Swimming is not a Drag with Dr. Carl Payton

Today on Biomechanics in the Wild, we will be talking with Dr. Carl Payton, a Professor of Sports Biomechanics at Manchester Metropolitan University in Manchester, England. He researches the movement of paraswimmers and is currently working with a team to develop a new classification system for the International Paralympics Committee. He also serves as a support scientist for Great Britain’s Olympic and Paralympic swimming teams.

Paraswimmers are allocated different classifications depending on their disability. Swimmers with a motor coordination, mobility, or limb deficiency are split into rankings S1 through S10, with S10 being those swimmers with the least level of impairment. Swimmers with a visual impairment (S11-S13) or a intellectual disability (S14) are also split into different classes. The goal of this system is to allow the swimmers to compete with swimmers of a similar ability level, to create a level competition field. 

Show Notes and References

The book that sparked Dr. Payton’s interest in sports biomechanics is “The Biomechanics of Sports Techniques” by James G. Hay [ISBN: 978-0130845344].

The on-land motion capture system that we were discussing utilizes reflective spheres on a dark background to track an individual’s motion. The platform that Dr. Payton mentioned is Vicon [www.vicon.com]. The underwater motion capture system that Dr. Payton discussed is Miqus Underwater (Qualisys, Göteborg, Sweden).

For further information on the subjectivity of the current classification system, please see either Sports Illustrated’s article “Will Cheating Ruin the Paralympic Games?” [Robert Sanchez] or Burkett et al. 2018 “Performance Characteristics of Para Swimmers: How Effective is the Swimming Classification System?”.

For further information on the different classification levels, please see this brief article describing the levels from the International Paralympic Committee [www.paralympic.org/swimming/classification].

Dr. Carl Payton’s email is c.payton@mmu.ac.uk. The research associate that is working closely with him on this project is Dr. Dawn O’Dowd (d.odowd@mmu.ac.uk). Dr. Brendan Burkett who is the co-investigator on the paraswimming re-classification study is a Professor of Sport Science at the University of the Sunshine Coast in Queensland, Australia (bburkett@usc.edu.au). He is also the Head Coach of the Australian Paralympic Swim Team. Dr. Luke Hogarth (lhogarth@usc.edu.au) is a Postdoctoral Research Fellow who is working closely with Dr. Burkett on the evidence-based classification system.

For further reading on the research of Dr. Payton and his team, as well as other resources on the topic please see the below document for articles.


Mia: Welcome back to the Biomechanics in the Wild Podcast. I’m Mia Hoffman and I will be your
host today. We’ll be talking with Doctor Carl Payton who is a professor of sports biomechanics
at Manchester Metropolitan University in Manchester, England. He’s also a sports consultant for
Great Britain’s Olympic and Paralympic swimming teams. Today we’ll be talking with him about his research into the biomechanics of Paraswimming. Doctor Carl would you mind explaining what really the biomechanics, sports biomechanics
really is?

Dr. Payton: As sports biomechanics is obviously the the study of sport through the use of biomechanics. I mean biomechanics is a scientific discipline that concerns itself with the way we move and what
causes those movements. So biomechanics would typically. Look at trying to measure and describe the way people move, and that’s that’s called kinematics. So kinematic analysis the way we move.
But perhaps the more interesting part of biomechanics is explaining those movements.
How we move, and that’s where we start studying the forces that cause those movements and that
that area of biomechanics is called the kinetics or kinetic analysis.
So in terms of swimming biomechanics, then I guess what we’re interested in is the way
swimmer’s move in the water.
So if you wanna put that technique but also the forces that influence that technique and in
swimming those forces or the main forces are the propulsion. And the resistance, or the drag.
So in a nutshell, that’s that’s swimming biomechanics.

Mia: So is propulsion how you move through the water and then the drag is the forces that the water impose on you to kind of slow you down?

Dr. Payton: Right, so so in terms of propulsion is the force that we want to maximize. So any swimmer is trying to, through their technique, create as much propulsion as possible, because those are the forces that go in the direction they’re swimming in. Unfortunately, in swimming there are forces that oppose that movement in the opposite direction, and those are the the drag forces, or the resistive forces.
So the secret of good swimming is to try and keep the drag forces as low as possible while trying
to maximize the propulsive forces. It’s a fine balance between the two.

Mia: Wonderful. So how did you really become interested in sports biomechanics and swimming in general?

