Structure (for review/critique)

Structure in jiu-jitsu is the concept of either building or tearing down a body configuration to achieve your goals. It is an incredibly deep topic in jiu-jitsu that is usually treated in the context of particular techniques, but when you start understanding the different types of structure, all of your jiu-jitsu becomes more efficient and your leverage is magnified.

I encourage fundamentals students to work through these concepts and start to understand them, and higher level students should view this as an abstract representation of things you may already instinctively know but don’t think about. The end goal is to give you a framework for understanding how to make your jiu-jitsu more efficient, as well as how to explore different aspects of techniques you already know are are being taught each time you train.

There are two ways to build structure, and countless ways to apply it and destroy it. Skeletal and muscle structure are the foundation of jiu-jitsu structure, and then how the structure is used is the rest of the architecture we use for individual techniques.

Skeletal Structure

The strongest structure you can build with your body is skeletal structure. Because you are using inherently strong bones, you can have structure that takes very little effort to maintain. Specifically, all you are doing is either maintaining a specific angle of the bones relative to joints, or you are using a single bone to prevent your opponent from increasing or decreasing their distance from you.

The easiest examples of bone structure involve looking at how the knees and elbows are used against your opponent:

Knees – Tension

  • Closed Guard, which is the quintessential jiu-jitsu technique, controls the opponent by preventing them from getting their body further away from your hips than your knees. This keeps them in range for a wide variety of attacks. Other guards such as rubber guard and half guard variations also apply this principle. By closing the lower leg behind your opponent, you create a situation where you need very little effort to maintain your position and hinder your opponent’s escapes.
  • Attacks such as the triangle, lock your opponent into position inside your biting leg, again preventing them from relieving the pressure of the attack
  • Leg lock variations such as the wedge position lock the femur in a fixed position. If they can’t withdraw or otherwise move their knee, the lower leg is more available for attacks.

Knees – Compression

  • Guard recovery from side control involves putting your knee on your opponents body to create a frame which helps prevent them from getting closer to your hips and back to side control
  • The logsplitter pass uses your knee against your partner’s butt to open the guard. Because the foot is planted on the ground, your shin can brace against all of your opponents weight if necessary.

Elbows – Tension

  • Back control seatbelt is an example of tension force instead of compression force. If you put your seatbelt grip all the way in the armpit, your opponent can’t get further away from your body than the distance between your shoulder and your elbow on the overhooking arm.
  • Clinches and overhooks are also scenarios where your goal is to prevent your opponent from getting outside of elbow range.
  • Scarf hold keeps your opponent’s head close to your body.
  • Arm triangles, like leg triangles, involve preventing your opponent from getting out of the choke  since they can’t get further away from your body than the distance between your shoulder and elbow.
  • Wrestling cradles control the head and leg of the opponent by effectively creating a link between the elbows.

Elbows – Compression

  • If your opponent is sprawling on your takedown, your last line of defense against total collapse to your chest is to have your elbows on the ground. Your humerus bones can easily support the weight of your opponent.
  • Bottom side control framing involves using your elbows against the top player. A great example of this is when you are framing off your opponent to keep them lower on your body.
  • Americanas from mount can be very efficiently done when you use your elbow against the wrist to force the arm down. Your body weight can be driven into your elbow, which is far more force than the bottom person’s shoulder can generate against it.
  • Many wristlocks effectively depend on the distance between the wrist and elbow staying the same.

In each of these examples, there is some muscle involvement, but it is mostly concerned with keeping the alignment of the bone directly against the opposing force. The bones passively carry most of the load.

Skeletal structure can also lead to passive techniques that don’t require energy, but still achieve a desired result. A perfect example of this is posture inside of guard. With correct body structure from your feet all the way up to your head, you can make your opponent have a much more difficult job while you are using very little energy. The correct posture inside guard also redirects the force your opponent applies to you. We will get back to this later.

