Comments
[deleted] t1_jeex85p wrote
F = ma not mv.
F = dP/dt = m*dv/dt = ma. I think you mixed up dP/dt and P. Impulse is P.
[deleted] t1_jeex92y wrote
*Impulse is I, but I =deltaP
Any_Branch_4379 OP t1_jeeqqx3 wrote
Thanks very much
Alundra828 t1_jef2uop wrote
It should also be noted that often the makeup of that weight, is likely primarily made up of muscle mass, which of course, generates more force.
TheCuriousSages t1_jeep0bi wrote
When you punch, your body weight and muscles help to create the force behind the punch. Think of your body like a car - the heavier and stronger the car, the more power it can put into moving forward. People who are lighter don't have as much weight or muscle to help them create a strong punch, so their punches might not be as hard as someone who is heavier.
However, this doesn't mean that lighter people can't learn to punch harder. By practicing good technique and building up their muscles, they can still throw strong punches. It's just that, in general, people who are heavier have a natural advantage when it comes to punching hard.
nighthawk_something t1_jeeyo75 wrote
Yeah at low levels, size is likely compensated by with proper training and technique. But at the high levels where everyone is highly skilled and trained, biological differences play a more important role.
GESNodoon t1_jeepc1g wrote
Yep, a proper punch utilizes way more than just arm strength. You should be putting your whole body into the motion of a punch and your weight will help make the punch harder. There are some pretty simple techniques you can find that will help your form and motion when throwing a punch or a kick that do not require a whole lot of training..
Any_Branch_4379 OP t1_jeeqnrp wrote
I have heard trainers talk about the “snapping” of the shoulder when trying to throw a punch.
It almost seems like you hit harder when you ‘whip’ a punch into someone (if you will) instead of forcefully just driving your arm and fist into someone/something.
Senrabekim t1_jef0kqg wrote
I'm not entirely sure what you mean by 'whipping' a punch. So I'll just go with what I know. There are 5 basic punches and the rest are just variations on them. Jab, Cross, Hook, uppercut, and overhand. Each of these punches is not just a different arm movement, but a different series of body movements. If we compare a jab and a weak side hook for example.
Jab: starts in the toes, and rear thigh, tensing those to give a rock solid base. Let the flex radiate upward to your core as you exhale sharply involving your abs and diaphram. Rotate your wrist as quickly as you can to unfold your arm straight out. You want your fist to impact at the exact moment that you fully clench your fist, the exhale completes and you flex your rear knee. Keep your center of balance directly under your shoulders the entire time, do not shift into putting more than 30% of your weight on your front leg. Your aim point should be about three inches behind the contact point. As soon as you make contact counter rotate your wrist to bring your arm back to your guard. This punch should be as fast and crisp as possible. You typically aren't looking for a knockout with a jab, you just want to take a small opening and wedge it open for a bigger punch.
Hook: From your back leg shift your weight from sode to side to your front leg. Load your front leg and prepare to drive back to the side that your weight just came from. This punch is all ass and obliques. Exhale sharply as you tilt your elbow to aim. Come across with your fist as hard and sharply as you can. Fully clench your fist and finish your exhale as you make contact. You want to drive this punch through something, I like to aim for putting the punch into the inside opposite wall of my opponents skull if I aim for the head and I want to drive it to the spine if I aim for the body. At the point of impact your entire body should be a wall of flexed muscle. Recover by twisting your elbow back into place for your guard.
In either punch you want to make an imaginary box, the top is your eyes, the bottom is your floating ribs, and the sides are the tips of your clavicle. This box extends out from your chest. Your hands do not leave this box. They are stuck in the box. We aren't getting fancy here, your hands stay in the box. And breathe dammit.
Any_Branch_4379 OP t1_jef0zgr wrote
Wow, just wow. With all these bodily movements involved in a simple variation of a punch, it makes me just wonder and appreciate how these fighters are able to just ‘do them’ as though they were second nature.
What I meant by “whipping a punch” was basically involving your shoulders in the punching motion. Snapping your shoulders like a whip as you’re extending your arm to punch seems to also give it more force. That’s what I was told
clairostan t1_jef46xz wrote
they're not able to do them by second nature. they've had to throw the same punches thousands of times since they were little kids to develop the technique they have. it's their job to be able to punch well. practice makes them good.
what you're talking about when you say whipping the punch to make it harder is basically just saying throwing it faster to make it hit harder, which is true. force = mass x acceleration and velocity is a component of acceleration. if you throw the punch with higher velocity, you're making one of the numbers you have to multiply to get your force output bigger, which makes the force itself bigger.
