SUBURI SWING SPEED STUDY
By: Ueda Fumio & Yoshida Yasumasa - Keoi University, Japan
Translated by: Matt (Kingofmyrrh - Kendo World Forum)
In your daily practice, to what angle do you swing up the shinai, and to what
position do you swing it down to? In Heisei 10, at the 31st Japanese Budo Forum,
two pieces of research were presented: 'Changes in suburi - in particular changes
caused by kensen position at the apex of the upswing - due to variations in kendo
teaching methods' and 'Suburi teaching methods in kendo - variations in arm action
at the terminal position during empty striking'.
The researchers were a group centered around Professor Ueda Fumio (kyoshi 7
dan) and Assistant Professor Yoshida Yasumasa (7 dan), both of Keio Gijuku University.
Both researchers have since further advanced their research into suburi, and
continue to scientifically search for the most effective suburi. Here, they
explain suburi that is effective in actual use.
DOUBTS TOWARD AMBIGUOUS INSTRUCTIONAL METHODS
I see this every year in my role as kendo club coach at
Keio University, but when it come to university kendo clubs, the members gather
together from all over the country. Even though we can raise suburi as an
example of something that each of the students has been taught, the fact is
that it varies wildly according to their home region. I felt that in order
to be able to instruct all of them, it would be necessary to start by teaching
them exactly what correct suburi was. At Keio University, there are not all
that many students who achieved superb results in competitions during their
high school years; in fact, there are many that are close to beginners [this
is a somewhat relative description!]. I thought that by having them master
correct basics as best they could during their 4 years here their skill level
would rise. Taking up a shinai and striking each other is something that cannot
be done without an opponent, but suburi is something that you can do by yourself.
I feel that important factors in kendo are kamae and suburi. These days we
have machines so we can easily do strength training, but in the old days they
didn't have such things. It was most likely suburi itself that was strength
training back then.
At every Japan Budo Forum, a research topic is presented. In Heisei 10,
Keio University was used as the venue, and we performed the role of hosts.
When we then wondered what we should present research on, we hit upon the
idea of presenting something about suburi. I looked into the position of
the downswing, while Yoshida sensei led those who got to work on the angle
of the upswing.
I first turned my eye to the instructional methods of 'swing
back until the shinai touches your buttocks' and 'swing up such that the angle
of the shinai reaches 45 degrees'.
Talking about the '45 degrees' method, we were somewhat
concerned as to whether one could discern what angle the shinai was at, since
it was in a position behind the body where it could not be seen. We wondered
whether it was really necessary to stipulate the angle to which the shinai
should be swung back to, and whether it wasn't possible just to teach a naturally
flowing backswing movement without specifying an angle. We also had our doubts
as to which stopping position was best for the downswing position. When talking
conceptually, suburi is often taught in terms of stopping the right fist at
the height of the right shoulder. However, we were aware that when we did
suburi we often stopped the kensen at the height of the opponent's head. If
you stop with your right hand at the height of your right shoulder, the kensen
comes to a halt at quite a high position. I carried out my research into the
downswing of the shinai from a stance of trying to find out just which of
these suburi methods was most effective.
As far as I am concerned, the suburi method in which you swing back until
the shinai touches the buttocks, so called 'jogeburi' suburi, is a method
used to instruct children. It's difficult for children to understand if
you just tell them to 'swing straight'. By having them line up the shinai
with the coccyx, you can teach them a straight shinai path.
In fact, in the suburi described in the All Japan Kendo Federation's 'Points
for the Instruction of Young Children' there are only two types, 'jogeburi'
and 'sayufuri'. Swinging straight down at an imaginary opponent is distinguished
with the name 'shomen strike'. In other words, it is seen not as suburi
but a movement that comes at the striking stage. Despite the fact that suburi
where one stops the shinai at shomen is actually carried out, it does not
exist as a term. In this research, we used the name 'air shomen suburi'.
