- Straighten the spine
- Roll the pelvis forward
- Put strength in the tanden
- Relax the lower back.
- Squeeze the buttocks
These sound familiar, right? When I first heard these, they sounded like totally separate instructions (some of which made more sense than others). However, over the years it has become clear to me that these instructions are (on one level) all describing the same thing. These all refer to aspects of the exact same motion: a pelvic tilt that minimizes the lumbar curve.
STRAIGHTEN THE BACK
|Straighten the spine|
ROLL THE PELVIS FORWARD
|Roll the pelvis (pelvic rotation)|
PUT STRENGTH IN THE TANDEN
|Put strength in the tanden|
The main muscles involved in rotation of the pelvis forward are in the lower abdomen, and activating the muscles in the tanden area (putting strength in the tanden) will automatically pull the the pelvis forward (assuming there isn't equal activation of antagonistic muscles like the erector spinae muscles). However, the activation of the tanden area abdominal muscles is also important for creating a firmer connection between upper and lower body (discussed below).
Practice the pelvic roll several times and pay attention to the muscles of the tanden area.... Did you feel that contraction just below the navel? That is putting strength in the tanden.
RELAX THE LOWER BACK
In order to tilt the pelvis forward and minimize the lumbar curve the muscles of the lower back must be relaxed (because they pull the pelvis and back the opposite direction).
Utilization of (or tension in) the muscles of the lower back (assuming there is not equal activation of antagonistic muscles) will automatically cause the pelvis to tilt backwards and the lumbar curve to become more pronounced. Too much tension in the lower back is unfortunately very common in modern karatedo, and it is not uncommon to see karateka actually leaning backwards while punching. Anyone with even a rudimentary (or just intuitive) grasp of body-mechanics will understand that leaning backwards is totally contrary to the the goal of projecting mechanical force forward (as in a punch). It guarantees one will not hit as hard as one is able to hit, and it compromises the stability of one's body structure (making it easier to lose one's balance). If there was one feature of old-style karate that I could get practitioners modern karatedo to adopt it would be to relax the lower back and eliminate this counter productive backwards lean.
|Leaning backwards & pronounced lumbar curve|
Practice the pelvic tilt several times. notice how the muscles of the lower back elongate rather than contract.
SQUEEZE THE BUTTOCKS
|Squeeze the buttocks|
Next to the tanden muscles, the muscles most most responsible for the pelvic tilt (and therefore also the minimization of the lumbar curve) are the muscles of the buttocks. In addition to this, squeezing the buttocks helps protect the groin (to some degree) and creates an internal tension that can be felt along the inner thigh.
Practice the pelvic tilt several times, notice how the buttocks are engaged in the motion.
While writing this article I stumbled onto the image below on a fitness website. It is remarkable in that the right side of the picture illustrates all five of the kuden and shows their relationship very explicitly: Straightening the spine, rolling the pelvis forward, putting strength in the lower abdomen (tanden), relaxing the lower back, squeezing the buttocks
|Click to enlarge|
OK, now that we have shown the relationship between these five oral instructions, we should at least briefly discuss why a pelvic tilt that minimizes the lumbar curve is important. This can be summed up in one word: gamaku.
|_Okinawan-English Wordbook_ pg 47|
The primary load bearing structures in the human body are bones. One look at the bones of the torso immediately reveals something very important about the gamaku (waist) area.
The muscles involved in this squeeze are mainly the external and internal obliques (the external obliques are also involved in the pelvic rotation).
So when you combine the minimization of the lumbar curve, engaging the rectus abdominis muscles, and squeezing the obliques, you've enhanced the structural connection and stability between the upper and lower body. This in turn means that you have optimized the transmission of force from lower to upper body (and the reverse).
Now I realize some readers are thinking to themselves "Wait, I thought gamaku was some kind of whipping energy created through hip motion". Since these hip motions utilize the gamaku area, they can be considered an application of gamaku, but only if the basic structural gamaku I outlined above is being employed to create a firmer connection between the hips and the upper body. So the above description is "structural gamaku". Hip motions of various sorts can be dynamic applications of this structural gamaku. Another way I have heard it discussed is that structural gamaku is "basic gamaku" and the "whipping energy" can be considered "advanced gamaku" (it being based on "basic gamaku").
It is very important to understand that only a small number of Okinawan martial arts use this whipping energy to a significant extent, but all Okinawan karate uses (or should use) "structural" gamaku.
For a more detailed look at the use of gamaku in punching techniques please read my earlier article on the difference between modern and classical tsuki waza.