We’ve all seen karate (and other martial arts, I presume) demonstrations where they will chop a stack of wood, bricks, etc. in half with their bare hands. How on earth is this possible? How can something made of flesh and bone split something made of a much harder material without causing injury? I know, they “focus their energy”, but I’m talking about it on a strictly physical (science) level. If you’re using enough force to cut these objects in half, isn’t there going to be some kind of effect on your hand? I mean, even cars, which are made of metal, are crushed when they hit something with enough force. Is my knowledge of physics that lacking (which is highly possible), or am I right in being skeptical? Anyone know if this is for real, or just a put-on?
You are fortunate that I am here, because I can direct you to a place where you may find this information. Look in Scientific American for April of 1979, page 150. There’s also an article in the American Journal of Physics for 1982 entitled “The Physics of Karate” by the same guys, but with more math. The same material was apparently referred to again recently in Discover magazine.
I know all this, because I wrote the article. Under my reak name, of course.
Short answer: when you break a stack of boards, or bricks, or patio blocks, or ice you are placing them in a very vulnerable situation – “simply supported” (ie – they rest on a support to which they are not attached at each end). Also, the substances being broken have a lot of compressive strength, but absolutely no tensile strength (concrete breakls when you pull it apart. And look closely at the direction of the grain in the wood they break.).
I don’t want to sell karatekas short – there’s an awful lot more to it than just yelling and hitting. But even a jerk like me, yelling and hitting, can break a stack of pine boards. I’ve done it.
It’s actually a lot easier than it looks. I’ve broken several pieces of wood before, though I’ve never done concrete. It’s a matter of hitting it correctly and following through.
It takes practice.
Wood or bricks are generally only supported that the sides when you break them, and conrete is pretty brittle to begin with. If you hit them with your hand, (put your fingers together and feel the bone between your pinky and your wrist, that’s what you hit it with, or you can hit it with a fist, in which case you hit with only your top two fingers) you’re directing a LOT of force to a very small area.
Boom.
I’ve never broken bricks, but in karate I have broken wooden boards.
Training plays a major role in it. The striking motion is performed thousands of times until the motion is smooth and utilizes all of the body’s power. There is more to the idea of “focusing” your energy than you might think. For many karate students there is an almost metaphysical aspect to the art. But if you prefer not to think of it in those terms think of it as simply concentrating on the task at hand. The blow must be delivered smoothly and without hesitation.
But here’s the real “trick”: you must punch through the target, not at the surface. If you distance yourself so that you hand simply strikes the surface, you will not go through the target. All of the energy of the blow will bounce off the target and back into your hand, most likely injuring it. If you strike through the target, the energy of the blow will not rebound into your hand. When I would punch through wooden boards it felt like I was punching through styrofoam. Note that punching through a target does not protect you from splinters or stone chips or whatever material you are punching through. You can get scratches and abrasions even when successful. Many martial arts masters have toughened their hands to the point where this does not affect them too often.
The other part of the “trick” involves making the strike properly. If you do not deliver the blow correctly you can injure yourself. One of my prefered strikes was with the elbow. At one demonstration I missed the target with my elbow and instead hit the board with my upper arm. I went through the target as planned, but my entire arm went numb for several minutes. There are certain areas of your hand, foot, elbow that can deliver a blow without suffering injury and others that cannot. If you strike a target in such a manner that the four knuckles of your hand all hit the target, you will probably sprain or break your wrist.
Another thing to note is that it is not just the hand or elbow that is used to deliver force on the target, but the entire body. Next time you see an actual demonstration watch the expert’s body and hips, most of the force comes from there.
While I never did do bricks, if you think about it, it’s not such an impossibility to break one with a hand. Bricks are brittle and break fairly easily. Just drop one and it will shatter.
One of the most amazing things I have ever seen concerning the marital arts was on a video my World Civilazation teacher showed the class a few months ago. It was an episode of the Discovery Channel’s “On The Inside” I think. In one part it showed a master of a particular martial art (I forget which it was) punching an iron block with his fists 1,000 times a day. He had been doing this everyday for like 30 years. His hands and especially knuckles had adapted to this by forming monstrous calluses. They said that if he punched anything that wasn’t as strong as the iron he punched, it would shatter. His fists were like two metal balls on the ends of his arms. I thought that was pretty neat.
Being somebody who breaks concrete on a regular basis I can say that the answer to this has been pretty well covered. The simple fact of the matter is from a science perspective, the materials used are brittle. Second, the manner in which they are propped up (on two blocks usually) gives good leverage for them to break. Think about it this way, the brick is pushed down in the middle but of course the whole blocks wants to move down; however, the ends can’t move down they try to push the propping blocks down which try to push the Earth “down” so the result is a lot of pressure is place on the middle of the brick, which if done with sufficient force (this is where the training part comes in) and conviction/confidence to punch all the way through (again training) then it breaks.
