The Biomechanics of Motion Part II – Jari Peuhkurinen

LINEAR MOTION AND THE SPRINTER THEORY

linear-motion

I have surmised that there are 5 different ways to create mass motion in order to create force/momentum;

1. Shifting weight to the desired direction where we want to deliver force.
2. Taking a step that moves our mass to the desired direction where we want to deliver force.
3. Moving our mass with a linear jump to the desired direction where we want to deliver force.
4. Rotational movement of the body. (this will be explained later).
5. Combination of these.

The sprinter theory is involved when we are producing linear forward / upwards motion. Start by thinking about the way we walk, run or jump forward. Think about the way sprinter aligns himself before explosive start or think about American football player ready to tackle and takedown his opponent. By looking our normal way of moving; walking, running and jumping reveals a lot about the economic way for creating forward motion. If we look sprinters or long jumpers accelerate their body mass to maximum speed, one could say that it reveals the way to accelerate your body mass most effectively. All movements like running, sprinting, tackling and so on, produce the kind of momentum we want to create in self-defense also. There is acceleration and velocity of mass, which give us the force and momentum.

Acceleration and velocity are most effectively developed in linear forward motion. It can be directed in straight line movements like sprinting or straight punch. Upwards movements like long jump or stepping-in uppercut. How are legs and body positioned for optimal motion development? In my opinion body alignment for the optimal motion is crucial;

1. The skeletal structure of our legs and upper body should be aligned towards desired direction of the motion. This means that head, shoulders, hips and knees are aligned. If it would be more efficient to align skeletal and muscle structure for example sideways, we would see Usain Bolt doing sideways explosive starts in the Olympics.

2. Feet-knee-hip alignment is crucial for the engine to be able to work in its maximum capacity. Muscles and joints and ligaments of the legs produce the motion. Joint alignment should support the mass we are trying to accelerate and the direction the mass is accelerated to. calf

3. Joints and muscles have certain angles which enable optimal muscle force production. Think about sprinting again. Would you be able to do explosive start from squat position? Or could you do it if your knee joints where locked to extension? From those positions your start would probably not be the best possible. Optimal angle for a muscle to produce force in its range of motion is in middle of that range.

In example when moving forearm in its full range from extension to flexion, its range of motion is about 145 degrees. This doesn’t put the middle of the range in 90 degrees as taught in many systems, but instead the optimal angle is less than 90 degrees. This same principle applies to knee joint also. So when we want that explosive acceleration the angles must be less than 90 degrees and most certainly the joint can’t be locked, like taught in many traditional systems.

This alignment of the legs and body and optimal joint/muscle angles enable the explosive acceleration and creation of force/momentum we need to be able to produce and deliver to our opponent. We can develop acceleration and velocity to other directions too, like sideways and backwards, but not as effectively. This doesn´t mean that those motions should not be practiced.

alignment

But there is more to take into the account when we are talking about self-defense. This sprinter theory only describes the optimal way to produce acceleration. If you want to examine the chain further up, and think about how the force continues towards you opponent you need to take into the account things like, maintaining balanced position, spinal alignment and angle, shoulder-elbow alignment, motion-contact timing, short/long impulse and so on.

I was already talking about linear forward / upwards motion, but let´s look upwards motion more closely. Let’s examine the way to produce upwards force from standing still position, which in self-defense can be used in lifting, takedowns and throws but also in striking techniques and pushing movements. The movement can be just weight moving upwards without losing the contact on the ground or a take-off, it can involve also rotational motion.

Think about weightlifter doing a squat, or yourself picking up something heavy from the ground, or just making a jump straight up in the air, any type of movement that involves creating force upwards straight against gravity. You can find that once more that, if you want to be able put into use all of that muscle force you have and produce explosive movement those alignments need to be in order.

Joints in your legs need to be aligned properly with your upper body. Balanced position ensures that you center of mass is located between points of balance and so on mass is aligned with feet-knee-hip line. Muscle/joint angle works the same way as in forward linear motion, middle of the range of movement. So again there is the same principle involved, how you align your whole body to get the maximum force out from your system and keep that alignment so that you can deliver that force and momentum to your target.

target

Motion downwards introduces a new physical concept into the picture; potential energy. In physics, potential energy is energy possessed by a body by virtue of its position relative to others. So basically if we lying on the ground, on our backs, we don’t have potential energy stored to our body. When we stand we have the potential to use gravity and drop our weight down. So because position of our body relative to ground we can use potential energy to produce
force/momentum.

Every time we have the possibility to use gravity as “an assistance” we can also utilize potential energy. If we raise our body upwards, or have the possibility to drop ourselves to the opponent the force will be greater.
Some arts, like ITF Taekwondo uses this in a principle called Sin-Wawe movement. It basically teaches you to raise your body straight upwards as much as you can and when you start to deliver the punch at the same time you go forward and downwards. I’m not sure about the effectiveness of this particular motion, but the principle is sound. If you can, always create motion of your body mass to the direction where you are executing your movement, be it linearly forward, upwards or downwards.

