 Hello and welcome back to the Sports Biomechanics Lecture Series supported by the International Society of Biomechanics in Sports and sponsored by Vicon. I'm Stuart McCurlay-Naylor from the University of Suffolk and with me today I have Professor Gareth Irwin who is head of Sports Biomechanics at Cardiff Metropolitan University. He's a former president of ISBS and his research interests include the interface between biomechanics and coaching, which he's going to talk about today. And his background as a former international gymnast, which I believe if I'm not mistaken includes competing at two Commonwealth Games and according to the university website and as a national gymnastics coach also informs his research, which makes him the perfect person today to talk about the interface between biomechanics, coaching and motor control in gymnastics. So if you've got any questions for Gareth then please as we go along, leave them in the live chat and we'll circle back to those at the end. And without further ado, I'll hand over to Gareth to tell us a little bit more. Thank you. Okay, thank you Stuart and I'd like to just thank you for organising these sessions, the ones that I've seen have been a really high standard and it's really nice to see this in place. And I'd like to thank ISBS for inviting me to give this talk as well. So I'm going to talk about the coaching biomechanics interface and I'm going to touch on a number of different topics. I'm going to talk about four main areas, which includes motor control and gymnastics and how the concepts of motor control can inform some of the decisions we make about exercise selection, about understanding control and understanding technique. So I'm going to look at this interface between biomechanics and coaching with a specific reference to the training principles. We're also then going to go into the evolution of skill with a specific focus on the catch on high bar. And then I'm also going to finish off with a little bit of insight into judging and the code of points and how potentially science and biomechanics can help inform some of the structures that are in place, and then kind of open it up in terms of a potential research area. So in terms of motor control and gymnastics, let's start right at the beginning and I apologise about going right back to the beginning, but let's look at what we mean by biomechanics. And it's two words as we know, there's the biological aspect of it in terms of understanding the musculoskeletal and neuromuscular system. There's a whole part of it in terms of understanding the physics and the maths behind performance about what makes up technique about how we can influence apparatus, how can we influence equipment design. And we know it's a huge area, we know that crash test biomechanics, animal biomechanics can give us huge insights into bipedal movement, for example, space flight biomechanics. So science is a huge area and human movement biomechanics is what we're interested in related to sport, it's just part of that. But we need to remember when we look at improving performance and looking after our athletes in terms of preparing them, nurturing them and developing them, that we're doing that in a robust adaptive innovative way that they become self aware and stable performance and stability is quite an important thing to understand and we'll come back to what the definition of that is in a little bit later. But ultimately we're trying to make training as safe and effective and efficient as possible. And from a coaching perspective, we know the importance of an individualized approach to understanding performance and understanding technique. And we know that there are three main categories that we must take into account when we look at how athletes or in this case how gymnasts create the techniques that they do to achieve the, the goal of the skill that they're trying to perform. And they fall into the categories of organism, environment and task. Now, these three categories or constraints that are placed upon everybody have an interactive effect over the performer. So when you see a gymnast performing a skill like the kept Jeff down in the bottom right hand corner. You, we know that they have challenges in terms of the apparatus that they're using in terms of the techniques that are available to them, and their morphological physiological and psychological characteristics. So in terms of tasks we have what are the effective techniques in terms of the environment we have one of the tactical awareness what decision making opportunities and what are the competitors and how does the competitive environment influence us, as well as from an a rhythmic perspective. How does the physiological psychological and indeed sociological aspects influence our performance. Now as you know this model is from a guy called Carl Newell who I work with. I've been working with him for about a decade now. And it emerged from the work from Kelso and Bernstein, and it really talks about how athletes self organized and technique emerges from these free interacting interactive constraints that self organization emerges in terms of coordination, how the body's interacting with this with the apparatus, how the joints are interacting with each other variability and stability to achieve the movement goal. And in gymnastics we know the movement goal is pretty set in terms of the international governing body telling you how the shapes and movement patterns of the skills need to need to look at understanding how the task the organism in the environment interact really allows us to look at what are the most effective techniques for a certain individual. How can we understand injury risk and reduce injury risk. How can we use this information to develop skill and physical preparation. This takes us back now to some of the first research that I did as a PhD student. And one of the papers that's linked below I think the students, including in this is highlights this this research, which was published in 2005. And what it does is it really explains how knowledge of biomechanics from a coaching perspective so as as a coach how is that actually helpful. And what the research showed so we did a big study where we interviewed all the coaches in Great Britain to try and identify how they use information, where do they get their knowledge from was one of the first things. And that was, how do they use information to make decisions about progression development skill selection and technique enhancement. And there were a number of things that we identified there were four main themes the first one were, were the coaches use progressions that they already know. And they modify those to the specific characteristics of the skill or the task they're trying to learn. The coaches come to a teaching or coaching environment with a certain level of coaching knowledge. It may be very small or it may be decades of experience, but there's some sort of coaching knowledge. What the study found