The Role Of Torque In Jumping And Training
Athletes think that they can jump just as high as Isaiah because their squat, their RDL, and their calf raise is as strong as him. However, that is not the entire picture. You have to take into consideration your levers. What's up guys? My name is John Evans.
John:I am the coach of the highest jumper in the world. This is Isaiah Rivera. He has a 50.5 inch vertical. And this is our podcast on how to jump higher, how to be more how to be more athletic, and how to stay healthy. So in today's episode, we're gonna be talking about torque.
John:But before we do that, we wanna give a shout out to our sponsors over at THB Strength. If you guys are looking to jump higher, get more athletic, go to thbstrength.com and sign up for coaching. You ready to get into it? Let's do it. Alright.
John:So Oh, wait. Wait. Before we get
Isaiah:into it, I wanna give them a discount. Okay. Use the code THP at checkout and you get 10% off of your first month. You're welcome.
John:Yeah. Wow. That was a good idea. Totally forgot about that. So getting into it.
John:We're gonna discuss why torque is so important. And one of the big, not misrepresentations, but misunderstandings related to this is that force is actually more important than torque. And you guys have obviously heard Newton's laws. Right? So you've probably heard about like every action has an equal and opposite reaction.
John:You know, f net equals m a. So if you apply net force to a mass, it's going to accelerate and and things of that nature. However, when we are looking at jumping, we're actually looking at a lever system. Right? We're looking at our skeletal system, and we're looking at forces applied to that skeletal system that moves our mass, our total center of mass into space.
John:How we actually get that acceleration though is through torque. Right? We're applying a mass to or applying a force to a lever. Right? So basics, right, of of motion, we know again f net equals m a.
John:So and I could mess up the physics of this, but I'm just gonna explain it in terms of torque. You know, mass times acceleration. So if you apply a force to a mass, you get an acceleration. However, when you're looking at a lever, you're not applying the force directly through the center of mass. So if I have a box like this, this is pretty simple.
John:Right? This is not a skeletal system. So if I take a hammer and I hit that box from the side of it, you know, here's my hammer. And I I strike it going this way, right through the center of mass, it's pretty simple. The box is gonna go as you're gonna create a an acceleration on the box.
John:Right? But what if I hit the box, you know, up here with the hammer? Well, then you get a rotation and then you're starting to look at torque. So when you're applying a force not through directly through the center of mass, you will you'll have rotation, you'll have different things happen. Right?
John:So I'll see the the eraser. And this is relevant to jumping because it explains a lot of the discrepancies that people have with strength levels. It explains discrepancies in jumping and accelerations that you see. It explains a lot of the differences in in why some people have better anthropometry because some people say, oh, they have better leverage for jumping, but they don't even really know what that means. So I'm gonna go explain what that actually means, how you can visually see that whenever you're looking at athletes or just a visual representation of a lift or an athlete doing a lift, and start to get a a better idea of why a half squat or a deep squat is different, etcetera, etcetera, and whether you hinge and do a low bar or deadlift certain ways.
John:Alright. So you can hold this here.
Isaiah:I I think something too before we get into it. Yeah. Go ahead. We need to differentiate because this is something that I struggle with and messed up a lot years ago. Is there's a difference between internal forces and external forces.
Isaiah:Yep. And so also internal torque and external torques. So internal forces is the interplay between your bones and tendons and muscles, and then external forces is the interplay, the relationship between your body exerting force into the environment and vice versa. And remember Newton's third law, every time there's a force, there's an opposite and equal reaction, something applying a force to the other object. And then a force is just a push or a pull between two objects.
John:Cool. So when we're looking at this, we're gonna label this
Isaiah:Oh, and then torque is force times distance.
John:The moment arm is the perpendicular distance from the axis to the line of action. That is the the moment arm. So, yeah, when we're looking at at this stuff, it's really important to understand these concepts. Right? So what Isaiah just said, right?
John:Torque internal is equal to the force that you apply internally times the moment arm, and that will give you your internal torque. Okay? So you can imagine if I have a shovel, you know, to a to a Can
Isaiah:we use a different acronym for this? Because What do mean? Seeing that as massive times acceleration.
