Evidence Strong
Science of optimal Olympic weightlifting technique - with Shyam Chavda
So we're in the catch and this will relate to pretty much what you'd look for at the bottom of a front squat through a clean or an overhead squat for a snatch but the stable components particularly will kind of translate into both. So the weight distribution ideally should be on the midfoot so you don't want to be raising up on the heels or moving your weight too far back and if you were to draw a line directly down from the bar it should be over the middle of the foot so directly over the base of support. Now variable components will be the height at which you actually catch the bar so some people may sit really deep into the hole because they have very reflexibility and very good strength some may not be able to do that so they might sit a bit higher and I think the most common one for being a variable component would be the foot position so what foot position do people adopt when they catch naturally your body will take the least path of resistance and will end up in the position where it feels strongest? Lovely to meet you finally and welcome to Avidane's strong show if you could briefly introduce yourself that would be great. Yeah thank you for having me on Avidane's appreciated so my name is Sean Chaptor I'm a program lead for the Masters in Strength and Conditioning at Middlesex University where I'm also the head weightlifting coach. My coaching career is just over a decade within the sport where I've been fortunate enough to not only coach some great national lifters but also coach at the Tokyo Olympic Games a few years back under the International Olympic Committee's refugee flag with Syrwell Chatchit where I continue to coach Tuesday and away from my coaching I'm also a senior performance scientist at British weightlifting where I work closely with the performance manager in providing performance diagnostics across all of our pathways and because all of that stuff doesn't take up enough of my time I'm also my PhD within the sport of weightlifting as well. Yeah is it okay to ask you about roughly about the topic? Yeah of course yeah ask where you are probably. In one sentence what your PhD will be about? Key performance in the case of weightlifting performance. Okay and we will leave it there because I think we will meet again and talk about it. But today I would to talk about the paper weightlifting and applied method of technical analysis and it's a recent paper. I enjoyed reading it. It has a lot of goodness in it. Thank you. So why this paper was written and why was needed? The reason the paper was written is that there was this concept of stable and variable components which will come on soon in a little bit and that's something that came up in a conversation with our education manager over at British weightlifting and it came to my attention that prior performance teams within the governing body I kind of used these stable and variable components to help identify technical errors within their coaching, namely these individuals were Charles Greenwood's and Sean Joff as well I believe was part of this idea of developing this concept of these stable and variable components. And you know it was a really good concept and all credit to them. But when the performance team changed ever so slightly these ideas of the stable and variable components that have been delivered in our education program. But me being born as a performance scientist what I felt was lacking was scientific backing to see if some of these concepts being delivered were true based on the findings of the literature and you know not just experience and knowledge of basic physics and biomechanics. But also if you look at the author list there's actually three nations that are part of this. You know there's British weightlifting myself and the performance manager Stuart Martin. There's Greg Haff who I think does some work with the Australian Weightlifting Federation and USA Weightlifting some years back as well and Anna Swisher who is the USA Weightlifting I suppose performance scientist and education manager I believe apologies if I've got the got the title incorrect but you essentially have three nations agreeing on these concepts which we should follow to make weightlifting analysis a lot more easier. And I think it's a really nice step forward to normalizing the language that we use as weightlifting coaches and as scientists within the sport of weightlifting. If you would have to explain almost like a definition what are stable and what are variable components? Yeah so if we take the concept of a stable component in the context of weightlifting consider these as kind of components of the lift which don't violate fundamental principles of biomechanics and physics. In doing so you kind of run the risk of missing the lift or at least increasing the likelihood of missing the lift. And these typically will relate to the bar central mass relative to the body central mass and the applied center of pressure as well. The variable component is where we kind of begin to be a little bit more accepting of individuals and topometries and differences and how kind of different lifters will display the stable components. For example if someone with really long arms might not necessarily have the bar at mid thigh during a power position during the clean or vice versa someone with really short arms may have it close to the hips. So while this shows variance in both instances the bar remains over the basis of order close to the body center of mass. So the variable component doesn't violate the stable component but allows for individuality when coaching individuals. I think that maybe the easiest way will be to go with examples. So if we could go through the positions with starting position and which compliance you would consider stable ones and which one would be viable. Yeah sure so if we go from the the set position and this is outlined in table two of the paper in the set position the stable components would be that the weight distribution will be on the middle of the foot. So you have your whole foot planted on the floor. The barbell should be essentially over the arch of the foot or over the first shoelace and the armpit crease should be directly above the barbell. And the reason we use armpit crease is because