Fun with physics

We made some good progress last night with smaller people using physics to control larger people.

Last night we were working on Tachi Gatame or standing controls.  Specifically head locks (Kubi Gatame) from linear motion (Irimi) and from opening motion (Hiraki)

Some of our smaller students were having trouble establishing the headlock on taller / bigger opponents.

One of the students is a mechanical engineer so I tried to explain the concept of Linear motion (MxA) generating circular force (F) in mechanical terms

Imagine a old fashioned steam locomotive

The piston’s linear motion drives the wheels causing them to turn creating circular motion

Now Imagine that on a different plane, parallel to the floor.

So for this technique the piston is your linear motion, entering to get off line.  That linear motion drives the wheel that is your arm (A).  So when your foot touches the mat your weight (M) is transferred to your arm.  Your arm (wheel) turns transforming linear motion into circular motion.  That circular motion (MA) becomes a scoop and you deliver that force (F) into your opponent’s neck destroying his balance (Kuzushi).  You continue that circular motion bringing your elbow down and back into your ribs.  Engaging all your large gross motor back muscles and trapping your opponents head on your shoulder.  Achieving the head lock.

Quod erat demonstratum.

The physical principles for opening are like a Matador’s cape

You open to get off line.  That motion pulls the wheel that is your arm (A).  So when your foot touches the mat your weight (M) is transferred to your arm.  Your arm (wheel) turns, that circular motion (MA) becomes a scoop and you deliver that force (F) into your opponent’s neck destroying his balance (Kuzushi).  You continue that circular motion bringing your elbow down and back into your ribs.  Engaging all your large gross motor back muscles and trapping your opponents head in your armpit.  Achieving the head lock.

Quod erat demonstratum.

From the video take what is good ignore the rest.  I chose this video because it is a nice example of using an opening motion to hook the head.  I do not advocate training off of "feeds" instead of attacks. 


[Violence happens: by surprise, closer, harder, and faster, then most dojo training]


Nor do I believe it is likely to be able to spin a guy a guy around in a tenkan out side of the Dojo.  However, this is a beautiful example of Hiraki that I can use as a visual aid.

Another motion we worked on last night was Shomen Irimi or direct entry.  Sometimes the only way to get off line is to go right up the middle.  It's not ideal but if you get stuck there you better have a way to get out. 

One of those ways is Juji Jime or cross choke.

The thing is this choke only works under Judo Gentalmen’s rules.  Namely I won’t hit you if you don’t hit me.  Also I’ll wear a heavy jacket you can use to get a grip on me if you wear one too.

So how do you make this technique work outside the dojo?


Impact Drives


I have come to use the term impact drive instead of striking.  The reason why is a drive implies the need to maintain a structure (Cow Catcher  / Plow ) and go through your opponent as opposed to striking and recoiling like a boxer.

 "In a real fight, 70% of Aikido is atemi (striking) and 30% of is throwing." There is a philosophy of striking that it's not simply about learning to punch and kick, but to use any part of the body to affect specific contact points.


 - Gozo Shioda quoting Morihei Ueshiba




Tachi Shime Waza (standing strangle techniques) Juji Jime (cross choke) Keishoukan Budo Style.
For what ever reasons you can enter, and you can't open so you have to go right up the middle.  In order to protect your self (cover the motion) you have to deliver an impact drive

Every move you do needs to

1) Secure your perimeter (keeps you covered)
2) Disrupts his ability to attack you
3) Sets up your next move.

So instead of reaching for your opponent's lapels, when you step through him (linear motion - Irimi ) between his legs you drive your forearms into the sides on his neck (Impact Drive).  Fold your palms over his scapula (shoulder blades).

[Bad guys might not be wearing a Gi, or even a shirt, but all bad guys have shoulder blades]

The bad guy will push back against your driving force or be off balanced both mentally (in the OODA loop) and physically. You can step and pivot in one motion.  So when your foot touches the mat your weight (M) is transferred to your arm (Impact drive).  As he freezes or pushes back, you pivot on that foot (open/ hiraki).  Use the open motion (MA) To deliver force (F) into the choke as you get off line.  Pull you hands push your elbows


Now you are off line - Secure your perimeter (keeps you covered)
He is off balanced and trapped on your line - Disrupts his ability to attack you
Best case he is asleep because blood is no longer getting to his brain. Worst case at least he will be easy to throw if the choke isn't working -  Sets up your next move.

OK, so this blog has been fairly technique and art specific.  What fundamental principles can you learn from this to apply to your own training?

Motion defeats strength. 

Learning how to generate and deliver force into your opponent is a vital key to any martial art. 
Gravity is a constant and unlike Ki, Chi, or the power of the force it doesn't take a leap of faith to use.

This is why you hear stories of tiny little masters tossing huge dudes across the room.  They understood applied physics and could deliver force into their opponent under dynamic conditions.
Train hard, train smart, be safe.....
and may the force (f=ma) be with you