was that a large proportion of this knowledge came from trial and error, mentor coaches, and that these were the main things the main avenues that these at the time elite level coaches that still elite level coaches. They gain their knowledge from all the coaches are also identified that they had a conceptual mental picture of the skill. And it was quite interesting because some coaches said that they saw skills in in kind of a strobed picture. Some coaches looked at had a movement of a slow motion movement of the image so it was quite individual, but they all had a mental image of the skill they all understood what they thought the skill should look like. It was really facilitated by the observation of elite performers, and I think that's one of the massive changes in gymnastics at the moment that we've got access to seeing elite performers performing techniques on places like YouTube. But interestingly they also said, or identified that by mechanics was something that allowed them to understand the skill. And when they talked about biomechanics, they talked about understanding at a very descriptive level in terms of what the shapes and what the movement patterns were that are required in order to be successful. And what we identified was from these four different themes, the coaches had a conceptual understanding of how skills work. And that conceptual understanding of when I go into a coaching environment, and I understand how a long swing works or a cartwheel works, or a ketchup works. The accuracy of that that information allows me to make decisions about the techniques that are available. And understanding those techniques allows me to then say how do I break this skill down into into phases logical phases, and what are the theories behind those phases that's quite important. And how do I then use that information to to understand the skill so let's look at a very common skill in gymnastics this is the long swing it starts in the top left hand corner the gymnast rotates around the bar back to the handstand position again. We know from a coaching perspective that if I spoke to most coaches in gymnastics they'd say the key part of this skill is what happens underneath the bar, as the gymnast moves from a position of an arch with their shoulders flexed and their hips extended to position of a dish where their shoulders are extended and their hips are flexed. And this functional phase is really what drives the skill. We know from a biomechanical perspective and studies that we've done that the joint kinetics during this phase, the forces around the hips the knees and the shoulders and particularly the hips and the shoulders provide the input of energy that allows the gymnast to create the angular momentum during the swinging phase. And that during this phase 70% of the work is done in that arch to dish phase in that functional phase. And that becomes very important. If we understand what the key phases of skills are, we can understand what makes the skill work. And that's where knowledge of biomechanics really helps a coach. We can look at this even further in terms of the energetic analysis, we did this me and Professor David Kerwin back in 2006 and presented it at the ICA conference in Munich, and demonstrated that 70% of the work was done by this functional phase, this key phase, and that two thirds of that work was done by the shoulders. So understanding that from a physical preparation perspective now allows me to know that there's a certain phase, that there's a certain joint contributing to this skill. And this is how much how important it is. And we know that that phase moves as a function of the different types of skills that are produced. So we did a study in 2016, where we looked at the Ketchev skill and the Kovac skill to complex release and regress movements, and identified that this arch to where at the top here, we have the Ketchev where the gymnast is in this huge arch position here, huge shoulder flexion, hip extension, and a much later position in the Kovac movement. Identifying that the functional phase is important, but it shifts around the bar dependent upon the angular momentum characteristics of the movement. So understanding the basic functional phase and then how it applies to more complex skills is a really useful thing. And then this leads to the probably the most important part of this model, this replication of the spatial and temporal characteristics of the final skill in the drills that you're using. And what this means is from a coaching perspective, it means that we're applying the specificity of training principle that we're trying to replicate the key characteristics, the shapes, the movement patterns, the coordination, the energy that occurs in the final skill in the drills that we're using. Where the key movements are where the key timings are from a more controlled perspective where the key relative phases are. So we did a number of studies and the papers are in the provided by Stuart. Where we examined the functional phase during this lot during the long swing so the gymnast again starts in handstand rotates back to handstand where that functional phase is in terms of the hips and shoulders. We replicated that or identified progressions based off what the coaches in during this study told us they used for developing the long swing on high bar to identify where the shapes and movement patterns were replicated in those drills. Not just the angular positions of the gymnast's shoulders and hips but how those joints are interacting and also how the joint kinetics were interacting as well. So this is for a number of different chalk bar long swings progressions. And what that does is it allows us to develop preparatory activities and pathways of development to become more effective efficient and safe. And it allows us to develop gymnastics skills and ultimately, and ultimately increase our knowledge and understanding of the need for biomechanics within a coaching, a coaching model. And that's really where we started talking about this idea that, you know, if you go back, maybe 50 years. You have this idea of bridging the gap between science and practice. And it's been a huge issue with with within sports science. And what we're saying is that if we have an understanding, and I've demonstrated that bridging a gap with a bridge you'll see that that is the seven bridge which I'm not allowed to go over at the moment. The gap is not just about bridging that gap but it's an interface between understanding what the key characteristics of skills are what is it that makes it work and understanding what the coach then can focus on in terms of skill development in terms of how Jim Nass learn and in terms of exercise selection. And it really does inform injury prevention skill and techniques selection and as I said, physical preparation. We're also helping a number of other ways in terms of understanding the techniques of the understanding the technical characteristics of a skill that