Neuromechanics Transcript

In a recent presentation, I discussed the, the biomechanics of increasing speed, neural mechanics um is a field of study that combines biomechanics and neurophysiology. So it looks at studying uh the skeleton. So the bones, the muscles and the nervous system and how they interact to allow athletes to produce forces and then the eventual movements in the sporting skills that they’re trying to accomplish. So uh very applicable to golf. So let’s take a look at uh the neural mechanics of increasing club head speed. So this should look familiar from a previous presentation um in order to discuss um how we’re gonna increase speed at any capacity. We want to have a a framework in our mind about um understanding what variables influence other variables that will eventually um influence club head speed. So I talked extensively about how um energy delivered to the club from the golfer. 100% determines uh driver club speed a little bit from driver specifications. Um But pretty much you have to influence one of these four things, hand path length, the force along the hand path, uh the amount of club rotation or the torque about that rotation axis if you’re gonna increase club head speed, and we talked about this in, in the context of swing techniques. So um any swing technique change that you think is gonna increase club head speed, whether it’s um ground reaction force pattern or segment sequencing and transition. Uh how you’re shifting your weight, your center of mass, even something, hey, we’re gonna change the grip or your posture, your stance with. If you expect that to have an influence on the club head speed, it’s gonna have to go through the way the uh energy is delivered to the club from the golfer. One of those four factors we just looked at percentage of uh max effort is another thing that can influence uh the energy delivered to the club from the golfers. That’s really the, the fraction of max speed potential given your current nus neuromuscular capabilities and swing mechanics. And then, um uh really, it’s about intention how fast you’re trying to swing. Although sometimes you can be intending to swing fast. We’ll look at this a bit today, but maybe you’re not um uh actually uh realizing uh what you’re intending to do. Um And then one that affects uh so many other things, uh the lowest hanging fruit, in my opinion, and the one that I’ve uh focused uh started to focus my career on is uh is physical training. So, uh things like lifting weights, throwing medicine balls, flexibility, mobility training. And I think uh the most important one, the most efficient way to um gain the most speed and most applicable is what I call variable inertia speed training. So we’re gonna look at these three things, the swing technique percent max effort and physical training through uh a neural mechanics lens. We’re gonna understand a little bit about how the muscles work, um how our nerves trigger the muscles to work. Um A a and, and get a better understanding of what we’re really changing in our system that allows us to, to increase speed. So I think it’s important, we’re kind of starting out bigger picture and we’re gonna uh drill down a little bit into specifics in this presentation and then we’re gonna pull back out and take a really big picture at uh looking at how we can change our speed across uh across a lifetime. But, and working our way down, we’re gonna need to learn a bit about some terms and sometimes terms um in the golfing industry aren’t exactly what uh what they were set out to be by. Um uh you know, Newton’s laws, we’ll say, or physicists or biomechanics. So what do we mean when we talk about work power and energy in a golf swing, power is probably the most misused term. So really, it’s, it’s energy that we want kinetic energy, the more kinetic energy in the club at impact, the more speed there’s gonna be 100% correlation there. Power is the rate at which we generate or transfer energy. Ok. So, um, they’re not the same thing. One is the rate at which the other one is changing. So you can think of, I like to use the analogy of filling a bucket with a hose. So the amount of water that’s in that bucket is the energy. Ok. We want to have a full bucket or as much water in the bucket as we can when we get down to impact more water, more club head speed, how quickly the hose fills? The bucket is power. Ok. So I’ve got a fire hose here so that fire hose has a lot more power than this garden hose. But if that fire hose is only on for a fraction of a second, we might not fill the bucket. So theoretically, we could have a, you know, really high power level, really high instantaneous rate at which we’re changing the energy of the club, but it doesn’t last for very long. Then we’re not gonna have a high club head speed. Um, and th this is a big relation in physics. So the, that the work done on something equals the change in energy. So the work that we do in the golf club by, uh, changing our hand path length, increasing the force along the hand path, um, increase in the angle, we rotated through the torque that we apply about that angle. But those are the, the equal the work that we’re doing on the club and that’s gonna equal the change, change in energy. So the water in the bucket represents, um, the work done by the hose and also the amount of energy we’re gonna have um, at impact and you can think of uh two players, John Rom versus say John Daley in, in his prime, John Rom. If they, if they generated the same ball speed and at some points in their career, they were probably uh very close um low one eighties ball speed probably out there. Um John Rom would be uh much more powerful in the technical sense of, of biomechanics. Um His downswing time is really, really short. Um So he, he’s maybe he has the same amount of energy in the club as John Daly, but he created that energy transfer that energy to the club in a much shorter period of time. Now overall, we do want our uh golfers to be uh very powerful athletes because in the grand scheme of things, uh the downswing is very short. So point uh point 25 seconds uh John Rums probably below 0.2 seconds for his downswing. Um So we wanna be able to, to get as much energy the club in a really, really short period of time, say uh a little bit different than say hammer throw where you, you’ve got um you know uh over a over a second to, to generate that even Hammer throwers still wanna be um, powerful. But, um, um, yeah, so I wanted to, to set up, uh a little bit better understanding of work power and, and energy, um, in the golf swing. Um, so let’s look at a AAA practical example. So you can kind of understand, um, uh, a little bit more about the magnitudes of what’s causing changes in club at speed. So, um, let’s take a look at uh 100 mile per hour driver example. So if, if your club at speeds 100 miles an hour, you’ve probably done about 220 joules of work on the, on the driver and that’s gonna result in about 220. Um joules of kinetic energy. It impacted work and energy at the same units. Where, where does this 220 come from? Well, linear work is gonna account for about 100 and 80 joules of that on average across a large group of golfers. So this is um data based on 60 golfers, I believe. Um angular work about 40 jewels. Gravity does some work, but it’s very small five Jes and, and drag is gonna account for about uh minus five joules. So drag is actually sucking energy um out of the system. Um We can convert that into MPH. What does that mean in terms of MPH? So, uh the linear work being done accounts for 82 MPH. So if you were to look at those numbers. Which one do you think is, um, the most important or the most influential? And it would be linear work. And not only is it the biggest in terms of an absolute sense, it’s also, uh gonna be what varies the most across two golfers that have different RHEAD speed. So if you swing at 100 MPH and your friend swings at 100 and 20 MPH, what accounts for that 20 MPH difference is more than uh uh it’s probably gonna be differences in linear work. Your gravity is gonna be almost uh identical. Um Drag is gonna be almost identical and, and angular work also tends not to vary that much between golfers. So if you really want to increase your club head speed, it’s gonna go through um linear work. It’s gonna be uh changing the amount of linear work you do. And just as a refresher, that linear work is a function of your hand path length and the force along the hand path. And of those two things, the force along the hand path um is the most important. So, um here’s a little uh image showing uh data that I collected um from a study on work and energy uh in the driver’s swing. Um So each dot represents uh a golfer, we’ve got club head speed on the Y axis here and we’ve got the average force that the golfers exerted along the hand path and these are averages of, um, a dozen swings at least. Um, so you can see that, hey, this fella up here, this golfer that was generating close to 100 and 20 MPH, clubhead speed. They had the most average, they were doing the most, uh, playing the most average force along the hand path. Whereas this individual down here just over 70 MPH, clubhead speed, um their average force was uh less than half of that of the person with the fastest club at speed. And there’s still some variability in there that’s not accounted for. But this is a really strong uh correlation. So 93% of the differences in club and speed were predicted by that, that average force along the hand path. So, um and it’s not just the force that uh we’re applying to the club. So it’s not just the, the total force and that force specifically, it’s the force in the direction that this mid grip point is traveling. So I could be a very uncoordinated individual and apply a lot of force to this grip. But if it’s not in the direction that that grip is traveling, then I’m not going to be changing the energy of the club. OK. It’s like um an an example I often use is um pushing a car, right? So let’s say we got to jumpstart a car, I’m gonna try to push it towards the camera. So I get behind the car, I’m, you know, I’m pushing against the trunk and I’m pushing this way. I’m not, you know, I’m having a bit of trouble. I’m not getting over fast and your buddy comes in, hey, I’ll give you a hand and they come around and they push on the, uh, driver side door, pushing in this direction. Well, they’re pushing, they might be applying a lot of force but it’s not in the direction that we’re moving. So they’re not changing the energy of the car at all. They’re actually not doing any work on the car. Uh That force has to be in the direction of, of motion uh of the point of force application in order for there to be uh uh any work done or in order for that to contribute to a change in energy. So, um that force that’s along the hand path. Um the average force over the course of the downswing is a uh a big determinant of um the biggest, by far, the most important factor in predicting clubhead speed. So that’s when we’re gonna kind of frame our discussion around today. Well, how then do we um you know, increase that average force? Um And let’s take just so you have uh you know, a better image in your hand. I’ve got uh an animation here that I’m gonna show. Um and this is um uh this is the animation I show and I’m working with um, tour players or coaches and we’re trying to understand, you know, where, where we could improve to change, uh, uh uh a golfer, club head speed, um maybe where they’re lacking relative to, um, uh you know, their colleagues. And what you can see here is that this orange line is going to represent their hand path, that red vector is the component of force that’s being applied um in the direction of the hand path. So I’ll just let this play once. Um, so you can watch how that force along the hand path develops and that length of that hand path. Ok. And we can see that we’ll just get that to, uh, just about before impact. So we can see that the length of this hand path is down here. It’s 1.5 millimeters, 1.6 m and that would be considered relatively long for an amateur. Um, interestingly, uh, that would be about the length of Tony Fino’s hand path and he’d be considered to have kind of a short hand path, um, for, uh, uh, a PGA tour player. Um Wilco, um, who’s, uh, has amazing, um, uh, ball speed ping player. Um, his hand half length would be closer to 1.8 m, ok. Um 1.1 0.591 0.6 is pretty good for an amateur. So this person’s generated um, 100 and seven MPH of clubhead speed and what we’ve plotted up here is that, that force that we’d like to increase. Ok, the average uh of that over the, the distance that the, the mid hand point travels. So, um if we get to a certain point here in the downswing where I can see the force. So right now, um most of the force that this golfer applying, you can see they’re applying uh a total of 33 newtons of force. We’re not showing up, but I’m giving you the digital readout here. Um Almost 28 newtons of that are uh in the direction that that mid he point is traveling. Um Right now along the x axis here is, is the distance the length of the hand path that’s been traveled so far. Ok. We’ve got that in uh in meters. Um Just drag it to an interesting uh point here. So about um shaft parallel in the downswing. Um So remember this is just the component of force uh that’s being exerted in the hand path direction. So that’s 271 newtons. It’s just about to peak here and be all drag to where it, where it peaks. So at this point in the swing, um the golfers peaked in terms of the amount of force they’re applying in the direction they’re moving, that, that grip. Um But you can see it’s actually quite a bit smaller than the net force. And so if we actually looked at the net force it would actually be pointing much more um vertical, but only that component that’s in the direction of travel is, is um doing um work on the club change in the energy of the club. And that’s what this blue line is. This is the uh the work done on the club, the change in energy um from uh that force being applied along the hand path, you can see that they’ve done 207 jewels of, of linear work. OK. So, um keep that in mind we’re trying to increase the, the raise the level of this um uh red line over the course of the downswing. That’s gonna do more work. That’s gonna give us more uh club head speed. So more kinetic energy transfer from the golfer to the club during the downswing, the higher club, its people beat impact. Biggest way we can change that is through increasing the, the average force along the hand path. It is important to realize the golfer’s muscles are the source of kinetic energy that makes it to the club. Ok? Um Gravity helps a bit and air resistance hurts a bit tiny, tiny values, but the muscles are the power source of the golf swing. We don’t get any power from the ground. The only power we get to change the amount of energy in the system is from our muscles. The ground can help uh our muscles generate um more power change the energy of the system