ROTATIONAL MOTION

radial

Rotational motion occurs around axis, that can be internal, like body parts rotating around a joint(s) or rotational motion of whole body, when spine acts as an axis. In here I’m taking a look into the concept of rotational motion in whole.
There are few physics terms that need to be explained. When taking about rotational motion we are talking about moment of force and rotational momentum to differentiate them from linear force and momentum. Same difference is with terms of speed; angular acceleration and angular velocity.
Rotational motion is used in several types of movements in martial arts. Most commonly rotational motion can be observed together with linear motion. This combination was called general motion; in forward linear motion body is also rotated strongly to cover more distance and produce that extra moment of force. The motion of body mass, shifting of weight or stepping in can be combined to rotational movement in all directions; forward, sideways or backwards, also to up/downwards. Only types of movements where rotational motion is not utilized are simultaneous movements with both hands in the same direction. Example when you are reaching forward with both hands.

To understand the production of moment of force and angular momentum you need to understand the relationship between axis and lever. Make a short test; stand straight, with hands relaxed at your sides. Now imagine that there is an axis running through the top of your head straight down to the ground. Now when you rotate your body around that imaginary axis the lever is the length of your clavicle to you shoulder. If you raise your elbow to the side, the levers length increases. If you straighten your whole arm, you have the maximum length of the lever you are able to use with your hands if there is no impact weapon included.

The moment of force is a simple concept; the lever arm travels certain distance depending how much you rotate your axis. If you rotate your body so that your hand moves from side to front, that’s 90 degrees, it is called rotational displacement of π2 rad. Distance the lever travels is shorter towards the point of axis and longer towards the end of the lever. Since it takes the same amount of time to the lever (arm) to travel different distances along the lever arm, this means that there has to be a difference in velocity. In the end of the lever the angular velocity is the greatest, so the conclusion is that because mass x velocity is momentum, the rotational momentum has to be greater in the end of the lever because the velocity is greater. That’s the magic of lever.

You can probably already see the numerous ways this can be used in self-defense and martial arts. To make matter at least little bit more complicated let’s think about how we can still produce great force with shorter lever arm. Think about for example short range body shots. The lever is not so long and still we can produce much moment force. The answer lies in the other variable; mass. When striking with straight arm, the mass of the arm is not that much (mass x velocity). Now when the lever is shorter our it is easier to utilize the weight of the body. Other variable also increases when the lever arm shortens; acceleration. It is easier to accelerate shorter lever than it is to accelerate long lever and as you remember mass x acceleration is force. In the case of rotational motion; mass x angular acceleration is moment of force.

How do we produce explosive rotational motion? Again because we want to get acceleration and develop velocity, we need to be able to utilize proper mechanics into the movement. If you take a look at athletics performances where powerful rotation is used, such as javelin throw or baseball strike, they use wide range of motion to create velocity. That is not a good mechanics for in martial arts. We need to be able to create rotation with shorter range of motion and not load our strikes or kicks. The degree of rotation is between 90 to 140 degrees, put even a shorter rotation does the trick of adding force. Note that I´m excluding the spinning type of movements that can be effectively used in sport martial arts, but are not recommended for self-defense.

Powerful rotation comes from the core muscles and is combined with weight shifting in the direction of target. Explosive hip movement functions as the engine for this motion.

So what can we do with rotational motion:
1. Increase force, by adding moment force in linear movement.
2. Increase reach by rotating body.
3. Produce moment force in ranges where linear movement is not possible.
4. We can also cause motion in our opponent by rotation, same as pushing. Rotation motion is usually combined with pulling, as in Thai clinch work for example.

“STATIC MOTION”

static-motion

From the point of view of physics if there is no motion, no work is being done. Still in self-defense pinning someone against a wall or ground, is work being done by muscles and bodyweight. I call this static motion. This is very useful form of producing effect in many situations.

Closely related to static motion is another principle that I call the power of locked joint, these two work together very well. If you think back about what I have explained earlier, you can see that muscles, joints and ligaments are the engine that we use to create motion. Let´s take an example; if you lock your knee joint your muscles in your thigh are in full extension. So there is no possibility for you to produce more movement forward or upwards with that leg, until you bend the knee joint and the muscles are in flexion. So the muscles are weak when in full extension and can´t produce motion, but here lies the power of the locked joint. When the joint is locked, it is strong and this can be used in various situation to our advantage. For example, when pinning opponent against stationary object we can lock the knee joint so that it remains strong and does not give in even when there is pressure directed back at us. Same goes when trying to maintain distance between bodies or opponents arm and your body. Even when opponent is significantly stronger, the locked elbow provides a strong mechanism to maintain distance.

SUMMARY
It is easy to see that understanding our basic body motion is crucial in learning martial arts and self-defense. Everything develops around motion. Every technique, no matter what style or system involves motion. How effective motion is produced in those systems or arts varies, but what doesn’t vary are the laws of physics and physiology behind human motion. Like I said there are limited number of ways we can create motion what is limited by how our body is designed and there are limited ways to produce force, because of that design.

 

Biomechanics of Power, Part II – Jari Peuhkurinen

PART TWO

Energy/Power Potential

Power potential is a term that I use to clarify importance of proper body biomechanics in training. Power potential is always present, no matter what the position of our body is, or the situation we are in. It is simply the capacity what we have (not yet produced), in that moment to produce momentum or muscle force and direct it to our opponent. Think of it as stored energy we have in our body, cause of our body´s positioning, ready to be delivered. We should train to maintain proper structure of our body in relation to our opponent’s body, so that in every situation we have the maximum power potential in our use.

Do not confuse this with the physics term potential energy, which is energy that accumulates in our body when we have the possibility to drop our body weight.