it means the shoulder is in advance of the barbell the armpit crease is directly above the barbell. Sorry did you want me to get through all the stable components first and then variable or stable variable and then the next phase? Maybe yeah let's maybe go through the positions. So staying with the set position then the variable components which you might see during the set position is the height of the hip relative to the knee. Often not a textbook example would be the hips should be higher than the knee knees but this will vary depending on the lift is anti-pometry. So for example if someone's got a very long torso and relatively shorter legs they may sit their hips slightly lower in a point that the hip may be in line or ever so slightly above the knee but that still allows them to keep their armpit directly over the barbell which is a stable component. The other obvious variable component in the set position is the adoption of the foot position. So to be different widths and stances that would be adopted by the individual and you know you can see that when you look at different nations lift where some may start slightly wider some may start in a frog stance where the heels are very close together and this kind of also falls under the style component as well where individuals have different styles are lifted. We've now identified stable and variable components from the set and now we're going to initiate the first going to the first pull. So when we move into the first pull the weight distribution at the end of the first pull the weight distribution would slightly shift towards the heel. We're not going to say on the heel because often not when you use a cute weight on the heels with the first pull the toes tend to lift up particularly with obvious lift. It's important to make a point of the whole foot shift when then planted in the foot. So weight distribution may move back slightly. Barbell typically would move towards the lift up although I believe this is more of a variable component now because when you look at the literature there are lots of different barbell trajectories that have been displayed by world champions and national lifters and all of them have been successful. So I think upon reflection bar moving back towards the lifter is idealistic because it's moving towards the lifters center of mass but it could possibly be a variable component set up for discussion. The on-pick crease will now become in advance of the bar and that's because you're extending the knees back. So as you extend the knees back and the shins become near vertical the torso angle should remain the same as it was in the set because you do that you're naturally going to have your shoulders more in front of the bar so your on-pick crease will then become over the barbell. This is really important to get this correct because if the weight distribution of feet moves slightly back you push with the legs and extend the knees back to the point where the shins are near vertical and the torso position remains constant then you're able to elicit a stretch reflex during the transition which is likely to occur based on the fact your quads and the hamstrings will be under a stretch. That's the importance of the first pull and of course a variable component will be the actual initiation of a first pull so you have individuals who might use a dynamic start or a more static start and just kind of jumping back to the set position I think it's important to understand taking the slack out of the bar is also really important because what that does is it reduces electro and mechanical delay so we start higher up the force time curve so we don't waste any energy or efforts being put into trying to lift that bar and over the kind of inertia. So we're now at the end of the first pull the bar finishes at a rounded knee and the transition into power position occurs. So during the transition the weight distribution will begin to shift from being slightly back to being slightly more towards the center. At this point the knees will feed through the barbell and the barbell should continue moving towards the lifter. So now your center of mass and the barbell center of mass are coming together. At this point if you were to freeze frame at the end of the transition you'll be in what we could term a power position and during this power position the bar will be in contact with the athlete and the bar will be directly over the base of support. So if you were to draw a line directly down it'd be straight down into the middle of that foot and typically that'll just be if you were to draw it straight line down from the side. And that'll be a stable component because you don't want your center of mass and the positive center of mass to be disassociated. Now the center of the shoulder will typically be directly over the center of the foot as well. Now again probably something that's up for discussion and upon reflection from right in this a few years back now the arm bent. So the arms should typically stay straight and the force should be coming from the legs although you may often notice individuals bending their arms to get the bar into a position that feels stronger for them to help them apply more force with the legs. As long as the athlete's not continually pulling with the arms I don't think it's too much of a problem but I certainly believe that's up for discussion in the debate. Whereas if someone has a slight bend in the arm and has it then fixed as they move through the transition although not idealistic it may not be too much of a detriment to the variable components of that power position following the transition would be where the barbell makes contact. Now like I mentioned before something with longer arms may contact with a lower point someone with short arms may contact at a higher point and then we end up all with I suppose end of the second ball and this is our triple extension so the hit knee and the ankle should be extending really aggressively. The weight distribution in this instance will now move to the forefront of the foot to allow you to plant a flex. The shin angle will be again near vertical maybe even slightly declined back and in terms of a variable component the displacement of the barbell relative to the athlete's center of mass may differ. Ideally you don't want to have a big loop