coach will provide correlating that with the biomechanical determinants of performance helps us in terms of feedback in terms of providing meaningful information and also drives technology development where you have an interface between the technology technology being used and the gymnast performance. Okay. So I'm going to move on to the the third part of the talk, the evolution of skill and skill selection. And for that I'm going to talk about a series of studies that we did a series of studies that we did looking at data from a number of different international level competitions, and we worked with colleagues from the international body of gymnastics the FIG, the IOC Medical Commission European gymnastics, as well as colleagues at the German University of Sport in clone at the Leipzig University, and also Loughborough University. We collected data across a number of world world university ads, Olympic Games World Championships European Championships and what this meant was that we were able to have highly ecologically valid data, data where we may only have one trial or one or two trials. So it's in terms of variability of practice it's not great for for that type of research, but understanding where people are in terms of at the best point in their training or the best point in their competition. It was very a very unique data set. Now the skill that I've chosen to talk about is is the Ketchup. It's an interesting movement for for a number of reasons two main reasons I think it's performed on the horizontal bar by men's gymnast men gymnast male gymnast and on the uneven parallel bars or the a bars by female gymnast. It's a fairly common skill. It's also biomechanically a skill where the gymnast rotates around in one direction and at the point of release needs to be rotating in the other direction in order to recapture the bar again. So they have to somehow reverse their angular momentum during the upward phase in order for them to be successful. They have to allow that use the angular momentum to create the right trajectory of their mass center to allow them to be in the right position and the right distance away from the bar to regress bit. The other reason that it's interesting is that during the Soviet era of gymnastics where the sport was used as a shopping window of the social cultural ideals of the Soviet Union. And they were asked to come up with skills that could potentially be performed. And the graph the graph the figure that you see here is by a Soviet scientist a coach methodologist biomechanist called Smivelevsky who came up with the Ketchup in 1969. And this is one of the original diagrams and you can see the gymnast rotating around the bar so they used a series of techniques in terms of mathematical modeling to understanding the physiological characteristics of the performer to make and create these skills. And it was performed in 1977 in the European Championships I think by the Russian gymnast called Alexander Ketchup and then later that decade going into the next decade by female gymnast. So it's a kind of an example of where biomechanics went ahead of a sport and the sport then followed in female gymnastics though it's become even more popular and it's became quite popular. During a phase where the marking criteria changed and gymnast were rewarded more points for performing this skill. The apparatus changed in 1996 the distance between the top and the lower bar was 1.6 meters. And after the Olympics, it moved to about 1.8 meters. And you see often see coaches winding the bars out tightening up the uprights to try and get more distance between those between those bars. And what happened was it allowed female gymnast to swing more freely around the apparatus. And on the left hand side you see a gymnast performing the old Ketchup. We'll call that one the outward Ketchup. And you can see as she swings from handstand she misses the bar in the descending phase and then performs the Ketchup. On the right hand side, because the bars are wider now, the gymnast started to perform this inward facing Ketchup. So they missed the bar on the upward phase then released the bar fly over the bar on the right hand side and catch it again. And the question that we were being asked was, we were asked this question by the international governing body and by various coaches across the world. What are the difference between these two skills? And also, can the inward version of this skill provide the gymnast with the opportunities to do more complex movements out of it? So can they be in the straight position that you saw the male gymnast doing? At this point in time a straight Ketchup hadn't been performed by a female. So it was kind of why is that and can this new technique allow us to allow us to allow gymnast to do that. So we collected data a number of different Olympic Games and World Championships. We used 3D DLT. We calculated joint motions at the knees, hips and shoulders. Focusing on the hips and shoulders. We knew that that was as a major driving point for this skill. We, and as we said before, 70% of this work is done during the hips and shoulder functional phases. We also looked at the key release parameters of angle of release velocity of release and angular momentum. So I'm going to put up a series of series of tables now the tables and this will kind of go on as we go to another type of catch up in a minute. The tables will always be the same. The variables on the left hand side, flight time, angle of release, horizontal velocity, vertical velocity, inertia, angular velocity and angular momentum. You'll see that angular momentum is in straight somersaults per second. And this is a normalised method of representing angular momentum that allows us to compare between gymnasts of different shapes and sizes, as well as between males and females. This is a useful, standardized way of representing angular momentum and emerged out of the Loughborough University group. So let's have a look at these two skills. And first of all, let's go to the bottom and have a look at this angular momentum. What you're going to notice is the angular momentum during the old catch of about minus 19.19 sorry, and of the inward catch of is nearly two thirds higher. So straight away you can see that there's more angular momentum capacity, performing the newer inward facing catch of their slightly more flight time, the vertical velocity is higher. The vertical velocity is about the same, which you would expect because they still only got to travel a certain distance over the bar. And, yeah, and those are the two, those are the main things, the angular momentum at the bottom is the key thing. The other thing that I was going to mention is that you can see that there's a negative sign by the angular momentum. And what this denotes is that the gymnast is now rotating in the other direction. So it would have been positive on the way down and up to the point of release it would have got more and more negative. And when they're in