a little bit more. Um, but none of that power is coming from, from the ground. Ok. Uh The ground can help us, you know, do other things. We, we would have to talk about how the ground helps. We have a conversation about, um, uh, impulse momentum would be the way to do that. But the fact of the matter remains that muscles are the power source of the golf swing. Um So let’s see how are the muscles generating power? What do we mean by muscle power? So, um this is a look at the, uh the leg here and we can see that this is called um plan flexion. You could think of maybe uh someone like a Justin Thomas or a Bubba Watson as we’re coming in impact, their plan reflexing are coming up on their toes. Um So the, the rate at which this muscle is changing the the energy uh or the speed of the golfer is considered muscle power. So you can see that this muscle is contracting, uh the, the achilles tendon there. This would be the gastrocnemius, it’s applying the force with the achilles tendon and that force is changing the energy in the foot. Ok. The rate at which that energy is changed is muscle power. Another way to think of that is a, at any given point in time, we can figure out the power in that muscle, if we know the force is exerting on the bone and how fast that point in the bone is traveling. So zoomed in here. And this is at one point in time if we know how much force the tendon is applying to that point. And we also know, so let’s say it’s 100 newtons of force. And we also know what the velocity of that point is. Let’s say it’s 2 m per second, then we can take that force 100 multiply it by the velocity too. So we have 200 units of power. That would be the instantaneous power that tells us how fast that muscle is changing the energy um in the system. And so from a speed perspective, an optimized neuromuscular system is one that’s gonna maximize the kinetic energy and the club and impact. So our muscles contract changes the energy of our segments. So our feet, our shins, our thighs, our torso and we want to coordinate that in such a way that we get that energy out to the club by applying force to the grip. And in turn, having our hands do do work on the club muscles create the energy. And then if we coordinate that our, our movements really well, we can uh do work um on the club through our hands. Um And I think that um you know, variable inertia speed training, that’s kind of the overall theme of this. Although looking at it from a uh neuro mechanical lens, it is the best way to change the neuromuscular system to get it to uh be able to um increase the amount of muscle power and change that um maxim uh change that kinetic energy that we get out to the club. So let’s uh keep going down this this pathway. We started a big picture. We’re gonna get um uh down a rabbit hole here in terms of understanding how the neuromuscular system works. And then we’re gonna uh come back out uh the other end. So I like to think of this as the controller, the, the nervous system. Um for the most part that stuff starts in the brain. OK. So we have uh a thought, hey, I would like to lift up this stack. Well, that’s gonna start in my motor cortex, that’s gonna send a signal down to my spinal cord and that’s gonna activate uh a motor neuron. OK? Um And uh a motor neuron will uh send a signal along its length down to the muscle level. And that motor neuron plus the muscle fiber that it innervates is considered a, a motor unit. Um So we can see if we look over here, these blue and red lines are different uh motor units. And what’s interesting is that a motor neuron could innervate thousands of fibers. Um the the smaller muscles um in the hands or in the eye for the eye, um innervates really small. Uh a motor neuron in the eye would innovate a very small number of muscles that gives us very fine control. Whereas a, a motor neuron that um uh is used to contract muscles in our gastro like our calf, um or our quadriceps might innervate thousands of, of fibers. So we, we don’t really want fine control. We just want to be able to produce a lot of force um quickly. So that’s a motor unit. So signal comes from the brain gets the spine and the spine decides all right at the spinal level, what uh motor neurons am I gonna fire here to do what the brain is, is asking me to do. Um And we get a fleeting twitch of muscle force. That signal comes down. If we stimulate a motor uh unit, then we get a little twitch and then it would relax. So we’d see a little tiny blip of, of motor force and that, that signal, it was actually called an an action potential. That’s the thing that’s traveling um through our body or to the muscles. And so here’s a little animation that’s gonna um better able you to visualize what I was just um talking about there. OK. So, uh here’s a brief overview of the neuromuscular process. So we are looking at the biceps muscle here, the biceps brachii, we’re gonna see what happens when um a signal comes from the brain um travels out from the spine um and tells this muscle to, to contract. So, um even though this is a, a single muscle, the the biceps, it’s composed of hundreds of thousands of individual muscle cells also called muscle fibers. And those uh muscle fibers are are grouped together um and controlled by a motor uh neuron. A single motor neuron controls several uh muscle fibers. So uh our muscle cells same thing. So in this image, we can see 1234 muscle fibers out of the hundreds of thousands that are in this muscle that are being controlled by a single motor neuron. So this green line is the motor neuron, an alpha motor neuron. And it, along with the muscle fibers make up a motor unit. OK. Now, um for the purpose of this animation, we’re showing four. but in reality, um there would be probably 1000 muscle fibers um being controlled by this single uh single signal, uh this single motor neuron. OK. But tough to draw and show clearly uh 1000 uh muscle fibers here. OK. Um So what’s gonna happen is uh is the signal is gonna be sent along um down into those muscle fibers and we’re gonna see a contraction. Um And we can uh measure the force of that contraction if we had a little um force transducer here in the, the biceps tendon that would tell us that the force that is being produced. Um And what actually happens is before we even measure a force, there’s actually um stuff going on So um there’s gonna be a, a signal that’s gonna be sent along um to that muscle uh those muscle fibers. And as soon as that, that signal reaches the muscle fibers, that’s gonna trigger some stuff happening inside uh the muscle fibers. So that signal is called an action potential. Um It’s gonna reach the muscle fiber and um this is a brief overview but what you’re gonna see is uh it’s gonna trigger the release of calcium ions and calcium is required to actually make the, the, the, the finer elements of the muscle fiber um contract. Um and shorten and we’ll get into this uh in a, in a different video a little bit later. Um But this is actually called the, the latent period because stuff’s happening. Um but we’re not measuring um actually any force in the muscle yet, ok. Um So stuff’s going on there. Um But not much is actually happening. There’s um elastic um uh properties in the muscle in the tendon. So those need to be stretched, essentially, the slack needs to be taken up in the muscle before we start to see um forces being transmitted uh to the, to the actual bone. OK. Um When that contraction actually starts to be measured, that’s actually called the contraction period. OK. So we’ve actually got uh sliding along here between the thick and the thin films, we’ll talk about that in a little bit. Um And then, um after that, uh occurs after the, the calcium has done its job, then it begins to um um go back um into the uh sarcoplasm reticulum and the muscle will, will relax. And I should say that this um single process here when that happens. And there’s a contraction that is called a uh muscle twitch. When uh you get a SSS single signal and muscle fibers producing a contraction that is a twitch and then we get the uh force being produced and then a relaxation. Um And what’s interesting is that um we have different numbers of muscle fibers um for different motor units. So um muscles in the hand would be considered a small motor unit. So that single motor neuron, um you know, might only connect to a few 100 fibers um showing three here. Whereas uh a larger muscle in the, in the leg like a uh a quadriceps muscle um would be um um innervated by uh thousands of fibers. So there’d be thousands of fibers um controlled by that uh single motor unit. OK. So that’s a brief overview of the neuromuscular process. And so you imagine finer movements um uh like writing versus um more gross movements like jumping require different levels of, of control. OK. So we can understand how force is is being developed um um through the control or what it’s doing to the muscle. Um But how then would it um increase the force within the muscle? So we understand how it produces a little bit of force. But what if we wanted more force? Well, it can do that by recruiting more motor units. That’s one way it can send signals to send those action potentials at a faster rate, faster discharge rate that’s called rate coding. Um Or it could synchronize the motor unit recruitment. So instead of saying, hey, let’s fire motor unit number one. All right. Ok, let’s wait. Oh yeah, let’s fire motor unit number two, we can synchronize those action potentials. So we can say, hey, let’s go 123 all on now. 123, all on now. So we can synchronize that that will result in an instantaneous um increase in in, in the force being produced by that muscle. So, um within a given muscle nervous system has these three options. And um here’s a little bit uh uh more detail on that. So you can kind of better visualize um how recruitment um rate coding and synchronizing work. OK. So how does the nervous system increase the force that’s being produced by a muscle? Well, uh we know that um we’re gonna produce um force in the muscle signal has to come down from the brain, from the spine. Um That single motor uh unit um consists of a motor neuron that sends a signal to multiple muscle fibers and that signal that single signal is called an action potential. Um And it is gonna tell those individual muscle fibers to contract and then they relax. So we get a little bit of a, a blip in force if we send signals a little bit faster, and you notice that that muscle doesn’t completely relax from the first signal and we get a little bit higher force and if we continue to send signals so that the muscle doesn’t completely relax. And those build on each other. This is called um wave summation. We get something that looks like this, which is called infused tetanus. So it’s increasing but dropping and dropping if we send the signals at a fast enough rate, and we get something that’s called on fused tetanus. And that’s gonna produce a sustained muscle contraction. So that um motor unit um is gonna be producing the, the maximum amount of force that it can produce and that’s gonna reach a, a constant uh peak value and for very fast movements in the golf swing, um those uh signals that discharge rate um uh could be up to 100 pulses per second. So that’s 100 action potentials being uh sent every second for very fast speed contractions like what happened in the, the golf swing. So this is called uh rate coding. So that’s one way the nervous system um can increase force is by sending signals um down individual uh motor units faster and faster. Um But we’ve got uh potentially 1000 different um motor units each controlling, you know, 1000 individual fibers. Um so that there’s another way that um force can be increased. So, in this example, here, we’re gonna see um three different motor units, each motor unit um being attached to uh different muscle fibers. Um And if we want to um produce just a little bit of force, then um the brain will send a signal down to the, the spinal level saying, hey, we just need a little bit of force and it’s actually at the spinal level that uh the decisions made in terms of what motor uh units are gonna be recruited. So if the brain’s like, ah I just want to pick up a glass of water, um then uh the the, the um signal will only be sent to uh one particular motor unit and probably a smaller motor unit. So uh motor units are uh recruited in order of their size. Um So if we need a little bit of force the spine, the sides, all right. Well, we’ll just recruit um this smaller unit over here to produce uh a little bit of force. Um If now we’re going to pick up a, you know, a bucket of water and it requires more force, then the spine will send out signals to multiple motor units. So we’ll get more and more fibers contracting. If we’re going to produce a maximal amount of force, then we’ll recruit as many motor units as we can. Um And that will mean that signals will go to all the motor units. Um And the more muscle fibers we have uh contracting the more potential force that um will be produced. So there are two ways um that uh the nervous system can increase the force being produced by muscle, we can increase recruitment. That’s what we’re seeing here. So we can send out signals along multiple motor neurons, accessing multiple um motor units. Um or we could increase the rate at which we are sending the signals out. Um And it seems like um probably four or uh faster movements, if we’re say swinging golf club, um and you try to swing faster and faster, then most likely that increased force is coming from an increase in the uh the discharge rate, the rate that we’re sending signals. So the pulse is per, per second. Um And then we have a third way um that we can um the nervous system can modulate the, the force. And what’s being shown here is um uh sending uh signals um in alternating fashion to, to different uh motor units. And um that can be helpful um if you want to maintain a constant level of muscle tension um over a certain period of time. So you can see um that, hey, let’s send a signal to this smaller group of motor units first and then we’ll activate this one and then we’ll activate this one and those fibers get time to uh within those motor units. Gets time to contract and relax and recover. Um So you can see that a period of time has gone here uh gone on before that first group of muscle fibers is asked to contract again. So by now they’ve recovered and this is great for um sustaining a low level contraction over a long period of time. Um This is called asynchronous um firing. But in a golf swing, um we actually maybe don’t want that to happen. We would like all these uh to be fired simultaneously. So, synchronicity of the, of the discharge rates is important if you’re trying to produce a maximal force in a very short period of time. So that’s the, the third way that the nervous system can increase force is by synchronizing. Um when these pulses are sent um to the individual motor units um or along the individual motor units. Um So while that