We don’t always have the distance required to produce a lot of momentum. As you remember, momentum is a product of mass and its velocity. What happens when we do not have the distance to produce a lot of velocity, but we have the possibility to produce movement? I have separated three different situations:

  1. There is no distance between your tool and the target, you are already in contact and the starting velocity is zero. You cannot produce momentum, but you can produce muscle force. So this is the situation where you use what you have in your muscles. For an example, a pushing movement with your hands to create distance between your bodies.
  2. There is short distance between the tool and the target. For example, in clinching position, you don’t have the room for maximum momentum, so it requires force; acceleration of the mass. Think about Bruce Lee´s 10-inch punch.
  3. You have the distance to produce momentum and you always try to maximize your body movement.

All these three positions need to be practiced. Be well versed in different distances so you can maintain the maximum power potential in all situations.

Balance is crucial if we want to produce and direct momentum. There can be no effective movement with direction if there is no balance. There can be no controlled movement without balance. So if there is not balanced structure, there is no power potential.

Definition for power potential could be something like this: balanced position, from where we have potential to use our muscle force to produce controlled, explosive linear or angular movement and direct it as needed.

Delivery Potential

(Power) Delivery Potential is another term of mine and it describes the variety in quantity of power potential. We always aim to have to have the maximum potential in our use in any particular position and situation, but we also need to understand that there is always loss of force during the movement. We should train to be better at delivering the whole potential and lose less in the delivery. So if we have power potential of 100 units, the maximum what we can have, there will always be less than that 100 units delivered to the opponent. There are several components that effect on the delivery:

Distance is an element in the equation of our technique and its effect. To put it simply. If you are too far away from the target you need to reach. That affects your structure and balance and it has direct effect on your delivery. If the distance is too short, you don´t have distance to build maximum momentum. Proper delivery movement has to choose based on distance.

Friction is the force resisting the relative motion of solid surfaces. If there is no friction, the power potential will have little or no effect on the target since most of the power potential will be lost from the ground to opposite direction. This is the reason why hockey players grab the opponent when they hit during a fight. This clarifies the importance of proper structure also. Friction force will work for us, when we deliver momentum.

Structure is composed of bones, joints, articular cartilage, ligaments, tendons, muscles and that kind of tissue that keeps internal organs at their place. This is our engine and vehicle that produces and delivers the energy to our opponent during altercation. Structure needs to be without a weak links, for us to optimize its energy production and delivery. Most common examples of poor structure you can see when people hit something and their joints give in and bend during impulse. That is force leaking from the delivery. Remember that according to Newtons III law every force has an equal and opposite force acting on the objects. That bent wrist during impulse is the Newtons law in action. Contact with the opponent produces the opposite force acting on our structure.  

Pressure (p) is multi versed term in martial arts and can be used to describe for example the psychological pressure you need to create for your opponent. In here it is a physics term that measures the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Pressure is measured in Pascals. Again to put it simply, we want to deliver and focus our power potential into small area to gain more pressure to the target and create more penetration. Think if could focus the power of our low roundhouse kick to a surface in size of a pin? It would have more penetrating power than a boot tip. The idea of pressure is the same as in impulse. Think about a bullet shot towards you, if you could divide the pressure bullet creates to your whole body area, you would hardly feel it, but because the momentum of that bullet is concentrated to a small area, it has a huge penetrating capacity.

But again there are situations where we want the momentum to effect on larger surface, for example to create more stopping movement.  

Angle in which the momentum is deliver to the target is also of consequence. As mentioned in the pressure is force applied perpendicular to the surface. So we look for 90-degree angle of delivering the momentum. Anything other than that and part of the force is redirected from the target and has no effect.

Effect Potential

Effect Potential is the last part of the movement. Maximum effect potential is ideal result that we look for in any movement we make. It is the proper delivery and directing of power potential that enables the maximum effect. From physical point of view, following two components create the maximum effect in our opponent, if the power potential and delivery are in order:

Tool and Target are important factors of effect. You need to deliver momentum with proper tool and choose the right target for that tool. To put it plainly, do not hit opponents kneecap with your fist. Even when you have the momentum and delivery potential, the effect will most likely be not in its maximum. However, if you change the tool, for example to tip of a boot, the effect will probably be closer to maximum what we could hope for.

These two components of effect potential could have been included in the earlier sections too, since all of the other components that result in the overall effect our movement has, is dependent on the opponent’s psychology and physiology.  Basically there are only six desired effects we can hope to achieve with our action:

  1. Pain in order to make opponent give up and comply
  2. Make him out of balance to better our position
  3. Cause unconsciousness (striking)
  4. Disrupt the flow of blood to the brain (strangle)
  5. Disrupt the flow of air to the lungs. (choking)
  6. Stop the heart from beating.

If you really think the whole concept on potential (power-delivery-effect) you can understand why the laws of physics, mechanics, biomechanics and kinesiology are not completely straight forward when talking about self-defense and martial arts and they need to be applied. Of course if we only want to measure how much force or momentum we have in our straight punch, we can use the biomechanical basics to better our movement that way, but for actual self-defense situation it holds almost no meaning, since the effect is only thing that matter, and that cannot be measured effectively.

What we can learn from these concepts is how to make our action and our training better. What to look for in the training.