Dr. Payton: Well, it’s many years ago, so when I was a teenager, when I was 18, I used to be a competitive
swimmer. And actually my coach at the time I bought a book after he gave me a book called the
“Biomechanics of sports techniques”. And so we’re talking over 30 years ago now when biomechanics and sports.
Science generally was quite a new discipline and of course I’d never heard of biomechanics and
this book was a revolution, a revelation. It had a chapter chapter actually on swimming biomechanics, and at the time I was studying physics and maths and I was into my swimming so I was able to combine my love of sport with my love of the Sciences and this was my opportunity.
So having having read this book, the biomechanics of sports techniques, it it just sort of
stimulated my interest and that’s what led me to to go to University, University to do my first
degree. And I were studied, obviously, just not just bio mechanics, but Physiology, psychology and such
like and then I wanted more. So I went on to do a Masters degree at Loughborough in the UK. And then I knew that you know that that that was the career for me. I I wanted to go on and teach
and research and work in sports biomechanics.

Mia: Thank you, that’s so interesting. We’ll find that book and will link it below. So you do a lot of work now with Paraswimming and the International Paraswimming commitee, Paralympics Committee.
So so really, how did you get involved with paraswimming?

Dr. Payton: Well, I started off working. Actually not with Paraswimming but with Olympic swimming. So I’ve been a consultant on on and off with the Olympic of Great Britain Olympic team for probably 30 years now. But then about 20-21 years ago, So in 2000, I was contacted by the Performance Director, so the big chief of the GB Paralympic swimming team and was asked whether I would like to do
some work with them as a as a consultant. And I panicked a little bit. I must admit and said I don’t really know much about paraswimming and disability and and essentially he said, well, you know plenty about
swimming biomechanics. You can learn the rest and I’ve never looked back since. So I’ve been working with the GB paraswimming team as a consultant and part of their sports science and sports medicine team since, yeah, for 21 years.

Mia: So does that mean you go down on deck and help them figure out how to correct their swims and

Dr. Payton: Yeah, very much so I I said I’ve got I’ve got a coaching background, but I’m not a coach. I’m a what we call a support scientist or an applied practitioner, so I I work alongside the coach. I support the coach. I provide them with sort of scientific evidence to back up their decisions. Help them make the right decisions in terms of technique. We also do a lot of monitoring of the swimmers in terms of their power, their drag. We did a lot of suit testing, so leading up to a major games, like Tokyo.
We want to make sure that our swimmers compete in the best suit, the one that keeps the drag to
a minimum so we do a lot of drag testing to see which which suit is is the most appropriate suit for each
of our athletes, so it’s quite a varied role.

Mia: So have you gotten to travel with the team to Rio and I guess London stayed local for you all?

Dr. Payton: Yeah my first Paralympics. Yeah. My first Paralympics was it was in 2000. I was in Sydney and
then Athens, then Beijing, and then London. I didn’t actually go to Rio and we’ll see what happens with Tokyo. They haven’t announced the team yet.

Mia: Yeah. That must have been very cool to get to travel and be with them for that.

Dr. Payton: It’s yeah I feel very lucky, very privileged to have seen quite a bit of the world with the team and it’s not as glamorous as people think, mine you. It’s a you know you do generally see that the hotel, the airport and the swimming pool not not a lot in between because obviously working well you there but still a fantastic opportunity. Yeah.

Mia: So something that makes paraswimming really unique is that people with different disabilities
compete against each other, correct? So you have people with cerebral palsy, swimming against people with amputations or maybe paraplegics. So can you briefly explain the classification system for us?

Dr. Payton: Yes, how long have we got? And so so essentially in obviously to to compete in any para sport, of course, in para swimming you have to be classified.

Mia: Mm-hmm

Dr. Payton: You’re not allowed to compete unless you have a a designated class. In paraswimming, there are 10 classes, or there are 10 classes for physically impaired swimmers. And then there are additional classes for visually impaired swimmers and then also a class for intellectually impaired swimmers. So in terms of the physically impaired swimmers, those that the higher the class number that you’re in, the lower your impairment in swimming. So for example, if you’re in the class S10 you’re certainly deemed eligible to compete in paraswimming, but your impairment would be considered relatively minor compared to someone in the S- in the lower classes. At the other end of the scale, swimmers in classes S1, S2, S3 are obviously far more severely impaired in terms of their swimming so swimmers go through this classification process, and then they’re allocated to a particular sport class as it’s called. And as you said, it’s not impairment specific, so you will have swimmers with different types of impairments.
So, for example, a limb deficiency, an amputee, competing against somebody with a motor control impairment, or someone with cerebral palsy, for example in the same race. And and that’s sometimes is difficult for people to understand when they look at these swimmers lining up on the block and they sort of say, well, that doesn’t look fair. Well the whole idea of classification is to make it fair.