Senrabekim t1_jefb50z wrote
This is a good start to thinking about fight physics, another thing from physics that you have to think about while training are Newton's laws of motion. The third comes up a lot for a strike.
If two bodies exert forces on each other, these forces have the same magnitude but opposite directions.
So I need my body to be a wall at the moment of impact, any give in me is less force that they have to take. So if I throw a hook, and do it with just my arm, and my feet arent set, my core and ass arent fully engaged and/or my legs are wobbly, then Im going to move and that will lessen the impact on my opponent.
Keeper151 t1_jefi67t wrote
>What I meant by “whipping a punch” was basically involving your shoulders in the punching motion. Snapping your shoulders like a whip as you’re extending your arm to punch seems to also give it more force.
The whole body should be involved, toes to knuckles. A proper punch or kick involves almost every muscle in the body, even the ones in the non-striking arm or leg. That's why proper technique has a twisting motion to the hips; you add the momentum of the entire upper body, not just the arm reaching out to strike. In my experience, setting the upper back solid when striking seems to make the biggest difference in the amount of force delivered as it provides a kind of backstop to the shoulder as the force of the strike is being transferred. If you don't keep your shoulders solid, and have good arm alignment when you strike, the force generated by your legs and hips goes into bending your wrist or shoulder instead of transferring into your target.
Wrist rotation is not 100% necessary; it's a technique I've encountered in some martial arts and ignored in others with no discernable difference in speed or power. I've personally had better results not rotating the wrist as I seem to have better alignment without rotation, but that may be a practice thing. It's also easier to get boxer fractures of the ring & pinky knuckle with a horizontal fist than it is with vertical or slightly angled fist. The slight gain of the twist (which is in itself debatable) is easily offset by having good alignment of the bones when striking.
GESNodoon t1_jeewqaq wrote
Your shoulder, hips and legs all play a big part in a well performed punch. Watch a professional fighter or martial artist.
Any_Branch_4379 OP t1_jeep8c3 wrote
Thank you for the explanation. I wanted a simple explanation, and I got it. I remember learning about “inertia” in highschool.
Does this “inertia” play a factor in how hard a human can hit? I think it ties into the analogy of the car that you wrote.
clairostan t1_jef4uof wrote
inertia plays a factor more so in how well someone can take a punch. inertia is resistance to change in velocity. that change in velocity in your face when you get punched dictates how hard your brain shakes inside your skull, which determines how hurt you get (and whether you go unconscious or not). if you're a bigger person with a bigger head, stronger neck muscles, denser skeleton, stronger base, etc, you'll be able to absorb a punch better than someone who is smaller because you can resist the change in velocity better than a smaller person can. it's why combat athletes fight people who are the same weight as them. keeps it fair (on top of the obvious fact that same size people can generate similar levels of force)
Keeper151 t1_jefe5z7 wrote
In addition, that inertia isn't always a good thing on part of the person getting hit.
An often overlooked factor in how damaged you get is the amount of force it takes to overcome inertia. Hit a smaller person in the body, they go flying without breaking ribs because the amount of force necessary to knock them over is less than what's required to break ribs. Hit a bigger person, and their body has to soak more impact before movement occurs. Depending on the size difference and the amount of tissue padding the larger person has, there is a wide range of potential outcomes.
This combines unfavorably with the kinetic force equation, as velocity has more effect on force than mass. Smaller object moving faster = more penetration, which is bad for the person getting hit. It's far more likely to break ribs/jaws/orbitals/teeth as the smaller bits will fail before inertia is overcome.
Training helps with this, as you learn when to strike for maximum effect. It's counterintuitive due to the desire to avoid pain, but it's best to hit someone that is coming straight at you (who is usually swinging for your face) because you're adding their mass & velocity to your own. Hitting someone that's retreating reduces the force of your strikes. Think of the difference between a head-on collision and getting rear ended by someone going 50 when you're going 35.
For example: putting strong kicks into someone my size is usually less useful than putting them into someone larger than me. I have to time my kick so the person my size is advancing into the strike, giving me more force to overcome (and therefore more force I can put into them before they start changing direction) which directly translates into damage inflicted. With a larger opponent, I can deliver a full-force kick to the abdomen and they will fold like an omlette before they go flying because all the energy of my kick went straight into their body instead of getting wasted.