the air, the negative angular momentum would have been sustained until they hit the bar again, caught the bar again. And this is a nice visual of these two skills kind of happening at the same time I'll let it run a couple of times so you can see it. You can see the female gymnast and I know this is only one gymnast and this is just a representation of it. But you can see that the female gymnast performing the outward version. This is this girl and this female gymnast here performing the inward version. She's clearly higher. She's more rotated in the air and potentially straight away coaches start to think, well, maybe I can change my body shape now in the air and change my moment of inertia. I've got more angular momentum now. So around about 2000, this skill emerged another version of the catch of a toe on ketchup. And we know that this is became quite popular Beth Tweddle used to perform this exquisitely in her in her competition career. And the same question emerges, how does this ketchup provide female gymnast with the opportunity to do a ketchup in the straight position. So same set of data again. Now we've got the old outward, the new inward and now even the newer toe on ketchup same set of variables on the left hand side. Let's put all the values up and let's look at the bottom again. Let's go straight to the bottom and have a look at the angular momentum characteristics in terms of the gymnast rotational capacity. And you can see there's the jump from outward to inward and there's still a slight increase in terms of the toe on ketchup. So maybe this is a good catch up to perform this straight version of the skill. And you can see that there's more flight time during this skill and the vertical velocity is also higher. But really what what the coaches and what the governing bodies wanted to know was is the direction of the evolution of this skill from the inward to the from the outward to the inward to the toe on ketchup. So we're going to provide the female gymnast with the opportunity to do this skill, the straight ketchup, and you can see that obviously during the aerial phase angular momentum has to be quite high because he's going to be in this straight position. The distribution of his master in the aerial phase is high. He's got a high moment of inertia. And consequently, he's got to produce and generate enough rotational capacity to perform this skill. So what we did was we used our methods of normalization so we could compare between males and females. And we looked at all of the skills now and we looked at the outward, the inward, the toe on the straddle and the straight ketchup. So these two on the right hand side of male performers and these three of the female gymnasts, same table again, same set of variables, a lot of numbers. Let's go straight to the bottom. Let's look at the angular momentum. And you can see if we go right over to here, the male performer performing a straight ketchup is producing a huge amount of angular momentum in comparison to, for example, the outward version of this ketchup of this skill. But the female toe on and the male straddle are too different to each other. So the question is, if it's not strength and we didn't think it was strength, what is it about these these skills that is preventing a female from performing this skill. Again, look at the flight times the flight times are much higher for the male performing this skill. Again, as you would expect a higher vertical velocity at take off. So what is it about the technique or the skill or the task that's making these these differences. Well, we'll come back to that in a second. We also interestingly measured the work done at the shoulders and the hips during this this skill. And what we found was at the hips at the point of release in all three of these female ketchup's the gymnast were doing the same, the same thing, the gymnast was opening their hip angle, causing their hips to extend at the point of release 90 80% of the work being done was being done in that direction. And if you look at the what the shoulders were doing during the inward ketchup and during the toe on ketchup 30% of the work was being done by the gymnast pulling and opening their shoulder angle. Whereas 30% of the work being done by the outward ketchup was working in the other way. Because of understanding the physical characteristics of the skill and how to condition for this movement. These two ketchup's are doing a completely different thing at the shoulder joint than these two ketchup's. So one, one is opening the shoulder and the other one at the point of release is very quickly closing the shoulder. One is an eccentric potentially an eccentric contraction and one is potentially concentric contraction, but we do know the movement patterns replicate that as well. So go back to that model of coaching. Understanding the, the technical requirements of the skill would allow us now to say okay, from a physical preparation perspective, we know that these are the shapes and movement patterns that we need in order to be successful. The reason I've got some confidence about that we had a we presented some of this to the British gymnastics. Maybe four or five years ago with the national coaches at the time, and they were able to explain why they thought that was the case. We really showed how understanding the mechanics of the skill and also understanding the coaching language of the skill allows us to drive the movement forward and help understand how we can make training more effective efficient and safe. And then what happened in 2011 in Berlin at the European Championships we saw this skill. So it is possible. It was one of the first times that we'd actually got a recording of it, and it's in terms of the shape in the air it's a fantastic shape, very straight. She does get quite close to the bar, she does nearly knock a teeth out, but she is producing enough angular momentum to be able to perform this skill. So what is it what's the limiting factor that is preventing female performers from performing this skill more often. Well, let's just go back to the basics of gymnastics. Females perform on a tensile steel horizontal bar. The energy being put into the bars returned very quickly back to the performer. It's a very stiff piece of apparatus. Females, they obviously have two bars that they've got another bar to contend with, but they're swinging around a composite material of fiberglass and wood that's less stiff. And the energy being put into the bar being returned. It's very different. So the female gymnast has to do more work. And the timing of the interaction of the gymnast and the bar really underpins how these gymnasts can be more successful. And it really highlights this environmental constraint, because it is a constraint on the performer, the environment that the gymnast are performing in has been changed. You could say, should the bar for the female gymnast be stiffer? Would that help gymnast? But then you've got to think about