different stages of load, bent knee, straight knee, landing into the eccentrics or below what we call that plane, that zero plane, which For you and I is known as deflection with load, but for normal people, you would just say it's into the negative. and I think that that just needs to kind of be be rehashed. You can look at an Achilles on an MRI that doesn't look very good or has micro tears or is thickened, and that can be reversed externally without surgery as long as you're you're careful. But why are we not doing that two years before we're demanding that someone is landing something that you know is never going to be all the time perfect? going back to your twisting. How many people do standing full jumps on a regular basis? Just start on one foot and just do a f a a a jump full and land. How many people are doing du doubles just so not like figure skating, still talking gymnastics because everyone knows I do both. In gymnastics, why are we not jumping off of mats and rotating? Well, that's an injury risk. You're having them do double full punch fronts or, you know, whatever. That's difficult. Tiago Bessa: Do you see, now that you mentioned when someone's tired, then they just kind of Gina Pongetti: yeah. Tiago Bessa: cut throughout the movement to speed up a twist or an entrance or rush out the takeoff. And this causes some. misposition I would call mispositioning of the of the Gina Pongetti: Yes. Tiago Bessa: feet or the hands or the position of the of the body itself and this also adds up throughout months and years of usage this this compounds into into Gina Pongetti: Sure. 30 degrees shy, 30 degrees shy, 30 degrees shy over and over and over again grinds away. I think you brought up a a a great point in that, in that the the load management at a cost, let's just say, where a coach will say, I want to do this many routines by Friday. And if if your athlete, if Jenny is sore and tired by Friday and shouldn't be doing them, maybe we need to understand that it's just the assignment. as I said in an earlier episode with Amy Borman, Simone's first coach, I said, you know, you can have all good plans in the world, but you do not set your plans by what your goal is. Your eventual plan is determined by what your athlete is responsive to. And if we are doing, let's say, we use vaulved testing, right? So we have force plates, force frames, everything at our offices, which is industry standard. And we do baseline testing for athletes. So we know where they are, how much they can bounce, how much they can absorb and rotate and power that they have. A because we want to see when they're injured, what they have to get back to. we always say no means no. If Tiago says, I'm ready to go. And I say you're still at 92%. I don't think you're ready to go yet. There's a psychological, physiologic trust difference. And or if it's yep. Well, but but but no means Tiago Bessa: It stops being subjective and it starts being objective and you rely on data to to to to to argument. Gina Pongetti: no means no subjectively too, though, Tiago. Because if I tell you you're at 100% testing and you tell me, Gina, I don't feel like I'm ready yet, no still means no, right? Yes, I am very much, very much. Tiago Bessa: No no, you're you're talking based on data. And I'm talking about when when you're talking when you're having this conversation without data, it becomes subjective. That that was my point. From the moment that you have from the moment you Gina Pongetti: Yes, you are correct. Somewhat absolut yes. Tiago Bessa: have data, it's objective. You have data and it's a hundred percent, it's ninety nine, or it's twenty, or it's sixty, it doesn't matter. But there is concrete evidence. Gina Pongetti: Yep. Yep. I do love the rate of r yeah, this rate of perceived exertion. Tiago, do you feel like that you've tried Tiago Bessa: Yeah. Gina Pongetti: hard today and it's like an eight out of ten? What does that even mean based on today? Are you mad? Are you angry? Do Tiago Bessa: Yeah. Gina Pongetti: you want to get back to gym? Do you feel like your parents are paying too much? So you have to say you're ready? I mean, there's so many Ugh. Tiago Bessa: I had I've I've done my fair share of physical therapy. My physical therapist Gina Pongetti: Yeah. Tiago Bessa: once said, Yeah, you're the you're the toughest patient to to deal with because pain for you is pain. You don't quantify from a scale one to ten. It's like pain is pain. I said, Yeah, pain is pain. If I feel pain, my body's telling me something. So when you're asking me, Do you Gina Pongetti: Right. Tiago Bessa: have pain? Yeah, I do. And Gina Pongetti: think about think about the constituents in that Tiago and this is a a someday when we do our sports psych episode we will talk about that your your eight out of ten one day when your mom is in the room if she has spent all of her life paying for your sports your pain might be a four because you just want to get back and you know she wants you to or you have an abusive coach and that coach is making you do something and you know that if you aren't ready you're gonna dumb that number down to a three because you just want to compete or you are really scared to do a skill, maybe your three out of ten pain is now a seven because you're making it harder because there's fear. So all the sh stakeholders, as we say, in any sort of subjective response, your response is always going to be different based on every single person asks you a question. and in in that aspect of it. I don't I care how you feel you're jumping. I really do. I care that if you do a standing back tuck, you tell me, Gina, I think I'm ready to go. I also care about what my data shows me. And we have force plates, force frames. I mean, they're available in many different capacities. We love using the valve equipment because it's so easy to use and innovative. but we're looking at numbers and we can't tell you what you need to get back to if we don't know what you were at in the first place. we did a course for the athletic trainers for the N Cou A this year also in trying to instill testing on a Monday versus a Friday, beginning of a month versus the end of the month, to say, Hey, if you're dropping, if your delta is eighteen percent in the quarter in the course of a week, maybe Friday shouldn't be the day that you're doing full routines. If you are so tired from the week that you are now an injury risk to do exactly what you just said, take off a little too soon. Tiago Bessa: The risk reward becomes something completely different to to to manage and to Gina Pongetti: You got it. And Tiago Bessa: understand. Gina Pongetti: and we say it comes with a cost. Yes, that cost might be that your plan is thwarted, but the the non-cost is that you are pr potentially avoiding or preventing injury. Well, it has been a delight, Tiago, talking to you and asking you all of these fantastic questions. it has been delightful to have you on the podcast. Thank you for spending the time. Tiago Bessa: Thank you. It was a pleasure. Thank you. Gina Pongetti: that was Tiago Bessa with Speeth talking science terms and bringing rebounding to a whole new level. one thing to carry out of today is the work and time that goes into keeping athletes healthy and balancing progress in our sport. is difficult. Look at your equipment in your gym and respect where it has come and how hard it works to make our athletes look and feel the best that they can. Every episode, the show notes, and our practitioner directory are available on medgym.net. Send this to one of the gymnastics fans in your life who has never thought about what's underneath the floor. Literally pop it over to someone that you know in the PT Athletic Training or Medical School community to understand what's behind each load and all of the work that goes into both engineering, physical therapy, and responsiveness to an Achilles. I'm Gina Pongetti Angeletti. Prevent, treat, perform, and we will see you next time. Have a great day.