Senrabekim t1_jegw5wx wrote
There's a really good example of the inertia thing you're talking about. Paquiao Vs Marquez 4 iirc where Paq gets knocked out. He's stepping into Marquez and moving directly into Marquez' hook and just gets obliterated. That hit was always going to be huge, but adding in Paquiao's own momentum is huge.
Keeper151 t1_jegxmsb wrote
That's a perfect example, thank you.
HeavyDT t1_jefa1yx wrote
Force equals mass times acceleration. More mass and or more acceleration produces a bigger force. For humans it's hard to drastically increase acceleration but you can increase mass to great effect.
[deleted] t1_jeeovie wrote
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TheDefected t1_jef4qqd wrote
Reaction mass is what some people have said, if you don't weigh much, when you connect, you're more likely to push yourself back off them than if you were heavier.
Another factor is the speed of your muscles. All things being equal, if you were lighter (and your fist/arm was too), you could make up for that with a faster punch.
Less mass in your arm, but more speed to make up for it. This is one of those Newtonian things involving collisions, if everything worked out without losses, if you wacked a 2kg ball into a 1kg ball and it transferred all the energy, the 1kg ball would shoot off at double the speed.
However, there's going to be a max speed based on your muscles, you wouldn't just be able to halve the weight of your arm and then expect it to move twice as fast. In other words, you can get faster with your punches, but there's a sort of preferred speed from your muscles which it'll tend to hang around.
eg- your muscles will move your arm in a particular speed range no matter what. Double the weight of your arm won't halve the speed, half-weight arms won't double the speed. You can add extra mass though, so if you gripped a lump of steel in your fist, you'd have a stronger punch, as there would be spare capacity in your muscles to account for the extra mass without taking a big hit in the speed to level it back out.
This part however is just one part of the whole punch, it's more like the mechanics of throwing a limp arm at someone, and doesn't account for the followthrough which would give you a stronger punch from having a heavy overall physique.
icount2tenanddrinkt t1_jef4xba wrote
science can explain this, acceleration * mass = force.
Quicker you can move your arm and more of your body weight behind it the harder the punch. SIMPLE... sort of.
Im an ex sprinter but I did play and train with some boxers many years ago, went to a science place and had some punches measured for speed and impact force. The boxers outscored me, by a good margin. They hit hard, really hard. Now I have a couple of black belts in kung fu and karate. The technique was similar but also very different.
My kung fu instructor talked about a punch should be like "an iron chain with an iron ball on the end" The karate guy told me it should feel like an iron stick. The boxers when I talked about this with them said, turn your hip and punch through their face, and if you use your legs you should punch with the mass of the world behind you. (not true but not a bad training lesson)
There is also for want of a better description magic at play, some boxers just have heavy hands. One of the boxers I was training/playing with punched me on the shoulder. Just a jab and my jaw rattled.
Think about a domestic cat, crazy little wannabe tiger, watch their paw speed. Crazy quick. will hit a toy 4 or 5 times a second ...bap, bap, bap, bap. But so little body weight behind this. Now watch a tourist on holiday that stands next to an elephant. One swing of the trunk and tourist is knocked over, elephant ways more than a cat.
SaltRharris t1_jef56f3 wrote
Imagine getting hit with a baseball vs a ball of paper. Same speed at you. It comes down to weight.
When someone punches, swings a bat, ect, they technically are throwing a percent of their weight behind the action. More weight =harder
Harder punch = weight x speed (ELI5 version) Force= mass x acceleration
DeadFyre t1_jef75ud wrote
The formula for momentum (what determines the energy contained in a moving body) is P = MV, where P is momentum, M is mass, and V is velocity. In general, the speed at which human muscles can move does not change with the size of the human involved. Mass, however, does.
So, all other things being equal, such as fitness, nutrition, and technique, a man who is 30% bigger will produce a blow which has 30% more momentum. It's worth noting here that momentum also informs your ability to take a punch, for the exact same reason. You're 30% larger, and have bigger bones, muscles, etc, and you can better absorb the force transferred from the punch to you.
PckMan t1_jefpy4d wrote
If you want two objects of unequal mass to impart the same force the lighter one has to be moving a lot faster than the heavier one.
[deleted] t1_jefrxir wrote
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raerlynn t1_jeeqfv6 wrote
Basic physics - specifically Newton's 2nd Law of Motion.
The force acting on an object (like a fist) is equal to mass times velocity. More mass, more force.
Same reason why the damage a vehicle accident causes varies depending on the size of the vehicles involved. Two cars at 30mph is generally survivable. A train hitting a car at 30mph... not so much.