 

Biomechanics of Power – Jari Peuhkurinen

”The degree of clarity with which you define something determines its usefulness to you” -Blauer Maxim

This article is part of a larger project of mine where I’m going to make laws of physics more understandable for martial arts and self-defense. My interest does not lie in the calculations or measurements of conventional physics, but in the practical part of physics; how can understanding basic physics make your action, training and teaching better?

My laboratory for these biomechanical basics is training and teaching concept called Improvement in Action. It´s not a martial art nor is it a system, but a structure of concepts and principles how to improve your training and teaching of self-defense.

When I started this project a few years back, I was looking for the right field of study what to follow, so that I can make sense of the laws that affect us all regardless of the art or a system of training that you follow. Finding the right field of science was not easy. Physics and laws of mechanics provide the basis for these concepts, but they do not tell us how to apply those in training. Biomechanics is a field of study what includes the human (bio) element into the picture, but biomechanics are a lot about measuring the performance. The only measurement in self-defense that we truly need is the effect of our action in the opponent, how can we measure that so that every time I perform a technique, the result is the same? Effect of action is not something we can measure in self-defense, we can only presume what the effects could be and train so that the technique we perform gives us the best possible probabilities of maximum effect.

Also biomechanics do not include the psychological part of the action in to the equation. As we all know, psychological part plays a huge part in our performance under stress and also in training. However, there is another field that includes the psychological part also, it’s called kinesiology. Kinesiology addresses biomechanical, and psychological mechanisms of movement. There is very little or no information on kinesiology and martial arts available. So you can see there is a lot of fields that need to be studied to make the information of basics physic laws applicable to self-defense training.

In this article I will address the proper terms that should be used when we talk about power – effect in the training and teaching.

Basic biomechanical terms

Power (P)is the rate of doing work. It is the amount of energy consumed per unit time. Power does not have direction and it is a vector quantity. and it is measured in watts (w). So power, when used normally in training context does not have the right properties to describe the energy in the movement. Of course we are interested in energy consumption, but since power dos not have a direction, it is not the proper term to use when talking about the energy that we deliver to our opponent during altercation via technique. Still just as a term, power is most commonly used, so there is nothing wrong with as long as you understand and can explain the real meaning of power.

Force (F) causes an object with mass to change its velocity. The original form of Newton’s second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time. Equation for force is F=ma (mass x acceleration) and it is measured in Newtons. This sounds more what could be used in training. So basically if we want to develop more force we can train on two things; increasing the mass or increasing the acceleration of that mass. In my opinion concentrating on acceleration in technique is too precise, if we compare it to developing over all speed in our technique. But we do use concept of force when we create force against the ground to cause motion. Motion enables production of momentum.

Momentum (p) is the product of the mass and velocity of an object, quantified in kilogram-meters per second.So momentum is measured in kilograms-meters per second. Mass and velocity of that mass; that´s something we can use in training. In my opinion, momentum is the proper term that should be used when talking about “power” in techniques. Momentum has direction and it has the element we can develop; velocity. We produce momentum with the movement of our body mass and the velocity of that mass.

Speed (v) is a scalar quantity that refers to “how fast an object is moving.” Speed can be thought of as the rate at which an object covers distance. A fast-moving object has a high speed and covers a relatively large distance in a short amount of time. Contrast this to a slow-moving object that has a low speed; it covers a relatively small amount of distance in the same amount of time.

Velocity (v) is a vector quantity that refers to “the rate at which an object changes its position.” Imagine a person moving rapidly – one step forward and one step back – always returning to the original starting position. While this might result in a frenzy of activity, it would result in a zero velocity. Because the person always returns to the original position, the motion would never result in a change in position. Since velocity is defined as the rate at which the position changes, this motion results in zero velocity. If a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. Every step must go into moving that person further from where he or she started. For certain, the person should never change directions and begin to return to the starting position.

So simply but, the speed of an object is the magnitude of its velocity, the rate of change of its position. 

While velocity is the magnitude of speed in the movement, Impulse is force over the time interval for which it acts on the target. You need to separate these two; velocity of the movement and the time which the force of that movement acts on the opponent.
This is very simple and useful concept to understand. If you have a force of 100 units and that force acts on the target period of 10 seconds. The target receives 10 units of force per second. However, if that 100 units of force acts for only 2 seconds (which is extremely long time for example for a strike) it delivers 50 units per second to the target. What you would prefer is the force of 100 units to act 10 seconds on the target, deliver the force of 100 every second. So basically you want the impulse to contain as much force as possible, for the longest time possible.

There a several ways we can use this concept:

  • We can shorten the time of our movements impulse as in striking. This means recoiling the movement. According to Newton´s III law every force has an equal counter force in opposite direction. So in reality when we strike our opponent, his counter force acts on us in opposite direction and collision transfers our momentum to the opponent. The sum of the momentums stays the same after a collision.
  • We make the acting time longer and utilize movement as a pushing movement. Still we want to have as much force as possible as long time as possible in the impulse. We don’t recoil the movement but keep applying the pressure forward.
  • Proper timing enables to increase the impulse by hitting the target while it has opposite direction to our movement. This two-way movement can be used with proper timing or by making it happen by pulling opponent or keeping target in place.
  • In defense we can utilize impulse by moving with the force so it affects us longer time and this way reducing the force acting on us. Basically the movement acts as shock-absorber so impulse time grows and movement loses its momentum.

