The Kinetics of Kokutsu dachi

 The Kinetics of Kokutsu dachi

 

Kinetics

·         a branch of science that deals with the effects of forces upon the motions of material bodies or with changes in a physical or chemical system

 

·         the rate of change in such a system

 

·         the mechanism by which a physical or chemical change is effected

 

Kinetics is the branch of physics that deals with the effects of force on materials to create change, in this case the change is motion, or stability….its a focus on generation and conduction of power from the ground to the target and it’s also how not to fall down.

The last part was in jest, but you do use stances to hold up your body and thus you are placing forces on the joints and controlling your body weight with the stance, which can lead to injury. The whole point of Kokutsu Dachi is to create distance between you and the opponent while also generation of kinetic energy from your stance to your target using the stance.

 

Kokutsu Dachi is one of several “Basic” Kata Dachi that we use in Karate, it’s a fundamental stance often characterized as being defensive. The stance uses approximately 70% of the body weight on the rear leg and 30% of the weight on the slightly bent front leg with the majority of the weight being on the ball of the front foot and the whole of the rear foot.  Bending your rear leg you sort of “Sit” into this stance.

As my students are well aware I have an affinity for this stance and also, I cringe when I see some “Masters” or high level instructors forming this stance, not only do they do it poorly they promote this poor position to their students and expect that the students wont pick up their bad habits.

 

Forming the stance

                The Kokutsu Dachi or back stance is formed by first placing the “front” foot straight out from the body, the rear foot aiming to the side or perpendicular to the front foot, or 90 degree angle from the front foot. Slide the front foot out or step back the rear foot keeping the angels the same. The feet should be roughly shoulder width apart.

                Bend the rear leg pointing the knee to the side or 90 degrees away from the front. 70% of the weight should remain on the rear leg while 30% of the weight is placed on the ball of the front foot, the front foots heal being slightly up or lightly touching the floor and all the weight on the ball of the front foot. The rear foot should have a balanced weight placed on it with some preasure on the outside blade of the foot.

                The front leg should be slightly bent at the knee, not pushing the knee forwards. The front hip should “Pinch” in as should the rear hip creating a flat position for the pelvic bones and the “Sits” bones aiming straight down.

                The feet can be aligned with the front heel aiming at the rear heal creating a “L” like stance or to the center of the foot forming a “T” type stance. The rear knee should bend hard towards the rear foots big toe. The hips should sink into the stance but remain limber and mobile.

 

 

Key Features and Structure

·         Position of the front foot: The front foot must aim directly straight forwards aiming the big toe straight forwards and all weight on the ball of the foot not the heel.

·         Weight distribution: Primarily the weight is on the rear leg, however with your center of gravity being dropped some weight will be placed on the ball of the front foot. The split is roughly 70/30%.  If your weight approaches 50/50% you have lost your stance and will have to reset. To much weight to the rear and you are forming more of an open Neko Dachi (Cat Stance).

·         Contraction of rear hip: Most people focus on the feeling of sitting down and if lucky they remember to contract the front hip, however the rear foot should feel like you are contracting here as well an focus on the “pinch” feeling as you squeeze the body down.

·         Contraction of front hip: My favorite instruction is to squeeze or “pinch” the front hip as your front foot pushes into the torso. Do not let the hip raise up or you will lose the pressure from the front foot. One of my instructors once said “ like a shark biting” as he showed the front hip pinching shut. This allows for a total torso drop wit the rear and front hip squeezing closed.

·         Slight bend of front Knee: straighten the front leg pushing the weight into the ball of the foot, then slightly bend the front knee to ensure that you control your stance and allow for more mobility. This also allows for more weight to be placed on the ball of the foot.

·         Turning the muscles of the front leg: one of the less talked about “Feelings” when forming a Kokutsu Dachi is the way that your thigh muscles twist or torque.  The thigh muscles should turn out or roll over the femur to the outside of the leg as you contract the hip. This will ensure your knee does not roll in and also allows for the hip to create pressure you can use for power into the techniques.

·         Counter torsion of the rear thigh muscles:

·         Angle of the hips: Hips are normally turned 45 degrees to the side, not a full 90 degrees.  Forcing the hips to 90 degrees or straight front is more done to add power to the techniques.

