The Physics of a stick strike

[Crafty_Dog]

Just got this question from a TV producer.  Anyone have a good and/or clever answer?
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Me again, in regards to the Time Warp segment you all did on stick fighting!  The Discovery Channel is asking for a bit more information on the force of the blows a rattan stick can wield.  Something along the lines of how a stick wielded at this speed striking a man weighing XXX pounds would exert XX force.  I’m not sure how we can address this (seems like too many variables) but
do you have any suggestions?

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[c - Shadow Dog]

A friend of mine is a doctor, while he was in medical school  many moon ago we were all on a camping trip sitting around the fire.  The question came up what exactly "was/is" fire.  He gave a long drawn out chemical explanation of fire, at the end of his explanation I simply added that fire is hot.

Some times science distorts the most primal reality's.

To me the answer to the physics question isn't a quantitative one but a more visceral one.

2 cents


woof,

terry

[maija]

Don't they have that 'impact gel" to tests like this?
My Toyama Ryu teacher was hired by the "Myth Buster" people to test the force of a katana strike (to test whether a sword could actually cut another sword, or not). They used this gel to cut into .....
Traditionally isn't there there old 'coconut test' ?

[Karunamama]

Speaking of the Mythbusters, why not see what damage a stick can do to a crash test dummy?  Some have instrumentation to record the data from a crash, I'm sure that would carry over to measuring the impact of a stick.

Karen

[Kaju Dog]

Im with Crafty on this one...   "Too many variables"

Size/weight of the stick
Speed of a power stroke
Target (soft/hard)
Contact surface of both the target and the stick
(just to name a few)


Just too much to analyze...

IMO, I say have one of the film crew put on a helmet, and then toss him/her into the kennel with a few of the Dogs.  Nothing speaks better than actual experience.
 

[Freki]

I have a question...What type of stick do you like to use.  A heavy one or a lighter one?  The reason I ask is I have heard that, and I might get this wrong this is not my thing, that the energy goes up linearly with mass but exponentially with the velocity.  So when you fight do you do more damage with a fast light stick or a more massive one?  Ideally you want a fast heavy stick if I got the physics right.  Maybe you could answer the question based on your feel during a fight.

My 2 cents hope it gives you an idea that might lead to the answer.

[Blackwolf_101]

Woof Crafty

I think the appropriate way to approach this from a scientific angle would be to determine The impact pressure in #/square inch.  the power formula looks like this

Power = Velocity x impetus or driving force.

you could have someone demonstrate the power of a stick strike On a heavy bag with some kind of Force plate which demonstrates the power in pounds or kilos or whatever and then  use either a radar gun or one of those machines that measures the velocity of arrows or paintballs to measure the speed of the swing -sorry i forgot what that machine is called...  - 

I saw a clip from a british series on you tube a while back where the host used a baton to crack open a coconut with a #2 strike. he stated that the thickness of the coconut was comparable to the thickness of a human skull. i was searching for that clip to  post a link to it in this reply but i think it has been deleted because I can no longer find it.  i am not sure of the power needed in pounds per square inch in order crack a human skull but I am sure that is can probably be replicated By a well targeted strike  with the end of a hard heavy stick.

[Kaju Dog]

I have a question...What type of stick do you like to use.  A heavy one or a lighter one?  The reason I ask is I have heard that, and I might get this wrong this is not my thing, that the energy goes up linearly with mass but exponentially with the velocity.  So when you fight do you do more damage with a fast light stick or a more massive one?  Ideally you want a fast heavy stick if I got the physics right.  Maybe you could answer the question based on your feel during a fight.

My 2 cents hope it gives you an idea that might lead to the answer.

Great question, one that opens up a whole new discussion.

Personally, I am aprox. 5'7"  and I inherited my mothers hands (small and boney)   (size 7 1/2 surgical glove)

I train alot with both heavy and light sticks.  I prefer to fight with roughly something in between.  The larger diameter, heavy sticks tend to not stay in my grasp when engaging but certainly pack a wolop.  "Big stick, big stars"  - GM Estalilla (Kabaroan) ...  but I better get it right the first time because I may not be able to hold onto the weapon after contact.

I find a lighter, smaller diameter stick can move like lightning and I am able to react faster (striking/blocking) as well as be more agile. 

I supose I could tapper down the handle/grip area on a larger stick, but then you get into stick balance, etc. 

It makes me think of the difference between a jab and an overhand right.  Both are great tools, but must be used with the right timing.

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"Ideally you want a fast heavy stick if I got the physics right."

IMHO - Yes, if the grip is right for you. 

Anyone that has transitioned to fighting with either Hockey Gloves on and then found themselves changing to a more form fitting glove after fighting with them on should understand.  As my confidence & skiill improves, I find that the less protective gear I wear when fighting, the more freedom I have to apply skill.  Depending on my opponent, I play the odds...  It's not, "am I going to get hurt, it's how bad Im going to hurt".

TAC

PS
I think I started to ramble - 

[C-Kumu Dog]

Does this help?

[youtube]http://www.youtube.com/watch?v=qH309YwzxsY[/youtube]

[Scurvy Dog]

If I'm not mistaken this clip continues and ends up showing the force exerted by Dan wielding the stick. I tried to find a continuation of this video but eventually gave up. I'm sure Guru Dan Inosanto has a copy of the video? They are for sale on the NG website as well...

 


Edit: Maybe not, I found a longer clip in French and didn't see it as I fast forwarded through.
http://www.dailymotion.com/video/x61wfg_la-science-des-armes-23-avec-dan-in_tech

[Stickgrappler]

woof all:

didn't discovery or nat geo have some program where they measured bas rutten's punch? or randy couture's GnP? they hit something which allowed the scientists to measure and quanitify the punches.  they should be able to set something up for stickwork.

re:  gripping a heavy stick and accelerating it at a target... there is the aluminum baseball bat where it's a smaller handle and the bigger bat head

[Tom Stillman]

              If I were to measure the power of a stick strike, I think a reverse back hand power strike would be the technique to use.   
           
                                                                                                                                                                                                                BTW, Guru Inosanto still moves like a young man.  He is simply amazing!   

[Karunamama]

woof all:

didn't discovery or nat geo have some program where they measured bas rutten's punch? or randy couture's GnP? they hit something which allowed the scientists to measure and quanitify the punches.  they should be able to set something up for stickwork.

The Mythbusters measured Jon Fitch's punch to calibrate a robot for testing the plausibility of the scene in "Kill Bill 2" where Uma Thurman's character punches her way out of a coffin.
http://www.youtube.com/watch?v=1iGzYZlaCOs