First of all, this is not an argument with anyone as to
which is “better”, more “powerful” or a tribute to “our style does it
this way
and thus it is the correct way”.  Whether
Karate, Kung Fu, Boxing, MMA, etc., is not the issue here;  I don’t care
to argue with students with experience from other styles
or no.   I recall a student who quit after 8 years of
study in Wu style Tai Chi when he said: 
“You are studying Classical Tai Chi and I don’t understand why.  I can
see where Wu Style gets its power but
for the life of me, I cannot see where Classical Tai Chi gets its
power”.  As my teacher,
Master Stephen Hwa says, “They  do not
do “internal” Jim, so how should they understand”.


Which brings me to my next point and that is how Classical
Tai Chi gets its power. For that we have to do a bit of an analysis on how
Classical Tai Chi utilizes the body to derive internal motion but by means of comparison and an
understanding that internal energy comes from places in the body that most do not even
know exist.   In external styles , the
power comes from a tremendous push and surge from the back leg, driving the
punch forward.  I will not do further
analysis on how external styles “use the hip”, suffice it to say, that the back
leg acts to push and drive forward.  What
is obvious in external stylists, or even beginning Tai Chi students with no
experience however,  is how their spine
and lower back is tilted. 


Most of the students I have taught in Classical Tai Chi,
come to the discipline holding the hips in a position where the buttocks
are in
an anterior tilt.  What is an “anterior”
tilt? When I ask them to stand with their back to a wall they readily
see that
the small of the back is normally an accentuated curve, an anterior
tilt.  It is of course unintentional that the hips
are positioned in this manner but for the most part I believe that it is
related to the lifelong habit of using the legs to push the body
forward and back…in other words what we call normal walking.  In moving
forward for instance, the back leg
pushes, the front leg reaches or some would say “swings” forward, the
accompanying hip also “swings” forward and the back leg straightens. 
When the back leg straightens, the hips will
tilt back by default.  At the same time I
studied Tae Kwon Do and Isshin Ryu Karate,  I was also studying Tai Chi
and I could notice
such a contrast where the deeper my stance even when I was motionless,
the more
my hips seemed to tilt.


Not with the “Taoist” Style, Yang Style or even Wu’s Style,
but it was finally with my own personal study of Classical Tai Chi that I found
how incredibly important it was for the hips to be tilted forward which is
called “tucking” the pelvis or a “posterior” tilt.  In the world of Tai Chi “stances”, or “frames”
(the size of things), Classical Tai Chi is incredibly compact but is the poster
child for the cliché’ that good things come in small packages. The tailbone is
pulled under and down in a process where the spine is stretched both downward and upward
if the rules about “stretching the head” up are followed correctly.  When I have my students stand with their back
to a wall, they readily see  and perhaps
for the first time, that the small of the back can be straightened.


To add to the problem of taking “command and control” of a
tilted back pelvis (anterior tilt) in Classical Tai Chi a beginner will find
that it is also  quite a distance from
their pelvis to their shoulders.  As a
former Tae Kwon Do and Karate practitioner I had the disconcerting and
sometimes painful experience as a beginner of hitting the enormous heavy bag
while it was swinging toward me and finding that my shoulder gave way.  I of course managed to learn to correct this
problem but it is only later in my advanced Tai Chi studies that I now
understand this as a corresponding “giving way” or “disconnect” in my body
structure.  As a beginner in Tae Kwon Do
I was amazed as a beginner, at how little power I had when punching the bag.

Where exactly does the power or ability to deliver force go
when the hips are tucked under and when they are not?  For one thing I
have come to realize that the
road to connecting the torso or “core” of the body to the legs, as my
teacher
says,  goes directly through the pelvis
and hips.  In any fashion I can do this
by tightening my abdominal muscles but what happens when I stretch my
abdominal
muscles?  In the “anterior” tilt of
beginners that I  described ?  Well, this “stretching”(energizing) and
not “tightening” (tensing) of the abdominal muscles is exactly what
happens when the hips are back and not
tucked.