·         Alignment of the heels: Both the “L” and the “T” alignment are perfectly correct.  The width of the feet from a more linear “L” to a more open “T” mainly is determined by the width of the pelvic bones and flexibility.  Both offer their own benefits and draw backs.  Personally I teach the T stance formation to start with and then based on the students flexibility, balance, strength and mobility we choose to stay the same or move to the L.

·         Pleasure from front foot to the rear hip: One of the most important points for the Kokutsu Dachi is that you put all the weight of the front leg on the ball of the foot and “Push” the front foot into the rear hip. This gives the stance stability and allows for better power transition from the ground to the arm technique. Use the front and rear hip for balance and power transition, but the front foot is integral to creating a powerful stance.

·         Dropping the body weight on the rear leg/slightly in front of rear hip: when you “pinch” both the front and rear hip properly you align the hips and create a balance as well as “Flattening” the hips to the floor.  Drop your body weight down when you contract both hips and drop your body weight onto the rear foot or just slightly in front of the rear leg.

·         Slight body tilt: Tilt your body forward, not to the rear. By bending to the front slightly you will avoid the lean back or to the side that some people experience when doing a proper stance. A big component of this is the dropping of the hips and contracting both hips to create balance and stability. This is a SLIGHT body bend not a hard lean.

·         “Sit down” feeling”: One of the most important things I teach is the “Sit down” on the piano stool method of forming the stance.  Pretend that the piano stool is sitting next to your rear leg and lower your body weight onto the rear leg pushing the rear down as if you are sitting on a stool.

 

 

Common Mistakes to Avoid

Leaning Back: Ensure the upper body is upright or slightly forward, not leaning back into the rear leg. This throws off your balance and opens the front hip, which it is also often caused by. This puts a lot of pressure on the rear hip and knee leading to injury.

Leaning to the side: One other common mistake is leaning to the side. Most people do this to avoid leaning back however. This also creates a balance issue and adds extra weight or force to your rear knee which could lead to knee issues.

Sticking the butt out: Not as common is the student who pushes their pelvis beyond their rear leg/hip.  This is very bad for the rear knee and leg. The injuries can also travel up the rear knee to the low back. This also eliminates balance and can cause technical problems with any arm techniques that the stance supports.

Rear Knee Collapse: The back knee must not buckle forward; keep it pushed out over the back toes. When the knee collapses it puts a lot of pressure on the knee ligaments and can cause overuse strain and even evulsion issues.

Lift the front foot too much/Not enough: In this case lifting the heal way to high or putting pressure down on the heel causes the power generated from the front leg to be limited if not totally lost.  Flat heal is what I call “Tripod” stance where you hold your body weight up but there is minimal translation of power from the front leg and stance to the arm techniques. Lifting it to high also limits the power transfer but also creates a different kind of tripod issue where you are just holding up your weight and can not translate power from the stance to the techniques.

Pushing the rear knee too far out: Opening the rear hip to much does not allow for the pressure that you create from the front foot to go into the techniques. This also stops you from contracting your rear hip properly. One other side effect of this is opening the knee laterally causing ligament damage from wear or suddenly.

Not squeezing the legs together when moving forwards/Back: When moving you must “come to the middle” or squeeze your knees and legs together before opening the legs again to form a new stance. If you do not squeeze the adductor muscles together then you slow down your movement and lose control of the stance. Stay low and use your contraction of the legs to form a centrifugal motion before extending the leg out straight.

Standing up to high: This can be a mistake made when moving or when standing. If you do not squeeze and maintain a lower posture, you lose the ability to draw power from the ground. The up and down movement also bleeds off energy and takes longer to complete the movement.

Letting the rear knee fall in: Almost as bad, or often worse, than having a stance to wide is letting the rear leg fall into the stance. This is dangerous for the rear knees stability and it also limits mobility. You need to pinch the rear and front hip down and ensure your rear hip, knee and big toe are all aiming 90 degrees to the side and roll the rear thigh muscle over (out) while maintaining the hip contraction.

Incorrect Hips: Avoid facing 90 degrees to the side; the hips should be set at a 45-degree angle.

 

 

Purpose and Usage

 

·         Defensive Stability: Excellent for blocking (e.g., *shuto-uke) and defending against incoming attacks due to the loaded, spring-like nature of the back leg.