Mia: Mhm.

Dr. Payton: And so, although their impairments are different. They’ve gone from classification process and it’s been deemed that they have the same level of impairment. Yep, in terms of their swimming performance.

Mia: Yeah.

Dr. Payton: And that’s the whole idea of classification is that you should be competing in a race against
people who are not that they don’t have the same impairment, but the same restriction to their

Mia: So with the current systems kind of objective, right? You’re going to have a kind of consultant come in and classify the person. They’re going to use some range of motion, some strength testing. Is that correct?

Dr. Payton: Yeah, so so.

Mia: Yeah.

Dr. Payton: The current system and it’s been around since 1990 so it was introduced the first Paralympics that it was used for was would be Barcelona in 1992. It’s called a functional classification system, and it’s really not changed that much in that for 30 years and and so it involves basically 2 main stages, one is a medical, It’s kinda a bed run. We call it the bench test so that’s those are land based tests that the swimmers undergoe and that’s conducted by the medical classifier who’s usually. medically trained or either a physiotherapist or an adult medical doctor. And then they do a technical or water based test, and that’s usually conducted by someone with coaching or sports science expertise. So the bench test is, as you say, it tests, uh, tries to determine the level of the impairment, and so that the swimmer will do strength tests, they will do well depending on the type of impairment. Of course, if they are, for example an arm amputee, they wouldn’t do a strength test, they wouldn’t do it because their impairment obviously is the is the limb deficiency itself. And but the type of bench test would be a strict like strength tests, a test of coordination and test of range of motion.
Yeah, and let’s say if you are missing, uh, if you have a limb deficiency, they will measure
the the length of the remaining limb. But also it, I think also included are swimmers with leg length discrepancy. So again, if you come under that category again you you’ll have your limbs, limb lengths
measured. See the bench test and then the water test is, as the name suggests, where the summers are
observed in the water, not not in a competition but in a controlled environment where they’re
asked to float to do a start up the block if they can. Some can’t stand, some have to do it seated, some actually starting the water of course. Turns. The various strokes at different speeds.
The water test is primarily to confirm what was observed in the bench test. But sometimes the the assessment, changes and swimmers are perhaps able to do a little bit more in the water than you thought.

Mia: Yeah.

Dr. Payton: They might be able to do based on that bench test and vice versa. And so based on those two assessments that someone is given a point score. The maximum is 300 so if you have no impairment, you should score 300, but then obviously you lose points or points are deducted depending on your performance on the bench test primarily, and then depending on your final point, score out of 300, that’s that’s what’s used to allocate you to one of the ten 10:10 classes.

Mia: So do all the classes, do all the classifier. Sorry, uh, do all the classifiers have to go to like a specific site to be trained before they go out and classify people into their different things? Or how do they standardize that?

Dr. Payton: Well, I think again that’s one of the criticisms is this not lack of standardization, but it’s an extremely difficult thing to to to ensure that you would get the same class, the same point score if you are classified by somebody else in a different location, they get matched. One of the uh, challenges is that really, we have, we need to have a system that is so objective and and uh measurement based, I guess that regardless of who you get classified by and where you should end up with the same class, the same, the same point point score and the I mean the other thing to note is that classification currently takes place not during competition, but normally in the two or three days leading into a competition.
Uh, which again has brings its own issues and challenges. And one thing I didn’t say about classification is there is a third step. So you got the bench test, you have the the water test, but then you are also observed in competition.

Mia: Yeah.

Dr. Payton: So you don’t get your final class number reclassification until you’ve actually been seen in competition, OK, ’cause again, you know occasionally you’ll get swimmer’s who can do things or are able to do things in competition that weren’t observed in the classification process.

Mia: So I think there’s been some bad news recently for the paraswimming with, kind of, people
“swimming down”, right trying to play up their disabilities to maybe being rated as an S8 instead
of an S9, right? So that’s kind of been creating an uneven playing field. You’ve seen people
retiring from the sport early or just leaving because they don’t want to be part of a system where they’re not gonna be able to compete fairly. Really.

