The three dimensions of the human body, for our purposes in martial arts math, are height, width, and depth.
The height zone runs vertically from the top of the head to the bottom at the feet. The width zone runs side to side, horizontally, left to right. The depth zone goes in, toward the person, you or the opponent you face.
In Kenpo, the standard fighting stance is called the Neutral Bow.
From a normal standing position, with feet shoulder width apart, pretend your feet are on railroad tracks, and slide one foot straight back, keeping the other in place, and settle into your stance, with feet turned at 45 degree angles.
As you can see, the body is angled to limit available targets and so protect the body, yet mobility is not hampered and use of the rear weapons are still available. You are not facing square to the opponent nor are you completely side-ways, taking the safe but mobile middle-ground; in addition, the stance is not too deep or low, allowing, also, for greater mobility as compared to a deeper lower stance.
Furthermore, it should be noted that not only should you control the dimensions of your own stance, but you can manipulate and penetrate your opponent’s height, width and depth zones.
Manipulating and Penetrating Dimensional Zones
Here we see a basic technique in which the defender grabs and controls the opponent’s wrist and thereby “checking” him, and pulls his arm downward and diagonal and, so, canceling both height and width zones; doing so, prevents the opponent from kicking and from using his rear hand to attack; he must be somewhat open and standing straight to use his weapons, but you’ve effectively closed him off.
Man on right grabs opponent’s wrist
Man on right delivers a punch to the face.
As shown, defender also has a clear shot to one of his opponent’s targets.
The depth zone, which goes in toward your opponent, can also be controlled. This is done, in the most obvious way, with straight-line strikes into the opponent’s center-line. The opponent is forced to back-pedal, cannot get a base to fight from, and is totally compromised. This is similar to what Sun Tzu called Momentum in war; momentum can take on a life of its own and shouldn’t be stopped or diverted once it starts. In this way, you can overwhelm your opponent with your commitment to penetrating and compromising his depth zone and finishing the fight.
As attacker’s head comes forward from the groin kick, defender delivers a heel palm strike, doubling the impact.
As the attacker swings the club, the defender steps in and blocks and strikes at the same time.
So, it is important to understand dimensional zones to protect your centerline (targets) and to penetrate and manipulate the attacker’s zones so you can control him and keep him from endangering you. The more you understand this basic principle, the better off you are and better able you will be to control and finish the fight.
These two volumes of Ed Parker’s Infinite Insights goes into more details about dimensional zones and applications of these principles.