um probably isn’t great for preventing fatigue, golf swing only lasts about um in the downswing, in particular about a quarter of a second. So we don’t really have to worry about um fatigue um setting it if you’re holding a plank, um then this might be a strategy that would be uh employed by the, the nervous system. OK. So, um now that we kind of understand how the nervous system is able to modulate um changes for what can we do to improve our ability to do that over time? How can we improve the controller with training. Well, um but the biggest way is through swing technique. So I if we do make a change in our swing technique, um we are doing a better job of shifting our center of mass to separate over from our center of pressure. We’re doing a better job of firing our um muscles across multiple joints in a co-ordinated sequence. So we have a lower body going, stretching the muscles across the torso and the upper body goes et cetera. So we have that nice proximal to distal sequencing that that would be changing the coordinate action of multiple muscles across multiple joints that that’s happening in our brain. Though those processes in our brain before we send the signals on our muscles are deciding, hey, this is a more coordinative way to move. That’s part of the nervous system. Any change in in swing technique is, is changing how our nervous system um is, is organizing our, our actions. OK. And that’s, that’s a big one. So um by doing um multiple uh repetitions as fast as we can and having the uh the feedback with a, with a uh a radar allows that learning process to occur. Um You can think of this as um kind of uh doing the most with the amount of kinetic energy that our muscles have have generated, right. So we haven’t really changed the properties of, of the nervous system below the, you know, the brain. Um And we haven’t really um improved muscles themselves. Um So we, we got a certain amount of kinetic energy. If we coordinate our body better, we can get more of that energy out to the club. But for a given technique, we can still potentially increase the kinetic energy. So we could adapt to recruit more motor units. Um So often times when um you uh you first start to train, we’re not actually recruiting um the, the larger fast faster twitch um motor units, they’re kind of the last ones to be recruited. And often times people don’t recruit them, they need, need train to be able to recruit more motor units. So if we’re saying, hey, we actually want more force, we want more speed, then we can start to learn to, to um recruit those uh those larger motor units, ones that are um have more fast twitch fibers associated with them, we can recruit them faster. So, um like the chemical processes that um have that, that nerve being sent to the muscle, well, that, you know, requires some uh release of, of certain um you know, chemicals and enzymes in the muscle. Well, maybe we can get better at releasing those. So things happen a little bit faster. We can adapt to improve um synchronization. So um we can improve the, the the the timing of when those motor units uh fire. Um jumping back up into swing technique, we can uh reduce cold contractions, right. So, this, uh something I talked about in an earlier video, I don’t want my, um, if I’m coming down late in the swing, right. Um I don’t want the muscles that are cocking my wrist to be still active if I’m trying to release the club head, right. Holding on there having cold contractions and hands can increase that joint stiffness. Um And that’s not gonna be beneficial. So that’s something else that the nervous system can improve with. Through training, we can improve the cognitive processes within the brain. So we can learn to actually um uh do things faster. In, in the brain. Our brain is very plastic, we can increase the, the myelination. That’s, that’s um that, that allow, you know, allows um better connections between the nervous system and and allows uh conduction velocity to uh increase so that the speed with which signals are, are sent. Um So that’s the how we control our muscles. But what’s actually happening um in the muscle itself, how does the muscular unit actually produce um force? And you can see a, a part of a muscle there um shortening uh in, in that image. So I know that an action potential triggers muscle fibers to contract and shorten, you know, and within a muscle fiber, there are two typess of filaments. We’ve got thick filaments that have attachments and grab onto thin filaments and, and that causes them to slide past each other, which results in the tendon, applying force to the bone. You can think back to that um to uh pointing example in the calf phrase a few slides ago, um that muscle shortens, it applies force uh to the bone through the tendon. So here’s a little animation that’s gonna dig a little bit deeper into what’s actually happening within the muscle to produce a contraction to produce force. OK. So let’s take a look at what actually happens inside a muscle inside the muscle fibers themselves to produce force. So we’re looking at the muscles that are on the top part of the hand and that would extend the fingers. We’re gonna zoom in here to look at the uh the breakdown. So this would be the entire muscle itself and inside the muscle are groups of muscle fibers called uh muscle fiber bundles. We haven’t looked at this yet. Um We did look at some earlier slides were the individual muscle fibers, but we haven’t. Uh we didn’t see how they were actually um collected into groups or bundles. Um And some uh muscle fibers or muscle cells can be up to 40 centimeters long. Some of them might be uh a couple of centimeters long depending on the muscle in the body. And it’s the muscle fiber um cell that is um stimulated. Um So this would be the uh motor neuron that we saw um in earlier slides. And the connection to the muscle fiber is called the neuromuscular junction So that’s where the signal makes it from the nerve um into the muscle. And the muscle fiber itself is actually composed of a whole bunch of myofibril. Um So this is looking at a myofiber, this is um part of the myofibril. All myofibril are made up of these things called Sarre mares. And they’re considered the, the functional element of a muscle. So it’s, it’s within these sarcomas that the actual uh force is produced. And um these myofibril have a whole bunch of Sarro mees that are connected um in, in series, they’re adjacent to, to one another. So let’s, let’s take a little closer look at um what, what comprises a sarcomere. Um We’ve got two types of filaments in the SAR here. Uh We have a thick filament um interspersed with thin filaments. That’s what gives muscle its uh striated appearance and it’s the sliding of the thick and thin filaments past each other that create the uh the shortening of the muscle. The thick filament is called Mycin. Um It’s the one you can see with these little attachments and the thin filament is called uh acting. Um Let me back up here for a second. So that um thick filament is actually rigidly attached um at this um in the middle of the C here to what’s called the, the M line. So the uh the, the thick filament, the myo is not gonna move relative to this um M line. The uh the thin filament um is acting and it’s actually rigidly attached to the end of the circular, which is called the Z line. So, um thick filaments rigidly attached in the middle of the sarcomere. And the uh thin filament Acton is attached at the end. Uh And that’s important because that allows the, um the two ends of the sarcomere to, to move closer together um when there is a contraction. So what’s causing that um that movement? Well, you have these uh cross bridges being formed between Mycin and Acton and there’s some complicated um chemical processes going on here which which we won’t get into. Um that allows these cross bridges to bind onto the active. And you can see that neither of the minds interacting are actually changing length. But what’s happening is um one of the filaments, the thin film is sliding past um the thick filament and this is called the uh sliding filament theory. Um So this should give you a, a bit of an understanding on, on how muscle contraction actually happens within the fiber understanding. Now, what, what what happens within the muscle to produce um tension. Um We can think of ways that uh we could improve that contract on machinery with training. So um uh one of the easiest things that comes to mind is hyper, you could increase the size of the muscle fibers that the more muscle fibers we have the bigger cross sectional area, the more force that, that muscle can produce. So that could be adding sar comers. So adding SAR comers next to each other or in series, um we could increase the number of myofibril in a particular sarcoma. So we could increase the amount of actinomycin um that are in a, in a sarcoma that’s would be increasing the density. So we’ve got more contractile units within um a given muscle fiber, we could also transition within a fiber type. So we, in general, we talk about having slow twitch and fast twitch. There’s really a continuum of, of fiber types and, and in general now, it’s kind of believe that you can’t really go from slow twitch to fast twitch from type one to a type two. But you can transition within uh type two fibers. So they can become um more uh type two fibers can be more adaptable to things like the golf where we don’t really care about fatigue. Um But we do want high forces at, at high velocities. Um So from fast twitch to really fast twitch, um we can also, you know, you can also modify uh fiber architecture. So uh I didn’t get into it, but there’s within muscles, there’s um tenation angles. So the angles that the fibers are actually in the muscle, they’re not always lined up along the length of the muscles. Sometimes they are at angles and that, that can allow um um different patterns of, of force to be produced. And with training that the, the way those fibers are aligned can change, um there’s also changes in tendon stiffness. So as our muscles get stronger and we start to apply more forces through the tendons. Um those tendons will adapt and become uh stiffer, uh adapting to the, the um the forces that, that they need to uh apply to the bone. Um So again, these are things that variable inertia speed training will act upon um to increase your, your club and speed to allow the, the muscle to um generate more power transfer more energy to the bones. And not because it’s going to potentially get it to the, to the club. Um So I just thought I, I, I’d take a minute just to unders uh So you could understand the importance of, of a fiber type or motor unit type. Um If we talk about uh slow twitch versus uh fast twitch, so we’ve got different um motor units in our body to accomplish different tasks. Um uh So motor units that are mostly connected to, to slow twitch fibers would have this kind of a force velocity profile. So there’s a feature of muscle that says the faster I’m contracting it, the less force it can produce. So we can see here is that this is a, a slow twitch um motor unit, the faster that, that, that those fibers are contracting, uh the less force that, that it can produce. And I would be using a lot of slow twitch muscles right now to give this presentation, slow twitch muscles. Um, they don’t produce a lot of force that the rate at which they can produce force is quite, um, low, but they don’t fatigue very easily. So, during this entire, uh, presentation, I’ve got the muscles in my, uh, trapezius contracting to prevent my head from doing this. And they’re constantly on, they’re constantly firing. They have uh uh this constant low level of, of muscle tone, same thing with the, one of the muscles um in my, in my calf. So the there’s two main muscle groups in the cast, but the soleus and the gastric neus and they’re very, very different. The soleus is the postural uh muscle mostly. So it’s the one that’s mostly activated as I’m standing here, it’s constantly contracting. It’s composed of, of slow twitch fibers that don’t fatigue very easily. But if I was gonna jump, my body would say, hey, yeah, so at least can help a bit. But we’re going to really start to recruit the gastro anemia. That’s the muscles that form those, those balls a little bit higher up in the calf. Um And they, they have more fast twitch motor units. And so if we take a look at the properties of something that’s more uh fast twitch in more, it’s more fast twitch, we can see that they’re going to produce more force even when they’re contracting slowly um, but in particular, we can see uh that they’re able to produce forces at really high shortening velocities. OK. And that’s really important for, for the golf swing. So we want to be recruiting in accessing those motor units um, during the golf swing. Ok. And, and by um doing overspeed training, we can start to maybe tell our muscle fibers that the type two mus fibers that exist in the continuum. But hey, we want you actually to be able to, I don’t really care if you get tired, I just want you to be able to, to contract a lot, a lot faster and give me some for at, at those really high velocities. And this is really important when, when we look at this force velocity curve, you can remember that power, the rate at which the muscles uh changing the energy of the system is the force times the velocity. So you can look at the slow twitch fiber and if we want to be moving fast, its force when we start moving fast is zero. So it has no ability during really fast movements to change the energy of the system. Only this fast twitch motor unit could do that. So if we actually look at what the power profiles look like between fast and slow twitch, we can see that really if we’re trying to do anything at fast speeds, that’s why we need those, those fast twitch um motor units. And while we need to adapt our muscles to be able to produce forces at higher speeds. They don’t start out that way. We’ve got a lot of um, um genetic differences as well between people. Hopefully. Um, if you’re a golfer looking to increase your club speed, you’ve got a higher proportion of fast twitch fibers in those muscles you need in the golf line. So le let’s do a little bit of a, of a summary in terms of the neuromuscular adaptations in, in order of, of speed increase. So if you start training, start doing some sta training, what you see speed increases, what have you changed? Um uh most likely, well, and these will all overlap a little bit, but a big one at the start is changing your um percent effort. So that’s where you can really see some increases um over time, especially with, um, you know, middle aged golfers. Um they uh have developed a swing where they’re trying to control the face. Um And, you know, things get a little bit more constrained and then a little bit more constrained. And eventually they’ve really lost a ton of speed because of how they’re um they’re swinging, they’re scared to swing really hard. Um So I if, if you give them a stack and a