 Hello and welcome back to the Sports Biomechanics Lecture Series supported by the International Society of Biomechanics and Sports and sponsored by Vicon. I'm Stuart McElaine Naylor from the University of Suffolk and today I'm really lucky to be joined by Wendy Holliday and Wendy is quite a broad range of skill sets really we were just talking about it but Wendy is a physiotherapist with a PhD on cycling biomechanics from the University of Cape Town in South Africa and she also works as a clinical bike fitter at the Science to Sport. So hopefully with today's topic of cycling biomechanics, Wendy is someone who's really well positioned to give a broad overview of some of the real topics relating to the biomechanics of cycling. So without kind of me talking for too long, I'll hand over to Wendy and we can get into the interesting stuff. So thank you Wendy. All right, thank you so much Stuart and thank you so much for organizing these talks and they really have covered a large range of topics which have been incredibly interesting so I'm sure everyone has enjoyed that. Today we're going to be talking about really the basics of cycling biomechanics, what muscles work when, what the normative joint angles are and some tips for future cycling studies. So let's get into it. First of all, when you're going to be doing cycling research, you really need to look at the bicycle and the cyclist. It's two components that work together, the machine and the driver and you can't look at one without looking at the other. So today we're going to be looking at the cyclist, basically their muscles and the joints, the kinematics, as well as just an overview of the bicycle and what you need to consider when you're doing some research, as well as I will be sharing some tips that I've had along the way with my research. So to start off with, you get different categories of cycling and every discipline will have different demands. If we look at your time trial, a huge factor is the aerodynamics and that itself is a talk on its own. So we're not going to be discussing that today. Most common would be the road cycling and this can either be for commuting or for sport and for racing. And then there's mountain biking, which has its own characteristics such as cross country, which is quite technical and marathon racing. For the purpose of today's talk, we'll be discussing road cycling as a competitive sport. And the reason that I mentioned that the bicycle and the rider need to be considered with research is that the rider has five contact points with the bike. So we've got the saddle, the two hands on the handlebars and the feet on the pedals. And changing any of these will have an effect on the cyclist with regards to their performance and their comfort on the bike. When you start off with cycling and cycling research and cyclists, you need to be familiar with the components of a bicycle. And there's certain terminologies that you should understand, such as your seat tube, your down tube, your top tube, handlebars, all the different components that make up a bicycle. And just being familiar with the jargon that comes with cycling. So I'm just going to cover some of those. The most important components of configuration would be the ones that I'm going to discuss now. And there are many different methods in which you can measure these. So the important is to choose one method and stick to it. Okay, don't change things. Find something that you're comfortable with, that you have the equipment to measure the bicycle and then always measure it the same. So if we look, the most common one would be your saddle height. And that's measured from what we call the bottom bracket. So in the middle of the crank up to the top of the seat of the saddle. Okay, it falls along the seat tube angle. This is your seat tube. And one must consider that that seat tube angle on different bikes will be different. Most of the geometries of the bike is 72 to 74 degrees. But it's important if you're going to be using a range of bicycles to measure that angle and ensure that you get the same distance, the same angle when you're taking your measurements. The other one is your saddle setback. And that is measured from your bottom bracket perpendicular up and the distance behind sometimes in front, but usually behind the bottom bracket. Just consider that you've got a variety of different saddles, and they also come in different saddle lengths. So you need to take that into consideration. I also talk about your handlebar reach. So how far your handlebars are away from your saddle and your handlebar drop. So how low are your handlebars compared to your saddle and different cycling and disciplines will be in different positions. So a commuter bike usually will have handlebars that are above the saddle. Whereas when you're racing, you're likely to have your handlebars below your saddle in terms of aerodynamics. So these are just the main measurements that need to be taken when you're working with bicycles. And we'll get into those in more detail a little bit later. But just getting you familiar with some of the terms. We also need to look at your hand position. So if we discuss road cycling, there are three main hand positions. We've got your hoods, which is where your hands are in a bit of a groove there near your brakes. We also have your hands in what we call the drops. So they're lowered down and then on the top bar. So it's important to know these different positions as they can change the shoulder and the wrist angle as well as your thoracic spine. Obviously dropping from your hoods to your drops is going to put you in a lower position through your thoracic spine. It's important to keep consistent as these changes in the body angles can have an effect on your metabolic, metabolic costs, your