because prior research is kind of mentioned a fair few times that minimizing the loop is important for a successful lift the more the loop the more likely they're missing the lift. So the idea is to keep the bar when you think about the stable components keep the bar over your base of support for as often as you can keep it as close to your center of mass as often as you can. That's if you were to simplify it all down into two things for the pool. So now the bar started to kind of travel upwards we've got this point where the bar hits its peak and we would have started turning over by then but if we take peak barbell high as a point of interest because it's easily identifiable particularly if you've got like a software or something to measure barbell protection with but even with a simple iPhone you can see when the bar's kind of momentarily weightless. So during this peak bar height the lifter should have already begun to get under the bar you know by flexing the knees and putting themselves into that squat position. Of course the variable component of this would be the height at which the barbell is being pulled that will vary depending on where this is saturated clean. Other variable components will be the displacement of the lifter center of mass so how high is the actual lifter during that point of return over and the foot position so some may adopt a slightly wider stance relative to their pool or some make it their feet the same but that will vary on individuals limiting factors of mobility flexibility and where they feel strong. Now we move on to the receive position so the receive position is the the point at which the barbell and the athlete connects okay that receive will be where the velocity of the barbell starts to will be at zero and then it will go into its lowest point in terms of its its negative. Then as we receive this barbell and kind of meet the bar ideally the bar should be over the base of support so directly over the middle of your foot. So that's a stable component if that happens you're more likely to to make that lift because it's not in front it's not moving too far back. Now the height at which you receive the barbell will be a variable component so if you think of your own lifts if you think of when you do a power clean you think of when you socket heavy and have your weights on what ends up happening is you're providing their all good lifts. The bar will always be over the base of support because you're making a lift well but the height at which you're catching the bar or receiving the bar sorry will will alter. If you know anything that could be helpful about drop height that would be great. Yeah okay so essentially in the in the paper what we've done is something which often probably gets overlooked and we've defined peak barbell height receive and the catch. Typically when you look at the research in particular you'll see the peak barbell height and you'll see a catch. Now if you imagine a lift pulling the bar to X height and then dropping their body mass directly down into the lowest point of their catch you've got this huge drop distance right and the barbell will then crash. So what ends up happening is the barbells got that distance to develop some speed and on the way on the way down whereas if we think about the receive section the receivers where you begin to contact with the bar so you essentially dampen that drop speed down into your catch. So a stronger lifter or someone that's able to lift very heavy loads will be able to to do that far more effectively than someone who's you know maybe has this really large drop distance so therefore you train elements that improve the receive which will then filter down into a better turnover into the receive and into the catch. So it becomes a little bit more seamless and it's just a way of kind of cushioning the weight coming down as opposed to the barbell crashing down on you. Okay so we are in a catch position now. So we're in the catch and this will relate to pretty much what you need to look for at the bottom of a front squat through a clean or an overhead squat for it for a snatch but the stable components particularly will kind of translate into both. So the weight distribution ideally should be on the midfoot so you don't want to be raising up on the heels or moving your weight too far back and if you were to draw a line directly down from the bar it should be over the the middle of the foot so directly over the base of support. Now variable components will be the height at which you actually catch the bar so some people may sit really deep into the hole because they have very good flexibility and very good strength some may not be able to do that so they might sit a bit higher. And I think the the most common one for being a variable component would be the foot position so what foot position do people adopt when they catch? Naturally your body will take the least path of resistance and will end up in the position where it feels strongest. So once we're in the catch we now got the recovery where again it's very much like the ascending phase of a front squat overhead squat the weight remains in the middle of the foot or remains directly over the base of support so if you true a line down it's directly over the middle of the foot and we have to consider the technical constraints that the judges look for so often have to finish parallel next to each other kind of like this or staggered and of course the variable component on this will be the width that you adopt and the foot position you adopt when coming into your recovery some athletes like to stand narrow some would maybe go slightly wider wherever they feel like they have the most balance and support with the bar over their head or on their shoulder coming out of the pain. Is there any metric you know coaches are measuring but there is no difference or the evidence is saying against using it? There's not that I'm aware of to be totally honest something I've monitored was barbell displacement during snatches and barbell displacement during highples and I also looked at peak barbell velocity vertical velocity for block snatches and for full snatches as well and didn't come to much conclusion from it other than the conversation I could have with the athlete meant he could make the association between if I'm creating this