Muscle Structure

Muscle structure is inherently weaker. You are essentially attempting to create force while a joint is involved, while skeletal structure along any one bone does not require energy to provide structure or support. A good way to think about this is the difference between holding someone away from you using your hands, or holding them away from you using your elbows. In the first case, you must use your triceps to prevent collapse of your arms, whereas you can hold them away with your elbows with much less effort.

Muscle structure is also used to redirect force to where you need it. One practical example is a no-gi collar and elbow control butterfly sweep. One hand is on the neck, one hand is on the elbow, and your feet are in-between your opponents knees as they kneel. By creating tension in your arms, the motion of your body is transferred to your hands, which applies force to your opponent. If your arms have no tension, body motion would have no effect on your opponents body. You would be in contact, but there would be no connection. Contact, connection, and attachment are topics for another day.

While muscle structure is not as strong and will cause you to get more fatigued the more you use it, it is essential any time you want to transfer force from one area to another, especially when you want to create more force than those muscles could create on their own. In the case of the butterfly sweep above, you could try to shove your opponent to the side with just your arms, but you would not get very far. However if you lock your arms in place and move your body, you have not only the force of your arms, but your entire core and legs to reinforce the desired motion.

So skeletal and muscle structure are important, but is there a more formal way to look at these types of structure? Of course, and the higher level way of looking at how structure and forces are applied can help us understand even more practical situations.

Kinematics and Dynamics

From a physics standpoint, there are two important ways to look at the structure of the human body. The first, kinematics, is simply what motion is possible without considering any resistance or energy usage. A hinge like your elbow and knees can bend and straighten. A ball and socket like your shoulders and hips has some rotation, and many orientations. The second aspect is dynamics, which takes the possible kinematic motions and determines how much force is needed to create or restrict motion.

Since kinematics does not deal with force, it is a good way to analyze what it’s possible to do with our bone structure. By creating linkages and chains of structure, we can create scenarios that immobilize our opponent. Leg and arm triangles, rear naked chokes, and leg locks (among other linkages) are examples of kinematic linkages that immobilize our opponent in preparation for a submission. If the ball joints did not work the way they do, any variety of triangle would not work. Hinge joints give us ways of controlling something by locking it inside the joint, like when you hug an arm during an armbar from mount, your upper and lower arm sandwich your opponent’s arm and reduce the number of possible directions they can move their arm. This also applies to finishing a leg triangle, where you lock your ankle under your knee. This reduces the possible directions of motion of your biting leg to the one direction that makes the triangle tighter.

Dynamics takes the kinematic structure and creates leverage. This is where things get more interesting. In the case of submissions, we initiate control and the start of the submission by getting our kinematic chains and linkages in place. Once that is done, we apply additional force on the kinematic system which is then transferred into the opponent’s joint or their neck to get the submission.

Redirection of Force with Structure

Now that we have a formal system, we can look at the deeper level of jiu-jitsu, where it’s not always clear what is going on just by looking at the scenario. Sometimes it seems like a black belt is able to magically resist every attempt of control or sweeps, and they are able to apply vastly more pressure and strength than you can. This is done by a combination of position and dynamics.

To illustrate, lets look at side control (a.k.a. cross side). There are numerous styles, but if all we want to know is which style applies the most weight to your opponent, we can use a bathroom scale as a proxy for our opponent. If you want, you can make the measurements more accurate by putting the scale on a block the thickness of a chest.

First, stay on your knees, with your knees close to the scale and put your forearms on the scale. Don’t engage your core; we are just trying to find out how much gravity alone can help us. Record this weight. My value is 63 pounds.

Next, move your knees out away from the scale, making your body as flat as possible, like you are doing cheat pushups on your knees, and record the weight. My value is 117.

Next, get on your toes, like you are doing a plank, similar to the 100 kilos position, and record this weight. Mine is 140.

So far, what you’ll see is that having the knees in close does not put very much pressure on your opponent because your knees are close to your center of gravity, and they are supporting most of your weight. As you progress out towards a plank position, you are forcing more of your weight to be carried by your opponent. What else can we do?