power as well as your comfort. And then we talk about your pedal revolution. So this is when you pedaling your foot action going around on the pedal. You've got your top dead center or zero or 360 degrees, your first quadrant to 90 degrees. And then bottom dead center, which is at 180 degrees, 270 and then back up to the top. It's also known as the push and the pull phase. It's not as clear cut as push and then pull. But in simplistic terms, we talk about the push phase and the pull phase. So especially when you clip in onto the pedals, as one leg pushes down, your other leg which is fixed onto the pedal can then pull up and help you to get a stronger force through those pedals to turn them over quickly. So we talk about your top dead center and your bottom dead center. All right, which muscles work when? This is obviously influenced by intensity and fatigue. And for today, we'll be discussing normal steady state patterns of muscle recruitment. And as my PhD study was determining what happens at different riding intensities, I will also be showing you some slides on how riding intensity affects the muscles. This is just an overview of the muscle system. So here you can see your pedal revolution. So your top dead center and your bottom dead center over there. And you can see the glute max where that works. Your hamstrings are working when your quads are working your calf muscles and then your tip and which is your bright pink muscle to pull your foot up and over the top dead center. So really just a quick overview of which muscles are working when through the pedal revolution. Here's a quite a simple video of when the muscles work and not 100% accurate, but we'll give you an idea of when they work. So your glutes, your quads, calf muscles on the push phase, tip and working hamstrings your hip flexes on that pull phase to pull the leg back up. Just gives you a good overview of when those muscles are working. And if we get into a little bit more detail, this is your glute max. It's a powerful hip extender. And it is active during the push phase from the top dead center to approximately 130 degrees of the pedal revolution. If we look at the research, you can see that it works from your top dead center to 90 and then down to the bottom dead center. And as the intensity of your ride increases, we can see that this is the quadrant one where it works the hardest. And that was where we had significant changes from 60 to 80 from 60 to 90% as well as from 80 to 90% intensity. And the other must the other quadrants were also significant mainly from 60% to 90% intensity. But you can see where this muscle works the hardest in this quadrant. And that's where we had the most significant changes in muscle activity. Your bicep fem, it's a biarticular muscle. So it crosses the hip and the knee and it works to extend the hip and to flex the knee. We can see here it works from top dead center down to bottom dead center. And that's where we saw the most significant changes with a change in riding intensity. So from 60 to 80 to 90%. And it controls the knee flexion. So from top dead center, it works for hip extension. And then in the second quadrant, it starts to control that knee flexion. If we look at your quad, your VMO and your VLO, they work to extend the knee. They're activated just before top dead center and they terminate at just beyond 90 degrees. So this is the quadrant that they work in the most. So that's top dead center to 90 degrees. And you can see the blue corresponds with the blue. And that's where you saw significant changes as the intensity increased. So they work from the top dead center and they push down to straighten that leg. Youric fem is also a biarticular muscle. So it flexes the hip and extends the knee. This muscle is active from 270 to 90 degrees. And we can see as the intensity increased that the hip flex was pulling the leg up and over the top dead center. And then it was working to start straightening that knee as you started pushing down. And we can see the significant changes with the riding intensity on that. So this muscle works to dorsiflex the ankle. And it's active from 270 degrees to lift that foot up and over the top dead center. And then it terminates shortly afterwards. You can see here, this is where it's mainly active. And that's where we saw significant changes from 60 to 80 percent as your riding intensity increases. So as the riding intensity increases, that tip and works harder to pull the foot up and over that top dead center. Gastrofemius also a biarticular muscle. So it works to plan to flex the foot and to flex the knee. It starts at approximately just after the termination of tip and tip about 30 degrees and works until 270 degrees in plan to flexing the ankle. And therefore forcing the foot down on the pedal. So as the ankle plan to flex it, it forces the foot down onto the pedal until the beginning of the knee flexion. And that just helps with the force going through the pedal as you're riding. So we can see here that this is where it's working hard to push down on that pedal. And we didn't see any significant changes through the different increasing riding intensity. And this may be due to the fact that the medial gastroc works even at low intensities. And it works to stabilize that ankle in order to transfer force through the pedal. We didn't observe soleus in my studies, but it has been demonstrated in other studies that soleus also works hard to stabilize the ankle and the foot to generate force through the pedal. So there might have been significant changes in soleus with the riding intensity, but we didn't find that in the in the main quadrant that it works for increasing riding intensity. So just to give you a recap, Glute Max works as a hip extensor from 340 to 130 degrees and its peak