radar, they can start to realize, well, actually I can free myself up. Um and, and actually apply more effort and then when they go to hit some balls, actually goes, oh, you know, I can actually still kind of uh kind of control this and maybe even actually a little bit better. Um that people don’t necessarily realize how important that that percentage of effort is in terms of generating club head speed. And the next biggest one would be changing the gross motor patterns and changing the swing technique. Um the order and the timing of the muscle contractions, reducing cold contractions, getting your hand path a little longer. Um timing the way that um you know, your wrist muscles are working with your elbow joint muscles to apply force to the club a little bit more. Um and, and an improved pattern to do work on the club. Um And we have the frequency of recruiting muscle fibers. So if, if, if we have improved that neuromuscular system odds are that, that we’re recruiting our existing fast twitch motor units at a higher rate. So, you know, remember that can be up to, you know, 100 pulses per second, maybe even a bit higher than that to certain muscles. Well, maybe you started with training and you’re recruiting those at 75 and then the system adapts and all of a sudden, you’re able to start recruiting at a faster rate, probably because you’ve been training with swinging things that are a bit lighter than your, than your driver. Um or we could also recruit more motor units, more motor neurons. Um And we would try to target that by swinging things that are slightly heavier than your driver. So we’d add more weight um to the stack. And that with the system would say, hey, you know, we’re still trying to swing really fast. We could use a bit more force. Well, um maybe we should try to recruit this more unit that we haven’t really um fired up lately. Um And then uh these, these processes take longer um to occur. We we would get changes in the of the architecture of the muscle. So the number of sarcoma is the density of the uh myofibril within a sarcomere, the penna angle. So the the the structure of the muscle and changes in, we didn’t get into this very much but changes in the histo chemical properties. So that’s how they, they identify certain um fiber types in particular. They want to know, well, how much of this chemical or what, what is the, the, the, the chemical makeup of these uh these fibers that we, that we’re looking at? And can we change that? Can we get, give them different uh different properties? Um We make a fast twitch motor unit become faster based on its um hist chemical properties. OK. So our system will adapt to, to change that if we apply the uh appropriate stimulus. And that’s where variable inertia speed training is so important because we’re, we’re doing things that target number one and number two, right? Because we’re making a very similar golf swing, but then we can also manipulate the load of the stack um to target those different elements that were just listed. So variable in initial speed, training is commonly referred to as overload or overspeed. Training move is nearly identical to the in competition skill. So swinging, the stock is very similar to swinging the driver with the overload stimulus. We’re uh we’re trying to increase the force that the, the muscle is producing mostly. And then with the overspeed, we’re trying to increase the rate at which that force has developed or how fast those muscles can maximally. Um And, and by by knowing what is required, what is the speed and the force is required from a driver? Ok. And that’s gonna be based on the inertial properties of the driver, then we can come up with an implement that will a appropriately stimulate the golfer for either overload or overspeed. So if we take an implement and we increase its mass, so driver weighs three point if we make the implement heavier and keep the other properties the same, that’s going to create an overload scenario if we keep the same mass and we in, but we move the center of mass further from the hands. That’s at 83 centimeters. Show here we get an overload scenario. If we increase the moment of inertia of the implement, that’s gonna create an overload scenario. So with the stack, we could load on 280 g on the end here. And that would create an overload scenario um where it’s heavier, the center of mass is further from the butt end and it’s got a higher moment of inertia. And so in this uh uh with this condition, we might be trying to stimulate the body to uh activate uh more motor units as an example, um in an overload scenario, or we could load it up with 20 g and reduce all of those properties. And now we’re swinging it much faster and now we might be training um increased conduction velocity or, you know, making the system adapt to increased conduction velocity or the rate at which we’re um activating um those motor units as an example or even within the muscle architecture itself, is there certain um chemical processes can allow those cross bridges to um uh go through their cycle a little bit faster over speed condition. And so uh we’ve developed the, the stack to um have a very fine resolution and adjust with the golfer. So uh we, we want that stimulus to be appropriate for them. So as you change your speed and strength, we’re, we’re getting that feedback from the greater information you’re providing the app. And that’s gonna allow us to figure out which of these speed training options we’re gonna tell you to um use um in your next uh your next set. Um And it also allows us um all those speed training options also allows us to come up with AAA specific program initially um for, for you to, to use, for the golfer to use to, to maximize those speed gains to get that stimulus just right. So on the screen here, I’m showing um Andrew Putnam’s data. Um If you look over here, you can see um what we’ve done here for an initial baseline test. So every golfer goes through a baseline test with the stack where you swing your driver. Um This is without a ball and initially without a ball, people tend to be a little bit slower. So I’m sure that’s um what, what was the case here with uh with Andrew? But then we want to know, hey, how fast do you swing things that are heavier than your driver? So here’s uh 280 g right here and he was swinging that at 84 MPH. Um And then we, we, we change that gradually go up to things that are a lot lighter than your driver. This gives us a forced velocity profile to help us understand which of those factors in the neuromuscular system. Do we need to, to target the most to improve your speed, the most efficiently with the least amount of effort? That that’s what’s gonna help us design the program. And so after six weeks, so the, the app said, hey, here’s a great program for uh for Andrew. Um in terms of when he should be working out, rest, how much weight we’re adding on how many uh sets he should do, et cetera. And six weeks later, you can see that, um, he’s improved across the board uh with all those weights. So this is a progress check that the app will do. It’s um, exactly the same as the baseline. So everything’s controlled. So it, it makes it um nice and uh comparable, um, same number of swings, same rest, everything’s identical. And we can see that in just six weeks, he’s uh uh really jumped up. Um His, uh his driver speed, I should say that each of these bars is the uh the median of multiple swings. Um So, um it evens out any, um any discrepancies that might exist in, in the radar, the drivers swings are actually 10. Um So we’re pretty confident in those driver speed numbers. So it was a pretty big jump over six weeks. Um So what I’d like to do now is to um take a bigger look. So we’re talking about, um, you know, neural mechanics and, and how we can increase speed by changing our neural mechanics. We know a little bit about the muscles and the nerves and I talked a little bit about training. What, what does that look like for a person across our lifetime? What does training to increase club speed look like for a golfer? Um You know, the during their entire playing career. So let’s take a look at, um, uh, a male golfer. They’re scratch, they’re 62, pretty athletic, you know. So they’ve got a reasonable amount of fast, which for example, what does their club head speed look like? Um, over the years. So starting from when they’re born here, zero, no speed when you’re zero. And then we’ve got it all the way up to 80 this individual we’re gonna say has done no special training whatsoever. They, they played a little bit of golf throughout their life, but let’s say that, ok. Um, and so we can see that, you know, when they were 12, they were swinging at 80 MPH and just through natural growth and development and a little bit of improvement through playing golf. Uh, by the time they hit 23 they’re swinging 100 and 60 MPH, that’s pretty fast. They might think, hey, I’m doing great. This is, you know, this is my, um, my potential, you know, and then, hey, age, uh, starts to, uh, take over, unfortunately. And by the time they hit 56 they’re down to, um, 100 MPH. So this, this is the general pattern that we would expect to see for pretty much, um, any human swinging a golf club, right. Eventually we’re gonna get slower. Um, but, you know, as we grow up from being a child to adult, our speed increases, right? Um, this is the general pattern peaks may be different. The rated increases and rate decreases may be slightly different. But this is the, this is the pattern. Um And a lot of this data comes from um uh tracking people across our lifetime. And also um cross sectional data looking at at, at um different users within uh the stack up. We’ve got about a 5, 5000 users now um taking a lot of swings um and their ages range from, from eight to over 80. Um It’s helpful to understand what would be this golfer’s theoretical maximum. So what if they optimally train for clubhead speed their entire life? What would their clubhead speed look like across their lifespan? So that would be this, this red curve here. So if this exact same person with their exact same genetics, this male golfer, 6 ft two and athletic, lots of fast twitch fibers if he trained off in his entire life and he would reach a peak of 100 and 38 MPH um at the age of 27. Ok. But he’s still following the same general pattern. He’s still susceptible to, um to the, you know, old man time, I guess we could call it right. But we’ll notice that because he’s been training his entire life. Hey, he’s gotten a lot faster, you know. So at age eight, he’s quite a bit fa or age 12, he’s quite a bit faster and he’s definitely really faster when he gets into his um, early twenties. Ok. And really what we’re doing when we do, um speed training is we’re kind of moving between this blue and red line throughout our golfing career. We can never exceed that red line. That, that, that red line is a theoretical maximum that’s just limited by our genetics. So, um as an example, um this would be Kyle Berkshire, right? So he’s got a much higher um uh potential based on his, based on his genetics. And he’s also been working really hard. So this might be his profile. He optimally trained for increasing club speed since he was born, say with a 45 inch driver. Um you know, he might peak around 100 and 60 MPH uh at the age of, at the age of 30 we’ll see. Um he’s very close right now. So obviously, uh I’m guessing with uh the height of that curve, but genetics are determining whether you’re gonna be that red line or that, that blue line. OK. And obviously Kyle Berkshire with special training would probably be at the red line or maybe even a little bit, a little bit higher. So we’re bouncing around between where we’re at now and where a theoretical um maximum would be at any point in our life. So let’s, let’s zoom in here. So you can see this uh X axis covers everything from zero up to 100. We’re gonna zoom in now and we’re just focusing on starting at age 20 we’ve got the same curves. OK. And now the uh the speed starts at seven years just so we can get a little bit better resolution. So these are the two curves that we’re gonna be bouncing around in between. So let’s say that um this individual um instead of just doing no special training through their entire life, they start stacking um at, at age 50. So those curves would overlap all the way to 50. And then if that optimal training commenced at 50 this is what the curve would look like. So the couple of things that you’ll notice is that, you know, over the course of five years, say from 50 to 55 they’ve really gained a ton of the total speed they’re gonna gain. Um by the time um you know, they’ve reached that flatline portion and, and age is just um taken over, right? So, um the other thing you can uh notice is that um you can certainly get faster from your current speed um at any age. Um There’s a lot of room, you can always move back up towards that, that theoretical um optimal. Um We also noticed that you never reach um where your uh full potential was. So there’s things that can happen um during our development, there’s changes we can make in our body that we just can’t make um as we get older we’re just not quite as plastic, still plastic, we can still adapt, but there are certain things that we can do when we are, um, developing, um, as a child that can lead to higher potential later on as adult. It doesn’t necessarily mean that we’re specifically doing golf stuff. It could just mean, hey, we did track and field, we did some gymnastics, um, whatever we did, the, the way we use our bodies can, can influence. Um um what happens later on. Um So, uh this would be if they started ultimately training um at 50. So now, uh it looks like they’re, they’ve taken them, you know, uh by the time they get to their about 60 they’ve really gained um a ton of speed um relative to if they had not done anything. So what would happen if they started training when they were 30? Well, um the rate at which they can increase their speed, that might be a little tougher to see, but the rate at which this line is increasing is a bit faster if you start at 30. Um you’re also gonna get a little bit closer um to that, that theoretical maximum. OK. Um Let’s, let’s dig down even further. Let’s take a look at this kind of 10 year period when these speed changes are, are occurring. So we’re kind of zoomed in here now. So we’re just gonna, that x axis is now gonna be between uh 3040 years next year we’re gonna look at between 3035 we’re gonna zoom right in. Um, so this is that 30 year old, there’s their, um, what, what their speed would be if they were often training, this was their speed if they really didn’t do anything. And we can take a look at a little bit finer resolution and, and, and I’ll mention this in a second, but this is, uh, you know, really their speed fitness. We’re, we’re kind of ignoring the, the day to day fluctuations. That’s where this curve looks nice and smooth. But we can see that after, uh, one year, this person’s gained nine