body mass and gymnast and that interaction of the apparatus. And we'll talk a little bit about that in a minute when I come on to the code of points and the differences between male and female performers. Okay, so we've talked a bit about mode control. We've defined biomechanics. I apologize about that again. We've talked about the coaching biomechanics interface and how that links to the principles of training. And we've now talked about the evolution of skill, giving a quick example of the Ketchev. I've included some links to some papers that are all biomechanics papers, not coaching papers at all. They're really for biomechanists. And included some others that you might find interesting that relate to Ketchev and gymnastics in particular. So let's move on to this judging idea and the code of points and as it underpins the sport so much, it's such an important area for us to have an idea of. And one of the things that the international governing body wanted to do a number of years ago was to challenge the idea of how similar males and male and female gymnasts were in terms of performing the same skill. So if a male performs a double tuck somersault on floor and a female performs a double tuck somersault on floor, are they the same? If you look at the code of points, one isn't always given the same value as the other. A double straight on floor for a female is awarded much more points than a double straight on front, double straight back on floor for a male. And that was the case when we did this study. It was an important question. It was topical. At the time, it was just after the 2004 Olympics. And it really came to the start of the change in the coding, the code of points and the judging structure of gymnastics where we no longer have a 10. It really underpins the governing bodies code of points. And that was ultimately what the system they wanted to have in place was a clear and transparent judging system that was clear for the participants, the coaches, the clinicians. And also for the public as well because I think one of the most important things is that the public are able to engage with the sport. So, as we know in gymnastics, males and females do compete separately. They are both logically and morphologically different. But they compete on similar apparatus, the stiffness characteristics of the floor the same for a 40 kilogram female compared to a 70 kilogram male. So the question that was a move that we want to look at is when we compare the technique requirements of skill in terms of females and the technique requirements in terms of males and then the physical demand between those two sexes. So the code of points. So the code of points is there in gymnastics to provide a standardized system of assessment. It's an objective means of evaluation. And ultimately it ranks the performance from the best to the worst. And the review of the code of points happened at the IOC of the IOC at the FIG conference in Geneva 2006. And when we and to help with this we need to understand where this code of points comes from. So the code of points, if you don't know is a book as a book basically. And I think there's a digital version now that has every skill in gymnastics and it's ranked from a is the easiest right up to H now being the hardest skill. And each of those skills A, B, C, D is given a is given a mark and you perform 10, 10 points, 10, 10 skills and each one is given a mark so you have 10, 10, 10 attempts to get the highest score you can. Judges, gymnasts and medical practitioners and scientists all provide expert domain knowledge. They all give that information to the technical committees. And at the forefront of all of this is safety and development considerations. The welfare of the athlete is put central in this process. And the skills are classified based on a combination of all of these things. It changes every year every four years as well. But let's look firstly at differences between males and male and female gymnasts from a physical characteristics perspective morphologically and we looked at a sample of data from 1994 and the 2000 Olympic Games. And we can see that there is is a significant difference between males and females in terms of the, the morphological characteristics, just by simply looking at their mass and their height. In the 2007 World Championships, we also collected some data and found staggeringly the lightest female gymnast was 29 kilograms. And the heaviest female gymnast, I think was 56 kilograms for 29 kilograms, which is may not be a problem at all. It's more morphological characteristics of her as a performer. The lightest male I believe was 52 kilograms and that went up to I think 76 kilograms in 2007. So it's just interesting to look at the spread of those masses of the performers and think about, you know, all of those females are competing on the same floor. They're competing on the same vault in terms of the springiness at the top as their male counterparts. So it becomes an interesting observation an interesting question to look at. So I'm going to, I'm going to, as we know, these are the apparatus that the males and female gymnast in artistic gymnast compete on. Females compete on floor beam vault and bars and males compete on floor pommel rings vault parallel bars and high bar. And obviously there's a similarity in terms of the floor and the vaulting apparatus. I'm going to focus on on floor for this and identify or show how potentially biomechanics can be used to inform some of the comparisons between skills and the quantification of the the code of points. In terms of apparatus we know that the since the change in the vaulting horse became to a vaulting table that the vaulting table now is about a meter square, slightly angled, a certain level of stiffness characteristic females vote on it on a 125 one meters 25 I think I'm not 100% sure though but 135. And we compete on a gymnast compete on a 12 meter square sprung sprung floor, and this is the same for all masses and all and both genders. And as we said, the similarities in terms of stiffness are different for the bars and, you know, how that's quantified is is again an interesting question. But in terms of what makes critical biomechanical variables. In terms of successful performance to a probably key, and they're ones that we're going to focus on one is rotation, and one is time in the air. So how long got in the air and how much rotation have we got to perform the number of some assaults or the types of some assaults that we want to perform. So for example, this is a picture drag a rescue, those who recognize him taking off into a double tuck some assault and a double straight some assault. The project the project the trajectory of the two some assaults is is different in terms of one is going to horizontally move much further than the other. When we look at the actual figures, we can see the time in the air is about a second. The angle of take off is slightly more upright for a double tuck some assault, and