activity is at about 80 degrees. VLO and VMO work to extend the knee from 300 to 130 degrees of the pedal revolution with their peak activity at 30 degrees. RECVEM works as a knee extensor and a hip flexor and it works from 200 degrees all the way around to 110 degrees of the pedal revolution with its peak activity at about 20 degrees. Soleus and gastroc ankle stabilizes as well as a knee flexor and that works from 340 to 270 degrees with their peak activity at between 90 and 110 degrees. TIB and ankle stabilizer ankle flexion works throughout the pedal revolution with its peak activity at 280 degrees to bring that foot up and over the top dead center. Hamstrings, they work as a knee flexion from 10 to 230 degrees of the pedal revolution with their peak activity at about 100 degrees. And if we look specifically at bicep fem, it works as a knee flexor as well as a hip extensor from 350 all the way through to 230 degrees with its peak activity at about 110 degrees. So this table is found in the SOETL paper from 2005 and I have given Stuart a list of references so you will be able to pick that up afterwards. It's really nice just a good summary of muscle action during the pedal revolution. Always good to recap on which muscles work when during the during cycling. So that was the general patterns for muscle activity during cycling but as always humans are individual and we see different ankle patterns during cycling. So most commonly is dorsiflexion of the ankle before bottom dead center and then just before bottom dead center they push into plant deflection to give them that extra force as the pedal hits what is commonly known as the dead spot. Just to keep it simple, that is where the area of the transition occurs from the pushing to the pulling phase. So as you're pushing down obviously with biomechanics and levers they get a point where there isn't maximum force on the crank and the pedal and that's what we term the dead spot. Some riders will ride with the dorsiflex ankle throughout the majority of the pedal revolution and they tend to activate ciliacinib and earlier on in the down stroke so that helps to keep the foot into that dorsiflexion and then they push through with dorsiflexion throughout the pedal revolution. You also get the pointy-toed riders, so they ride with plant deflection throughout the pedal revolution and one needs to evaluate if this is their riding style or if their saddle is too high and they're merely reaching for the pedals at the bottom dead center. So we get all these different ankle movements during the pedal revolution and just something to observe with your cyclist. So there are quite a few studies on muscle synergies during cycling and the impact of intensity of riding position such as sitting or standing as well as different fatigue on the muscle synergies. So just to summarize it in five short points you'll see that single joint muscles are concerned with a generation of positive work where two joint muscles are responsible for the fine regulation of the work. Rec fem is assists with hip flexion during the pull phase and also works with knee extension in the push phase. Gastroc is a knee flexor in the pull phase and an ankle stabilizer during the push phase. So the co-activation of muscle pairs may serve to protect the joints and if one is too strong it may put strain onto a joint and this is important to balance muscle development when you're designing muscle training and rehab for the cyclists because you don't want one muscle to be dominant and then you put pressure onto the all strain through the joints as they're riding. So just something to bear in mind. It is a fascinating if you want to deep dive into all the research there are a lot of articles on what happens during muscles when you're standing, when you're sitting, when you're fatigued, when you're sprinting. So we're not going to get into all of those details now but just to remember that the synergies do change with cycling. Alright, if we look at joint kinematics. So for my study we used Vicon. This is an early video of the Vicon and you can see our cyclist having a drink of water and this is one of our study participants with all the Vicon markers with the EMG. We also had the metabolic cart so we were taking a whole lot of measurements. You can see they were all wired up. It took us about 45 minutes to set up each participant. I'm sure you're all familiar with that process. Alright, so there's some general guidelines of where the joint angle should be when they're on the bike. The ankle and the knee are measured at bottom dead center and the hip is commonly measured at top dead center. That's just a recommendation. That's what previous research has done. So just to keep that in mind and to take note that you can discuss your findings with other studies. You don't want to go and measure at three o'clock and then you don't have anything to compare your results with. So usually the ankle and the knee are measured at bottom dead center and the hip is commonly measured at top dead center or reported. So it's measured throughout but reported at those points of the pedal revolution. If we look at the ankle, approximately 5 to 15 degrees of plant deflection at the bottom dead center, but just to remember to take into account the different pedaling styles that I spoke about earlier and your ankle plant deflection, dorsiflexion is obviously affected by your saddle height as well as your cleat position. Just some things to bear in mind. Your hip, the hip and the shoulder are controversial joints and anyone who has heard me present on this before will know it's the one thing that I keep going on about. So the hip previously has been measured from the knee to the greater tricanta and then as an angle parallel to the floor. Now physiotherapy was my