Then we come face to face with Newtonian physics as well
because we find our high school science teacher was right when he
drilled
“every action has an equal and opposite reaction” into us.  Hitting that
heavy bag with a punch “action”
can only be accomplished if your force is less than the amount of
“reaction”
support.  If the body muscles achieve a
great amount of muscular energizing (there are many who abhor the word
tension so we use energize)  when the fist hits the bag, then the
greater
the power in the punch.  I should point
out at this juncture however, that  the
“internal” style of Classical Tai Chi achieves such “great muscular
energizing” in
a manner far different than “external” styles as I explain forthwith.


There is another problem with the body’s ability to
withstand reaction force and that has to do with how much strain its structure
can withstand in delivering the punch. 
It is true that in an external punch the back leg “drives” forward but
that drive is mostly in a horizontal fashion. 
All of us humans align our body vertically however.  The horizontal “drive” line of force from the
back leg intersects the body at the point where it becomes vertical.  The result is an increase of pressure at the
hips and pelvis…where the hips are either tucked or not tucked.


One only has to think of a basic analysis of the physics
involved in why  sprinter’s start all races
in such a crouched position.  It is also
easy to see that sprinter’s keep the hip very “tucked” and in fact very well
“tucked” in the starting position. In that crouched position, with hips
tucked,  the push from the back leg will
also support a great amount of reaction force and as we know a great
acceleration can be achieved.  It is
interesting however that videos of sprinters taken while they are walking show
they have almost severe “anterior” pelvic tilts and buttocks that protrude
quite a bit.  Humorously, these folks do
not need belts to hold their pants up. 


Classical Tai Chi is where it all comes together because the
action at the hips and pelvis is dynamic. 
That is to say that the body will fluctuate appropriately between
“anterior” and “posterior” tilts of the hips. The back leg is also not acting
to powerfully “push off” like a sprinter. 
In fact, whether moving forward or back the lead leg (after all
depending on your viewing angle, a “back” leg can be in either front or back) is
pulling and not pushing.  Quite frankly,
the step size and vertical structure of Classical Tai Chi will not accommodate
a powerful “push off” from the leg, it would topple your body.  So the extreme “energizing” necessary to drive a
punch has to come from skillful movements of  the core and not the back leg.  In Classical Tai Chi we call such movements
“quarter body movement” and as an example, one “quarter” of the core itself is
actually fully engaged with the arm.  
The “quarter” of the body achieves extreme energizing and then it relaxes
instantaneously after the power is delivered. In doing so we can accomplish the
famed “one inch punch” so popularized by Bruce Lee…but we do not have to stand
in the large stance that he adopted to do so.

Any muscular energizing from the core will use the back leg to
act as a shock absorber to the reaction force from the punch. Not a
perfectly
straight back leg which had to work to drive the body forward either.
 Here is why we see,  it is also not necessary for the aficionado
of Classical Tai Chi to beat on a makiwara or heavy bag to “practice
their
punches”.  This in contrast to the
protestations of a student who lamented to both Master Hwa and I that he
had
not developed “self defense abilities” in his Tai Chi practice.  He was
going to study Wing Chun instead of
Tai Chi and build a makiwara so that he could practice his “power”
punches. In
studying the small frame stance of Wing Chun stylists, it is relatively
easy to
see they also “tuck” their hips under. 
The disillusioned student will be right back where he was in the first
place.  He certainly will not achieve
power if he punches the makiwara or heavy bag by holding back his hips
in an
“anterior” tilt from such an upright stance. 
Every time he punches with that tilt a great pressure will be exerted
against the spine in an unusual direction. 
Does he also plan to straighten his back leg in such a small frame
stance, thus compounding  the pressures
on the spine and small of the back?  How
will he stay “rooted” if he pushes off, or does he plan on his body
leaving the
ground with every punch?