Dr. Payton: Yeah, I mean I, I think because I don’t think there’s anything new and I don’t think it’s unique
to paraswimming, parasport or sport in general. I mean you you will always get athletes who will try and play the system and the rules. I don’t think paraswimming is any different from any any other sport. Obviously it’s a high profile. Parasport, and so the the cases of intentional misrepresentation, it’s a nice word for cheating, tend to be quite high profile and obviously on the Internet. So yeah, it is a controversial area, but but also, I think there’s there’s also the danger that sometimes when you have a swimmer who wins a race by, you know quite a margin, people are quick to jump and say, well, that swimmer is either cheating, which is it’s often not the case, or they’re in the wrong class, which again sometimes just isn’t the case.

Mia: Nice.

Dr. Payton: I mean you, you see people winning able-bodied races in swimming and athletics by a long way and you know sometimes you get you know elite athletes in the are in the right right class. But yeah, you you will always get you know people questioning when athletes win a race by a long way or in fact lose a race by a long way. And yeah, it works both ways, though people often so tell you you’re in the wrong class and you need to be you know you’re more impaired than you’ve been, so it of course it’s a very challenging aspect of the sport. But yeah, without without classification the sport wouldn’t exist.

Mia: So the international Olympaic paraswimming committee have come to you guys and asked you guys to kind of help create a new objective, Non objective science based system using biomechanics so can you kind of explain what your guys’ goal is and how you guys plan on doing that.

Dr. Payton: OK, so the so the IPC, the international International Paralympic Committee, uh, approached myself at Manchester Metropolitan University and also professor Brendan Burkett at the University of the Sunshine Coast, so I should emphasize, this is a sort of collaborative effort between those two institutions, and actually it’s broader than that. I mean, we are the two principal investigators on the project, Brendan and myself, but then we each both have a postdoctoral research assistant or research associate working with us and, to be honest, doing most of the work, but then also obviously we tap into as much expertise beyond that team as we can, because it’s obviously it’s a big project. It requires a lot of lot of like what? So yeah, that was in 2016. I think it was when we were approached. We agreed to take take it on and I should also say perhaps that we are purely focusing on the physical impairment classification process, there are two separate research groups similarly, working on developing or improving the classification system for visually impaired swimmers and for intellectually impaired swimmers.. So there are three separate research projects going on within world paraswimming at the moment.
So so our brief really was well, we started with a blank sheet of paper we were told, you know, we need a system that, as you say, is more objective, transparent, understandable,
to the views that can you know withstand scrutiny, that’s evidence based measurement based and I suppose fairer and more understandable at the end of the day. Uh, we were only told one thing we mustn’t do and that was to have more classes. Currently there are 10 classes for physical impairment and we were told don’t come back to us and say we need 20 classes, so that’s not going to happen. But beyond that we were given, you know, fairly wide rains to sort of think outside the box and develop something that you know will hopefully stand the test of time and be more transparent, objective and fair for all concerned.
So that was our starting point. The first, I suppose there’s two main phases to the project, which is ongoing, by the way, and and the first was to to do the research to do the underpinning research because the research simply isn’t there or certainly wasn’t. You know, if you do a search of performance determinants in paraswimming, there is very, very little research. In terms of able bodied swimmer. In terms of non-impaired swimmers, there’s a huge database but very little on paraswimming. So that was our first and that is our main first role, it is to do that research to do research that evaluates valid measures of impairment.
So what is a valid measure of coordination? Range of motion and also to come up with research that measures the not just impairments but also the the determinants of performance. So I mean by that is we can easily measure someone swimming performance and just measure the time they take to do a race., but what we actually want to understand better is how an impairment. So for example, it could be a limb deficiency, it could be a brain injury, cerebral palsy, it could be a spinal cord injury. How does a particular impairment type affect performance? You know how is it limiting their performance and to do that we don’t look at the performance per say. We need to look at the sub components of the performance, the performance determinants. So as we talked about earlier: propulsion, drag, coordination; so all the building blocks of a good performance. So a lot of our research is focused on the relationship between somebody’s impairment type, so what type of impairment do they have and how severe is it, and how that influences their ability to produce propulsion, how it influences their ability to reduce drag, how it influences their ability to coordinate their limbs in the water so a lot of our researchers focus on that aspect, and that’s where the biomechanics comes in, of course.