first study option and if you're a clinician you'll know that that is not a clinical hip angle. So it's a really nice angle to measure parallel to the floor you've done but that doesn't measure a true hip angle and the same with other methods where they've measured from the knee to the hip and then across to the shoulder joints that completely eliminates the spine and the thoracic curve, the lower back curve and they measure the shoulder angle through there. So what we did is we actually measured a true clinical hip angle and a true shoulder angle and you can see the difference if you just take a straight line how that angle is different to a clinical angle for the hip and the shoulder. So we've been very fortunate in recently there have been some papers on how to calculate hip center so we don't need to drill the vicon marker into the bone anymore. This study not surprisingly only had one participant where they actually drilled the marker into the hip bone into the hip center so thankfully we don't need to do that anymore and some clever people have come up with calculations to work out the hip joint center. So going back to this, at this stage there are no recommendations for the shoulder angle on the bicycle that is changing there are some studies coming up. The elbow angle roughly 20 to 30 degrees and that would be with your hands on the hoods. So remember we spoke about the hoods and the drops and the top bar that is measured with the hands on the hoods and then your torso angle is roughly between 30 to 60 degrees and you can see that that changes if it's a recreational rider, a fast road cyclist or just a casual cyclist that obviously has an impact on aerodynamics and you know what is the aim for the cycling is it a recreational cyclist or do they really want to get into an aerodynamic position? What you can also notice is that all of these recommendations are based on personal experience and as I said more and more research is coming up to give us more scientific recommendations for these angles. But what it comes down to is more the rider's comfort and their performance on the bike as to where within that range they should be positioned. This chart is also in one of my papers that has been published so you'll be able to guess that. If we look at how the body position changes over intensities I haven't gone through each graph one by one as I think sometimes we get a little bit bogged down with all the graphs but you can see that there were significant changes in the majority of the joints from 60 to 80 to 90 percent and if I just give you a little video you'll be able to see. So this is one of our colleagues and he was riding at 60 percent really fast and then at 80 percent and then down to 90 percent and you can see what happens to his joints as he rides at different intensities which is why it's so important to take the training intensity into account when you're configuring a bicycle as the extended knee position and the forward thoracic lean may place the rider in a suboptimal position when riding at higher or lower intensities. Something also to consider with your research is that if you're going to get them to ride at a higher intensity those angles that we spoke about earlier might not apply because it changes with the intensity. So bear that in mind if you're doing any research and then the bicycle which is obviously a very important path and the aspect of bicycle configuration open to the most discussion has been the saddle height and consequently has been the focus of most studies to date regarding body position on the bicycle. We can see here there have been many studies on optimal saddle height these are just the popular or the trusted methods of setting saddle height I'm not going to go into all of these this is from one of the papers that Dr Swart and I published and it is included in the reference list so you'll be able to go through that but what you need to ask is what is optimal so these are all based on optimal saddle height but what is optimal? Is it optimal cycling performance? Is it optimal efficiency? Is it to optimize muscle activity? Is it to reduce the knee joint forces? Or is it to prevent injuries from occurring? And so you really need to work out what is your aim with that saddle height? What do you want to do with that saddle height? Do you want to prevent an injury or do you want them to get into the fastest position that they can get into? The consensus at this stage is that static knee flexion angle should be between 25 and 35 degrees at bottom dead center with dynamic measures ranging between 30 and 45 degrees of knee flexion depending on the riding intensity so what's nice is that technology has really advanced this study had four VHS video cameras can you just imagine VHS video cameras which they placed around the cyclist and they called that 3D so nowadays we're really lucky to have Vicon where we can get an accurate assessment of 3D motion we also have saddle pressure mapping and force vector pedals to really measure all the components of cycling we need to remember that cycling isn't a sagittal straight line sport as much as you think the knees just go up and down movement does occur in other planes particularly at the knee and at the pelvis and with systems such as Vicon we can now measure that quite accurately so in this video you can see how that knee is moving in towards the frame and then back up so you can see that it's not just a straight line movement rotation does start occurring so now that we have the ability to test in real time previous studies and normative values that were all based on static measures ongoing research in this field and was kind of more towards dynamic and different intensities and that was the main part of my thesis so we know that there's a difference