Energy/Power Potential

Power potentialis a term that I use to clarify importance of proper body biomechanics in training. Power potential is always present, no matter what the position of our body is, or the situation we are in. It is simply the capacity what we have (not yet produced), in that moment to produce momentum or muscle force and direct it to our opponent. Think of it as stored energy we have in our body, cause of our body´s positioning, ready to be delivered. We should train to maintain proper structure of our body in relation to our opponent’s body, so that in every situation we have the maximum power potential in our use.

Do not confuse this with the physics term potential energy, which is energy that accumulates in our body when we have the possibility to drop our body weight.

We don’t always have the distance required to produce a lot of momentum. As you remember, momentum is a product of mass and its velocity. What happens when we do not have the distance to produce a lot of velocity, but we have the possibility to produce movement? I have separated three different situations:

  1. There is no distance between your tool and the target, you are already in contact and the starting velocity is zero. You cannot produce momentum, but you can produce muscleforce. So this is the situation where you use what you have in your muscles. For an example, a pushing movement with your hands to create distance between your bodies.
  2. There is short distance between the tool and the target. For example, in clinching position, you don’t have the room for maximum momentum, so it requires force; acceleration of the mass. Think about Bruce Lee´s 10-inch punch.
  3. You have the distance to produce momentum and you always try to maximize your body movement.

All these three positions need to be practiced. Be well versed in different distances so you can maintain the maximum power potential in all situations.

Balance is crucial if we want to produce and direct momentum. There can be no effective movement with direction if there is no balance. There can be no controlled movement without balance. So if there is not balanced structure, there is no power potential.

Definition for power potential could be something like this: balanced position, from where we have potential to use our muscle force to produce controlled, explosive linear or angular movement and direct it as needed.

Delivery Potential

(Power) Delivery Potential is another term of mine and it describes the variety in quantity of power potential. We always aim to have to have the maximum potential in our use in any particular position and situation, but we also need to understand that there is always loss of force during the movement. We should train to be better at delivering the whole potential and lose less in the delivery. So if we have power potential of 100 units, the maximum what we can have, there will always be less than that 100 units delivered to the opponent. There are several components that effect on the delivery:

Distance is an element in the equation of our technique and its effect. To put it simply. If you are too far away from the target you need to reach. That affects your structure and balance and it has direct effect on your delivery. If the distance is too short, you don´t have distance to build maximum momentum. Proper delivery movement has to choose based on distance.

Friction is the force resisting the relative motion of solid surfaces. If there is no friction, the power potential will have little or no effect on the target since most of the power potential will be lost from the ground to opposite direction. This is the reason why hockey players grab the opponent when they hit during a fight. This clarifies the importance of proper structure also. Friction force will work for us, when we deliver momentum.

Structure is composed of bones, joints, articular cartilage, ligaments, tendons, muscles and that kind of tissue that keeps internal organs at their place. This is our engine and vehicle that produces and delivers the energy to our opponent during altercation. Structure needs to be without a weak links, for us to optimize its energy production and delivery. Most common examples of poor structure you can see when people hit something and their joints give in and bend during impulse. That is force leaking from the delivery. Remember that according to Newton’s 3rd law every force has an equal and opposite force acting on the objects. That bent wrist during impulse is the Newton’s law in action. Contact with the opponent produces the opposite force acting on our structure.  

Pressure (p) is multi versed term in martial arts and can be used to describe for example the psychological pressure you need to create for your opponent. In here it is a physics term that measures the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Pressure is measured in Pascals. Again to put it simply, we want to deliver and focus our power potential into small area to gain more pressure to the target and create more penetration. Think if could focus the power of our low roundhouse kick to a surface in size of a pin? It would have more penetrating power than a boot tip. The idea of pressure is the same as in impulse. Think about a bullet shot towards you, if you could divide the pressure bullet creates to your whole body area, you would hardly feel it, but because the momentum of that bullet is concentrated to a small area, it has a huge penetrating capacity.

But again there are situations where we want the momentum to effect on larger surface, for example to create more stopping movement.  

Angle in which the momentum is deliver to the target is also of consequence. As mentioned in the pressure is force applied perpendicular to the surface. So we look for 90-degree angle of delivering the momentum. Anything other than that and part of the force is redirected from the target and has no effect.

Effect Potential

Effect Potential is the last part of the movement. Maximum effect potential is ideal result that we look for in any movement we make. It is the proper delivery and directing of power potential that enables the maximum effect. From physical point of view, following two components create the maximum effect in our opponent, if the power potential and delivery are in order:

Tool and Target are important factors of effect. You need to deliver momentum with proper tool and choose the right target for that tool. To put it plainly, do not hit opponent’s kneecap with your fist. Even when you have the momentum and delivery potential, the effect will most likely be not in its maximum. However, if you change the tool, for example to tip of a boot, the effect will probably be closer to maximum what we could hope for.

These two components of effect potential could have been included in the earlier sections too, since all of the other components that result in the overall effect our movement has, is dependent on the opponent’s psychology and physiology.  Basically there are only six desired effects we can hope to achieve with our action:

  1. Pain in order to make opponent give up and comply
  2. Make him out of balance to better our position
  3. Cause unconsciousness (striking)
  4. Disrupt the flow of blood to the brain (strangle)
  5. Disrupt the flow of air to the lungs. (choking)
  6. Stop the heart from beating.