Mia: Cool. Yeah. So what kind of so you’re saying you’re going? How are you measuring propulsion? How you measure it? Do you guys track the metabolic rate? Do you guys track oxygen consumption? Are you trying to figure out how much energy they’re expanding to do these movements?

Dr. Payton: Some places, so we’re getting into the realms of Physiology there and but, but I think that’s
important because the this isn’t a biomechanics project, which shouldn’t be come about. I mean, yes it is very biomechanics focused because swimming is a very technically based sport, but of course what we must also as you’re suggesting I guess there is it. We must consider the energetics, the Physiology and the effect of somebody’s impairment on their efficiency, economy and those sorts of things so we don’t just look at the technique in isolation, we need to look at, but when this person gets fatigued, how does that technique change? Does their drag go up? Does their propulsion go down? Does the… So
what, what changes? And that’s really important because some impairments are more susceptible to fatigue, or part of the impairment is at sort of an accelerated fatigue and that has to be factored into it as well. In terms of measuring stuff in the water? Yeah, that that is that’s challenging. Yeah yeah, I think it’s it’s not easy to measure forces or even movement in the water ’cause water brings its own challenges.
and so propulsion. I guess the problem with propulsion and drag is that when a swimmer is going down the pool, both of those forces are acting simultaneously, and so the real challenge I suppose the Holy Grail in swimming is to try and separate them out and say, right, uh during that swim this was the amount of propulsion that someone was producing, and this was the amount of drag that was holding them back or practice.
It’s not really possible to do that directly, so there are indirect methods of estimating drag and
propulsion. So for for propulsion we use something called tethered swimming. So essentially as the name suggests, we tether, or tie a swimmer, well, as it sounds, we put a belt around their waist and we attach them to a load cell, so they’re essentially swimming on the spot, and so it’s not real, something it’s simulated swimming.

Mia: So is this in the water or on land?

Dr. Payton: In the water. Yeah, so essentially swimming on the spot and we we record the forces that they produce, and because they’re not going anywhere because they’re swimming on the spot, we’ve pretty much removed the drag factor because the drag only really exists when they start moving down the pool.

Mia: Yeah.

Dr. Payton: So that gives us a an idea of their propulsive potential. In terms of drag again, one of the Holy Grails in swing by mechanics system measure the swimmers drag or resistance. There’s two elements of drag. The first is called passive drag and the second one is called active dragging and all that simply
means is that as well as passive drag is how much resistance their body creates when moving through the water, but in a fixed position. Essentially all we do to measure passive drag is we tow the swimmer’s down the pool, so we attached them to, a big electric motor at the end of the pool. We put belt around their waist or they hold on to a small handle and we just tow them down the pool at a set speed and we measure how much force is needed to them and that essentially is the drag that that is the passive drag
that that some is creating. So that’s relatively easy.

Mia: It must be a pretty fun one to do. It’s kind of like water skiing, but laying on your belly, right?

Dr. Payton: We did test the swimmer I said we’ve published quite a few papers on on the influence of
impairment or the relationship between impairment type and passive drag we tested. We first started testing in London 2012 and we did have a guy who was a surfer from Australia and we tested him and he insisted that he wanted to go faster and faster and faster and actually he would have been quite happy to Bodysurf on our on our device.

Mia: Yes.

Dr. Payton: So, so that’s passive drag that that’s relatively easy.

Mia: Yes.

Dr. Payton: But of course what we’re really interested in is when a swimmer is swimming. When
they’re actually moving their arms and their legs, how much drag are they creating? That’s called active drag, and that’s that’s a lot more challenging to measure or to estimate. So we’ve developed a method. We use a method. It was actually developed at Southampton University a few years ago, called the Naval
Architecture based approach. I won’t bore you with the details at this stage, but essentially it involves towing the swimmer in a passive position, towing them again while they’re actually swimming, so we actually tow them faster than they can swim and we combine the information from those two tests, the passive towing and the active towing to come up with a good estimate of their per active drag.
But again, it’s it’s interesting to see that different impairment types are affected in different ways
in terms of both their passive and their active drag.

Mia: Yeah.

Dr. Payton: But we need to know that we need to know, you know, if you’re short stature swimmer or you
have a spinal cord injury or you’ve got multiple limbs missing, you know that that will affect the drag that you create and that will affect your performance and that needs to be factored into the end class I suppose, yeah.

