Board breaking

[skribs]

In a self-defence scenario I believe the goal should be to either disengage or (if necessary) incapacitate the attacker without causing any permanent injury. Something like this:

Aggressor incapacitated without anyone getting injured. Of course, this particular scenario only worked out because the guy doing the choke was able to approach the aggressor unnoticed from behind and apply the move before the guy had a chance to react. Now, is breaking someone's ribs going to stop a fight? Potentially, but it's also possible that the attacker will ignore the pain or not even notice it through adrenaline until afterwards. The same could be said of attacks to the Liver and Kidneys. Yes these attacks could cause a lot of damage, but probably won't stop the fight immediately.

My first priority is my own survival, my second priority is the survival of my friends and family, my third priority is that I act within the law and within my morals, and my fourth priority is that I protect any innocent strangers that I can.

The survival or the prognosis of the bad guy is at least my fifth priority.

That doesn't mean I'm out to hurt him. I'm just saying my goal is to stop him from attacking and protect those I love.

 

[JR 137]

I understand your point but then again those you speak of train fully in all areas and are Martial Artists I was referring to the one that don't. Ever see an MMA fighter that walks around talking about ripping his oppents arm of and beating him with it and then when the first punch is thrown just covers up and runs. That's the guy I'm talking about.

My friends and I were walking out of a bar in Montreal late one night. Two guys outside are arguing and one guy says “You’d better walk away. I’m a Navy SEAL. I train to kill people with my bare hands.” The other guy hit him in the jaw with a pretty slow and weak punch, knocking him unconscious with it. The whole crowd laughed hysterically. Navy SEAL my ***.

 

[drop bear]

My friends and I were walking out of a bar in Montreal late one night. Two guys outside are arguing and one guy says “You’d better walk away. I’m a Navy SEAL. I train to kill people with my bare hands.” The other guy hit him in the jaw with a pretty slow and weak punch, knocking him unconscious with it. The whole crowd laughed hysterically. Navy SEAL my ***.

Maybe he meant performing

 

[Gerry Seymour]

Maybe he meant performing

Was there a beach ball nearby? A bucket of fish? What's your evidence??

 

[Earl Weiss]

Couple of additional points. 1. A main purpose of breaking is the courage to attempt. Breaking often has a potential for injury . Just as in a SD situation you need to focus on the goal and not be distracted by the possibility of injury. 2. Totaly TKD had an article in the last year where force needed to break additional boards was measured. It was not a factor of 10 If one boars was a factor of , then each addittional board was represented by 1 + 1xY. I will see if I can find the article to get the exact formula.

 

[RTKDCMB]

Couple of additional points. 1. A main purpose of breaking is the courage to attempt. Breaking often has a potential for injury . Just as in a SD situation you need to focus on the goal and not be distracted by the possibility of injury. 2. Totaly TKD had an article in the last year where force needed to break additional boards was measured. It was not a factor of 10 If one boars was a factor of , then each addittional board was represented by 1 + 1xY. I will see if I can find the article to get the exact formula.

One of these days I would like to do a scientific study to measure the forces required to break each additional board. If only I had the time.

 

[Earl Weiss]

One of these days I would like to do a scientific study to measure the forces required to break each additional board. If only I had the time.

Before you spend time on that just get a copy of the article. It was well done with a fist made from a lead casting as the contact instrument and some great force measuring instruments.

 

[Buka]

I'm thinking that the formula might be different depending on the wood?

 

[Gerry Seymour]

I'm thinking that the formula might be different depending on the wood?

Maybe, but I'd think the variation would be more in the starting number. So, if X is the force required to break one board (of whatever wood), then the formula for adding N boards is probably a variation from X. Intuitively, I can't decide if using thicker or thinner boards (which would change X) would change the formula.

 

[Dirty Dog]

I'm thinking that the formula might be different depending on the wood?

Absolutely. And not just the type of wood (pine vs oak, for example) but condition. What's the moisture content? Wet wood is springy and as the moisture content goes up, it will be more difficult to break. How knotty is it? Is it flat or warped? If it's dry, did it split or crack?
Personally I prefer to break concrete pavers. They're more consistent, and unaffected by weather, for starters.

 

[RTKDCMB]

Before you spend time on that just get a copy of the article.

A review of the literature is always one of the first steps before conducting any scientific study.

 

[Earl Weiss]

Absolutely. And not just the type of wood (pine vs oak, for example) but condition. What's the moisture content? Wet wood is springy and as the moisture content goes up, it will be more difficult to break. How knotty is it? Is it flat or warped? If it's dry, did it split or crack?
Personally I prefer to break concrete pavers. They're more consistent, and unaffected by weather, for starters.

I think the initial factor of X to break one item would change but the multiplying factor would be similar. I think he may plan to use a man made material next due to elastic properties of wood vs Cement or tiles. I asked him to consider "Crown Up" vs "Crown Down" and how that might affect the force.