If you really think the whole concept on potential (power-delivery-effect) you can understand why the laws of physics, mechanics, biomechanics and kinesiology are not completely straight forward when talking about self-defense and martial arts and they need to be applied. Of course if we only want to measure how much force or momentum we have in our straight punch, we can use the biomechanical basics to better our movement that way, but for actual self-defense situation it holds almost no meaning, since the effect is only thing that matter, and that cannot be measured effectively.

What we can learn from these concepts is how to make our action and our training better. What to look for in the training.

Reflexes Reactions and Conditioned Responses – Jari Peuhkurinen

This material is quite scientific in nature and direct application to self defense training might be lost to some of the readers, but it is my opinion that as an instructor one should always know the science and principles behind human behaviour under stress. Other thing is that I strongly believe that understanding helps to comprehend principles and concepts behind action faster and this directly affects how fast one is able to absorb new skills.

Selective Attention; Vigilance

By using selective attention an individual is able to pick out the most important information for processing from all the information that is received by the senses. Selective attention is regulating memory information and information picked out by our senses and deciding what to bring to our consciousness. This is also called cocktail party -phenomenon, meaning that when you are surrounded by lot of people talking, you can still pick out the important words for you, for example if you hear your name mentioned.

Life would be surprisingly difficult without the selective attention. In a noisy train station it would be difficult to hear the announcement when you train is leaving, if we could not consciously guide  our attention to the information we want to. Same goes for recognizing a friend in a crowd, if you could not pick out the information needed to recognize a friend and compare it to the memory information that you have about him or her, think about that for a second.

So we can guide our attention consciously, but if there is a stimulus that surprises us or stimulus that needs our attention, even when our conscious mind is not at that moment concentrating on it, it will be guided to our attention. This is called the Orienting Reflex or Orienting Response.

Reflex, Reaction and Response

Before going into details I need to define a couple of terms used in this article. I do not like Wikipedia definitions so much, but I will use them here to make a difference between these terms;

A reflex (lat. reflexus < reflectere = bend back) is an involuntary and nearly instantaneous movement in response to a stimulus. It recurs in similar way each time. It is fast and automatic. Some of the reflexes and inborn and some are learned. Scientific use of the term “reflex” refers to a behaviour that is mediated via the reflex arc; this does not apply to casual uses of the term ‘reflex’.

A reaction (lat. reactio) refers to response to other event. In psychology reaction is a response to stimulus, in physiology it is a change that happens in body.

Reflex and reaction is often used concurrently and for the clarity of this article I will use the word reflex to describe responses to stimulus that is not activated by our conscious mind. In my mind reaction is somehow more conscious than reflex. Reactions can also be natural responses to different stimulus, but reactions can also be chemical and reactions can be also acted consciously. For example reacting to bad news received in phone. Reflex in its essence is something more unconscious, something we do not decide to do. Only important thing here is that you make the difference and are able to tell apart action that is conscious and unconscious.

Orienting Reflex

The orienting reflex is an autonomic reflex, this means that it can not be controlled consciously. It guides our attention to stimulus that come to our conscious mind despite of all the other stimuli affecting our senses. The orienting reflex is very primal reflex and is part of the behaviour of most animals, this reflex has been programmed to our genes since very early in our evolution and its main function is to keep us alive. It literally grabs our attention, it is our inbuilt early warning device, the creak on the stairs in the night, the new smell that we do not know.

Think about situation where you are in middle of training and talking to students and suddenly a window or door closes loudly. Everyone’s attention shifts to direction of the noise and whilst the overall responses to the stimulus might differ a lot in a group; everybody has a shift of attention at minimum. Some may merely glance in the direction of the sudden noise others may adopt a  kind of startle response, where hands come up and head goes down and at once the direction of the stimulus, it is a spectrum but there will be a response.

If the door or window closes frequently, there will be familiarization to the stimulus and responses will not be that strong people will allow the noise to become background. In the end of the training it might be that there is no shift of attention at all. The stimulus that results in the orienting reflex is sudden and unexpected, if there is preparation and expectation the reflex is not so strong or it will not appear. If there is no preparation the reflex is strong, just try slapping your focus pads together unexpectedly during a training session.

Stimulation of the orienting reflex will abort any ongoing task. That is its function. It forces our attention to shift to possible threat and at the same time the amygdala will initiate the flight or fight response. All this happens in milliseconds and our human brain has not yet have time to process the information for us to even know what the stimulus is. Is it something that is threatening our safety and life or is it something harmless? Once the information from the stimulus is processed and it is recognized as not life threatening, one will experience the feeling of relief. We can feel it in our body as the stress hormones are standing down and preparations to fight or flight will cease.

From the point of view of self defense this is meaningful reflex to understand. This can not be unlearned, at least not completely, but getting used to unexpected stimulus during a confrontation will reduce the time for us to consciously understand what is happening, allowing us to recover faster and process our thoughts and actions more effectively.

Protective Reflexes

The protective reflexes are closely related to the orienting reflex, while the orienting reflex shifts our attention in the direction of the stimulus and is more psychological in nature, the protective reflexes will protect us physically. We can separate out two distinct functions  two parts of the physical response that protects us.

The first is the well known startle reflex that is a universal response to threat stimuli. It is most clearly seen when the direction or the source of the stimulus can not immediately be identified. This is a primary reflex, where shoulders go up and protect the neck whilst the head and chin go down and basically whole body tries to go to fetus position when standing. The hands come up to protect the head and when this happens our lizard brain has got the lead and human brain has not yet had  time to process the information to realize what is going on. This is our primitive response of the oldest part of our brain, the amygdala automatically triggers the preparations for fight or flight.