MPH, that’s pretty impressive. That, that’s, that’s really gonna change your, uh, your golfing. You go from, uh, your golf game, you go from 100 and 15 MPH up to 100 and 24. Uh, uh, the golf course is different and that’s over the course of a, of a year. Ok. So you start training in June and next golf season, uh, you’re a completely new golfer, but then after the second year, yeah, you’re still working, but now you’ve, uh, you’ve only improved an extra five MPH after year three, you’ve only gone up two MPH, ok. And this is just the, the, the general principle of what’s called accommodation, um, with, uh, biological structures like us. Ok. Um, we just, um, even though we continue to apply stimulus, we can, based on our genetics, we can only continue to adapt at a certain, at a certain rate. Um So what, what are the sources of these increases? Well, let’s reflect back and think of those things that I talked about in terms of what’s changing in the neuromuscular system to improve speed. So, you know, during that first year, we’re learning to uh actually swing with a little bit um more intent, um We’re able to apply a higher percentage of our maximum effort. Um We’ve become more coordinate, that would be a huge part of that jump. So we’ve improved our swing mechanics. And then during that first year, we also have improvements to the other groups in our muscular system. Like we’re recruiting more and more units, we’re recruiting them faster. Um And some changes in the muscle, um when we get into uh year two and, and this the, the speed gains start to get a little bit slower. Well, maybe our mechanics are now improving a little bit. But, um, you know, we don’t, we don’t have these big uh low hanging fruit changes in, in the way we’re swinging if our hand path is getting slightly longer, stuff like that. But um it’s probably more down to now the muscle architecture stuff. So we’re, we’re starting to change the actual structure of our, of our muscle. Maybe we’re doing a better job of recruiting um, more motor units, maybe we’re slowly transitioning our fibers a little bit. Um, and then again, the, the, the, the places where we have left where we’re left to adapt, um, get, get smaller and smaller and, and those games become harder and harder, we have to, you know, put in a bit more time, we have to, um work a little bit harder. The sessions become longer and we’re seeing um, fewer and fewer uh returns on our investment. Ok. But is it worth it? So now this golfer started training when they’re 30 when they’re 35. If they can do any special training, they’re, you know, down around 100 and 13 MPH. But if they put in that time, trained ally, they could be up around 100 and 32. Now, in reality, if we reflect, uh, with just say, stock training, um, you know, maybe this is taking you hundreds of hours a year to maintain this yellow curve. But if you just did some stock training, um, and it wasn’t hundreds and hundreds of hours. Um, yeah, your rate of increase may be a little bit lower and maybe take a little bit longer to get to the peak and maybe you don’t quite reach it, but it might be a much more efficient use of your time. Maybe you don’t want to be a long drive guy, but maybe, you know, PGA tour players are, are an excellent example. They do not have the time to train to follow this yellow curve. A long drive guy. It would be the representative of that yellow yellow curve PGA tour player has to spend time p they have to spend time playing. They’ve got a family, they should still put some time into speed training. Where should they put that effort? Um Is a great question. So we want to be, I think very long speed training is probably the most valuable. So we wanna get as much increase in club and speed as we can, but we also want to do that with this minimal time required. Um And, and also maybe minimal um chance of, of uh of incurring an injury. Sure. Now, what would happen if that male scratch golfer that was 6 ft two athletic and fast twitch? What, what would happen if we replace that with a male scratch golfer? But now they’re 56 and a little bit more awkward. Ok, awkward is, but they’ve still got more slow twitch motor units. So what, what does this look like now? Well, if this golfer now is no longer the 6 ft two athletic, lots of fast twitch individual. Um So in order for this uh slower twitch, more awkward golfer to be at 100 and 50 MPH in the 30 only drop to this level in the 35 they must have done some training because they don’t have the same genetics as the taller faster twitch, uh individual with no training. So in order to be at that level, they must have done some training. So I’m gonna say that they’ve done some high school track, you know, maybe even some university tracks, they did some sprinting, they did some uh javelin throwing, maybe. So they, they’ve already seen some improvement that move them up towards what their theoretical maximum should be. But remember that that red line is 100% determined by your genetics. So we’re assuming that that that’s the only other thing um that’s different with that red line. Everybody was optimally trained. Uh We’re not all gonna get to the same level club speed. Why not? Because our genetics are different. So this uh slow twitch golfer, his ceiling is gonna be a lot lower. It’s gonna be down around here. Well, and we can only that yellow curve has to bounce around between where we are and where a theoretical mass it can’t exceeded it. So that yellow curve no longer makes sense. So the yellow curve is gonna look something like like this if that individual started training at 30. And so when you start to do speed training, if you jump on the stack, you really don’t know where your red curve is initially and you really don’t know. Well, how conditioned am I already for swinging fast? What is the gap? We don’t know where that red curve is and we don’t know what the gap is between where you’re starting and where that red curve is if that, if that makes sense. Um, but because we’re taking all sorts of data in with the ST gap, we can start to figure out, well, we gotta get a pretty good idea of where you are based on, um, the rate of your increase. So you can see that this golfer isn’t gonna increase at the same rate as the other golfer. So now after that first year, they’re only gonna gain seven MPH and maybe after year two, only two MPH. Ok. And year three, they’re down to one mile per hour. Ok. Um, so when you’re comparing yourself yourself to other golfers or looking across golfers, some golfers would see massive jumps in club and that’s because they could have had terrible swing mechanics. Um, and they made some really big improvements with the radar feedback. They were completely on train but had a ton of potential, um, versus someone who’s maybe already done a little bit of speed training is already starting out, um, with, you know, not great genetics. Ok. But regardless of who you are there, there will always be this, this potential uh for improvement and to get up to your, uh, as close to your theoretical maximum, um, as you can as efficiently as you can. Um So now let’s, let’s, we’ll jump back now to the, um, uh, 6 ft two fast twitch individual Ok. And we’re gonna zoom further in on that, that first year. So, what does that training look like? Um, during that, that first year? So now we’ve zoomed in and we’ve gone from 30 to 31. So, uh, this would be after, um, we, we’re down to like 30.5 would be six months of, of training. Right. Um, and after that first year, they’ve increased about, about nine MPH. So, kind of flipping the purpose of why I’m showing you this is to, to understand, um, uh, fluctuations in, in the speed you might see from, from day to day. So, what that, that, um, gold line really is, is what I would call your, your speed fitness. Ok. And this is a, an underlying property that you, that you have, that, that may or may not be realized on a given day. So, right now, if I step out, um, I’m not particularly warm, um, I warmed up. So if I was to take a maximal swing here and try to take a natural thing, I probably hurt myself. I might get a reading of 90 MPH, but I know I just did a stack session yesterday and I’ve got 100 and 95 g loaded on here and I swung this at 100 and 40 MPH. So that’s more reflective of my true speed fitness when I’m warmed up, had a lot of sleep. Um, right. Now that, that number that I would generate that 90 it’s not a reflection of my fitness. It’s a reflection of what I would call, um, what’s been called, uh, Zato. He’s done a good job of explaining the stuff. Um, your, uh, preparedness. Ok. So your speed preparedness. So that speed dropping down to 90 MPH isn’t a reflection of my fitness. It’s a reflection of, I’m not prepared, um, to swing right now and, and, and preparedness could also be because maybe yesterday, maybe I do warm up and I’ve had a great night’s sleep and I swing, I feel great. Everything’s good. Yesterday I hit 114 and today I swing and it’s 110. Um, and I feel like I’m sweating and I feel awesome. God, why am I not getting to that 114? Well, that’s still a function of my, uh, preparedness. So I’m still recovering potentially from that workout yesterday where I hit 114. So I’m warmed up, had a good night’s sleep, all those things. But I’m, uh, I’m still recovering the muscles that muscular systems that are trying to adapt to improve, to improve my speed fitness have been kind of, you know, um, they, they’re recovering from yesterday. Ok. So we see these fluctuations in speed speed is, is sensitive. And, um, uh, you have to realize that if you’re gonna gain nine MPH over the course of a year and, and you’re looking at say, um, stack training for a six week program, 18 sessions, there’s gonna be a lot of fluctuations um, from, from, from day to day. So let, let’s take a look at what, what that might look like. So this is, um, uh, Andrew Putnam’s, um, data and we can see that this is across 18 sessions or about six weeks and we can see that the actual speed fitness is, is massed. It’s, you know, it’s massed by your, your current state of recovery. Um, so we can see right away, uh, Andrew’s gone from, you know, 103 and he had a big jump all the way up to 111. So that was probably, um, percent of max’s effort was a big factor there. So swinging without a ball and I’m not really sure, I’m super comfortable in that first session. The ball is not there. Um, I’m gonna start slowing down before impact so that, um, you know, I can make sure I can handle the momentum in the club. Ok. Then he comes to the next session because he’s taken a whole bunch of swings in the first section and he’s like, oh, hey, I can swing harder. I can still slow it down. And we see this big jump to 110. But now maybe, um, you know, if we see that, that, that, that drop in the next few days because he’s swinging really fast, that’s really stimulated. His, his, his body the, the processes in his body that are not gonna say, ok, well, hey, you want us to swing this fast, but I don’t wanna use the word damage, but they’re starting to recover. Ok. So we see this drop in speed in sessions 34 and five. But then now he’s recovered from that. Maybe he’s had a good night sleep as well. He’s really warmed up. He’s learned to um swing with maximum effort and maybe some of the swing mechanics have improved and boom, we see another big jump up to 115. Ok. Remember each of these bars, um, is the average of multiple swings. So we’re not really getting variations, um, in, in radar here at all. This is true variations in um, speed preparedness, right? So underneath here though, you would have a line, let’s see if I can, uh, see if I can draw a line on here. Red line. We would have a line so that this line that’s jagged going up and down following the bars would be the speed preparedness, but we would have a speed fitness that’s actually probably starting higher than we would have, um, shown there. You know, this might be the speed, um, fitness. OK? And things like the amount of sleep you get uh your warm up level, other physical activities, pre workout, um, your level of caffeine intake variations in swing mechanics. Um, you know, so that you, you could be a little tight maybe it’s left a little fun, even though you feel great, you’re not aware of it. Maybe your hand path length isn’t quite as, as long. So, I hope you enjoy the, that presentation on the uh neural mechanics of increasing club speed. Thanks

Biomechanics Transcript

OK. I would like to discuss the biomechanics of training for clubhead speed. Particular look at the variables that occur during the golf swing such as the forces the golfer applies to the club, the forces that the golfer applies to the ground and how fast we’re moving the golf club in order to better understand how we can design training programs to increase the club head speed. So first, let’s take a look at a framework for increasing clubhead speed. Ok? We have to understand what variables influence other variables that will eventually influence clubhead speed. So I’m going to show what’s called the deterministic model. Here, we’ve got driver clubhead speed up at the top and driver clubhead speed is going to be almost completely determined by the energy that’s delivered to the club from the golfer. Ok. And it’s also going to be a little bit uh determined by driver specifications. Ok. So first I’m going to show an outline of this framework and then we’ll dig into each little piece um a bit more so you can understand a little bit more about what I’m talking about. So what determines the energy that the golfer can deliver from the deliver to the club that depends on swing technique and the percent of maximum effort that they are using. And now we can take a look at, well, what determines swing technique. We’ve got physical training as an option. And also driver specifications can influence swing technique. Physical training can also influence a percent of Mac’s effort. So let’s take a look at these a little bit more closely. But, but first, I want you to understand that that for sure, the things that are on the bottom influence, the things are at the top. So we have this hierarchy. So we can understand how the variables will, will interact. So in particular, what do I mean by energy delivered to the club from the golfer? Well, we can further break that down into four things. OK. So in order for the golfer to change the energy in the club, they need to do work on the club. And these four things that you’re seeing on the screen now, a hand path length, the force along the hand path, the amount of club rotation and the torque that’s applied throughout that rotation are the four things that will change the golfer’s club head speed. So I’m going to use a simpler analogy instead of talking about the full golf swing here for a second, imagine that we’re going to try to increase the speed that this head is moving when it hits my hand. OK. So we could increase the length that my hand path is traveling before it gets to that point. So let’s say if I started here and