Kenshusei Training Jan 08: The use and effect of the opposite side of the body during striking.

In karate training we seek to draw maximum effectiveness and power from each technique. This is achieved by using the human body to its fullest. Through extensive study and many thousands of hours of practice and training it is possible to achieve levels of speed and power that may seem beyond the reach of “normal people.” Although we do train or bodies to be stronger and faster, the primary reason for a karate person’s ability to hit harder and faster is a function of muscle control. This is a function of contracting one and relaxing another muscle to achieve maximum speed while at the same time bringing the entire body’s weight to bear.
In each movement whether we are walking, jumping or punching there are multiple muscle groups involved. All movement requires the relaxing of one muscle or muscle group, while the other side contracts. Abductor muscles pull a body part away from the center line of the body. Adductor muscles pull toward the bodies mid line. The power that can be generated with one or the other will be greater if the opposite muscle can be fully relaxed and not pull against the movement. Additionally through the combined use of both muscle groups working in concert it is possible to generate much more power and speed than by using only one muscle group at a time.
One of the first things we learn in karate training speaks to this point, the idea of hikitte. In executing a technique with the upper body, punch, strike or block, the opposite hand is drawn back to a ready position at the hip. This movement is done vigorously and finishes at the same time as the primary technique. The goal is for both sides of the body to be contributing to the power of the technique.
There are many ways to generate power utilized by Karate-ka; changing vertical distance, rotation, vibration, contraction and expansion. Each of these is augmented by bringing the opposite side of the body into the movement.
There are people who, because of their size and strength, can strike with great effect. After learning to harness the power of the entire body focused into the same strike the effect is radically more devastating. A recent example of this was shown in a program aired on the Discovery channel called “The Human Weapon.” This is fairly anecdotal, but they tried to be as scientific as possible. Several martial arts styles were represented and each was given a variety of tasks is order to demonstrate whose style was best. Representatives from Tae Kwon Do, Karate, Boxing, Ninjutsu and others all participated. One of the few truly conclusive tests done allowed each practitioner to pick their most devastating technique in order to demonstrate the “killing blow”. A dummy was used and rigged with sensors and diagnostic equipment. From the data collected the scientists tried to show what the effect of each person’s strike would have been on the human body.
To make a long story short, the most devastating technique used was a hammer fist strike delivered to the solar plexus by the Ninjustsu practitioner. There were some striking things about this. One, he was the smallest of the group in terms of stature and weight. Two, there was no elaborate set up or grab necessary. And three, the strike was delivered from a standing position. How is it possible that this was the most devastating blow delivered from a group of self proclaimed masters? There was total body commitment and focus. No extra energy was wasted. The entire left side of his body was engaged as the right side delivered the blow.
In every technique there will be a dominant and non-dominant side. There will be muscles contracting and relaxing to complete the movement. The goal in every movement is for these opposing groups to work together to allow maximum function.
Punching: In delivering a straight punch or oi-tzuki there are several main points to keep in mind. For simplicity sake I will describe the right side oi-tzuki. As the right leg is propelled forward by the straightening of the left, the body should remain erect. As the lunch leaves the hip it should stay close to the body and only snap into fully rotated, final position as the front foot makes contact with the floor. The left side of the body must remain forward as the left hand is pulled into hikitte position. When the movement is finished, the right fist will be centered in front of the chest with the shoulders and hips square to the target.
There are many muscle groups involved in this motion. The abdominal muscles first and most importantly must keep the body upright and fully connected with the hips. The legs propel the body forward: the rear thigh and calf contract, the toes gripping the floor as the ham-string relaxes. The right arm is propelled up and forward by contracting the shoulder, tricep and pectoral muscle together. This requires relaxing the muscle of the bicep and latisimus. At the same time the opposite muscles are working on the left side to pull the left are back to the hip. The most important part of throwing the oi-tzuki and generating power is that the opposite (left) hip must remain even with the right so that the entire body weight can be propelled toward as a unit. All of the body weight is behind the blow and at the moment of impact the joints of the wrist, elbow, shoulder, hips, knee and ankle are all connected for a split second as the energy is transferred through the first two knuckles of the fist into the target. Force = Mass * Acceleration. The mass is provided by the body, the acceleration by the legs. In order for the full weight of the body to be utilized, the left side must be even with the right.
Striking with other weapons may be somewhat different but the same principals apply. Oi-tzuki is a specialized technique in Shotokan karate and we practice it continuously. There are many other weapons available to us. As an example of a different method of achieving a similar result let us look at chudan ude-uke. With the idea in mind that all blocks are also strikes and all strikes are also blocks, the fore-arm block is an excellent example of F=M*A through a round as opposed to linear movement.
The leg movements will be similar for block or punching but it is the upper body which follows a very different path. Again I will use the right side as an example. The beginning position of the arm for ude-uke has the elbow level with the shoulder, the elbow bent and fist close to the ear. The body begins square to the front/target area. As the left arm pulls back in the usual hikitte movement, the right arm is pulled around and down by the pectoral and latisimus muscles. This in turn requires that the back muscles relax to allow the arm to move quickly around into position in front of the body with the fist level with the shoulder and the elbow pointed toward the floor. The true power is generated not by the movement of the arm but by the rotation of the body. The left hip rotates sharply back while the right hip moves forward leaving the body turned 90 degrees from the target. The rotation of the entire trunk along with the movement of the arm puts the entire body’s weight behind the block. The center line of the body is the center of the rotation as well. As both sides of the body spin the total energy is transferred to the target through the contact point of the arm.
Based on these principals of contraction and relaxation coupled with rotation, the power of the human body is magnified dramatically. It is through use of the entire body as a complete system that this is possible. All blocks, strikes, kicks and punches are thrown not with the limb delivering the blow alone. The opposite side of the body has as much to do with a powerful technique.