Mia: I also did competition swim when I was younger. Do you guys also try to track their actual movements? I imagine in some cases they’re not going to have the full like you know snap their elbows, a good perfect form that we all practice for hours especially, you know maybe they’re paraplegic or hemiplegic, can’t get like their arm full motion. How do you guys accommodate for that?

Dr. Payton: OK, so so again so I’ve talked about the forces so the the the drag, the propulsion.

Mia: Yeah.

Dr. Payton: But again ultimately we’re interested in the way the swimmer’s moving in the water so that their technique and how that technique differs from a non impaired summer. And again we need to understand that if you have an arm amputation or you’re affected down one side of your body due to hemiplegia, that that is going to impact a new technique and that’s going to limit ultimately your performance. So we do have 3D motion analysis, so we have an 8 camera system that we use it’s video based, so we basically calibrate the volume of the pool, so essentially have a big calibration frame that we put into the swimming pool. It’s about 6 meters long, but we can make it as long as we want and then all eight cameras are trained on that volume of water, and then the swimmers obviously swim, and this is obviously in a research set up not in competition. Yeah the swimmer swims through that volume. All of the cameras are synchronized. Then we extract coordinates from each of the eight cameras. Combine all of those coordinates together and that gives you a 3 dimensional model of the swimmer and then from that, as you say we we can get basic things like the the ranges of motion, the amount of body roll, the speed of the hand for the water, so basic kinematics. But then we can also calculate other things of interest. Things like, for example, propelling efficiency, intra cyclic speed fluctuations. So how much does their speed fluctuate within a within a stroke because again depending on the type of impairment they have, we might expect them to fluctuate perhaps a lot more than a unimpaired swimmer. So yeah, once you have 3D data there’s a lot of things that you can calculate that are relevant to swimming performance.

Mia: Yeah. So now above the water, biomechanics Lab’s a lot of the time we put like reflective markers that look kind of like marbles that we put on people to kind of track their position in space. Obviously you can’t put sticky marbles on people in the water. They’re going to fly right off. Uhm, how do you guys keep track of like an individual position?

Dr. Payton: That’s a really good question. I mean, you’re talking about sort of commercially available
systems like Vicon. Yeah, this is one of the more popular ones which are really yeah, ideal in
a lab based situation. For gait analysis. You know it gives you instantaneous 3D data.
Unfortunately, Vicon doesn’t work underwater. And I mean funny enough there is there is a system. There’s a 3D system called Aquas that is an automatic underwater tracking system, but as you say it, it relies on quite heavily preparing the swimmer in terms of marker sets on each of their limbs, which is a time consuming process and also sometimes the markers as you say, don’t stay on. They fly, fly off underwater and you know we found that they have inhibit movement. So we do, we do put marks on the swimmers, but they tend to be passive, us- usually black. We tend to use, uh, permanent marker pen. It’s not quite permanent. It stays on well and comes off with hairspray. And so yeah, so so, let’s say there’s a video based system, so it’s not an automatic tracking system, although the
software that we use will automatically track quite a few of the markers on the body. Some of the markers need manual intervention.You need to physically go in and, but that’s the nature of swimming. You know when an arm hits the water as you know, it creates a lot of turbulence, it creates a lot of bubbles. No automatic tracking system is going to see the hand or the the arm at that point, so, it’s quite a time consuming process, but once you’ve got your 3D data you can do you know some really interesting things with the data.

Mia: Have you found that, uh, like that they generally, so let’s say we’re talking about somebody with, Uhm, that’s hemiplegic, do they generally on their uneffective side? Would their arm track the same way as their affective side? Or does it kind of follow a different path?

Dr. Payton: Completely different path I I say I mean funny enough, I have a PhD student just started last year who his PhD is focusing exclusively on kinematics of motor impaired swimmers, so it will include hemiplegic athletes. And so, yeah, her PhD is looking at exactly that. So things like asymmetry. Obviously someone with hemiplegia will be very non symmetrical, and that brings its own challenges. But like you said their range of motion is affected on one side. Their ability to generate a good hand speed will be affected on that side, so of course if you can’t generate good hand speed in swimming then that affects propulsion. So, so again, it’s tying all these pieces of the jigsaw together so we can measure the strength, we can measure that range of motion coordination, but ultimately we’re interested in how does
that affect what they can do in the water, and how does it limit their performance?

Mia: Yep. So what kind of biomechanical markers do you guys see yourselves utilizing in this new
classification system you’re working on? Are you guys going to be measuring kick grade? Are you going to be doing all winters tables and measuring length limb or like..?