The protective reflex is the physical movement of body and hands that  follows the startle reflex. It happens when the direction of the threat is recognized. Recognition can happen through seeing the threat, hearing or feeling it.

The protective reflex is not so universal in its nature it as the startle response, it varies from person to person, from one situation to another. It can be strong or weak, it can lead to freezing or sudden action, the power of the stimuli can be an influencing factor, if a dog attacks you, would you react the same if it were a toy Poodle or a Rottweiler?

Usually the reflex promotes symmetrical movement where hands move the same line forward or backwards towards the head. However,this is not fixed it can be that only one hand is pushing forward, while other hand protects the head. The main thing is that it does not matter how much one has trained to develop a certain response to a threat the automatic protective reflex cannot be overridden by training, we may alter it but rarely will we eradicate it.

What we can train for is how fast we are able to start productive action after the protective reflex has occurred.

In Training

From training point of view it is important to understand that even when training helps us make use of these reflexes and training helps us to get used to different stimulus that normally produce strong uncontrollable reflexes, these responses cannot entirely be shut down. If and when the stimulus is strong, autonomic reflexes will reappear. Not all reflex responses can be transformed into something tactical. Sometimes it can be that reflex makes you take a step backwards. This has to be taken into account when training the action after protective reflex has occurred.  What we need to think about is how fast can we get back into the game?

My answer, it depends. After we orientate towards the threat and the protective reflex occurs it then depends on many variables how fast we are able to make the conscious decision to go forward against the threat or retreat as fast as possible. How strong is the pressure created by the stimulus? How close to the reflex is our trained response? Training can make a difference but we need to know what is happening.

It is also a question of how early in moment we are able to pick out the stimulus. The earlier we pick out the incoming stimulus the more we have time to process the information, the less the pressure created by incoming stimuli will be.

The more simple, more symmetrical, more close to the original reflex our trained response is the more able and faster we are able to make it into something tactical.  When training it is important to train conscious action after the stimulus has been created by a strong protective reflex. This training cannot be done by deciding that now I will make protective reflex, it has to produced naturally.

Reflexes can not be omitted in training by thinking that all it requires is more training to make them go away or manage them tactically. Reflexes need to be taken as something that are within us and will stay within us, no matter how much we train. We can use them to our advantage and we can experience them in training and practise getting into action faster after such reflexes appear. Exposure and experience will make these reflexes our friends.

Many times I have heard, and also trained myself, using the natural reaction of human being to defend against an attack. The principle is sound. Techniques and tools, based on the movement of natural reflexes is good. It can be moulded by training into something tactical and usable in real life situation. However, if you really think about the original, the ultimate purpose of these reflexes, it is something that is out of our hands. They are unconscious reflexes produced without our frontal cortext, our human brain,  processing the information or selecting the logical response. Nobody decides to have an reflex, it is decided for us by the lizard brain, the amygdala.

Intention – Beginning – Movement – Hit

One needs to train for different stages of response to threat stimuli  and how to react and respond to them.

  • Intention of an attack: This means simply that when attacker shows intention of attacking by closing distance  the defender will go into action.
  • Beginning refers to beginning of the movement, where the pressure of the attack is weakest, the pre-contact cues.
  • Movement means training against the actual attack which is already on its way to target. This is the most common stage of practising against attacks. This is most likely stage of producing autonomous protective reflex.
  • Hit, refers to situation where defender has not been able to defend and the attacker hits its target. This is also important thing to practise. If consciousness is not lost, the defender needs to be able to get back into the game asap. An attack that hits will produce some form of reflex, may it be just psychological momentary freeze, before the defender is able to burst into action. This depends on the training and experiences.

Operant Conditioned Responses

Operant conditioning responses to certain stimuli is the method most commonly used when training animals. It is also method used when training self defense. The purpose of conditioning is to produce desired response to a stimulus that triggers it. In training, response is either rewarded with success when the defender is able to thwart the attack and evades being hit. Or it is punished by failing to produce desired response, what results in being hit. Positive experiences make the behaviour more likely to repeat, whereas negative experiences reduce the behaviour.  

Operant conditioning is best produced by repetition. The desired response is repeated again and again in response to a certain stimulus, in different situations, so that it will become the most likely action taken when the stimulus is identified. We literally programme the brains response to the stimulus.

This brings us to the main point of operant conditioning. Conditioning can be  universal in nature, for certain stimuli, for example being hit produces psychological and physical response of attacking with an offensive attitude to gain upper hand in a fight. Conditioning can also be more specific. A straight punch attackwill be conditioned to produce certain defensive response and circular punch will produce another response and a knife attack downwards a third response and so on.  This is the most common way of training MA/SD, it is what we do.

The problem with this type of conditioning is the identification of the stimulus  before an appropriate response can be triggered. If the conditioning is specific to the attack, then the need for identification and proper response selection from memory needs to happen before action takes place. This is where OODA -loop comes into play, if the stimulus is something general in nature, for example the identification of pre-attack indicators like in a monkey dance then the response is also something general in nature such as adopting a defensive stance.  Here the trained response is easier to perform and more likely to succeed in real life. No need for specific identification and no need for selection from multiple attack specific responses.

