Force and Power of Okinawan Nunchaku

Dai-Shihan Ben Froidevaux, 6th dan and All-Europe 
representative of Seiyo no Shorin-Ryu Karate
Kobudo Kai

With today's unrest, one might consider carrying self-defense weapons, such as nunchaku. Nunchaku can generate tremendous forces when handled by a properly trained martial artist. But, the weapon must have sufficient mass, and the martial artist using nunchaku must be able to rapidly accelerate the tool to develop necessary kinetic energy to cause damage. 

Those who train at the Seiyo Hombu start with foam-rubber chuks during bunkai (self-defense) and kumite (sparring), or some train with DIY magazine-chuks (see link in list under the blog title). But even foam-rubber and magazine chuks can generate considerable force when handled correctly. 

We had a father and daughter combo in our dojo some years ago, and was able to film her (about 7 years old) creaming her dad with foam-chuks. The father ended hopping up and down on one foot, holding the other foot in his hand, after she had smashed his foot without warning with foam chuks, I asked permission to send the video to America's Funniest Home Videos and told him I would divide the winnings with him because we had a winner - but the father refused. 

In Shorin-Ryu Karate and Kobudo, students are taught not to use their karate or kobudo against another except in self-defense, as nunchaku can produce some impressive forces. According to one source, a nunchaku tip of 6.3 ounces, can accelerate to 88 meters/second (282 feet/second) and generate 350 joules of kinetic energy. According to this source, this would equal the energy generated by a bullet fired from a Colt M1911! But, a nunchaku will not penetrate a body, unlike aerial dynamic bullets with high specific gravity. Luckily, few can generate this kind of force with nunchaku.

Nunchaku made from two magazines and tape

Human bones are strong! For instance, a bone can survive a strike of 10,000 joules of kinetic energy (3,700 foot-pounds of force) as long at the strike is perpendicular to the surface. Additionally, most bones are padded with soft tissue to adsorb the impact. But a strike at an angle of less than 15 degrees can potentially fracture a bone with about 375 joules of kinetic energy (277 foot-pounds of force). Keep in mind that each bone in the human body, had different masses and different amounts of padding.

The impact-force of nunchaku depends on the speed of the nunchaku and surface area of impact. The damage to a person depends on how fast that chuk travels, the mass of the chuk, and the surface area the force is applied to. In addition, if the surface is soft, such as a stomach, the flesh will absorb considerable amounts of kinetic energy. But if the surface is a hard (such as a collar bone with little surrounding flesh) the damage will be greater (Hausel, in prep).

The tip of a Colt M1911 bullet has a surface of 25 square-millimeters, thus the impact force is calculated as 350/25 = 14 joules/square-millimeter. But if a nunchaku strikes the same surface, the impact force will be notably less because of the surface area, or size of nunchaku. So, we might end up with about 350/100 = 3.5 joules/square millimeter, or essentially 4 times lower impact force than a bullet (assuming that the striking area of the nunchaku is about 1 square-centimeter (0.15 square-inch)). This is why octagonal nunchaku are more effective than round nunchaku. Because of the geometry of the octagonal chuks, the chance of hitting a target with one of the eight octagonal edges is relatively high, and such a smaller surface area will result in an increase in impact force. 

Nunchaku-jutsu, Seiyo Hombu in Mesa, Arizona

Because of small bone diameters with minimum amounts of soft flesh enclosing finger and hand bones (as well as many nerve endings), fingers and hands provide good striking surfaces. Other targets with little soft tissue include toes, ankles, shins, elbows, collar bones, and the head. But one should always avoid the head, which has areas that could lead to death if struck with nunchaku.

In the following video, Soke Hausel of Seiyo no Shorin-Ryu Karate Kobudo Kai, demonstrates one of many kata. It is important to learn to handle kobudo weapons, with force, speed and power, but don't try this without proper guidance, as you can easily end up with a serious injury if you strike yourself, or are struck by another person, or receive a strike from a ricochet of nunchaku. And hospitals today, are places to avoid, unless you appreciate violation of constitutional and human rights. 

Hausel, W.D., in prep., Making of a Grandmaster: traditional Okinawan Karate & Koabudo in North America, in preparation.

