Discussion in 'Hapkido' started by Bubble99, Jan 29, 2015.
Pretty sure that formula is wrong.
I just said it was... "very simplistic"... but much easier to demonstrate and see than the force formula...
How hard you hit = your mass times the speed it is travelling, and speed is the key component. the simple atomic formula shows this very easily
No, even in terms of basic physics:
K.E. = 1/2 m v2
But the human body is not a simple object impacting another simple object. You have considerations of muscular tension, structure and angle of the appendage on impact, contraction and hence tensile strength and stress of the muscles through the kinetic chain, structure of the surface being impacted, direction and speed of the person being impacted, friction on and surface area of the support.... It's a lot more complex than a simple equation.
At best you can say mass is a factor.
And you want to try to explain that to some one in a simple manner?
And it is simple. A hapkidoist will "whip" his weapon... keeping the body loose to maximize "speed" until the moment of impact, "tensing" just as his weapon is about to impact the target.
The faster your weapon is travelling at the point of impact with the total mass moving behind it, the greater the impact...
Speed is generated through "circular" motion. A straight line between A and B may be the most direct, but your Mass will be travelling slower than if that mass has traveled a greater distance in the same amount of time in a circular arc.... not rocket science there, no matter how complicated you want to make it sound...
Structure, timing and angling have always meant more than speed in terms of effect on target. This is true of strikes, throws, trips and locks. The fastest looking, strongest feeling guy in the room is rarely the biggest or fastest.
Even in your example the harder hitting guy will be the one with the straight strikes, as the mass behind a long, arcing strike is negligible compared to a properly structured straight. The straight is moving slower but the difference in involved mass is so great that a wide swinging strike doesnt even come close.
Absolutely. Timing is especially important in this case, because a strike following a parabolic path can be interrupted by a straight line strike or jam, in which case that extra power is all for nought.
This may be true for a wide swinging strike, but if your straights are more powerful than a well-structured hook, then I would say that there is something wrong in your technique.
Bushidoka makes an erroneous assumption though - that greater distance equals greater power. This does not take into account moment of inertia. Ice skating spins show this effect very dramatically:
[ame="https://www.youtube.com/watch?v=jeB4aAVQMug"]Physics of Spins in Figure Skating - YouTube[/ame]
This particular thread is talking about the importance of size in relation to the sciences utilizing it... not accuracy, angles etc, but two equally trained fighters, one small, one large. You guys are just skewing specifics to suit your own argument.
"Even in your example the harder hitting guy will be the one with the straight strikes, as the mass behind a long, arcing strike is negligible compared to a properly structured straight. The straight is moving slower but the difference in involved mass is so great that a wide swinging strike doesnt even come close."
"This may be true for a wide swinging strike, but if your straights are more powerful than a well-structured hook, then I would say that there is something wrong in your technique."
"long, arcing strike"
I have to assume from the above quotes that you are not familiar with how HKD generates power within small circles, (not large looping strikes) starting from the foot pivots and whipping through the body to the striking weapon. That being the case, I can neither teach you that here, nor be bothered to attempt to argue semantics if you do know but are blatantly baiting...
And David, your ice skating vid, is an attempt to explain the relationship between centrifugal and centripetal forces. But not as it applies to generating force in a strike. Sooo... if you are using it to debunk what I have said, it is actually not relavant It could be made to be relevant to the argument... Do you know how? Neither does it attempt to address the fact that these forces are only theoretical in science. More so one than the other...
I have to assume that you also have not had some one set up the experiment of dropping a ball straight down, and another down a curved ramp set the same distance from the ground. Science dictates that they hit the ground at the same time... thus, the one travelling on a curved ramp is covering a greater distance in the same amount of time, thus, travelling faster.
If a 1,000 lb car hits you at 10 mph, or at 60 mph, in which instance do you suppose the mass is striking you harder? And which will do more damage?
I'm not digging at you guys, just replying to your posts Both of which are off topic of the thread I was replying too. You are both addressing different and unrelated aspects. More than happy to discuss what ever you want, as long as you stay within the confines of that subject
I agree about the hook; the problem is his idea that a greater radius moves at a greater speed while still involving the mass of the entire body. The hook is powerful in large part because it's kept in close and doesnt lose much connection to the mass and muscles that drive it. With a haymaker you're really only dealing with the mass of the fist and some of the arm. Straights and hooks can get nearly the full weight of the body in on it.
I thought your point was that through circular motion, the fist can be moving much faster since it's covering a greater distance in the same time. If that were true, the widest, fastest swings would be the most powerful strikes.
In reality, the wider and more circular the strike is, the less body mass is actually moving. It can be very fast but it doesnt matter since the mass in motion is pretty much just the arm. A good hook travels a very shallow, close arc and is driven by the whole body's mass in motion.
And this is coming from someone that uses casting punches pretty much constantly.
There are two kinds of speed.
1. how fast travels an object from A to B
2. timing (being in the right spot at the right time)
With more training comes better timing. However as you grow older, you type 1 speed will decrease, but your experience grows and with it your type 2 speed.