Now, how about multiple bricks (5 or less)? This is simply a matter of delivering enough force to the top brick so that it is transferred to the next.
How about a whole mess of bricks (6 or more)? This gets trickier assuming they aren’t “cooked” bricks. You really need to punch through the first few, which I can assure you is very difficult and murder on the knuckles. But in any event it still comes to well done technique, fueled by will and power.
However, I do feel the need to break in here(pun quite intended, I assure you!) and state that I have broken boards and a few bricks. 90% of all of that has been covered, but there is one aspect that hasn’t…
The unsupported break…
My fav to do, was a jump spin kick to a board that was being held gently with 2 fingers. If you hit wrong, or don’t have the speed and power, the board goes flying and you can end up with a sore foot… but if your “Ki” if right (or your “Umeki”, for that matter) you get toothpicks.
I’ve never done the unsupported brick (the brick would be set on edge on a table or somesuch, and then kicked or punched) and probably never will unless I can get back into my arts hard-core, but I’ve seen it. Wow…
That was the most impressive one I’d seen… a row of five bricks set on end, all spaced about 5 inches apart, and a spear hand delivered by one of the Masters ended in so much dust and rubble…
Soup Nazi:
In the course of my research on karate trikes I accumulted quite a file on karate injuries. A lot of people managed to do themselves injuries by striking makewara boards, bags of rice, and other such things in their efforts to “toughen” their hands. My advice is DON’T DO IT. If you must, find yourself an expert to act as mentor. It ain’t worththe damage you can do yourself.
I’ve taken Tae Kwon do, through Deputy II. In our Do Jang, that meant I had about another year of review before my 1st Dan. I broke for each test, 1/2" wooden boards.
Once, we took the kids to a tournament. We all did our forms, and the kids did breaking. We don’t spar. I was told that for my registration fee, I could do two events. I chose the breaking of course. I quickly got with one of the high ranking Dans, and devised a three break set.
I took Third Place trophy out of a field of maybe…hmm…15? 18? I laughed when they told me. I wasn’t sweating it, I just laid into them and had fun. I did do an elbow break, and that’s an effortless break, done correctly.
At any rate, the real thing I wanted to say is this. I read the posts, and it should be made clear- when bricks or cinder blocks are broken, they are separated by wooden blocks at their edges. There is air space between each one, as as one poster said, if you break the first few, the compressive force can carry you through a few more. I’m NOT trying to take away from those bagwahns who can do 11 blocks at a shot. Clearly, there’s a LONG road of prep for that stuff. But, any single break- wood, brick, whatever- can be done cleanly with a lot of focus, and the understanding of how to move past the item in space. My bad test moments only included missed kicks. I’d aim, but not strike through hard enough, and so my foot would deflect. Almost never did that with my hands- like most bipeds, I am used to standing on two feet, and moving one hand but not the opposite.
I never saw it as a showboat thing. It truly does require intense focus. I’m 6’ 2" tall, pudgy and fairly muscular. I can do a board with an elbow with little grace, but the rest of the breaks require the same focus and liquid strike from me as they would from a more petit human.
My humble two cents 
Cartooniverse
When we did multiple bricks (not me, but the more advanced students) they liked to space them with nickles. And we didn’t space our boards… when I put my head through 2 1" boards, it was 2", no spacing.
That was my thing for demo’s… breaking boards with the head.
Another thing for the non-martial arts trained person to keep in mind is simple physics.
I had my first lesson in karate almost twenty years ago. But the real secret, besides proper form upon impact, is that kinetic energy is a function of velocity squared. A person trained in delivering a punch (martial artist or boxer) can deliver that impact with great speed–which translates into an exponential increase in kinetic energy delivered to the point of impact of say a brick or board.
IIRC there was something on the Discovery channel about the martial arts where they measured the speed of a blow delivered by an expert vs a novice in breaking some boards with computer enhanced photography. The speed of the expert delivering the strike was much noticably faster than the novice (even though they might have been of equilivalent physical strength)–and so the KE was exponentially greater.
As anybody who has trained knows–practice makes you better and faster.
When they do wood notice that its with the grain of the wood? It’s easy.
I haven’t seen anyone do bricks, at least not those red ones you have in the yard.
You must mean a cement bLock? Well, they have thin walls & air space. Anything think or piled must have some air space.
With respect Handy, you don’t strike me as much of an expert in this, and your post certainly indicates such.