between the static and the dynamic measurement systems such as measuring with a goniometer or one sagittal camera taking a still shot compared to 3D motion capture that records during the cycling action and we also know that it depends on the intensity of the ride so more research is needed to evaluate the optimal angles for the different intensities as well as at that dynamic capture and then once again we need to work out optimal for what? for performance, for injury prevention, for aerodynamics we really need to ask everyone talks about optimal but optimal for what? you need to really define what optimal is for you so when studying an aspect of cycling it's important to take both the cyclist and the bicycle into consideration because changing one part of the bicycle will have an influence on other parts of the bike so just some tips for cycling studies as I said if you change one aspect of the bike it will have an effect on other parts as well as on the rider's position sorry this slide always comes first and then does that so let me jump to there if you're changing any aspect of the configuration you need to give the rider or the participant adequate time to adapt to the new configuration and this will depend on how many hours of riding that they are doing so some studies that I've reviewed they did not give adequate adaptation time and so the participants sliding forward on the saddle to gain a more comfortable or more powerful position and this negatively affected the results because the rider wasn't where they wanted them to be for the study a few of the studies have allowed the participants to wear cycling shoes and running shoes so some participants had running shoes some participants had cycling shoes as well as some had cycling shorts and some had running shorts and you need to take these into account when you're doing research cycling shoes are much stiffer than running shoes and they would probably have cleats on so the foot is fixed on the pedal which means that when you're doing particularly if you're doing testing now and then at a later stage they come in in a week's time if they don't have those cleats their foot might move on the pedal they might not be putting their foot exactly in the same place and this can influence your results whereas if you've got a cleat when they clipped in they're going to be in the same position on the pedal and the same with your cycling shorts so cycling shorts have got padding and yes it's only a few millimeters but this is important to consider when you're doing a scientific project so you can't have some cyclists or participants just in normal running shorts and some with padding because those few millimeters can make a difference if you're looking at kinematics you also need to take into account their riding styles such as that peddling style that I discussed earlier you need a relatively high sample number to normalize your data as everyone has will have a different style of riding and then you need to record all the components so a chain in the saddle angle of only 1 to 3 degrees can dramatically change the rider's position and participants will also be used to their width of the saddle and saddles come with cutouts they come with relief channels they come in different lengths so you really need to just record all of these components if they're using their own bike handlebars also come in different widths and different shapes and which can have an impact on the torso, the shoulder, the elbow and the wrist angle so if you think of a petite lady riding a bike with wide handlebars compared to a lady who have the same height but as a wider or broader shoulder span she's going to be more comfortable on those bars compared to the petite lady who will be out there so all of these need to be considered before you start out on the study and we all make these mistakes so I'm hoping to share some with you just consider all the aspects that are movable on the bike such as your saddle and your handlebar and your handlebar angle, handlebar fill and then lastly to design your protocol based on individual heart rate or power output so one person riding at 200 watts might find that an easy ride for them but somebody else might find that quite a maximal effort so what we recommend is that you start with a peak power output test to determine their max and then set according to a percentage of that so that everything is averaged out alright thank you Short and Sweet just covering the basics of cycling by mechanics Stuart Brilliant, thanks Wendy Yeah it's really good, it's short and sweet it was definitely sweet Yeah I really like that I think there are a lot of not individual moments but really useful points I think my personal favourite I said before, I really like your graphics where you've got the muscle activity of different muscles all the way around the revolution you can really intuitively see that and personally I really like those graphics but then at the end there's the kind of implications for the design of future studies and that's something that's really good to show, especially with students watching it or anyone really thinking of conducting their own study Yeah so thank you Have you got the next slide There we go Brilliant, so yeah thank you just while I give people chance because I know there's a bit of a delay at the speed, if you've got any questions then type those in the live chat on YouTube but yeah just while we wait for it to catch up that's just a bit of a highlight of what's coming up in the next four weeks starting with a really, hopefully really exciting talk next week on engaging youth such as school children in biomechanics and using biomechanics as a stem outreach vehicle and I'm really looking forward to that one and yeah so I think as Wendy mentioned all of the references