The same is true for power
1. how hard do you hit a surface
2. combined with timing, more precision, etc. even a 'weak' strike can hit hard
With age your type 1 force will decrease, but you type 2 force can still grow
With technique it is the reverse, you start with no technical skills, but over time you will acquire more skill and improve that skill. Improved skill with type 2 speed and force is what I see as the goal of training in traditional martial arts.
That together with keeping your body in shape, having a healthy diet and live a good life ;-)
just my 2 cents
"Science" doesn't dictate that at all? The ball in free fall is going to hit the ground quicker and move faster (due to friction and less-than-perfect elasticity) than a ball rolling along any kind of obstruction.
I think he's confusing ramp with the other experiment. If you drop a ball from a cliff and kick a ball horizontally off the cliff at the same time, they will drop st the same rate.
One thing that maybe hasn't been covered (can't be arsed to read the whole thread) is that the flips and elaborate breakfalls are a training device. People flip to save their joints. Without that the joint would/should just go "crunch".
Which then also brings on issues of follow up because the flip often means the person doesn't land as they would if the tech' was really applied on someone that couldn't breakfall.
And it means people don't often, if ever, practice follow up from failed techniques.
Size does not equal power. Mass helps, but strength and muscle recruitment help just as much. A person weighing 300lbs does not necessarily punch harder than a person who weighs 150lbs. In relation to the OP, context is important, and that includes technical aspects such as timing and accuracy.
Just to remind everyone:
This video explains very nicely why the kind of "whipping" you describe is not at all optimal:
[ame="https://www.youtube.com/watch?v=iRWrwkAWtro"]Tai Chi Basics: Lesson 2 - Power like a whip - YouTube[/ame]
Centrifugal force is a fictitious force, so the relationship between centrifugal and centripetal force is only one of frame of reference. The skating video is relevant because it brings moment of inertia into the discussion, which has consequences in the application of a limb rotating around the axis of the spine.
That's the thing though; the mass behind a punch is not a constant. If we were just talking about the effect of velocity on the mass of a fist, then you would be entirely correct. However, the power of a punch comes from correct structure and muscle recruitment in getting more mass behind that fist.
If you want to rag on us for not sticking to the OP, then we should really only be talking about joint locks, takedowns and throws. In which case, leverage, timing and technical skill are more relevant than pure mass. If two people of equal skill are grappling, one morbidly obese and the other slim but muscular, it is not a given that the morbidly obese person will always win.
I believe bushidoka may have meant this:
[ame="https://www.youtube.com/watch?v=qN6amRT1UaM"]Physics experiment Part 2: Ball rolling down curved and straight ramp - YouTube[/ame]
I'm no physicist, but aren't the balls travelling at the same speed when they get to the end of the ramp?
Assuming negligible friction and perfect elasticity, yes. They certainly don't get to the bottom at the same time, though...
"Size does not equal power" True, but the 'Size' involved is part of the equation that results in the Impact... you are just mincing words there David.
"Mass helps, but strength and muscle recruitment help just as much" You do not strike with your 'strength' or 'Muscle'. Striking with either slows down your attack. The body has to travel 'loosely' until just before the point of impact. Then you can tense and utilize your 'strength or muscle'. At least as far as HKD is concerned. Not so with some forms of Boxing, linear arts, etc, that do not share this belief. That said, I was a golden gloves boxer and sparing partner to Shawn O'Sullivan at the time of his Olympic bid, and I can tell you that speed and movement of mass when striking were very integral to our stye of boxing.
"This video explains very nicely why the kind of "whipping" you describe" -It does to some extent. It does not use HKD style pivots, or the 'coiling' or 'loading' of the body used in the strike. Neither does HKD lock out the elbow joint when striking. A straight punch at point of impact will be maybe 1 foot from the center of our mass. So, while it does attempt to show the process, it does so very poorly (he does not have the understanding himself to try to teach or demonstrate this tech, or perhaps he does as it applies to Tai Chi)... I will see what I can find for video of our style of striking, as you do not seem to know how we strike. And I seem to lack the linguistic ability to describe it to you... I will look shortly though
"Strong and well trained will always beat Well Trained...
Impact = mass (size) x Speed (how fast that mass is travelling) Squared... very simplistic formula, I know, but easiest to show the weighing factors." --This was my original posting... stating that all things being equal, the 'size' or Mass does make a difference. Very simple post. Y'all are just trying to debunk (as simplistic as it is, I can't fathom why, lol) it by going outside of those parameters to do so. Which is OK... if that's the route you have to take to try to disprove some thing, I can stick with you on the sciences no problem I just happen to have the right letters behind my name to do so which includes a BSc in Kinesiology...
"That's the thing though; the mass behind a punch is not a constant." -- And that David, is not a technically true statement... argue it as you will, your 'constant' is at the point of impact. That is the point of data as it applies to our impact. The point where speed and mass comes together resulting in the impact.
If you want to blur that, then of course you can start discussing absorption, body fading, muscle vs fat impact ratios, center of mass in relation to point of impact, and on, and on, and on... and never ever end up with your 'constant', thus never end up with a value placed upon your impact.
LOL, any ways David, I'm just rambling now Brother I'll pass it back to y'all now
That is not quite the experiment... I will do a quick search now though and see if I can find it
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