John:Oh. We can do
Isaiah:Yeah. D and then D is moment arm.
John:Alright. We can do D. Yeah. You like the D? Yeah.
John:You know D major, not a D flat. That's a Drake reference. Alright. So if I have a seesaw and I push on the seesaw here, right, versus out here, you can see that if I push on the outer part, you're going to accelerate, you know, let's say this is little Isaiah. Actually, don't know why I drew your hair that way.
John:Here we go. There's you. Little Isaiah sitting on the seesaw. He's got he's got his little hands here on the seesaw, and he's he's having a grand old time. Right?
John:So if I take a freaking hammer, a big old freaking sledgehammer, and I hammer down, right, with let's just say a 100 newtons, and let's say that this distance is one meter. In this case, this is an external force working on on the seesaw. The external torque is gonna be the force 100 times the distance, which is one meter, So it's one newton meter. Now there's other ways to measure torque. You can measure it in foot pound is another way to do it.
John:I think newton meter is the one they use for cars. Right? Is that the one they use for cars?
Isaiah:Think foot pounds is cars.
John:No. No. No. For the metric system.
Isaiah:Oh, yeah. Yeah. Is that what it is? I think it is.
John:Yeah. Okay. So, yeah. This is that's how we have torque in this equation. Right?
John:Let's say Isaiah weighs 80 and he's four meters away. Right? Then we have 80 times four, assume again this is perpendicular, then we know what the torque is in this scenario. Right? So this is gonna be what is that?
John:80 times four, that's three twenty? Yeah. Alright? Three twenty. So we have a torque of three twenty, we have a torque of 100.
John:This side has more torque, therefore the hammer wouldn't really cause any acceleration. Right? It's probably not gonna budge. So when we're looking at the human body and we're looking at lifts, we are considering external torque. So anytime you're looking at a lift, you're looking at external torque.
John:Now how you overcome that external torque is with your internal torque or the human body, the limbs, the bones, how the tendons insert. Alright. So we're gonna give you a quick diagram of this and we're gonna explain it in terms of squatting. I feel like that'll be actually grab the tape measure, Isaac. You got the tape measure out here?
John:Yeah. It should be out there. Grab that real quick. So we're gonna see exactly what your limb length is because this will be interesting. So go ahead, put this on the ground, go to your
Isaiah:What do you wanna measure?
John:Let's go to the greater trochanter of the femur. So put your hand on your side, you're gonna rotate your leg back and forth. You know where that bump is on the Right where your IT band issue is?
Isaiah:Yeah.
John:Alright. So your total to there is 36 inches.
Isaiah:Right? Wait. Wait. Wait. 39.
John:39? Yeah. To the trocana. So leg, 39. We'll say leg, it's actually, we'll put GT for greater trochanter.
John:We'll do the tibia length. So go from your lateral malleolus right there, and go up to we'll go to the protuberance of the tibia, which is right there. Not the protuberance of what is that called?
Isaiah:I have no idea.
John:Epicondyle. Epicondyle? That's not it. I don't know. I'll look it up later.
John:Condyle of the tibia. Alright. So we'll say 16 and a half. Alright. Right there.
John:Slide that down. So I'm going to the condyle of the femur up to your greater trochanter. And where are you at? 17. 17.
John:So we know the femur. Now there's some soft tissue in there. Right? We got the meniscus. We got that's creating a little bit of space.
John:But so we what did we say it was? 17. 17. Okay. So now we know if your foot is the remainder of that or your shoe to the ground.
John:You have six That's weird, my femur
Isaiah:and tibia is the same length.
John:Yeah, about. You're a perfect anatomical structure. So your foot is five and a half. From the malleolus down, it's five and a half. So we'll say foot, height.
John:Yep. Was it? Yeah. Alright. Our math is perfect.
John:Alright. That's good. Now we have actual numbers behind this. Now we're gonna this is inches. So we need to turn this into meters.
John:And this is torque. How to get the same torque as Isaiah Rivera to jump 50.5 inches. Okay? This is how it works out. That look good?