Most likely 'shomen strike' refers not to suburi but to
the movement that comes at the stage when bogu is worn and actual striking
is carried out. In Nakano Yasoji's 'An Illustrated kendo Dictionary' there
is something called 'advancing and retreating men strike suburi', which is
probably safe to think of as shomen suburi.
Kendo suburi and basic techniques came to be standardised
after the war, from around the latter half of Showa 30s to the Showa 40s.
The central figure of that time was Nakano Yasoji sensei. Since 'An Illustrated
Kendo Dictionary' was put out by Nakano sensei, it naturally became the basis
of postwar instructional method.
If we go even further back from there, we arrive at Takano
Sasaburo sensei's 'Kendo'. This 'Kendo' is the start point. As such, the makeup
of many instructional texts that followed was the same as that of 'Kendo',
and there are many texts that use almost the same terms.
At present, research into kendo is carried out from every
possible viewpoint, but surprisingly, there has been almost no research or
data on suburi.
RESEARCH INTO THE UPSWING MOVEMENT
For this investigation, we obtained the cooperation of five
subjects with kendo experience, ranging from 3rd dan to 7th dan, and five
subjects without kendo experience. Yoshida sensei also used the same subjects
in his research.
Yes, Ueda sensei looked at an electromyogram (EMG), and I
carried out analysis of movements using a high speed camera. For these observations,
we first divided ways of swinging up the shinai into four types (see illustration).
We designated swinging back as far as the buttocks as suburi 1, and from there
suburi 2, suburi 3, and finally we designated swinging up to 45 degrees as
suburi 4. We selected these 4 classifications based upon photographs of suburi
that we had seen in various instructional texts and kendo magazines. Actually,
while no matter which book you read the explanatory text is pretty much the
same; the photographs of suburi are almost completely inconsistent. We looked
at these photographs, and while there was a suburi method in which one touches
the buttocks, there was also talk of swinging up such that the kensen would
thrust into a wall behind you, with the shinai horizontal. Then again there
was some where the shinai was swung so that it pointed diagonally up. We divided
these into four types.
4 Types of Suburi Tested:
- Swinging upward at a 270 degree angle
- Swinging upward at a 225 degree angle
- Swinging upward at a 180 degree angle
- Swinging upward at a 135 degree angle
When Yoshida sensei said to me, 'It seems that there's also
a method in which you swing back as if thrusting into a wall behind you,'
I argued that that was ridiculous. This is because if you swing back as if
to thrust into a wall, your elbows will end up going behind your head. I felt
that this type of upswing was probably inefficient.
Before starting the investigation, we had our subjects actually
practice the four types of suburi. We made the same subjects perform all four
types. Next, we measured which of these swinging methods produced the greatest
kensen speed at the point of swinging down, measured at phase 8 (see phase
Speaking from the results, suburi 3 was found to give the fastest kensen
speed. The slowest was suburi 4. If I were to try to explain, it would seem
that because with suburi 4 you are in a situation where the shinai has merely
been thrust upwards, it is not possible to smoothly switch to a downswing
action. In the end, all that you can do is swing using just the power of
Additionally, from doing this research we became aware of how difficult
it is for humans to calibrate angles at a position not visible to themselves.
Speed Comparison Graph
During the investigation, when we had the subjects perform the four types
of suburi, we instructed them to 'swing back to this position,' but the
point to which they swung was rather varied. At first they swung to roughly
the designated point, but there was a trend for their upswing to become
steadily larger as they continued to swing the shinai. The result was that
suburi 3 was the fastest, but their actual backswing was somewhere between
suburi 2 and suburi 3. I think you'll see what I mean if you look at the
graph of 'variation in kensen speed'. This graph is of subject M. In his
case, suburi 2 is fastest. Next is suburi 1 and suburi 3.
Based upon these results, we tend to feel that while there
is no problem as long as the angle is at a position that can be seen, trying
to specify angles outside of the field of vision is not a good idea. Expressing
it in terms of getting somebody to look from the side and find the rough angle
is probably better.