Back in 1979 or so I ran across this:

https://blogs.otago.ac.nz/ouassa/files/2013/09/scientificamerican0479-1501.pdf

Not exactly focused on additional force for more materials but IMO interesting concerning elastic properties of materials and the human body.

 

[Dirty Dog]

I think the initial factor of X to break one item would change but the multiplying factor would be similar.

Maybe, but only if things like moisture content/knots/warp/etc were pretty much the same for each board in the stack, I suspect.

 

[Earl Weiss]

Maybe, but only if things like moisture content/knots/warp/etc were pretty much the same for each board in the stack, I suspect.

If material stacked items were dissimilar i don't think you could get any meaningful results. For the crown up Vs Crown down tests the material compared would be pieces cut from the same board and alternate the pieces so if one en of the board had different grain /moisture than the other the results would not be thrown off as they might if you did the first 5 pieces one way and the next five, all from the same board another

 

[Dirty Dog]

If material stacked items were dissimilar i don't think you could get any meaningful results. For the crown up Vs Crown down tests the material compared would be pieces cut from the same board and alternate the pieces so if one en of the board had different grain /moisture than the other the results would not be thrown off as they might if you did the first 5 pieces one way and the next five, all from the same board another

The results would still be different, I suspect. Because it is unlikely that one board is going to vary much from one end to the other, so much as one board to another. Best you could do would be to break X stacks of random boards and calculate a mean.
And people wonder why I prefer concrete...

 

[Gerry Seymour]

The results would still be different, I suspect. Because it is unlikely that one board is going to vary much from one end to the other, so much as one board to another. Best you could do would be to break X stacks of random boards and calculate a mean.
And people wonder why I prefer concrete...

Agreed. Any formula would be theoretical - using a theoretically identical set of boards.

 

[Earl Weiss]

Agreed. Any formula would be theoretical - using a theoretically identical set of boards.

Found the article. If you PM me with your e-mail i can send a copy. He used about 5 different materials including re breakables. he came up with this formula. Let say force required to break one was 12.09. The formula for each additional board was that additional force times the number of "Junctions" between boards. (so 2 boards had one junction, 3 boards had 2.) times a force multiplier of 1.2. So, using the first example 2 boards was 12.09 + 12.09 =24.18 x 1.02 or 29.016 and 3 boards was 12.09 + 12.09 +, 12.09 = 36.27 x 1,2 x 1.2 = 52.28.
He used 4 different materials and measured 3-5 samples from each.
The multiplier varied by material from 1.2-1.25 and variations from predictions to test results varied from 0.27 -13%

 

[Anarax]

One of my old school karate teachers told me that board breaking's end goal is to teach how to use vibrations. Some competitive board breakers have demonstrated by striking two boards(one behind the other) but only breaking the back one, the front one remaining intact. Though confidence and proper hand alignment are other things to be gained by doing so. Granted they're actual boards and not the pre-cut ones you unfortunately see a lot in dojos.

 

[sangchae]

I always wondered if board breaking, in some instances, encouraged bad practices.

For example, downward strikes. Now, I don't know how power is generated in most forms of Karate, but in my art, it's important that the "ground" is behind our strike; the elbow is underneath the fist, the body and stance is underneath the elbow, and the ground is underneath the body. However, if you're breaking something by striking down, aren't you using only your upper body strength, and getting absolutely no help from the stance and the ground?

As I said, most forms of Karate are probably different, but even in Karate, I'm sure that engaging your lower body when striking is important, is it not?

I like using board breaking to develop the ability to accelerate into a strike. I practice with unsupported boards (ie. throw it in the air and hit it). If your punch isn't fast enough it doesn't break. I usually use re-breakable plastic ones because it gives me a measure of improvement as I progress through the different grades of boards. It certainly lets you measure your progress, and for me destroyed my illusion that my left hand punched anywhere near as fast as my right! Even for downward strikes it helps you to develop the timing to drop your body weight into the strike at the right time. You're still using your whole body, just in a different way.

 

[JR 137]

I like using board breaking to develop the ability to accelerate into a strike. I practice with unsupported boards (ie. throw it in the air and hit it). If your punch isn't fast enough it doesn't break. I usually use re-breakable plastic ones because it gives me a measure of improvement as I progress through the different grades of boards. It certainly lets you measure your progress, and for me destroyed my illusion that my left hand punched anywhere near as fast as my right! Even for downward strikes it helps you to develop the timing to drop your body weight into the strike at the right time. You're still using your whole body, just in a different way.

I’m not the biggest fan of rebreakable boards, but I don’t hate them either; I’m pretty much indifferent to them.

The one thing I like most about them is they seem to have a significantly smaller margin of error regarding the striking target. I’d imagine breaking them in the air would be a lot harder than wooden boards. Have you noticed a difference?