the horizontal velocity is much higher in a double straight some assault. And we could talk about the mechanical characteristics of why this is the case, but that's not for that's not for now. The take off of some other movements, for example, the catch of in male and female gymnast time in the air very similar, the angles very similar, and the difference here being the vertical velocity at take off. And that vertical velocity at release gives that opportunity for the gymnast to create angular momentum, and also create a higher longer time in the air, if necessary. Angular momentum is particularly important our capacity to rotate and angular momentum, as we know during the aerial phase of any movement is set, it doesn't change. And we need a way of examining angular momentum between different people. So we can normalize it as I said before, and in order to do that we calculate a thing called straight summer socks per second. So here we have an angular momentum profile of a performer performing a catch of, and here we have the angular momentum profile normalizing as you can see the normalization just changes the values it doesn't change the profile at all. So, let's look at the, let's look at the ranking of of skills on the floor exercise. Let's look through this so on the left hand side here, you've got male performer male code of points, and you've got the double tuckback summer so double pipe back summer so double layout summer so and the same in the females, and these images were taken from the code of points. And at the moment, these are worth the same, both of them are see a C value up here point three you'll get for doing that skill. And if a male does a double pike in this position where his hips are completely folded, he'll get a C and a female will get a D. If a male does a double straight he'll get a D and a female will get an F. So she'll get significantly more points for doing this skill. And the question is, is that fair. And if you talk to coaches you'd say yeah female gymnast have to are battling against, you know, less muscle mass than a male, and also having to interact with an apparatus that's that's the same stiffness as a male male performing. So they, you know, you could argue that that's right, just from a kind of qualitative perspective. But let's look at the flight time of these skills. When you look at the flight time, the flight time between males and females. You get a little bit more in males, but not not not massively. So during the double tuck and during a double straight. The male performer has much more flight time in the air. So you could say well yeah, it's actually going to be easier for a male to perform this skill, because he's got more flight time he's able to generate more flight time. But let's look at the angle of momentum, if who can create more angular momentum. So in terms of the double tuck and the double pike, there's around about 1.1 somersaults per second to 1.2 somersaults per second so they're very similar. So you could say well a female doing a double pike and a male doing a double pike are probably similar. And when you look at the angular momentum characteristics of a male and a female performing a double layout somersault, the differences aren't as great as one might expect. So the skill score, and you said this so the skill scores them is the product of the flight time and the angular momentum, and this is our idea of maybe we can use this to rank different skills. You would see that the male gymnast is higher than the female gymnast. What that means is that when the skill score is produced, when the gymnast performs this skill, it's actually not that much more difficult for a female performer to perform this skill. So let's look across the across the different movements. And I think we can only really interpret this skill score when we look at the difference between the easiest skill and the hardest skill. So here we have in the in the yellow, a male performing a double tuckback somersault and a male performing a double layout somersault. And you can see that that the female is very similar to the male in terms of the angular momentum and the flight time. The skill score for a female is much lower than a male. But the ratio between going from a double tuck to a double straight isn't isn't that great. So the difference between going from a double tuck in a female performer and a male performer, it is slightly harder, but does it constitute going from a C compared to an F. So the code of points currently looks like this, C to D for males for tuck and double layout and C to F for females. Based on just looking at how much rotational capacity the performer has and how much time in the air, would that look better? I'd suggest it wouldn't. I'd suggest that actually it is more difficult for a female to perform a double layout somersault. So maybe that looks better. So in summary, we've shown that these skills, these skills are biomechanically different, even though they have the same name, and that this could identify anomalies in the code. It could demonstrate that a skill score ratio may allow these different steps between these levels of skill to quantify and program training and also the code of points in a more effective way. By itself, I think it would be wrong to say we use biomechanics solely to create the code of points. We always have to take into account other things. And I think the history of the sport expert domain knowledge and other variables need to be taken into account. But I think what this quick snapshot did was allowed us to see that science could actually provide some information in this. It could also help us decide whether we want to adapt apparatus or codes of points, changes in apparatus in terms of the vault. We know that the vault changed. And any changes need to be done with caution in terms of safety, history and tradition, but biomechanics can help. It can help develop multi and interdisciplinary approaches to code design. And it also sits well with the ISPS mission statement of linking science and practice. So I'm going to finish there. I've got a couple of take home messages. So this will only take a couple of minutes. And then we're open for questions. I think I've gone on roughly about to time. So the take home messages are really that coaching knowledge is vital. Understanding and being able to communicate with coaches from a scientific perspective underpins this all of this. Linking that to scientific understanding allows us to identify the most effective techniques election that drives our ability to identify training drills skill development and physical preparation. And we need to keep in mind that in order for the gymnast techniques to emerge and the emergent properties of those characteristics of the interactions of the body segments to create the goal to achieve those techniques. Is a combination of the task, the skill, the technique that we know to gymnast, their morphology, their physiology and the environment