John:Yeah. Alright. So now we have actual numbers for this. Now we're gonna go through how his squat differs from other people. So let's say that Isaiah is doing a barbell back squat.
John:Right? And he's doing a deep squat. The bar is pushing down right through the center of his foot, so it goes down like this. And then this is, you know, the axis of rotation is here, and it comes straight up. Alright.
John:There's the ground reaction force. So you have the bar pushing down, the ground pushing back on him, this is in a static position. So this is gonna be his external torque. So we have the force. We know the force is 100 and that's kilograms.
John:So what's kilograms in Newtons? Do you know? Is that right?
Isaiah:Yeah. One kilogram 9.81 force of gravity.
John:Is one newton?
Isaiah:Mhmm.
John:So it's about ten ten x?
Isaiah:Yeah. Alright.
John:Yeah. So this is 800 newtons. Alright. For perspective, when he jumps, he's creating like 3,400 on the ground. 3,400 newtons on the ground.
John:Right? So when you're looking at torque, have to go specifically to from an axis and you're looking at a limb. Right? So let's look at your femur in this first example. Right?
John:So we need to look at the knee joint. Right? And we know that this is about let's say it's going through about halfway. Right? I guess we could actually measure it.
John:Go down on a squat. Squat all the way down. So again, the bars sit upright like you're doing a front squat. So the bar is gonna be sitting here. So we know it's gonna go right down through the ball of his foot roughly.
John:So let's say that the bar is going down through there. That's a vertical line, a plumb line. So we need to measure the distance from his knee joint through there. That's about six inches. Right?
John:So to your hip is going to be the remainder of that which is yeah. That's perfect. Alright. So six inches. About six inches.
John:So how it Yeah. Shoots Are you gonna hold this? So if you're looking at the hip, right, you're gonna look at and you're looking at the torque, you would look at the distance, the perpendicular distance from his hip to the line of action. So this dotted line represents that distance. Right?
John:Same thing's true here. Right? This is 90 degrees. So if we're looking at the knee, that same thing is true. So the perpendicular distance should be about here.
John:We're gonna measure the perpendicular distance. Right? So if this is parallel to the ground, the bar is traveling through here, perpendicular distance. We've got about from the knee joint. We've got about in centimeter.
John:Oh, this this is only inches?
Isaiah:Yeah.
John:That's crazy. We got about 5.25 inches for the knee, for the moment arm, and then the hip is looking like about maybe 10 inches. So we'll call it 10. 10 here, and we'll call it what did say? Five and a
Isaiah:half? Yeah. Or five.
John:Five inches? Yeah. Five inches. Alright. So now, we actually are able to figure out the torque, the external torque that a 225 pound bar or a 100 kilograms is gonna have on his body.
John:Right? So we know again, the bar is is 800 newtons. Alright. So then we multiply these by 800, and then we can get the torque respectively for his squat. So at the hip, we get 200, and that is going to be newton meters.
John:And then at the knee, we get point one three times 800. We get one zero four newton meters. Same external force on the knee, but it's torque. Right? So even though he's lifting a 100 this is important.
John:Even though he's lifting a 100 kilogram bar, he is experiencing more torque at the knee than he is experienced external torque. Right? Because of his position, if he leans forward, that's gonna change the moment arm. If he leans back, that's gonna change the moment arm. But he's experiencing 200 and a 104 Newton meters.
John:While we're looking at this guys, he is experiencing way more torque at the hip even when he's in a high bar position than he is at the knee. Now if he leans forward a lot like this, like an RDL, this number is gonna shift completely. Right? This diagram is gonna look totally different. Instead of that, so then it just disproportionately loads the hip more than it does the knee.
John:That line of action starts to decrease and now they're creating weight. The bar is generating more external torque on the hip than it is the knee. Here's the thing. Remember what I said. Rotation happens or movement happens when f net equals m a.
John:So there's a net force applied to a mass. Okay? So if you wanna see the same thing is true for torque. So if you have a an acceleration, then you have to have one torque exceed the other torque. So this is just in a static position.