I applied some force along this distance of my hand path, you can see my hand is going to travel a certain distance, right? So let’s say I move the club that distance. So I’ve got a certain length of hand path. Well, what happens if I increase the hand path length? But I apply that same amount of force but over a larger distance. So my hand path length is going to be a bit longer and I’m going to get a little bit more energy delivered to the club a little bit more speed in the club head by increasing the length of the hand path, I can also increase the force along that hand path. So I can keep the length of the hand path the same. But in this example, I’m going to now increase that force but over the same length of hand path and that’s going to give me a little bit more club head speed. OK? Or we could think about rotation. We also have rotation happening in the golf swing. And it’s important in terms of changing the energy of the club. So and the full golf swing is a little bit more complex than what I’m demonstrating here because the rotational motions are blended with the linear motions. But I’m going to separate them here because I’m grabbing this club at the, at the center of mass. So what do you mean by an amount of rotation? Well, I could, if I want to use some torque to change the amount of energy in this club, change the club at speed, I’m going to try to rotate it through a certain angle. So let’s say I keep the torque that I’m applying constant. OK. But what I’m going to do is I’m going to increase the length of rotation. So I’m going to increase the amount of rotation. So I’m all the way down through 90 degrees. I’m gonna keep the torque the same. But that’s going to give me more clubhead speed just by increasing that angle of rotation. But on keeping the torque the same. So on the big rotation, add more rotation, I get more club head speed or I could increase the torque that I’m applying over that angle. So I could have this for an angle and I could apply a given amount of torque. I’m gonna keep that angle the same and say double the torque, then I’m gonna get more clubhead speed. Ok. So those four things, the hand path length force along the hand path, the amount of rotation and the torque applied around that rotation will determine the energy that the golfer delivers to the club. So what does that look like for an actual golf swing? Well, we can literally think of a trace that’s being arced out during the swing during the downswing, in particular of a point in the middle of my hands as representing hand path length. So if I wanted to increase my hand path length, I could perhaps lift my lead heel off the ground, turn my pelvis a little bit more, get those hands a little bit higher in the air. Ok? That those are things that are going to increase the length of my hands, the hand path on the downswing, OK. If I wanted to increase the force along the hand path during the downswing, then maybe I could just apply a little bit more effort. Maybe I could have a better transition sequence, making sure that my lower body is going before my hands start down. Those things can improve the, the force along the hand path. And when we’re talking about that rotation angle, it’s literally the angle that you can see face on that this club is, is making. So this wouldn’t be as much rotation in the downswing as if I got to shaft parallel or we could be like a long drive guy and get that club all the way around here. That would maximize that rotation angle. And you can think of the torque as the pushing and pulling between the hands, the forces across the shaft. We talk about the torque that the golfer is applying to the club. That’s predominantly what we’re talking about. The pushing and pulling within the hands So that’s, that’s a deeper look at the four things that the golfer can do to change the energy in the club. Ok. Um So if any type of swing technique is going to increase clubhead speed, it must have an influence on one of those four factors. So if you’re thinking about improving the ground reaction forces leading to an increase in club head speed, it must influence one of those four factors. Um segment sequencing and transition center of mass motion. Um Even things like grip, posture and stance with all those things are going into swing technique when I’m considering swing technique, um and they will influence the amount of energy that the golfer can deliver to the club. Um We also have driver specifications, influencing carpet speed and that’s things like the shaft length, the shaft flex and the mass of the club had the shaft and the grip and also the aerodynamics ping’s got some great turb designs to uh increase club speed by a couple of MPH. Um Something else that will influence the energy delivered to the club from the golfer is percent of max effort. So even given a certain swing technique, if you choose to swing a little bit harder, you’re going to see an increase in the amount of energy you’re delivering to the club. So you can think of it as a fraction of max speed potential given the current neuromuscular capabilities and swing mechanics of the golfer. Ok. And related to this is, is intention. How fast are you trying to swing? Now, those things are kind of separate because you could, early in training before you’ve done some physical training. Um, or maybe you’re not used to explosive sports, you might perceive yourself to be, uh at a really high level of your max percentage of your maximum effort. Um, but actually you’re not, so it’s not just about intent, right? You could be intending to swing as hard as you can, but you haven’t quite tapped into those research and learned how to swing at a high percentage of your maximum speed yet. Um And what we’re going to focus most on uh in this uh presentation is physical training. So uh things like um lifting weights, throwing medicine balls, flexibility and mobility training, speed drills. Um But in particular, we’re gonna look at uh what I’ve called, uh what I’m calling here is variable inertia, speed training, ok? Um You may have heard of it as overload or overspeed training and we’re gonna look at how the biomechanics of that, the physics of that um can, can and should influence um how we dream. So, uh variable speed training is commonly referred to as overload and overspeed training. Um The training movements when you’re doing uh overload or overspeed training are nearly identical to the movements that you perform. Um in the competition overload, training um will increase the force stimulus while overspeed training increases the speed stimulus. That’s gonna be a focus to me. We, we really want to understand what should the stimulus be that we are trying to influence um, through our training. Ok. So, um, this, this concept of overload and overspeed isn’t particularly new. It’s been, it’s been done a little bit in golf before we’re just gonna refine it a bit and, and let’s take a look at some to have a better grasp on the, on the concept. Let’s take a look at some, some other activities. So, um it’s, it’s been commonly done in, in jumping. So if we were to do, um, um look at a, a jumping study um and try to or some jump training to increase jump height and we’re looking at the over concept of overload, we’d be thinking about um using a weighted bar, a weighted vest, um, bungee tied to the floor, um, or like Markovic has done here. Um You can see there’s a pulley system set up, uh where that, that tension in the pulley is actually pulling the, the jumper down or we could look at overspeed, we could use a horizontal sledge which I’ll show in the next slide, an overhead pulley or an overhead bungee. So you can see in this example, Markovic has the pulley set up now, so that it’s actually pulling up on the jumper, ok. So actually making them a little bit lighter if you will. And actually in their study. They found that both overload and overspeed training can improve jump pipe to about the same degree. But the mechanisms underlying mechanisms why these athletes improve their vertical jump pipe are slightly different. So they found that uh you know, we’re not really targeting the same things. Why it’s important maybe to, to look at both overload and overspeed training in golf. Um Here is an image of that horizontal sledge. So um when we’re jumping, gravity is constantly pulling us down, that’s, that’s increasing the work we need to do to jump. It slows down our jump. If we want to do over speed training with jumping, we could lie horizontally and now we don’t have gravity slowing us down. So we’re able to generate higher, higher speeds while lying on our back a little, little bit more, more awkward of a, of a jumping motion um with something lying against her back. Um Very common in sprinting overload and uh overspeed training. That’s my background is in track and field. So I’m familiar with implementing these um these techniques both as a coach um as as and as an athlete. Um So overload training, uh you could be towing a sled, pulling a parachute. Slight uphill running is very common. Uh Jamaican athletes use this uh quite frequently um or overspeed where you get uh pulled by a pulley system, um pulled with a part partner on a bungee. You could be doing slight downhill running um or uh running with a car on a windscreen. So here’s an interesting um uh video uh of Marcel Jacobs the 2020 Olympic 100 m champ. Um and he has this car um in front of him that is reducing the, the drag force from the air. So he’s actually able to do some overspeed training by removing that drag, ok? And it’s, it’s important that you, that, you know exactly how you’re manipulating those forces so that you know, what are the, the speed you’re trying to attain or the loads you’re trying to attain the body to get the best training effect. Um So if we’re looking to overload and overspeed training in golf, um it’s slightly different than, than sprinting and jumping where we can have external forces uh applied to us like pulleys and bungee and, and reducing uh air resistance. Um The nuances of a golf swing are such that it makes it difficult to, to have lo loads of changing loads applied to the body, something that could make a swing faster even um slows down a bit. Um So I’m showing uh Robo Golf Pro here. Um So currently it’s not really practical for something like that, an external device to, to increase the speed or low during the swing. Um maybe in the future with a really um advanced and, and fast feedback loop. Um We, we could make that uh become a reality, but right now, um it’s not really an option. Um And, and that’s where we have variable uh inertia speed training. Um And that’s uh that’s what we’re going to talk mostly about today. So, um, overload and overspeed conditions are met by varying uh club inertia. And I’m using that as a blanket term. We’re gonna dive a bit more into what I mean by um club inertia in a second. Um So it’s, it’s essentially swinging a club that is weighted differently from a driver. Um So the overs stimulus overload stimulus that we need would be increased forces across the shaft early in the downswing. Ok. So, in transition, uh we’re applying forces across the shaft, but sometimes people need a little bit, a little bit of an improvement with. Um So we would like to see some form of that overload training that we do. Um increasing that pushing and pulling force that we apply to the shaft early in the downswing. Um increased force along the shaft, you can think of pulling, pulling the grip off late in the swing. So for um you know, PGA tour player swinging a seven iron at 100 miles an hour that seven iron is going to be pulling on their hands. They’re gonna be pulling on the seven iron through impact with £110 of force. So it can be helpful to train with slightly higher loads than that so that we can improve our ability to apply those forces with overspeed stimulus, we need essentially increased grip angular velocity during the whole downswing, but in particular through impact. So what do I mean by angular velocity? Well, that’s how fast this angle is changing. So you can see that that club is rotating through an angle. It would be nice if I could swing something that had that shaft rotating faster than it normally does. Um during an actual swing, that’s going to provide the stimulus that I need to improve my club at speed with the driver. And changing the inertia of the club is the best way to meet these criteria. So there are three inertial properties. When I say the best way to do that is changing the inertia of the club. There are really three inertial properties that we can manipulate to allow us to either increase the load or increase the speed that we’re we’re swinging. So let’s first take a look at a driver. Ok. And a typical driver has a mass of about 320 g and the center of mass would be about um 83 centimeters from the butt of the club. And that’s going to give a moment of inertia of about 3000 kg times centimeter squared moment of inertia is just the resistance to change in angular motion. So the mass of the club is a resistance to change in linear motion if I’m going to try to move this thing in straight lines the weight of it is is resisting changes in linear motion or the mass. But the moment of inertia is what resists changes to angular motion. OK. So if I really want to increase or decrease the speed that I’m rotating this at that is influenced by the moment of inertia. And since we want to both change the linear and anglo motion in the club, both of those variables are important. And if you’ve ever done any um club matching, a common way, I’m showing this about the button, the club a common way to measure that with an auditor speed match um mo I machine. Um So this is what a driver looks like, but we could take um the stack to speed training systems while I’m holding my hand and we can change the weights on the end to create um different stimulus for the golfer. OK. So here’s a stack with 280 g loaded on the end. Um And if that’s the case, if I load 280 g at the end of this, then what I’ll get is a mass that’s 480 g, a center of mass location that’s 85 centimeters down from the butt and a moment of inertia about the butt that is 4000 kg times centimeter squared. So all of these three things create an overload scenario for the golfer. So with 280 g loaded on the end of the stack, they’re going to see a higher torque and transition and they’re going to see increased force along the shaft through impact. Um Essentially anytime you see an increase in mass center mass location, that’s further from the hands or an increase in moment of inertia, those those are gonna tend to increase the load that’s being applied to the golfer. To the contrary, we could take the stack and load on 20 g. These are the stacks, this un screws and we can manipulate the weights on it. And with only 20 g on the end, um that means that the whole stack is only gonna weigh 240 g. Uh The center mass is gonna be much closer to the hands only 68 centimeters down from the, the butt of the