in which they're performing. Ultimately, we want to try and make our performance as adaptive and innovative and stable as possible. So biomechanics can help. It can inform technique selection, it can develop effective drills, and it can help the coach develop a mindset of how skills work, how we can break skills down. But we need to maintain ecological validity throughout our approach. If we don't have that will lose the audience will lose the coaches will lose that compact communication with the sport. We need to try and strive towards interdisciplinary research, not multidisciplinary, which is a challenge and I think that's been known for a long time. And we need to address questions from a question specific perspective, look at the question and then decide what the methodology is that we're going to use to answer that question. Just because we're biomechanist doesn't mean that we can't address questions from other perspectives. The biology part of biomechanics is particularly important. Collaborating with the right people, making strategic alliances to address these meaningful questions also underpins all of this is tremendously important. This whole scientific approach is trying to make training more effective is trying to make it more efficient and safer. Thank you for your attention. Brilliant. Thanks, Gareth. Yeah, I really enjoyed that. I think what you referred to as a quick snapshot, you went through really well specific examples so I like that you kind of went through the biomechanics motor control and coaching of the same skill, but also talked about the like the task, the organism and the environment, all for the same skill as well so it was really nice to just see how that all links in which I guess then tied back to your take home messages where you kind of showed us exactly how that's done with a few specific examples. So I really liked that. Thank you. Yeah, so just, have you got the next slide. Yeah, cheers. But yeah, just while I give people a chance for the live stream to catch up. If you've got any questions just drop it in the live chat on YouTube and I'll read them out. And yeah, just another mention as Gareth said during the presentation, links to lots of the papers are in the description below the video as well. But have a look on there at what's coming up in the next few weeks. Going over methods in EMG statistics, some simulation modeling, and also different analysis methods leading up to then the ISPS conference week at the end where the ISPS YouTube channel will have lots of things to interact and engage with as well. So keep updated. Subscribe and click the bell and you should say get notifications whenever things are updated. Okay, so I think that brings me on to the questions. So we've got a couple on YouTube, Gareth. The first one was from Nadim Youssef, who I know has been watching quite a few of these lectures. So I think you kind of covered this to some extent after the question was posed, but he asks if you could explain the important kinetics and kinematics involved in the execution of gymnastics skills. So yes, because you kind of went over that a bit maybe if you could just talk about the relative importance of kinetics and kinematics and some of the things that you discussed. Yeah, so so obviously when we talk about the kinematics of the gymnastics skill we're talking about the shapes and movement patterns, the body positions. We're also interested in the interaction of the joints or the body segments, and that allows us to measure coordination, and that sits, sits within this idea of motor control. And the thing that drives what are the key variables in terms of the kinematics, and also the kinetics the forces the turning forces around the joints is the task is the skill that we're trying to perform. And that's the most important thing, you know that the sport of gymnastics dictates that during a cross on rings, or during a long swing on high bar, my body is in specific is in a specific shape. And those movement patterns and body positions are achieved by musculoskeletal forces that are interacting with the apparatus to create the right techniques so it's very much down to the task or the skill. And, you know, and, and we could look at something more general like landings or impact and say that we're trying to attenuate forces that we experience in terms of loading rates and peak reaction forces, and we can change the stiffness of maths etc. But yeah, it's there are one or two key variables, you know there's some important ones angle momentum is always important in gymnastics we're always rotating and that drives it so if you know what the task or the skill is, then you can go further into understanding what those important kinematics and kinetics are. Well, thank you. And then yeah, got a couple of questions from Holly stock. First one is, are FIG using these methods to inform the scoring systems, or is this just kind of something you're proposing for future. And then the second part of the question was, what aspects of timing. Did you decide we're associated with successful female capture performance. So that so the first the answer the first question is quite quite simple we, we propose this quite a few years ago actually, and we were working at the time we were working with some colleagues, Petrie human in the news in New Zealand. Some colleagues in Alberta in Canada, Keith Russell and Pierre Gervais, and as well as in the UK and we kind of tried to come up with a way that the FIG could look at this and the, the, it was presented then to the FIG scientific committee when that existed which doesn't exist anymore by Professor David Kerwin and Peter Bruggeman in 2006. And, but recently I was invited to give a talk at the university in Osaka with other colleagues from the FIG and international physics, and had a very good talk with the MTC, one of the MTC members about looking at this as a way forward in terms of making a more, I guess reliable and objective code of points, or having something that is may contribute to it. And if it's meaningful and if it's useful then that's that's great and hopefully it would you know it would allow technique to be understood to a better level and and hopefully keep recent keep injuries to a minimum and performance to to the right level. So I think that answer that that question is that right? Yeah, yeah. So the second part was just which timing aspects were linked with successful female capture of performance. So that so the variables that we focused on in in this particular study, we're all at the point of release. So, when I was showing you the angle of momentum characteristics. When I was showing you the moment of inertia of the performer, the angles of release these were all, these were all selected because they are the characteristics that are linked to producing the trajectory of the projector of the athlete in the air. The athlete has left the bar, their projector, their trajectory of their mass center is set their angle of