However, if the conditioning is more specific, for example a defence against straight punch, the movement itself needs to go through the identification process before action can be taken. This brings the attacker already so much closer to hitting his target that active, forward moving response is really difficult to produce. Here the protective response is more likely to kick in not trained responses, because the lizard brain will take charge from the human brain once the threat (the punch) is seeing coming towards the face.

It is important to understand that no matter how well conditioned we are to respond to a particular stimulus, it is something that will not erase the protective reflex. If the stimulus is sudden and takes us by surprise the protective reflex will dominate. Too many times in conditioning training, these protective reflexes are seen as a mistakes, rather that opportunity to train productive action after the reflex. This is itself a major mistake, think about how you train!

Operant conditioning is is a great method of training and some form of conditioning always happens when training. It just depends on what we are training to condition ourselves to. Think about this and re-read the Intention – Beginning – Movement – Hit paragraph again.

Taking Control – Jari Peuhkurinen

It’s almost dawn and you have been out with your friends celebrating. Your friends took a taxi, but you decided to walk because it’s just a short way home. You are walking down a quiet road. It’s kind of dark still, since the sun hasn’t come up yet. During the night you didn’t drink too much, but you can feel that you are little bit intoxicated, but most of all you are tired. You just want to get home to sleep.

You are just about to cross a road to your home, when you see two men hanging out in front of your apartment building. They are not doing anything, just standing there, but obviously checking you out. You feel how your stress hormones start raging through your bloodstream, those little buggers that make your mind and body wake up… you are feeling fear.

Luckily you had been aware of your surroundings and you spotted the possible threat in time and you have a chance to affect what happens and avoid possible encounter by simply not entering a situation. Perhaps you change a direction or grab your phone and make a call. Maybe you go and get help from somewhere or someone.
When you are able to perceive a threat early it gives you time to react and plan. Time gives you a possibility to control your emotions better if you have the tools for it. This because the stimulus that causes fear, in this case observation of those two guys, is still somehow controllable.

On the other hand the stress hormones can be slowly paralyzing and draining your energy down. This can happen when you have the knowledge of future conflict and you know it cannot be avoided and you have to wait for it. The tools to control your thoughts and affect your emotions in these situations are very practical; concentrate your thoughts and energy on observation and planning.

When you exit the scene and get distance to the threat you can feel that stress is decreasing, since you feel you are going to be safe. You are coping through by your decisions and actions and take charge of the situation at an early stage.

Same thing happens during a physical conflict; stress starts to decrease and you can get some of your cognitive functions back the moment you feel that you are in control of the situation.

Let’s take the scenario further…

You have spotted those two suspicious guys standing in front of your home and you’ve decided to head back the way you came from, to get away from them. As you turn around to head back you see a third guy who’s been following you, but you hadn’t noticed him before. Seems they are all part of the same group and working together.

Situation has developed to a point where you cannot avoid by simply exiting the situation. There is nowhere to escape, not at least without some form of action towards the threats. Some form of encounter with them is unavoidable. You can make a conscious choice and start adapting to the situation.

Firstly you need to assess the situation again with this new information. Make a quick threat analysis; map your options and form a plan of action, make the goal clear for yourself. This is a conscious decision not to let your feelings of fear guide your thinking. You are coping with the situation and your actions will be goal oriented.

Threat analysis gives you information to plan your action. Forming a threat analysis is a skill you can practise everyday and it really helps to take charge of your thoughts and emotions.  

With this said it is not always easy to control those thoughts and you may find yourself in situation where your cognitive thinking doesn’t work too well and you seem to be thinking that if I don’t say anything and just ignore them, don’t look them in the eye and just walk away, everything will be fine. “how did I end up here?” what’s going to happen to me?” If I don’t notice them, maybe they don’t notice me” etc. You are denying the reality of the situation.

Denying the situation is our internal defense mechanism. Our internal defense mechanisms can protect our mind, but they also chain our thoughts. Defenses are about denying and distorting the reality around us and adjusting and suppressing our internal reality. It can help to cope with the pressing feeling of fear. When you are submitting yourself into this cycle of denying, you are forcing yourself to just react to everything that happens and that will increase your feeling of fear and you become a victim. All that is left is coping with what has happened after the situation.

It is also possible that fear literally makes you freeze. Makes you incapable to act in anyway. The possibility for this is especially high if the stimulus (the situation) develops without any warning. There is no time for denial. The stress hormones rush to prepare your body to fight or flight so suddenly that you just freeze. Simply you are not coping in anyway. This is no better than previous stage, you become a victim. There are drills to practise braking the freeze, but firstly you need to be able to recognize when you are freezing and that’s not always easy to do under control circumstances.

This was an example of coping in threat of physical conflict, but the same model applies for conflict management in general. Put yourself in a situation where the threat, the factor causing stress, is an upcoming conflict with your boss. You have those same tools at your disposal to cope with the immediate stress; if you have time and tools to avoid, the stress will be decreased. If you cannot avoid, but have time to make a plan of action (how you handle the situation) it will affect the stress levels and your action in a positive way. If, however, you are denying the reality the internal defense mechanisms may kick in and will distort the internal or outside reality to relieve stress. Or you may just freeze, not being able to respond or defend yourself.

It all comes down to two things;

  1. how much you have time to prepare and how you use that time
  2. what tools of coping you have in your disposal.

Both are things that we need to train for and train our students for. If either one of these elements missing and your action and coping will be severely compromised, facing the threat of a physical conflict you need to get your mind working for you, not against you, remaining in control is key.