club. Um And it’s going to have a much smaller moment of inertia with the insult, those three inertial parameters are going to set up an overspeed situation. So the golfer is going to be able to attain much higher shaft angular velocities and get that stimuli over speed stimulus that’s needed. Um So with the ST a system, we’ve got up to 30 speed training options depending on the um the weight configuration on the end. And each of those speed training options is gonna manipulate the mass center of mass and, and moment of inertia. Um So what are the mechanisms? So I mentioned with Markovic um that uh even though you do that one isolated study, looking at overspeed, jumping versus overload, jumping, um Both show an increase in, in jump height. Um But if you dig in and look at what changed with the way they jumped, um or you know what was different from the way they power their jump, you can see slight differences hinting at, hey, these types of training are, are working on different mechanisms. What is improving in the body that allows them to jump high. It’s the same for golf. So with an overspeed training mechanism, we’re, we’re trying to get the neuromuscular system to operate at a faster rate during the swing. So things like reducing antagonistic agonist, cold contraction. So what do I mean by that? Well, um the muscles that I use uh in the back swing, um I do not want them on for the most part when I’m making my downswing. So the muscles that would cock the wrist, ok. If they’re active while I’m trying to un cock the wrist, then that’s going to slow down. Um The the club head speed that I’m trying to generate. If I have muscles in my torso that are, you know, that rotate me in the backswing direction, I don’t want those activated at all or very, very little when I’m trying to rotate in the down swing direction and that’s going to slow things down. So by doing some overspeed training that’s going to allow me to adapt and and, and, and reduce those, those co contractions. Um we also faster nerve muscle communication. So if, if, if we’re telling our system, hey, we’re trying to swing this uh this object faster and faster it will adapt um to allow um faster communications from, from the brain to the muscle and then even faster contractions within the, the machinery of the muscle um itself. Um And in a separate presentation, I will talk about um muscle physiology and a little bit deeper on what’s actually happening there with the, the muscle machinery. We also train mechanic, mechanical receptors um to allow us to swing faster. So we’ve got regulators in our system that are trying to prevent us under normal circumstances from becoming injured. So, hey, when we first start to, to try and swing as fast as we can, our body is like, well, we’ve never done this before. Maybe we’ll injure yourself. So let’s start sending signals to the brain to deregulate, to down regulate how fast we’re swinging. So as our conditioning improves with overspeed training, then we can start to tone down those signals that are, that are telling us, you know, hey, pump the brakes, we don’t want to pump the brakes, we want to swing faster. And so with overspeed training, the stimulus is speed and that’s directly measured with the radar. So I can I know that, hey, if I’m swinging my, my driver um at 100 and 10 MPH. Um, and, or, uh, maybe in this case since we’ll keep the same line. So if I load 195 g on this stack, it’s, it’s gonna have about the same speed as my driver. Um, accounting for the fact that it’s shorter. So if I take off 100 g of that’s, and I’m left with only 95 on there, I’m gonna swing that a lot faster. Um, and I’m gonna be able to tell, hey, look, the radar is telling me now that I’m swinging that at 120 miles an hour. So I know that I’m getting uh speed stus it’s directly measurable from the, from the radar. Um And here is um uh participant in uh some of the research that I’ve done, this is um Eric Banks Canadian tour player and this is a uh overspeed condition and you can see he’s got very little weight loaded on the stack standing on a couple of force plates. And in that case, he swung that at 135 MPH. So this was research, this wasn’t actually part of his training. This would actually be likely a little bit um fast to see an optimal training benefit. Um Then we have overload training mechanisms, they’re going to be slightly different. Um So it’s gonna hopefully train the system to generate higher forces, but still, while swinging as fast as possible, this is, is different than than lifting weights really heavy weights because even though our intent, maybe if we’re trying to train between, we’re lifting heavy weights is to move things really fast. We actually aren’t getting those muscles to move as fast as they can. So, um, uh with overload training, um when we swinging the stock, we want slightly higher forces. Um, but we still want to be moving as fast as possible. So we might increase the number of participating uh muscle fibers. We only have so many um muscle, uh fast twitch, muscle fibers in our, in our body. And we probably want those to be firing while we’re swinging. But maybe if we, if our system says, hey, we need a little bit more force, we’ll start to recruit um motor neurons, muscle fibers that aren’t quite up to uh the speed of our, of our regular driver uh speed. But if we go a little bit slower, they can take to apply force and maybe we can start to have them adapt to move over to uh to a state that allows them to, to swing or to contract faster club head speeds. If we want to increase force production from each fiber, we want to train the ability to apply higher forces in transition and trains the ability to accommodate increased club momentum through impact. So there’s a, there’s a practical one. Those last two are practical ones. So um what I mean by train, the ability train our ability to, to manage that increased momentum through impact. Well, the faster I swing after I swing here, the figure the force through impact, uh from that grip that’s going to be pulling me out. I don’t want to fall over when we swing, that’s probably going to lead to a bad outcome in the golf shop. So if I’m not used to accommodating 100 the force is associated with say 100 and 20 mile an hour clubhead speed. And I think to myself, well, subconsciously as I start to down saying, hey, you know what if I get this going any faster through here, then I’m probably gonna fall over. So I never do, I never actually get that going as fast as I could. But if I’m able to practice that um without a golf ball there and every once in a while, hey, I do get that going faster and I accidentally stepped forward. And I’m like, ok, well, now I can get used to accommodating that increased momentum and I can learn that, hey, yeah, I can actually start to apply larger forces here. Get that going faster because I’m now going to be used to accommodating that increased momentum through the impact area. So this is a little more nuanced so that the stimulus is the load that’s applied to the club and to the ground. But we can’t measure that directly through the radar. We need to have force plates. Um like these in my lab. So while we’re, while we’re swinging, we can measure the forces that are being applied. We also need to be able to do inverse dynamics. So we can measure the forces that are being applied to the club. So if I add 20 g, it’s not, it’s not like going to the gym, right? If I’m gonna do a bicep curl and this is a £20 dumbbell. OK? And I want to increase the load by £5 and I go over and I grab the £25 dumbbells right on it. That’s the, how much I’ve increased the load by £5. But with the stack or a golf club, if I throw an extra 20 g on there and swing it, I haven’t increased the load on my body by 20 g. I’ve increased the load maybe by £20 maybe £10. What’s, what’s happened at my feet? We don’t know, we have to measure that first. Um, and that information will help inform, uh, the training studies. Um, and so this is, uh, Eric, um, uh, in an overload condition, I think he’s got, uh, about 300 g on there and he’s swinging at 100 and six MPH. So this might actually be a little bit too heavy for him to get the best, um, load stimulus. Ok. So I’ve been hinting at this, but it’s really important to be able to measure the biomechanics to determine the stimulus, right. I’ll say it again just because we put 20 g on here. That doesn’t tell us that we’re applying 20 more grams to the grip. There’s a complex relationship between the inertial properties of the club. We’re swinging and the low that we are experiencing um, as a golfer. Um And so this is from, uh, uh, this, this quote is from a, uh a research study I did looking at um uh jump training, uh squat training, uh squat jump training versus Olympic lifting. Um So for a training exercise to facilitate an improvement in performance in the sport, such as a golf swing, the exercise must stimulate a trainable feature of the neuromuscular system beyond the level that’s achieved while playing the sport. OK. So we, we first need to know what is the trainable feature that we’re targeting. We need to know what that level is in the sport. And then we need to make sure that when we’re doing the training that we’re exceeding that level and exceeding it by an appropriate amount, we don’t want to double it. For example, um you know, we want to be manipulating that within a, within a certain range. So what is the actual stimulus? So um how do we determine what should the loads be? What should the weights be loaded on the stack in order to get the best overload stimulus in order to get the best overspeed stimulus? So I mentioned this before about measuring the inverse dynamics of the club as well as the ground reaction forces. So what you’ll see on the screen are the the ground reaction forces that are being applied to participant in a research study while they’re swinging the stack as well as the forces that are being applied to the stack by the golfer. And this happens to be a lefty, lots of lefties uh in this presentation. Um And I’ll just pause it here. Um Actually, I’m going to play once. Um Actually, before I get into this, I’ll mention that I discussed hand path earlier, this orange line here. Um That’s kind of tracing at the new point in the group. That would be the hand path. So that uh that orange line there, the length of that line that’s the length of the dancing would be the length of the hand path. Um So that’s one of the things that we’d be trying to increase in order to um um increase the amount of energy that we’re delivering to the club is that hand pathway. Um So if one of the things we want to measure throughout the swing is this purple vector here that corresponds to the purple line over here in the graph also corresponds to this um this digital readout. So that’s the force that the golfer is applying to the club. OK. So we can see the direction that it’s being applied to the club over here right now, it’s, it’s £3 and we can see how that force increases um throughout the swing. OK? So for example, we know, and this is 195 g on the stack. So this person for the swing at impact or through the impact area is applying £99.1 of force to the stack. So we want to be able to compare that to how much force they’re applying with their driver. Ok. Um And what’s interesting and I mentioned this earlier is that we, we aren’t just applying a force to the a net force to the, to the club. We’re also applying a torque. So that force is mostly the force we’re applying is mostly a kind of pulling the grip off direction through impact in transition. The torque we’re applying is kind of a a pushing and pulling across the shaft. So those are two different load stimulus that we, we need to target. And the torque you can see here is this, this red curve and you can see that it’s peaking at a different time than the force. And in fact, the total torque that we’re applying to the club actually drops to zero through impact. Ok. So we need to be able to understand what is the force we’re applying to the training club. And what is the torque we’re applying to the training club. And then we can also look at the the ground reaction forces So um this uh this yellow vector that’s coming out of the, the force plate here, that’s the um the combined ground reaction force vector. So I’m applying forces to the ground with my lead foot forces to the ground with my trail foot. And that yellow vector um is the combination of the two of those. And that’s what I’m spitting out here. So you can see that um at around shaft vertical in the downswing is somewhere around there is where that, that force is going to, the size of that force is going to be really important to generating clubhead speed and we’re up around £300. So um how do those forces change when we change the, the inertial properties that implement were being swung, does swinging a certain way to implement, improve our ability to change the angular momentum that we’re putting into the, into the system. So we want to know both um the, the, the influence of the weight we’re loading on the, on the stack here in terms of the forces we apply to the stack as well as the ground. We want to relate those back to what’s happening with the, with the driver. So that’s what we’re gonna take a look at. Um Now, so let’s take a look at uh club head speed during the downswing. So this is um one participant um in each of these curves is the, the average of three swings. Um And we’re looking at just the last parts we can actually is the last part of the downswing. So these graphs ended impact and we’re already 70% of the way um into the downswing, um which would probably be uh somewhere around, somewhere around here. Ok. Um So, uh we’re just looking at the last part of the downswing. The uh the gray curve here is, is driver. Um So this person reaches the speed of 110 MPH with the driver with a 1 95 g uh stack condition. They also reach about 110 MPH, the driver. So I’ve rounded those. You can see they’re both very close to 100 and 10. So rounded them to 100 and 10. Um So the 100 this is very common that we see uh with uh uh especially um adult nails. Uh Most drivers are, are pretty similar and we see that when we load 100 and 95 g on the stack, we get very similar um clubhead speeds as we do with, with the driver. Um And to be able to compare those speeds, I’ve created a virtual marker set. So imagine a virtual head here that there would be a face, a virtual face, it would be the same location as a driver. So I’m extrapolating how fast the stack is moving to how fast a driver had would be moving if it was attached to the stack. So that, that allows us to compare them. We could also compare shaft angular velocities. And that’s also we see very similar shaft angular velocities between the 195 g stack condition. Um And the driver. So in terms of an overspeed stimulus, if we had 100 and 95 g on there, we’re, we’re not, uh we’re not getting anything, we would need to go to um a 45 g stack or something later than 195 to