·         Rapid Transition: Allows quick shifting into forward stance (zenkutsu-dachi) or cat stance (neko-ashi dachi).

·         Distance maintenance: One of the other benefits of Kokutsu Dachi is that you can use this stance to maintain defensive distance and then shift into Zenkutsu or front stance and to instantly adjust distance from a more defensive posture to a more aggressive offensive one.

 

 

Physics and applying it to the Back stance

                I am not going to get to much into the weeds with physics here but more describe the transition of power from the floor to the arm waza. Lets take Uchi Uke (inside block) Kokutsu Dachi (Back stance) and show the transition.

                Staring at the front foot the weight of the body is on the front foot and pushing up into the ground slightly to create a refractive preasure up the front leg into the front hip. The front hip should be contracted, flattening the pelvis and putting more force up the leg into the front hip area.  This then transitions into the rear hip which is held in place with the rear portion of the stance, creating a “wall” to bounce the force off of.

                The force bouncing off the rear hip travels up the torso, which is slightly leaning forwards. The force from the rear hip, traveling up the torso, goes into the lead arm which is forming the Uchi uke. (see diagram).  This transition of power, along with the proper form of the stance is much like a “ping pong” or “pinball” game. This force is slightly continuous but also a “pulse” of power can be generated by applying a force to the ground and feeling it travel up the body and into the arm instantly.

                One could break down the physics and look at force, frictional energy loss and the rest, but the description given is more than likely more helpful to the majority of people.

 

How to improve your Kokutsu Dachi

                Over the years I have studied this stance from a students point of view and a instructors point of view trying to create a better stance in myself and my students. Some of the key training components and exercises that I have used to help my students and myself are unique, most I feel are used by all instructors in the JKA and other Shotokan groups, these are the key exercises I use to improve the stance.

 

Use of the wall:

                The wall can be used to push the rear hip, knee and foot against to ensure that you are not over or under moving the knee in or out. Push into the wall at first and then give yourself a bit of room from the wall but maintain the same feel of pushing the front foot into the rear hip and then ricochet the energy to the lead hand.

 

Partner work:

                Use the partner much like the wall at first. Both partners take up a Kokutsu Dachi and push the hip and knee together so that you touch, ensure that both partners are pushing equally and not one leaving a gap that the other then must overcompensate for.

                Partners can, of course, be used to check the stability of the Kokutsu by gently shoving the student when they take up the stance, remind the student of the need for the joints to be in specific positions by again doing light pushing.

               

Focus on “Sitting on the piano stool:

                One other key to use visualization for the technique is to visualize sitting on a piano stool and pushing down into the stance. Ensure that the “imaginary stool” is situated under your pelvis and you simply drop your weight down.

 

End notes

                Kokutsu is one of the key Kata Dachi for Shotokan Karate, it appears in almost all Kata and most students do it poorly. This is not only a defensive stance, it has a lot of dynamic uses if you practice it and watch the details in training. Do not think of this as only a defensive stance as it can be used to sneak your front foot into an attackers lead foot and then Ashi Barai/Foot sweep the opponent. This can only be done however if you have a solid, flexible stance.

                I did not go into use of rotation in Kokutsu as I think only the most advanced student should focus on this. The hip rotation adjusts or augments the thigh muscle position and could be a whole blog entry unto itself.

                One reason that I advocate a deeper dive into the training in this Kata is the fact that doing it poorly can cause knee and hip issues. The human knee is essentially held together with very firm connective tissue outside and inside the knee, normal movement is made safe by the four major structures associated with the knee joint as well as other tissues that cross over the joint such as the patellar tendon, however the cruciate ligaments and the Lateral and medial collateral ligaments are susceptible to excess wear and injury. The improper use of the stance or mechanical issues that arise from doing the stance incorrectly can lead to painful consequences. If the stance is done correctly however, the outcome is stronger legs, a very useful tool in your tool box and much nicer looking Kata.

                As Kokutsu is a very important and often ignored stance, work on it as often as you can each month and make it part of your regular routine. Once you have mastered this stance or at least have worked it to the point that you understand how to make the stance you will see the value in its use beyond just using it in Kata.