amount of speed I think I'm able to snatch x amount at this time time point and we know learning velocity has a relationship where as load goes up velocity is naturally going to go down so it's you know it's a good predict but one of the things I think it's important to be able to do is especially in research is try and standardize our definitions of phases so typically speaking the literature will use near to an angle to identify the phases so first peak is first pool first or minimal knee extension will be the transition and then second peak knee extension is the end of the second pool and then you have the catch position which is maximum knee flexion but there's also other ways of doing it which has been done since the 1980s using using the force force time curve on its own some have used velocity so it's really difficult to although they're all very close to one another I think we need to find a way of standardizing it and that's something we've attempted to do in our in our lit review which will only to get at some point but if you are using accelerations and velocities for example just be aware that it becomes difficult to identify the first pool because not everyone has like a first inflection point on the velocity during the first pool which is typically defined or has been used to define the first pool previously before it drops and goes back up some people have a continuous quite a nice steady rise and it's very hard to identify where velocity kind of plateaus a bit will drop a little bit because it may not exist and I think that's where I came to the realization that all these measures are really difficult to use within individuals sometime because each rep is different maybe different may display a different time series acceleration time series to a velocity time series so that's what made me think I need to go and find out what is actually useful what is not what can be used to identify phases if we haven't got new new angle or just look at the paper if you use a phone you can pretty much identify the new angles without even having the number you can just do it frame by frame that's very useful so are there any implications we haven't mentioned yet for coaches raising from this paper no I think this paper kind of serves as a foundation for especially early career coaches kind of help simplify the analysis process on what to look for what to try and change or or affect whether that be through coaching cues or using special drills and exercises at least they have something to go back to to help identify key limiting factors but I also think for the more seasoned coach it kind of helps support some of the practices that we often overlook and take for granted with some sort of scientific underpin it and really to me it's just important as a coach to be open-minded and critical of your own practice like being able to discuss, justify and defend your coaching is a really important step in kind of developing yourself but also the athletes too because ultimately it's them who wear disseminating knowledge too through exercise selection or the coaching that we give them and essentially this paper just aims to kind of simplify that process and hopefully aids in some sort of common terminology and languages adopted by coaches or those that use weightlifting for training. Okay so from here where are we going what is the future of research and what it means for coaches? I think the future research for weightlifting in particular is going to be case studies. I think samples of elite individuals is really useful but also maybe having an elite individual and having someone who's maybe a regional or a national lifter for example and just having some sort of indication as to the different things you can monitor with them or the different characteristics that would be quite useful. I think that's pretty much it in terms of moving forward with with the research. There's definitely more to be unpacked but with such small sample sizes and weightlifting it becomes very difficult and then that's why I think you may find some things have a very consistent pattern within the literature and other times it can be like different depending on the sample size they've used and the samples that they've used and whether they're mixed, many women as well, it's also another consideration. Longitudinal studies I think is definitely needed in a way to do so. Longitudinal technical analysis however you monitor that technical analysis I think that's the next thing like are we actually able to create change with our programs and our coaching in weightlifting and it can be evidence that we're longitudinally. We've done it with physical performance measures and usually some sort of proxy so mid-typal jumps but what about the technical elements and how does that all marry together? Then that's the next big step which is misinformed from the research and the everything's a lot more accessible now which is great so now hopefully it's about finding out which of those metrics are useful which are reliable, use them, monitor them, put an intervention in place, design intervention course challenge if it does great if it doesn't why not and once we can get down to that then I think we're in a good place. Did it favor the color? Oh I've got to say like a dark navy blue probably or black. Okay but I've been told black's not a color. Oh it is it is fine for graphics. So I think dark navy, dark navy is my favorite color. Right, note it so your next infographic from your PhD paper will will come from evidence strong in dark navy. That's all. Thank you. Great. What do people can find you? So I'm on most social media platforms so Twitter, Instagram, probably more so the weightlifting clubs Instagram. I've got a little bit on my personal one but I don't really use it too much but I'm happy for people to contact me through either of those two means Instagram or Twitter and email as well. So yeah my Twitter handle is shy_ the number two and then tweet. Okay. And my Instagram is @coach_chabda which is my surname CHABDA and my email address is s.chabda @mdx.ac.uk And club Instagram did you say? Yep. Club Instagram is the handle is mdx_weightlifting. Awesome. Thank you so much. It was a pleasure and I wanted to thank you for your time. See you next time. Thank you very much for having me. Thanks Alex. [BLANK_AUDIO]