John:Right? So to maintain that position, to hold that position, you know, you would have to generate that amount of force at the knee and the hips. So this is external. This is what the bar is applying on the human body. Now where his limbs actually insert and originate changes even more of this equation.
John:Right? Now we're gonna look at the internal. Alright? You can draw this. And this is where things get really complex.
John:Okay? So how his knee actually applies torque at the at the knee joint changes everything. And there's things anatomically that can happen that allow you to actually have better leverage and it's not just height.
Isaiah:A common question you might ask is, okay, you're squatting, right? You have an athlete with longer limbs and you're comparing it to an athlete with shorter limbs. The athlete with longer limbs needs to generate more torque to lift the same weight, so it's harder. Exactly. When you're jumping, you might think logically, well shouldn't the athlete with shorter limbs jump higher because
John:They have more force, they can lift more weight.
Isaiah:Yeah.
John:Right? But because in that position for him to lift, for him to lift a 100 kilos, right, his axis is really far away from the line of action. Right? When he's down in that squat, the axis is moving away from the barbell. The line of action, the force going straight down, that it's moving away.
John:So the moment arm is getting increasingly longer, meaning he needs it's creating a lot of external torque. Right? To overcome that force, that external torque, he needs a lot of internal muscle force. Right? So he's able to generate more external torque when he overcomes that weight.
John:He has more internal forces. Okay? That is going to allow him to accelerate his body into space.
Isaiah:And guess those higher peak forces also will allow you to do? Stretch the
John:tendon. So in this scenario, right, this is Isaiah's leg or a hypothetical leg. So we have the tent here's the the bone, the patella bone. We have the the tendon coming down into tibial tuberosity here, and then we have the the femur. Okay?
John:That's coming here, articulating here. We have his tibia and the condyle. This is that. And then the fibula is on the other side. Here's his calf muscle.
John:Right? So the axis of rotation is about here. Right? Here's the thing. The line of pull is the tendon.
John:That's how the tendon is pulling. Okay? So if we're looking at the patella, right? This is the line of pull. So we're looking at the bone, it pulls across that, you know, let's say it does this type of thing.
John:That's the line of action. Okay? It's gonna react on the bone and you're gonna get some form of a a movement. Right? This is the internal force that is applied by the quadriceps through this this tendon as well.
John:So we're just gonna look at the patella tendon first, really in that force. Alright? And you could summon these, An
Isaiah:anatomy question?
John:Yes. This is your quad, your fat ole freaking quad. Big boy. Yeah.
Isaiah:So the patellar tendon's attached at the tibial tuberosity and the bottom of the patella. The quad tendon is at the quad and at the top of the patella. Yep. Is the patellar tendon pulled by the quad pulling the quad tendon which pulls the patella, which The pulls bone This
John:is what the patella bone does. It increases your torque. Right? Yeah. So this is the line of action right here, right?
John:We're looking at the patella tendon.
Isaiah:Yeah.
John:Okay? So if we're looking at the summation of this, let's say this is the summated force of those two forces happening on the patella bone. Let's call it, you know, an imaginary line for the line of action. The moment arm is this distance right here. From here to here.
John:That small distance is the internal moment arm. Now hypothetically So
Isaiah:can you just so that
John:you can Alright. See So you guys can see. Here's the here's the joint axis. Right? Right here.
John:Here's the patella bone. The distance from that axis to the end of his patella bone, that is going to be the moment arm. That perpendicular distance. Okay? So if his kneecap was hypothetically out here, he's gonna be able to generate way more torque with less force.
John:Right?
Isaiah:Internally.
John:Internally, which will help him overcome that force. So we know that TE external was 800. Right? With a with a 100 kilogram bar. So let's say that that distance go ahead.
John:Let's let's just measure it out. Grab the the tape measure. Okay. Go ahead. So we'll call it that perpendicular distance from It's there to we'll call it there.
John:That's about two and a half. Two and a half to three inches. This is about that's about two and a half to three inches. Right?
Isaiah:Yeah. It's like that much.