are below the video in the description, so if you want to find out more then feel free to go and click on those because I've put the links there to each of the papers before we get into questions if anyone wants to contact you Wendy is there a best way of finding out what you're up to or getting in touch with them so I'm just going to jump back to that slide reachable on Twitter and then that's my email address if anyone wants to email me more than welcome to throw some questions at me yeah go for it brilliant thank you yes I think in terms of the questions there's some on YouTube I'm going to be selfish and kick it off with one of my own I think one of the reasons I really liked that talk is that it ties in with a topic I try and teach but don't do anywhere near as well so it's part of our ergonomics in sport module I try and talk about the interaction between the cyclist and the bike in one of our lectures but just to touch on one of the things that you kind of hinted at could maybe go into a bit more detail what kind of role would the actual course play so say if it is a road cyclist when you talk about the activity of different muscles how would it make a different pedaling uphill compared to downhill or say out on your own compared to within a bunch of other riders so you'd need me here for about five more hours to go into detail on that what's quite nice is that there have been some studies on that and your muscles definitely change from sitting to a standing position your joint forces also change so you need to take that into account so when you're riding uphill you tend to if you're going to be powering up let's say you're going to be standing you're going to be standing up and driving forwards so the muscles will be working differently versus when you just sitting and kind of grinding uphill it depends on each of the rider and how quickly they fatigue because we know that that pattern changes when one muscle fatigues and another one starts working so I can't give you specifics as I said we'd really have to go into detail but in short there is a change from riding uphill to riding to them are going to be freewheeling downhill but the other thing that comes into it is your road surface so that will also make a difference I just think with cycling there's so many elements that we need to look at so it's not just the rider but it's also the bicycle and the surface where they're riding, whether they're riding gravel or tar so we can delve into some more details on uphill riding but there are some studies out there that show that there is a big difference with the muscles muscle recruitment patterns for that OK, brilliant thanks really interesting that further highlights why it's such an interesting topic where you've got all of these different factors kind of interplaying whether it's the human the bike, the environment other races, tactical aspects and it all has a role on which muscles are being used and I guess you throw in aerodynamics and kind of your team time trial and the aerodynamic effect of that of where you positioned in your team and how much aerodynamic advantage you get or win factor you get so that's also as I say a whole talk on its own but also very interesting definitely I think I'll stop hogging you and I'll go to some questions that someone else has asked Ron George has said this was early on so you kind of touched on biarticular muscles after the question had been asked I think it's still a very relevant question he said biceps femoris is a biarticular muscle when strength training these muscles do they require a specific stimulus compared to monorail? I think what you need to look at is and this was the aim of the talk was which muscles work where during the pedal revolution and then come off the bike and strengthen them in the ranges where they work so if it's going to be to flex the hip and to extend the knee then you want to work both aspects but you also want to work on the other side so that you're not really tightened to hip flexion and weak into hip extension you really want to try and balance those so you need to understand which muscles work when and then strengthen within those ranges off the bike I hope that answers the question yeah I think it does definitely I think the question is probably on the right kind of lines where what you're just talking about becomes even more complicated when you throw in biarticular muscles because you're not just saying put the knee or put the hip in the position that muscle works in but you're saying you've actually got to position two different joints yeah okay I highly emphasise that off the bike work I always say to my clients if you are cycling in a bad pattern you're just strengthening that bad pattern so you need to do some off the bike work to strengthen those muscles where they should be strong and stretch the muscles where they need to be stretched okay and talking about different patterns I guess it kind of links into biarticular as well around the ankle this time something I found really interesting is when you talked about the three different patterns of cycling kinematics at the ankle and I could immediately sort of imagine myself as a terrible cyclist doing one or two of the different patterns I wondered is there any indication of which pattern is best or maybe if it's participant specific how can you work out best for different people I think your best it's so hard to change somebody's pedaling pattern as such or their pedaling style but it has been done your best is really to work with a power meter or your pedal power meter because then you can measure how much force is going through the pedals and is it better for that person to ride with pointed toes or is it better for them to ride with dorsiflexion and then push into plant deflection as