Yes, boards are broken with the grain (and also with the curvature of the board btw) and although a single board is relatively easy breaking several boards is far from easy, even with the grain. The strength of the boards (without spacers) is not additive, 4 boards for example is far more difficult than 3, and 5 is far more difficult than 4, etc.
As for breaking unsupported bricks and boards the concept is still the same except the importance of speed increases. You need to punch through the target before it has a chance to start moving much. But still it comes down to delivering such pressure to the center of the object that it snaps in too.
If you look at Shaolin training, the monks also concentrate on toughning their hands . They use vases of sand, stones, rocks, and other such things that the thrust their hand and striking palms into. Do this everyday for about a year and your hand begins to feel like its carved out of wood.
The man Soup Nazi saw was Shaolin Master Pan Qing Fu - also known as the Iron Fist of China. It was because of his legendary power, in fact, that the Chinese police came to him for help in capturing 23 of China’s toughest gang leaders. Master Pan rose to the task. While Master Pan’s iron fist can devastate an opponent using just 30% of his power, the same iron fist is capable of healing people to the extent that some have called it a miracle. And that is only one of his 15 masteries, but one of his deadliest.
One of the best examples of focused KE was Bruce Lee’s ‘one inch punch’. It was a true demonstration of KE energy as Bruce would ask anyone in competitions to come up and stand in front of him. He asked them to hold fast to their position, like they were going to catch something heavy. He would then do basically what it was, a one inch punch directly into the center of the person with no windback and no actual force of his arms into it, almost pure KE. Because he focused so much of himself into the punch, he could get them to stagger back a step. There are a lot of movies from competitions showing him doing this, and it is a wonder to watch.
My class started easy and worked up, we started with jello, which (after a few sessions) I was able to chop in two with the edge of my bare hand.
When we got up to pretzels, though, I have to say that the little pieces of salt really stung.
Just curious, guys. Those of you who break boards/bricks/etc. Why do you do it? How does it complement your MA training? What is the goal of your MA training? Given limited time and resources, how is a MA student’s effort best spent breaking items, instead of elsewhere? I’ve trained a bit for a few years, but never with anyone who requested that I break an inatimate object, oor even strike an unpadded inanimate object.
Heath - does your “KE” refer to kinetic energy? Sorry if I’m a little slow on the uptake. Now I can understand some practical implications of the concepts behind the 1" punch. I have been on the receiving end of such punches (Tho unaccompanied by a measuring tape) and can attest to the power attainable.
Yes it is focused Kinetic Energy
To use the one inch punch you must have exceptional focus and speed. From what I have learned it is a recussion technique, in that after punching several inches through the target the punch is withdrawn as fast if not faster than it came in. This leaves all the energy created during the punching action inside the unmoved recipiant, instead of wasting the energy actually pushing the person.
And I think that breaking a inanimate object is more of a signifigant goal accomplishment akin to breaking the tape at a long marathon. It makes the student feel they have accomplished something that normal people would not do and gives them positive feedback. I don’t know of any forms that study exclusively to break stuff though some work around the advantage of having to disable weapons from opponents Shaolin training has masteries of ‘iron arm, iron hand’ etc.(I say Shaolin since I am currently studying techniques) that Masters have demonstrated to show their strength by breaking wielded weapons with a upraised arm (sorta reverse KE where the immovable object turns the KE back on itself). It is impressive to watch but not a part of the training, just a impressive after effect. Shaolin’s real talent lies within its speed and accuracy as well.
bart: i already know how not to hit a guy. when do we break out the nunchucks?
akira: ah, the impetuousness of youth. first you must fill your head with wisdom. then you can break ice with it.
Dinsdale: Breaking (or tameshiwari) is a tool or test of many of a martial artist’s skills: technique, power, speed, focus, calm, balance, etc. To be successful at breaking you need to develop all these, and develop them to a great and confident degree lest you hurt yourself.
When breaking you can utilize the full extent of your power without fear of hurting somebody like if you were sparring and actually see the effects of full power unlike striking air or a heavy bag in a very “concrete” 
way.
Is breaking an absolute necessity to be a good martial artist? Of course not, but there is little doubt that it can be of great benefit as well.
Plus, speaking personally, I find it fun, and it impresses the locals. 
You have all probably seen the trick were they rest with their bare bellies on top of spear and walk away unharmed. What’s up with that (scientificaly)? Iron abdominals? I imagine a pressure of say 60kg against a not incredibly sharp but not blunt either spear would be enought to cause damage. Oh and it was 3 pointed I think so that could allow for less pressure but still impressive Ki. Anyone?