John:It's like that much? Yeah. Okay. So in a static position, if t e equals t I, then we know that 800 is the external. So we know the internal has to be this has to equal 800 as well.
John:Right? So now looking at the knee, we know that t e is equal to the distance times force. We don't know force. Right? We know torque.
John:Torque is 800. Equals t I. So we know this is t I, so 800. Damn. I need more space.
John:And then the distance is point o six four, we'll call it
Isaiah:that.
John:Yeah. Zero point o sorry. Zero point o six four meters times we don't know force. Okay? So we just have to divide.
John:And now we can figure out how much force internally he's applying, which is a glorious and this is why it matters. F equals 12,500 intramuscularly. This tendon is pulling with this summated force is 12,500 newtons. The torque he has to apply internally from the or the force he has to apply intramuscularly is over 12 it's over 12,000 as Vegeta says. Alright?
John:Crazy crazy high. Remember, it was a it was in a 100 kilogram bar or 800 newtons. Right? But because he doesn't have any freaking moment arm internally, his muscles have to apply a ton a ton of force. Now hypothetically, if he had a kneecap that was, you know, really insanely high, you know, maybe he has patella ulta or something and his knee looks like this, you know, just fat old freaking kneecap.
John:Okay. Now we were able to increase that torque. Right? So if this is the the line of pull right here, that's a summated line of pull. The distance now might be five centimeters.
John:Right? So if he has a big old patella and we cut that, you know, or we double the moment arm, now it's point one two, he only needs to apply half as mount a much half as much force internally to lift that bar. Right? So you might be asking, well, why is it that shorter people can lift more weight? Right?
John:And that's because you're noticing way bigger shifts in the external torque that that person has to apply compared to the internal torque changes. Right? If someone has a femur that's four inches shorter, right, that's a way bigger change than internally Than a one centimeter. Than one than a half a centimeter change in the patella bone. Right?
John:So the anatomy thickness of that bone isn't gonna change much, but if your femur is way shorter, then you're going to need less force to lift that bar. And that's why torque is so important because we're looking at a lever system in the human body. We're not looking at a block that we're striking directly through the center.
Isaiah:So a taller athlete Can I raise Yeah? This Like let's say so you're comparing me to someone that's five nine. Right? The same exact weight. We weigh the same.
Isaiah:I need to generate way higher external torque.
John:No no no no. Your external torque is going to affect you more.
Isaiah:Yeah. So
John:you need to apply more internal But
Isaiah:I probably have higher, better leverage.
John:Maybe a little bit. Maybe you know, is your patella maybe it is, maybe it's not. Some people might have a thick old fat freaking patella bone. Right? Who knows?
John:I mean my patella is pretty high. You look at it like this, it sits pretty high. You know, maybe I have a higher patella than you, but your intramuscular force is way higher. You can get the same torque different ways. You might have a five centimeter patella or you might have a two and a half centimeter Is
Isaiah:the main reason that applies to jumping more because you're able to stretch the tendon more?
John:Let's just use jumping as an example. You launch yourself into the into the plant foot, your block foot hits the ground.
Isaiah:Yeah.
John:Okay? If you don't apply force internally, there's an external torque applied. Yeah. You're just gonna plop into the So your muscles have to apply a force. If your muscle applies a lot of force very quickly to a soft tendon, it's gonna stretch a ton.
John:Yeah. Right? So it I mean, potentially, I see what you're saying now is if that muscle is
Isaiah:Can generate a lot
John:of forces. If you have great leverage internally, but your muscles don't generate a lot of force, you might not be able to stretch that tension. Yeah. That's a good point. Yeah, didn't think about that.
John:That's a really good point. Your muscle has to generate a lot of force.
Isaiah:And you're not gonna see that.
John:So if you have someone that's super short and relatively seemingly strong, right? Yeah. Their internal tension might be less and therefore, and their RFD might be less. Yeah. So now
Isaiah:they're You're not stretching stretching the tendon. You don't see that in a squat because in a squat you don't stretch it. It's only
John:a It's stretch shortening just a muscle. Yeah. In a stretch shortening cycle, yes, you'll see this tendon stretch way more. Yeah. So being taller, if you're strong and tall, you might get even more tendon stretch.