Dr. Payton: Limb length.

Mia: When’s it start?

Dr. Payton: Yeah. Yeah, I mean I think I I guess the easiest, uh, group of swimmers to assess their impairment are the limb deficient swimmers because you can, you can see it. You can’t misrepresent it. You know if if you’re missing an arm at the elbow. It’s simple, we can measure that. The more challenging ones are obviously those with a motor impairment, a motor control impairment because that’s a far more complicated thing to assess and to quantify, but even once she quantified that this is the amount of limb you have missing, or this is the amount of strength deficit you have because of spinal cord injury, for example. Or this is how your coordination is impacted and again we can, we can measure these things. We are measuring these things. That’s only half the story because we then have to take all that information say, OK, yes, you’ve got a strength deficiency, yes, you’ve got the range of motion deficiency, and yes, your coordination is impaired. How do we take those numbers from those tests, then come up with a single number, which is the class that you’re going going to compete in? OK, that’s the challenge. You’re asking me for an answer, you’re not going to get one today, unfortunately. You have to invite me back in a couple of years because we haven’t actually got to that point, but to answer your question in terms of classification, the process, I think we will continue to measure the things that are currently assessed, but we will measure them rather than subjectively assess them. ‘Cause you might not be aware of, but at the moment, for example strength as from a strength is assessed in the bench test, but it’s done using manual muscle testing, so the swimmer will push against the assessors hand and they’ll be asked to push as hard as they can push, push pushing and will be given a grade between naught and five.

Mia: Can they not just lift some weight plates or?

Dr. Payton: No, at the moment it’s done, so it’s subjective. You know no two ways about it.

Mia: Yeah.

Dr. Payton: It is subjective. Similarly, the coordination test, again, this is the bench test, so it’s done on land, so this is obviously for swimmer’s who have a coordination impairment. It wouldn’t be double certain, but the swimmers will be asked to do alternating limb movements. So for example, shoulder flexion, extension, elbow flexion on sort of opposite sides of the body and again the assessor will observe them and ask them to go faster and then will again give a grade out of nought to
five for the left arm, for the right arm, for flexion extension all the also with the legs as well, so
they will get marked out of five based on which ultimately is quite a subjective assessment, of that coordination. So I think one of the I guess major improvements to the system that we’ll be
bringing in is to measure these things objectively, empirically.

Mia: Yeah.

Dr. Payton: So so we will. We may be doing additional measurements as well. So for example, I measured mentioned passive drag. Yeah, now nothing is off the table, Nothing’s on the table at the moment, but it might well be, and the evidence suggests that swimmer’s passive drag is a is a very useful measure of their impairment and how it affects performance, so it might well be that in addition to the
traditional measures: strength, coordination, and range of motion and and limb deficiency; there
may well be some additional pool-based tests that are part of the classification process as well.

Mia: OK.

Dr. Payton: So I think classification or the new system when it comes in will look very different from the
existing one. I think it will be probably a much lengthier process. But I don’t think that’s a.. I don’t think that’s a bad thing. I think you know if I was a swimmer, I’d want to feel that I’ve been thoroughly assessed, and yeah, it had been done properly and objectively and scientifically, and now I can be confident in my score. So I think because it would involve much more measurement, it will take longer, but it will standardize it a lot better. You know, so regardless of where you have your assessment done, your classification done, you should be getting pretty much the same scores. It it takes the human subjective judgment out of it to a large extent.

Mia: Wonderful, well we’ll have to follow up in 2024 and 2028 and see if how the new classification
systems coming and see how that’s changing the sport. Thank you so much for talking with us today, Doctor Payton.

Dr. Payton: Always a pleasure. You’re very welcome and I say if if any of the people that listen to this podcast are interested in more information, they’re very welcome to contact, contact me at Manchester Metropolitan University and I’m sure Brendan at the University of the Sunshine Coast would also be, you know, welcome any inquiry. And I should just mention as I didn’t at the beginning, the two research associates who are doing a lot of the work on this project and that’s Doctor Luke Hogarth who’s at the University of the Sunshine Coast and Doctor Dawn O’Dowd, who’s at Manchester Metropolitan University. It would be unfair for me to finish this without mentioning the two workers.

Mia: Thank you so much.

Dr. Payton: You’re very welcome.

Featured image by David Mark from Pixabay