get an overspeed stimulus. So you can see that um If we put 45 g on there, we’re probably going a little bit too fast um to get uh the ideal uh training um effect. Um If we went all the way down to, to 45 g, we get a big jump of 25 MPH. Um If we go up to 280 g, then um we’re, we’re probably into uh an overload uh scenario. Um We’re swinging at uh at only 100 and two MPH, but it’s important to know what percentage of speed we’re swinging these different uh stack uh weeks at. That’s gonna inform um how we design our training programs. So now this is interesting watch this, this is called speed during the downswing, but now we’re gonna flip over to the Gulf replied force and this is that um purple um vector, this purple curve that we’re looking at here, but we’re going to look at it for several different conditions. So watch what happens with a 195 g condition. Now, so the driver, for this particular golfer, they’re playing £110 of force to the driver, um, at impact. Ok. Now we’ve got the, we’re looking at the entire downswing here. Um, but with the, the stack because it’s a little bit heavier, um, it’s got uh um not quite the same moment of inertia, but it has a little bit more mass. The load stimulus is actually um pretty important. It’s actually um appropriate um compared to what you would get with swinging driver. So there was no speed stimulus swinging 100 and 95 g stack. But if you train with the 195 g stack, you are getting a load stimulus, you’re learning to get a little bit more accustomed to um accommodating that an increased amount of momentum uh through impact, for example. So, and that, you know that um extra £20 is appropriate. Um um If you’re swinging, um even though you’re swinging it much faster, so the 45 g stack was being swung at 100 and 35 MPH. Um So you think maybe that extra speed will actually result in a higher level force. It doesn’t, um it’s, it’s only £100 of force being applied through impact. Um Whereas the, the 280 g, um jumps up to 100 and £40 of force and that would be a quite a large um load stimulus. Um And remember I talked about how the, the torque is a different type of stimulus uh than the force when you’re designing the training program. You know, hey, for this particular weight we voted on for the set. Are we getting a stimulus that’s going to increase that force along the shaft or is the stimulus that’s gonna target uh the torque we’re applying to the group. Um and the torque and in particular, we’re now looking at the start of the downswing. Ok. So this would be just in transition at 0%. Um And we’re only looking at 40% into the downswing just so we can get a closer look at, at these values we’ve kind of zoomed in. You can see that the driver we’re applying uh 21 Newton meters and this is the, the couple that’s being applied to the club. We don’t need to exactly know what that is, but that is the, the forces that we’d be applying the pushing and pulling across the grip. There’s also some pushing and pulling happening within each hand. Ok. So that, that torque for the driver for this particular golfer at the start of the downswing of about 21 Newton meters. Um And it’s very similar for the 195 g stack condition. So under 95 g stack condition applies a load stimulus that that’s appropriate and overload through impact. But it doesn’t apply a torque stimulus in transition. So we’d actually need to go to something heavier like the 280 g stack to get a stimulus in transition that would allow the golfer to, to adjust and improve. Um And that is quite small um down to seven newton meters when we, when we go all the way down to the 45 g condition. Um So the, the knowledge that we gain from doing these um uh inverse dynamics analysis and the ground reaction forces that then informs what training studies would be. So we, we could, I could just say, hey, let’s um let’s do a training study, let’s put on uh whatever weight uh we want on here and, and let’s start, but that’s very inefficient. I mean, we’ll really never know if we’re in the, the appropriate range. So it’s, it’s not about a certain percentage just to clarify. It’s not about a certain percentage of weight. So it’s like, oh let’s swing stuff that’s 10% lighter than the driver and 10% heavier if we actually want a stimulus that’s within plus or minus 10%. Um then we need to be able to measure what the load stimulus and speed stimulus is in the body to get to that 10%. It’s not just by manipulating the weight directly. So changing the weight by 10% doesn’t change the load by 10% necessarily. Ok, we have to, we have to be able to measure that out. So once we know what those stimulus are going to be on the body, then we can figure out. Ok, well, when we start doing some research, what weights do we want to have loaded on here to explore for the training studies, right? At what speed does overspeed, training effects start to decrease. So what, you know, how light can we go before we start to see decreases in, in, in um in speed improvement. And what load does overload? Training effects start to decrease, should overload and overspeed be performed in the same program, the same phase of the same session. So iteratively over the past seven years, um I’ve been doing these studies. Um the CK where is the, where is the sweet spot? Um And you know, we’ve kind of found that hey, if you go, uh if you’re swinging something that’s so heavy that you’re swinging at, say, uh slower than 92% of your driver speed. If you want, you want reference everything back to the driver, then you probably aren’t going to be getting um the most of the training. If you’re swinging stuff that’s faster than 112% of your driver, then you’re probably not gonna be getting as much as you can um out of your training. Um And, and then you can start to mix. OK, while answering some of the questions that I’m showing here, um You know, should you combine overload and over speed in the same in the same session? Um And what’s the most efficient way to, to gain the most beats the number of sets, the number of reps, the rest. Um So there’s a lot of variables that go into figuring out just, just what should be the, the appropriate um stimulus And then you can take it one step further and ask what training program is best for the individual golfer. What is, is best for this golfer? That’s, that’s in front of me right now. Um So when we take a look back at all the training studies, we’ve done, you can see that, hey, there are certain golfers that tended to respond better to overload, um training and there are certain golfers that tend to respond better to overspeed training or programs that had more overspeed or more overload in them. And you can start to figure out, you know, you can do a statistical analysis, it’ll say, ok, well, what, what characteristics were specific to that golfer that maybe predispose them from improving more with that particular type of training. So, um we would, you know, ask all sorts of questions, but we have their age, their handicap, um you know what their current speed is, but in particular, um what, what is the best predictor is trying to get what I call like a, a force velocity or a load speed profile of the individual. Essentially. How fast do you swing things that are slightly lighter than your driver? And how fast do you swing things that are slightly heavier than your driver? Um So if, if you tend to swing light stuff, hey, really fast compared to your driver and heavy stuff, not so much that’s gonna push you more towards a program that is more overload. Um Training. Um We can also look at um in the testing we do in the app, an initial baseline test, we have you swing left arm only right arm, only leader trail arm only to determine if one of the arms is a, is a limiting factor. So we baked all that, that science into the stack app. So we, we’ve taken that the biomechanics of the of the golfer swinging the driver, look at the biomechanics of swinging various stack weights to determine what is the appropriate stimulus. That that was the start. That’s the kind of the point of um uh the discussion we’re having today. So you can understand that, that there’s some, some science that’s gone into determining um the best uh the best protocols for increasing speed with overload and overspeed training. Um And to highlight a couple of uh a couple of things here in the, in the closing slides, um training needs to exceed the stimulus and competition. So, uh we have a lot of tour players, uh, using the app. And you’d think that, um, hey, how are they going to increase their club speed? They’re, they’re training for, um, improving their driver speed every day. They’re, you know, potentially hitting dozens and dozens of drivers every day. Um, how we doing, you know, 40 minutes more of swinging a club a week. Um, move the needle. Well, the key is that, that stimulus, um, needs to exceed what’s happening in competition. So here, here’s a, you know, an um an email that I got from uh John Koach in Cincinnati. He said, you know, I’m already taking 500 hard driver swings each week. How replacing that with stack training, about 90 swings per week um increase my club head speed. Well, it’s because that, that hard driver swing um is never going to exceed that, that stimulus of going all out um without a ball. Um just even the presence of having the ball there. You will usually um after a bit of training kind of rein us in act as act as a governor. And certainly when you’re, when you’re hitting balls to try and um you know, um improve your score on the course, you won’t be swinging at a full out um max effort. Perfect example is, is sprint training um at 90% effort, you could go out feel like you’re working really hard. Um do 10 reps of 100 m, but at 90% of your maximum effort. Um But eventually, uh you know, within, you know, a few months, you, you’re gonna stop increasing speed because you’re not stimulating your body enough. And all of a sudden you start training where you’re now going, uh sprinting at 100%. Um Now your body will start to adapt. Uh your, your muscles will start to apply more force. Uh your limbs will start to move faster because you’re, you’re uh stimulating the body, um, to adapt. Um, um, and Bryson is a great example of someone who’s off the course. Um, really, uh, done a lot to take as many maximum swings as he can. And he also competes in long drive, which is a little bit different than regular golf. So he, he’s, uh, it’s kind of a little bit maybe into the, uh, the speed endurance side of things as well. Um, long drive competitions, um, you’re swinging, uh, constantly throughout the day, um, um, over a couple of days. So, uh, it’s, it’s, it’s different than, um, swinging a driver 14 times, uh, over the course of, uh, five hours, which is required in a, you know, a regular round of golf, hopefully three hours, but sometimes five hours. Um, here’s a common question when we think about the, the, the biomechanics of, um, of speed training. Should you just swing it as fast as you possibly can or should you think about improving your swing? So, uh, you know, when we’re working on our drivers who might have particular swing thoughts we have that we want to incorporate. Um, and I think that swing thoughts that uh encourage increases in speed are great. Ok. So, um, if maybe the thought is ok. Well, um, let’s, uh, let’s lift that, that lead heel a little bit in transition so I can get a longer hand bath. That’s great. Maybe I wanna focus on improving my, my transition to the downswing. So maybe, nor my normal swing. I, I tend to cast a bit, the club moves before my lower body goes. Well, hey, that’s a good thing to focus on during my stack training. I wanna, you know, feel like as that club’s going back, I’m already starting my my lower body, right? Um Things that emphasize speed are, are great, longer hand faster. Boxing me, maybe a squat in transition, I would avoid biomechanical movements that tend to constrain speed. So thinking about keeping the shaft on plane, trying to hold the face square through impact or trying to hold a balanced finish. Those are going to result in reps that are probably too slow for you to get a AAA decent enough training effect. And then there, there’s, you know, a gray area like working on path through impact. So let’s say you’re uh you’re a slicer, you come over the top of it. I’m a lefty. So for me, that would be a, a swing path that’s, you know, way over to the right. Well, maybe when I’m doing my stack training and I’ve got 100 and 95 g on here and my full out hard as I can swing is 100 miles an hour. But I’ve got a 12 right path. Well, you know, probably a good idea to try and do some things to improve that path. Um, through back, maybe, maybe even get it down to, you know, three or four to the right. Um, but if I’m swinging 100 miles an hour with that and I try to improve my path and it drops down to 80. Well, now I’m more so just working on improving my path, I’m not gonna get a speed training effect. But if I, you know, in trying to improve that path, my, my speeds go from 100 down to 98 and I’m actually able to swing, um, inside to out and only lose a couple of miles an hour of that training speed. That’s probably ok. There’s probably a net benefit, um, to my golf game. So I, I just thought I’d end with, um, you know, so what is the end result of packing, um, all the science, um, into the stack app? Well, what’s cool is that for every swing taken in the app? We know the speed that it was being swung out. We know the profile of the individual, their, their age, their handicap, et cetera. Um, and, and we we know the, the weight and speed that that was being swung. So that, that’s um and we know the, the rest time, um We know how many days they took off in between. It’s a lot of, a lot of information that allows us to continually improve the app and to see, hey, are these protocols really working? So, um here’s a graph of um the driver speeds gained uh during the 570 most recently completed um stack program. So we’re, we’re approaching 5000 users right now. So, uh we’ve got programs being, you know, kind of completed all the time and some of these people in this graph would have already done a couple of programs. Um But what we can see is that um on the y axis here, we have a number of golfers. Um We can see that the, the average uh gain for the last 570 programs that have been completed and they’re between 18 and 24 sessions long. Um taking, you know, 6 to 8 weeks ish um with six MPH, um we have some individuals probably new to train that are, you know, uh getting upwards of 20 MPH with the driver. But if, uh you know, if you’re in your third program, um and you’ve already been um you know, speed training for a while, um even gaining one or two MPH, um you know, every couple of months is, is pretty impressive as well. It’s gonna um really start to move the needle after a few years. Ok. Um That’s the presentation on biomechanics of, of, of training for increasing club speed. Thanks.

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