In 40 years of martial arts study, there have been a few lightbulb moments - times when I feel I uncovered something special in my understanding. I am still a beginner, but my foundation in aikido and Japanese traditional methods coupled with my Kali Majapahit research and study has helped me find various points of common ground and make some sense of what my teachers have tried to instill in me. In particular, Guro Fred Evrard's careful lectures on body structure and mechanics deepened my own understanding significantly.
We are principally concerned with three physical power chains in the body, recognizing that our main goal is to keep these active and functional for ourselves, while at the same time (or at least as a minimum) denying them to our opponent. These chains are:
Head/Neck/Spine
Shoulders/Hips
Elbows/Knees
All three have important roles to play for various reasons, and it helps to consider how we use them and also prevent their use against us. Taken together they form a kind of sideways "letter H" or an uppercase "I" across the body, in some similarity to the design of an automobile powertrain which delivers energy from the engine to the wheels.
Head/Neck/Spine
This is the central drivetrain of the human body, where electrical impulses beginning in the brain are carried through the neck down the spine to activate muscular action. Head/neck/spine are also aligned on the body's centerline. As such, this is the most important chain of the three. If the head/neck/spine does not maintain integrity we cannot generate power and strong disruption can even short-circuit the body's central nervous system. The neck is a critical part of this chain since without a bone structure such as the ribcage, much of the soft tissue and nerves are exposed and vulnerable to attack.
The head is encased in bone (skull) designed to protect the brain. Thus, as a target it is generally inferior to the neck. However, soft tissue such as eye sockets/temples still exist and can be leveraged. Furthermore, moving the head has a chain reaction effect on the neck and spine and the head has natural handholds (ears/hair/eye sockets/mouth) which make it easy to grab and manipulate.
When training, we should pay careful attention to the posture and alignment of the head/neck/spine chain since if it is not straight it limits power generation achieved through spinal rotation. Many students lean or cock their heads and this is to be avoided/corrected so the spine remains straight.
For the spine, it is usually well protected by muscles of the back and can be hard to attack. The tailbone is a notable exception and can cause disruption through the whole spinal chain when damaged. This can be done using strong, direct knee strikes or also by causing the opponent to land heavily when sitting down backward from a sweep or drop.
Shoulders/Hips
These are the identical ball joint structures on the high and low lines which are responsible for transferring power from the spine to the extremities (arms and legs). Both are extremely useful in reading the opponent since these need to move before the extremity moves. Thus, when keeping peripheral vision tuned to the shoulders/hips it becomes far easier to understand the opponent's intent and respond accordingly. Of the two, the hips are the body's principal engine of momentum and where the greatest power generation can occur. Denying the opponent the ability to engage their hips is tantamount to victory on the ground, and key to reducing mobility when standing. When we employ throws, it is very common to load the opponent onto our hips in order to deliver strong spinal rotation and drop our bodyweight on top of them. Success in judo relies on strong hip rotation and naturally many judo counters depend on stopping the opponent's hips.
The shoulders as well are a key area of focus, and strikes to the front of the shoulder can result in checking the opponent's arms, often as we enter into close range. There are a variety of locks and controls that can be applied to the shoulder in order to dislocate it or to secure the lower arm. It is far easier to control the head/neck/spine via the shoulder than it is via the wrist since it is closer to the centerline.
Taken together, the 4 points (both shoulders and both hips) represent "the box" within which most of our vital organs are contained. Therefore, keeping the opponent outside this box, and conversely gaining entry to this box on our opponent, becomes of primary importance when fighting.
Elbows/Knees
Often overlooked, elbows and knees are critically important in maintaining body structure. Like the barrel of a gun, where they point, the energy goes. As such, it is important to consider the line of the elbows and knees when transferring power from the spine to the hands/feet via shoulder/hip rotation. Likewise, manipulating the opponent's elbow creates a direct path the the head/neck/spine via the shoulders. Since the elbows are a more easily accessible contact point, a variety of aikido techniques (Ikkajo, for example) focus on controlling the elbow in order to take balance and control the opponent. Organizing aikido techniques based on which point is used to control the head/neck/spine is a good exercise for clarifying what understanding is meant to be learned by practicing each specific technique. Basic practices such as hiriki no yosei (elbow power generation) are, as the name implies, specifically designed to emphasize the connection between elbows and hips to improve technique. Keeping elbows in/armpits closed is good advice from a variety of arts including the Hakka systems as well as Aikido.
Knees of course can be used to disrupt the hip line and therefore the spinal integrity from the bottom up. However, it is also very important to understand how important knee alignment is when transferring hip power. The knees are critical not just for delivering hip power through kicks, but also for delivering hip power into upper body strikes, throws and projections as well. The knees and feet should point in the same direction and be aligned the the facing of the hips to allow for maximum rotation and energy transfer from the feet into the spine via the hips. We keep this connection by use of the sliding step (suriashi) and by flexing bodyweight onto the balls of the feet by bending the knees and pointing them into the target. The same body mechanic can be observed by baseball batters, golfers, cricket batsmen, football quarterbacks/baseball pitchers, soccer players, gymnasts, skaters and other athletes whose performance depends on generating power through spinal rotation.
A lot of conversation is spent comparing one martial art to another, but in the end those arts concerned with body mechanics have in common the fact that humans are all fundamentally the same. Our bodies generate power using the same basic principles, regardless of whether we do aikido, karate, tae kwon do, muay thai or anything else. In our studies, we should learn elements of psychology, philosophy, anatomy and body mechanics in order to be a well-rounded martial artist. There is no substitute for training, but thinking deeply about the WHY of our movement may also yield some practical insights.