that pedal comes down to the bottom do they get a more powerful advantage with different styles and then start teaching them to ride in those patterns so I personally think that you lose a fair amount of power and plant deflects the whole way through but I have been proved wrong so my kind of go to would be a normal movement within what we call kind of swiping the mud off your foot at the bottom so going into that little bit of plant deflection at the bottom and then coming through I find riders who use dorsiflexion throughout the pedal revolution end up with really tight calves and tip and gets quite sore because they're pulling up into dorsiflexion almost throughout the pedal revolution and they end up with quite tight calves and often pain so it's good to get that free ankle movement and then really just pushing down as the pedal comes down to that bottom dead center but I have been proved wrong so as you say all humans are individual definitely and I really like the cure of swiping the mud off the bottom of your shoe as well so yeah another question that's coming from Reese McDonald he says Wendy what role does the riders flexibility play when bike fitting so is it important to assess their flexibility prior to a fitment yeah so that paper that was one of I looked at intrinsic factors related to bike fitting or bicycle configuration one of my chapters of my PhD and will hopefully be published soon it's with the reviewers at the moment and flexibility has a huge role so you'll usually find me standing and demonstrating but because I'm on a camera and I'm not in front of an audience it's a little bit difficult but your flexibility not only your hamstring flexibility but also your spinal flexibility makes importance in how far you can get your handlebars away from you and down to get an aerodynamic position particularly in time trial and positions and your hamstring so if you've got that hamstring flexibility you can push your saddle higher up and we know that a higher saddle gives you more power obviously it gets to a point where you start losing power but a higher saddle will give you more power so if you've got that hamstring flexibility to reach the bottom of your pedal but not start tilting your pelvis because your hamstrings are pulling you back being able to if I do stand if you'll be able to see me because I've always demonstrated this you need to be able to lean forward and have that flexibility so almost like you're doing reaching for your toes that position that's how you cycle that's the position that you would aim for with your hands on the handlebars and lower down so flexibility is very important and I would definitely measure it before doing or as part of your if you're going to be doing a bike fit definitely measure it as part of your bike fit okay thank you thanks for that I think probably the last question unless any more come in while we're quickly talking about this but I don't know the answer mine's no but is there any scope for thinking out loud but any scope for using position on the bike or the setup of the bike in a rehabilitation setting so say I've torn my hamstring and I'm starting to cycle because I'm not allowed to run yet is there any scope for playing around with the position and setup of the bike to either off the hamstring or stress the hamstring more so that's that's where my my passion comes in where I can combine my physio and background with my PHD cycling bike fitting background and I work with a lot of cyclists who are injured or are in pain or don't have the flexibility and changing their position so they don't fit into those normal ranges of that 25 to 35 degree knee flexion angle for example but I've got them into a position where they are able to ride pain free without putting more stress onto the hamstrings so things like ITB hamstrings the tip and pain we do change the saddle to account for that and it might not be a permanent change it might be as they're going through that rehab process that you know initially because the hamstring is injured it doesn't have that flexibility so we drop the saddle ever so slightly and then as they progress through their rehab and they're able to flex and extend through the hip more freely and more comfortably we can start lifting that saddle a little bit more a lot of people with another question is more hamstring related so yes definitely we do change the saddle height to accommodate that but another example would be neck pain I don't put your older cyclists who have a history of neck pain either osteoarthritis or tension headaches into a very aerodynamic position because I know that that's going to put strain onto their neck so it is working within each individual and setting the bike up for them they might not fit into those normative values but for them they are comfortable and that's what's important and it might not be their forever position as they work through their rehab and as they get better we can start changing it it's an ongoing process thank you yeah I think I think that's a perfect example of like evidence based person specific kind of holistic practice so yeah really kind of everything we've talked about and putting it all together and actually considering the individual to help them out really and so yeah thanks ever so much Wendy I really it's been a brilliant talk so thank you so much for joining and giving the lecture thank you thank you for inviting me to come and speak no worries and then yeah all that's left of things for me to do a little bit I hate doing the horrible YouTube a bit where I say if you want to find out more remember to subscribe and click on the bell thing next to it and then you should get notifications when other lectures are happening so to stay up to date but yeah just thanks again Wendy and yeah thank you