
I belong to several aiki discussion groups on social media, through which I've been able to establish connections (no pun intended) with numerous, top level instructors in the aiki community. One such group is led by Bill Dockery, the author of the "Aiki Secrets" book series which I have had the honor to review and highly recommend (to purchase a copy, click here), who is the inspiration for this article. An engineer by trade, Mr. Dockery always surprises me with his ability to articulate the fundamental principles of an otherwise misunderstood and somewhat esoteric practice such as aiki.
Mr. Dockery shared the video of this performer with the following analysis:
"The two most mis-used words in Aikido: Balance and Stability. This woman was balanced the entire time (she never fell), but had extremely little stability (a good shove from a toddler would have toppled her). Pop Quiz: A flat foot on the ground improves which: stability or balance? Have you though it through? Read on...
You are no more balanced with your entire foot on the ground than you are with just the ball of your foot, or even a toe. In all of these cases, you are not falling, so you are balanced! But they do vary in their stability. Thus, Uke's balance is not broken until you throw Uke, i.e., until Uke falls. What most call a 'balance break' is actually de-stabilization, the reduction in stability. It sounds pedantic, until you ask yourself,
'How do I make Uke unstable?, How do I 'willow' them?'
'What is the measure of stability?'
'If I know, will I know better how to create it in my opponent?'
'When, or at least what happens in that 'break' between stability and falling?'"

If you ask the average instructor, they will tell you that to achieve kuzushi is to "off balance" your opponent. It is the fundamental principle in every grappling art, the key to making your techniques actually work. However, Mr. Dockery's distinction that kuzushi is actually a "de-stabilization" rather than an "off balancing" couldn't be more accurate.
As aiki practitioners, we emphasize achieving kuzushi through internal vs. external means. While that sounds esoteric in nature, it's really just a misnomer that refers to making your movements so small that they are nearly imperceptible to the untrained eye. The most fundamental method of achieving kuzushi for us is called "aiki age," which is to uproot your opponent. Aiki age is the staple of Daito Ryu and all descendent systems, the benchmark by which you are measured on whether you know what aiki is and if you "have" it.
The classic form of aiki age is usually demonstrated from ryotedori (double wrist grab), and after what looks like a flick of the wrist the opponent is thrust into the air, standing on the balls of their feet and often accompanied by an uncomfortable look on their face. I won't get into the mechanics of how to make this actually work in this article, but most martial artists would agree that after the opponent is standing on the balls of their feet they are "off balanced," thus kuzushi has been achieved, right? Yes and no...

Most people can walk on the balls of their feet, so why do we work so hard to get our opponent into that position? As Mr. Dockery said in his post, it's because it's actually the stability that is removed when the opponent is uprooted, making the subsequent technique "effortless."
The most difficult training partners when practicing kuzushi, in my experience, are surfers and skateboarders. They have such a refined sensitivity to changes in stability that they are able to make micro-adjustments in their center of gravity faster than they can cognitively recognize the shift. Conversely, that is also the purpose of aiki - to be able to make micro-adjustments to the opponent's center of gravity faster than they can cognitively recognize, thereby creating an opening for us to apply our technique before they realize they have been compromised. The common maxim is that if you understand what just happened to you, it wasn't aiki. My own teacher, Steven Hatfield, puts it eloquently by saying, "Aiki makes you feel stupid" and it's true. You lie on the floor wondering what just happened, and how you ended up there.
The aiki arts specialize on the ability to capitalize on otherwise minor shifts in the opponent's stability, achieved through highly refined biomechanics, to subsequently subdue them with either a lock, throw or takedown. In the video below, I talk about the actual biomechanical processes used to create aiki sage, the opposite of aiki age which crushes your opponent down instead of uprooting them. Pay attention to the effects in the uke's body, and his reaction around the 1:45 mark.
At the end of the day, no matter how kuzushi is achieved, its purpose is to de-stabilize the opponent so that our follow-up technique is exponentially more effective in subduing them. As Kano once put it, "maximum effect, minimum effort." Kuzushi is the fundamental piece of the puzzle in the efficiency of any close-quarter technique, and having the most accurate understanding of what it really is, is the first step in being able achieve it.