Monday, April 16, 2012
Using The One-Inch Punch to Understand All Punches
I'm currently working on an article tentatively titled: Injury Science: The Science Behind Striking and Kicking Techniques. My previous blog was in relation to a study comparing the reverse punch to the three-inch punch. Last weekend I used the one-inch punch, a sibling of the three-inch punch, to teach the science behind striking and kicking techniques. The science is common to all striking and kicking techniques and can be used to understand all of these techniques taught in any martial art or used in violence generally.
Check out YouTube for demonstrations of the one-inch punch. They usually comprise of a subject holding a thick book on their chest and the puncher executing the punch resulting in the subject staggering backwards and a lot of times falling to the ground or slumping in a chair.
I got my guys to hold a thick financial modelling text (the most interesting use that text has been put to) on their chest and one of them to punch it using a one-inch punch. A one-inch punch refers to the distance between fist and target with no withdrawal permitted.
The result of their first attempts were, to say the least, less than impressive. The conclusion could have been that the technique is ineffective.
How do you analyse the one-inch punch (or any striking and kicking technique for that matter). Firstly, divide the skill into phases. Injury science divides an injury event into three phases: pre-event, event, post-event. An injury derived from an impact can be divided into pre-impact, impact, post-impact. Uniquely, Nakayama (in Dynamic Karate 1966) divided the execution of a karate technique into phases when explaining stances: pre-execution, execution, post-execution.
Let's look at the pre-impact/pre-execution phase of a technique. What are the important things to look for in this phase? When using science to understand striking and kicking techniques, many refer to momentum and/or kinetic energy. Both concepts are quantities of motion. Every striking and kicking possesses momentum and kinetic energy. So what? To cut a long story short, you'll have to read my article to see the confusion and sometimes misdirection that authors present when attempting to use science to explain striking and kicking techniques.
Injury science, the relatively new science that studies injuries, defines injury in terms of exposure to energy in excess of the body's tolerance levels or the absence of such vital elements such as oxygen and heat. Energy = kinetic energy. No need to consider momentum. If anyone refers to momentum to explain striking and/or kicking techniques, ask 'So what?'.
Kinetic energy is a property of a moving body or object. It doesn't cause anything. Forces cause changes. Kinetic energy can be used to understand the pre-impact/pre-execution phase of a technique. Force can be used to understand the impact/execution phase of a technique. This blog will focus on the former phase.
Kinetic energy is the potential to cause injury or to cause a change in the motion of a body or object. Force actually causes the injury or change in motion. Kinetic energy (KE) is calculated as one half of the product of mass (m) and velocity (v) squared: KE = 1/2mv^2. This is all you need to look to in order to understand the potential to cause injury or a change in motion of a body (opponent) or object (breaking board). What is being done in terms of mass and/or velocity in the execution of the technique? There are many different answers provided in the many different striking and kicking methods taught by the martial arts.
How do you increase velocity? The greater the distance between the fist and target, the greater the opportunity to build velocity. The right cross is more powerful than a jab from an orthodox stance in boxing because of, among other possible things, the greater distance between fist and target. Jeet kune do often suggest the changing of the boxer's stance so that the 'strong side' is forward increases the potency of their now leading strong fist because it is faster. It is faster because it is closer the target. That means it takes less time to reach the target, but, the shorter distance means it does not have the same amount of time to build velocity and kinetic energy in its journey. Those attempting to explain the increased power of this punch need to find an alternative explanation other than it's closer to the target. So is the jab, and it is often considered a less powerful technique.
My guys quite correctly pointed out their lack of power was attributable to their inability to 'wind up' on the punch. So, how do you increase velocity when you don't have that opportunity. The use of a kinetic chain is one option. The coordinated sequencing of body parts which transfers motion and kinetic energy from one segment to another culminating in increased velocity of the distal segment, in this case the fist.
Kinetic energy involves both mass and velocity. What about mass? How can you increase mass into the one-inch punch. Lean into it. Check out anyone demonstrating a one-inch punch. They always lean into it thereby increasing the mass of the punch.
Another way is through 'focus'. Focus is 'tightening all the muscles at the moment of impact thereby locking the fist, arm, and upper body into a single unit (high mass)' (Blum 1977: Physics and the art of kicking and punching; American Journal of Physics). Neto, Magini, and Saba (2007) suggest that in addition to contributing more effective mass to the strike, 'the correct bone alignment and muscle contraction timing are responsible to turn the hand, forearm, and arm into a very firm unit,' and that it might also serve to distribute the reaction forces of a strike. The latter is referring to the impact and post-impact phases so we'll skip over that for now.
How can you increase mass? Footwork. Often footwork is described in terms of evading an attack or position to attack, but, it is also used to execute an attack. Jack Dempsey advocates taking a step forward - a falling step - in order to increase the mass behind a punch. You can take a full step forward such as with the karate lunge much. You can also subtly shift your bodyweight from the rear leg to the front leg to increase the mass behind the punch.
KE = 1/2mv^2: what should you focus on in your training? Mass or velocity? I detail in my article the various authors that refer to kinetic energy to explain striking and kicking techniques in the martial arts literature who focus on velocity. Mention kinetic energy and the discussion always focuses on velocity. Many advocate orienting the training of striking and kicking techniques to velocity. It makes sense, if you only refer to the formula for kinetic energy.
Studies overwhelmingly show that increased force in punching techniques is related to increased mass. These studies provide evidence that better trained/more experienced practitioners produce more force because they are better able to contribute more effective mass to the strike or kick. This is what Neto, Magini, and Saba found, which supported a number of other studies in different martial arts, when they studied the role of effective mass and hand speed in the performance of kung fu 'athletes' compared with nonpractitioners. They suggest that this might be one of the reasons why martial arts masters pay more attention to proper striking techniques, bone alignment, coordination, and proper timing of muscle contractions, than to hand speed.
Pre-execution of a striking or kicking technique - what is being done in terms of mass and/or velocity? Moving the body or body segments may or may not be contributing to mass behind the technique, it may be being moved as part of a kinetic chain to increase the velocity of the fist or foot. A distinction needs to be made between moving body segments to increase velocity or moving the same segments to increase the mass. After all, mass and velocity make different contributions to kinetic energy which is the potential to cause injury or the change in motion of an opponent.
I've never attempted a one-inch punch before. Must to my surprise, my first attempt resulted in a Bruce Lee-like result with the recipient staggering backwards before falling to the ground because their upper body had been accelerated faster than their legs could move to create a base of support over which their centre of gravity could located. Yes, I'm deliberately throwing in some basic science that I'm using to understand and study the tactics and techniques on the martial arts and those used in violence generally. I had an understanding of what I wanted to achieve because I was able to analyse what others were doing. I wasn't simply trying to copy them, I understood what they were doing and therefore had a better first-up understanding of what I wanted to do in terms of mass and velocity.
Mass and velocity - that is all you need to look at during the pre-execution phase of a technique.