John:Exactly. That's that's a really good point. So if you're short, to get that to happen, you gotta be insanely insanely strong.
Isaiah:Yeah. Like if you're comparing my numbers, you'd have to like let's say we both squat four zero five, but you're a five nine.
John:That's not even taking RFD into account how
Isaiah:fast you apply that risk. I would want an athlete, if you're comparing strength levels, generally I would want to see them jump as high, and obviously they jump a lot and do the correct training. But you'd want to see, can ask the grass four zero five, you'd want to see a five nine guy going like five hundreds. Yeah. Like ask the grass.
John:Maybe more. Yeah. It depends on the the, you know, to get the same external To get the same internal forces. To the same internal forces. But the reason why you need more of a squat is because the shorter guy let's let's exaggerate this.
John:Right?
Isaiah:Yeah.
John:Let's say this is the shorter guy squatting. Okay? Let's say this is the taller guy squatting. Let's just really exaggerate this. Just to because exaggerations tend to make things a little bit more obvious.
John:Right? So if he so if he does a 100 kilos but he's a 10 meter, you know, he got a moment arm of 10 meters, his femur's 20 meter or his legs are 20 meters long. You know, his torque is, you know, that's a thousand times 10, that's 10,000. Okay? 10,000 Newton meters for a giant.
John:This smaller giant that can do a thousand kilograms and with a meter long moment arm also gets 10,000 Newton meters. They're the same. This guy lifted a thousand kilograms, which is like 2,200 pounds. This guy lifted a 100 kilograms, which is two twenty five. But because he's a giant, and he you know, getting your butt all the way down is probably generating more torque than just body weight.
John:Right? But if he did a 100, a 100 kilograms, and he did a thousand, at the knee, in terms of torque, it was the same. This guy lifted 10 x the amount of weight, but at the knee, he was only he was experiencing the same amount of torque. Yep. Or sorry.
John:Yeah. Same amount of torque at the knee, but he had to lift 10 x the amount And
Isaiah:now, let's say they're both doing a thousand kilograms.
John:If they're both doing a thousand kilograms.
Isaiah:So now this guy's doing
John:So our our fucking fifty foot giant is lifting Yeah. A thousand kilograms.
Isaiah:His vert is gonna be And
John:our our two meter guy is, or wait, he's probably like a four meter guy. He's like a four meter tall guy and he's like a twenty meter tall guy.
Isaiah:Like a tag on Titan,
John:the small ones, which is
Isaiah:the big giant. So now he's doing what, a 100,000?
John:Yeah. That would be a A thousand times 10 is 10,000 times 10 is a 100,000.
Isaiah:Yeah.
John:So the giant is now doing a 100,000 and the little the little giant is only doing still 10,000. Just 10 x. He's experiencing 10 x the torque. So if he can lift a thousand, that means internally, right? Yeah.
John:He's probably doing like 10 x that intramuscularly. Yeah. His muscles would have to be something that is not even feasible. It'd be like a hydraulic press. Yeah.
John:And that is an exaggerated reason of why I told people when strong generate way more intramuscular force and therefore can stretch the tendon more and therefore jump higher. This is super important. Very complex. Was the conclusion. Very important.
John:That was the conclusion.
Isaiah:You can stretch the tendon more.
John:You can stretch the tendon more. You can generate, but you can also just generate more force on the ground. Yeah. I mean you just, you are better at generating, you are better at moving your body because your lever system is better at having knee extension torque and half extension ankle torque and hip torque. Mhmm.
John:It's better. So if you're a short guy, you gotta be
Isaiah:really, really, really, really, really You have different standards.
John:You have there's no reason
Isaiah:why I'm not the standard.
John:To him. Yeah. It's not even tall. It's if you have short limbs. Yeah.
John:If you have short short legs, you gotta be strong. Like stupidly strong. Yep.
Isaiah:Got it. Get in the weight room. And if you wanna get in the weight room doing the correct stuff, go to thbstrength.com. Sign up for Coachman.
John:See you guys.