momentum is set. So in terms of timings. It was that was the point in time that we examine that discrete point. We did though look at the functional phases. I can't remember what they are at the moment because it's but it's certainly in the paper where we looked at inward and outward catch as it's one of the papers. And there's another paper on the evolution of the ketchup, which is in international biomechanics 2018 I think. And that certainly looks at timings in terms of the functional phase, the tap swing that we talk about in. In terms of the going from arch to dish to arch in the ketchup, those are those characteristics and looked at but yeah but the key variables ultimately, no matter what the gymnast does at that point of release. They have to achieve the certain mechanical dictates and we know that that arch to dishes kind of underpins all of that. Thanks and then yes last question unless any more pop up. There's a really good question here when we talk about the interface between biomechanics and coaching. Carol D is asked whether there are any tools that coaches can use to help them use biomechanics in day to day coaching. So, I guess, I guess I'd start from a very simple level and say, being able to be able to understand the shapes and movement patterns that performers undertake to achieve certain skills is the first part. So if we were to look at a female gymnast doing long swings on bars, and we saw maybe the three different types of long swings that they do with the pike down the straddle straddle pike or the arch. You know, straight away we see that those there are three techniques that exist that are all being successful. And then then the next question is well which one is best for which type of gymnast for the maybe short or the toward gymnast or for the, for the, you know, slightly heavier or lighter gymnast. But ultimately understanding that and observing as much gymnastics as possible kind of underpins a lot of it. And I think that's where, you know, we've we've developed certainly the UK developed as a nation because we've had access to so much good quality information just visual information on, on what makes skills or what good skills look like. And so in terms of the first level of tool, first tool is increasing that knowledge of what those movement patterns are. And then the next bit is is kind of understanding and explaining the link between things like how did how did gymnast generate angular momentum at take off. What are the shapes and moving patterns that actually achieve that. How does the gymnast get into the reversal of angular momentum at release on the bar. So, you've got a conceptual understanding of the skill. And that is kind of built being built up by, you know, various resources that you can use and, you know, I think some of the some of the resources that we've produced in British gymnastics. I know I've been working with British gymnastics on their kind of reframing of their coach education program and trying to impart this kind of understanding of conceptual understanding of skill in it. And I think as well. One of the things that is highly useful is being able to longitudinally track your athlete. So being able to say okay let's look at even if it's a gymnast learning a cartwheel. Let's look at the cartwheel. These are the characters these are the shapes and moving patterns we want. Now, I'm going to now track them every time they perform it. You know, video five per session over over the year that we're producing it or performing it or maybe years too much. And that allows you to to understand how these mechanisms are working by mechanics is kind of a continuum really you can go right to one extreme of research and try and understand how muscle fibers work. Right to the other end where you've got understanding that if we hit the floor with a certain amount of force before the floor will exert a certain amount of force back to us. But I think in terms of from a coaching perspective, understanding what the key principles of movement are, and then apply that in terms of what are those key functional shapes and movement patterns that we have in gymnastics, swinging, circling, landing, those sorts of things. So how do they work. That would be my that would be my answer. Thank you. Yeah, I think, I think that advice applies to a lot of sports as well not necessarily just gymnastics. And yeah, and I think just last question I'm going to throw my own one into the mix, but it's for me. If you had a magic wand is that you could wave. Is there anything from a coaching or motor control perspective that you wish biomechanists would do more or less of in their research. If that makes sense. Yeah, certainly I think there's a there's a big hole in the market. There's a big gap in knowledge about how skills develop. And we have studies where we have Jim Nass learning the long swing, for example, and we're about to publish another study now. We've got Carl Newell on the emergence of cognitive structures. But they're all university students learning it. What we want is how do eight year olds learn the cartwheel the long swing, the, you know, how what is that process of learning at that younger age. And there are lots of theories out there. We've got Einstein's theories of learning. We've got Carl Newell's theories of skill development, as well as things like fits and postures. But I think that's the longitudinal longitudinal research is is not done because one it's, it's really hard, hard work, hard to do underfunded. And ultimately that's, you know, you know, as well as I do sport isn't isn't sports science isn't particularly well funded within certain sports. And, you know, I'm fortunate enough to work across a number of different sports with big governing bodies like FIFA and World Rugby. And, and, you know, there's just not the resources to do all of this research. So, yeah, I think if I could have a magic wand I'd get more research that's longitudinal. I'd also have more interaction with coaches as well. I think that's the key thing and bridge that gap a little bit better and a little bit more funding as well. Well, you've got that magic wand in your hand. Brilliant. Yeah, thanks ever so much for that Gareth and I know the few comments on YouTube thanking you as well for a brilliant lecture. Yeah, thanks very much and just quickly I guess if anyone does have any more questions if they're watching this back in the coming days. Is there a best way of kind of getting in touch or asking any follow up questions. Yeah, 100% if you if you can put my email down in YouTube somewhere. I'll add that to the bottom of the below where all the papers are. Twitter account on there as well. And yeah, do that. That's all right. Yeah, brilliant. Thanks again, Gareth. Thank you very much. Thank you for putting this together Stuart. It's really useful and certainly at this time I hope everyone stays safe and well and yeah I look forward to the next talk on the 25th of June related to EMG. Thank you.