One common tactic is to push with your toes, which will add some weight, and is a useful tactic from 100 kilos. We haven’t changed the geometry, but we have added a little muscle. Since we are looking only at what gravity can do for us, we are going to ignore this for now.

Move your feet closer to the scale, like you are doing a downward dog yoga position. What does this accomplish? It brings your center of gravity closer to the scale. The closer your center of gravity is to the contact point, the more weight you will apply to the scale. For me, I recorded a weight of 160 pounds when I brought my feet closer. The maximum amount of weight you could possibly apply with just gravity is to stand on your opponent. That got me up to a little over 200 pounds (ouch, definitely not my competition weight). That means I was able to let gravity apply anywhere from 30-80% of my full weight, without significant usage of muscle.

Since it’s not practical to do a headstand on your opponent, using a position that resembles a downward dog lets you use gravity to do as much work as possible. Any muscle pressure you add with foot or leg extension is a bonus, but it doesn’t add significant weight; it just changes the angle of how the weight is applied.

There are many lessons in this experiment, but the primary structural lesson is that by altering your body geometry, you can redirect your weight into your opponent and use very little energy in doing so. The kinematics aspect is nothing more than starting in a plank position and bending at the waist to bring your center of gravity closer to your opponent. The dynamics aspect is simply gravity and the amount of muscle it takes to maintain the position. We aren’t trying to move anything, so the dynamics are simplified.

Note: This is not intended as an instructional on side control. There are ways to use this information for side control, as well as guard passing, but the details are more complicated and involve much more than just gravity, so there are many other considerations that this experiment does not deal with when the concept is applied to real world technique.

How can we apply this lesson to another position? A perfect example is body structure inside the guard, and we only need to look at one sub-element of good technique. If you are in closed guard with your opponent’s legs around your waist, any forward pressure they apply to your body has to go somewhere. Your opponent’s legs are like gravity in the experiment above, but applied horizontally instead of down.

If you do nothing but try to have your butt down and your head up, which is extremely common posture, your legs have static structure, meaning they won’t move anywhere, but your upper body will bend forward at your hip joint. You get broken down, and you start to have a bad day.

How can we alter where the force is being directed? We know we want to redirect it to our legs. One way of doing this is to lean extremely far back. With this, you make a more straight line between where the force is being applied and where you want it to go, similar to how you structure your upper body to be more in line with the scale in the weight distribution experiment. Unfortunately, bending so far back puts you at extreme risk of a very simple push over sweep, so we need a different solution.

The key to dealing with this is to rotate your pelvis backward, as if you are slouching into a chair. There are many benefits to this, but for this one isolated purpose, you are lowering your pelvis to be more in line with your legs, and any pressure that is applied near your pelvis will be redirected down your femur to your knees, which are effectively immobile. If your opponent wants to break you down, they effectively have to lift you up and forward so that you  are hinging at your knees instead of your hip. As they lift, the higher you go, the more you can double down on your hip rotation until you are almost in a straight line from your knees to your shoulder and still leaning back as much as you can.

Instead of the simple case of pulling your upper body forward to break you down, you can create structure with your pelvis and angles that redirect the majority of the force down to your knees. The first time you experience the difference between beginner hip structure and proper hip and lower back structure, it’s astonishing.

Back down to earth

How does all this make your jiu-jitsu better? This is the longest post I’ve made, and it only scratches the surface of what structure means in jiu-jitsu. What you should be taking away from this is when you are learning new techniques, pay attention to what motions are possible, what bone structure makes the technique easy, and what muscle structure is required.

As much as you can, shift the effort of the technique towards bone structure and gravity. Then determine when and how much muscle is required to achieve whatever goal you have. This sequence of thought will conserve your energy and make your jiu-jitsu more efficient and more effective.

Credits

A great deal of the inspiration for this article goes to Henry Akins and a week long seminar I did with him about a year and a half ago. In followup seminars I refined my understanding of structure, especially using muscle structure to reinforce skeletal structure. I wholeheartedly recommend that you take advantage of his Hidden Jiu-Jitsu website.