INVESTIGATION INTO THE TERMINAL POSITION OF THE DOWNSWING
We designated two kensen stopping positions. One was the
position reached when stopping the right hand at the height of the right shoulder,
and the other was the position reached when stopping the kensen at the position
of the head of an imaginary opponent (see illustration). Since opponents come
in all shapes and sizes, we went for roughly one's own head height. What we
were looking for as a result was a movement close to that of actual combat.
The fact is that suburi that has an effect on the actions of actual fighting
is good, so the suburi that showed a balanced distribution of power use when
viewed on kindenzu would be the best.
We investigated which of suburi 1 and suburi 2 used the muscles most effectively.
We took measurements with an EMG, constructed a graph and looked at the
results (see 'muscular electrical output of suburi 1 against suburi 2').
For this, we did not make any stipulations with regard to the backswing.
Looking at the results, with suburi 1, where the right hand
stops at the height of the right shoulder, we see a situation in which tension
remains in the right arm for a long period. Tension in the right deltoid was
seen especially frequently. It continued to be tense even after finishing
cutting men. On the other hand, with suburi 2, where the kensen was stopped
at head height, the tension soon disappeared when cutting down.
In actual fighting, two step strikes and continuous strikes
are essential. In order to move quickly to the next movement, it is essential
to first shift to a state of relaxation from the state of tension that exists
after making a strike. With suburi 1, the muscles are constantly tense, and
the shift to the next action is not smooth. We can state that suburi 2 enables
muscle usage more in line with the movements of actual fighting.
As an aside, we only specified the kensen stopping height for suburi 2, but
when we started the experiment, we saw that most of the subjects brought their
fists down to the solar plexus.
In this experiment, we stretched a piece of rubber at each
of the stopping positions of right shoulder height and head height, and measured
the tip speed when the kensen touched this rubber. In the case of suburi 1,
we saw that the maximum tip speed occurred not when it touched the rubber,
but prior to that point.
THE MOST EFFICIENT SUBURI
We would like people to think of Yoshida sensei's research
on the backswing, and my own on the downswing, not separately but together.
That is, that suburi performed with the upswing and downswing that resulted
from this research is effective. In conclusion, effective suburi would be
something like the following:
First, with regards to the upswing, 'from kamae, raise both elbows as far
as they will go'. The position of the kensen is not specified.
However, there is one important condition here, which is
not to loosen the grip of the left hand. If you loosen it, you end up with
a different movement.
That's right; you must raise the arms whilst gripping the
shinai properly. This is an important condition. If you think about it, it's
doubtful whether suburi 1 from the upswing investigation can be performed
with correct te no uchi in the first place.
That's right. As long as you don't loosen the grip, it's
pretty difficult to get the shinai to reach the buttocks.
As for the downswing, you should 'swing down so that the kensen reaches
your own head height'. It's best to just specify the kensen height, and
not the height of the arms. Since everybody has a different physique, the
position of their head will also vary.
One other thing that I can explain with confidence from
the results of this research is that you must use the shoulders, then the
elbows, then the wrists, in that order, such that it becomes a shoulder
joint-centric movement. Best of all is to make full use of the snap of the
wrists, rather like a whip. Something often seen with suburi where the right
hand stops at shoulder height is people who go directly from the shoulder
to the wrist. It ends up being a movement like a pole, not a whip.
If you do suburi in this pole-like state, the extra effort
required leads to extra fatigue, and repeated many times, there is even
the possibility of damaging the elbows. If the elbows extend flexibly, the
burden on them should be less.
There is a teaching often used when striking men, 'after
you've struck men, extend both arms'. You'll soon see if you try to do this
that if you try to extend the right arm when the body is facing forwards
then the left arm bends. To extend both arms, you have no choice but to
take a hanmi stance. It's difficult to describe this as correct suburi.
Yoshida: If those teaching just say, 'Stretch out your arms, stretch them!'
then it's difficult for those being taught as that's just what they will
try to do. Something like 'you should end up with both arms extended in
front of you' is probably a better expression.