LEARNING TO USE NUNCHUKS

Ouch, momma mia, thud, whomp, eeeek. Some sounds expressed by real people when learning nunchaku - an Okinawa peasant tool converted into a weapon. Yes, in the old days, it was a pain to learn to use nunchaku, that’s because all nunchaku were hand made from hard wood and chains. But nowadays, this is remedied by foam-rubber chuks, paper chuks, etc. 

It wasn’t until about 1969, that I was introduced to kobudo (5 years after I began training in karate). The first Okinawan weapon I was introduced to was nunchaku. Nunchaku at the time was new in the US, but made very popular by Bruce Lee’s movie Enter the Dragon and also introduced by Sensei Yamashita about the same time. The origin of this weapon/tool is controversial, but thought to be indigenous to Okinawa, with possibilities of originating in China. 

At the time I was introduced to Nunchaku I was a student of geology at the University of Utah. Apparently, no one had thought to make nunchaku out of a material that would not bruise those of us who trained with it. In fact, nunchaku was not available on the market in the US as far as I’m aware, so we typically made our own using two pieces of hard wood, added a crown bolt to the end of the sticks, and attached a short chain between the crown bolts.

So bruises were self induced during kobudo training. Swinging a nunchaku around the head, against ones hip, under the arm, between the legs either made one tough, or quit. Me, I continued to train and periodically negative reinforcement from hitting myself in the shin or elbow began to imprint in my mind that if I wanted to survive kobudo, I had to remember not to bring that stick so close to my shin when swinging downward. Self-preservation kicked in and I seldom hit myself again. But learning nunchaku provided some unique sounds in the dojo when various individuals would strike shins, elbows, groins, and even their heads as each appendage provided a different sound and different response from the person learning to use nunchaku. 

Today, nunchaku is a lot easier to learn. Martial arts supply houses sell padded chucks, and one can even make their own chuks using magazines and/or duct tape. And I still teach nunchaku to my students around the world and at my Arizona Hombu Dojo in Mesa, Arizona. The tool is not as popular as it once was, but it is something that I still love to train with in kata and self-defense applications known as bunkai.

Soke Hausel teaching nunchaku clinic at the University of Wyoming

Training in kobudo at the Arizona Hombu Karate Dojo in Mesa, AZ

Soke Hausel demonstrates applications of nunchaku to members of the Utah Shorin-Kai at an outdoor clinic at the East Canyon resort near Park City, Utah.

Okinawa Nunchaku classes in Chandler, Gilbert, Mesa Arizona

The nunchaku is a challenge to learn, but with today's foam chuks, it is easier than in the old days when all we had were
  nunchaku we made ourselves from whatever wood and chain we could find. It resulted in many bruises and in some
practitioners not being able to have children (just kidding). But we mastered the weapon after many bruises. Most people
 today have it easy as they start with foam chuks. The problem with foam chuks is that  they are very cheaply made with a
 breakable plastic cylinder that shatters. Nunchaku was designed as a blocking, striking and grappling weapon that did not
require many release (swinging) strikes. Kata will teach you proper muscle memory, blocks, strikes, etc.

Nunchaku (ヌンチャク,), a traditional karate weapon of kobudo (沖縄古武道), can be found at the Seiyo no Shorin-Ryu Karate Kobudo Kai Hombu in Mesa Arizona. This traditional karate weapon is taught along with the empty hand of karate as has been the case for karate and kobudo for  centuries on Okinawa. Classes in this Okinawa weapon are taught to all of our adult and family students at the border of Chandler with Gilbert & Mesa Arizona on Kobudo nights at our dojo (martial arts school). Children are also introduced to kobudo weapons as they train with their parents.

Members of the Mesa Karate school (dojo - 道場) and learn to use the nunchaku, not like a twirlers baton seen in many schools where a martial artist is more of a danger to oneself than to others, but instead, students at the Arizona Hombu learn to use this classical kobudo tool as it was intended: a weapon of self-defense along with kata and bunkai.

Seiyo No Shorin-Ryu Karate Kobudo Kai members can receive certification in this karate weapon after about a year of  training where they learn kihon (基本) (basic blocks, strikes, stances, chokes), several kata (型) (forms) along with bunkai (分解) (practical applications) and kumite (組手) (sparring). One must also come into the dojo with the proper spirit of learning 'Self-Defense' rather than 'Self-Offense', if they want to learn.

Both men and women learn to use the nunchaku at the Hombu dojo. 

Ben attacks with knife only to have it parried by nunchaku during kobudo class