Thursday, May 24, 2012

Best of Kojutsukan Posts

Yes folks, it's time for a 'best of' post. What are the top 10 Kojutsukan posts?

Before the top 10, it is an opportune moment to reflect on the Kojutsukan mission. Yes, over the years of research a mission has evolved. That mission is to use theory to inform practice. To use theory to facilitate practice. This concept is relatively unique in the martial art world which is generally a bastion of anti-intellectualism - to its detriment. Many instructors attempt to provide theoretical support for their methods. Those same instructors should often refrain from attempting to explain the whys and stick to the hows. They have not done the work, nor have their instructors, into understanding the whys. My work is about providing the whys. Whys that have practical use; that facilitate the understanding and study of martial arts techniques and those used in violence generally in a practical way.

No. 10 Women Self Defence Courses: Effective or Not? Pt 1.

This blog was posted in December 2011 and the fact it made the top ten reflects the interest in women self defence and violence directed at women. These blogs have attracted the greatest amount of comments both on the blog site and to my personal email. Many from women thanking me for airing issues that they've experienced but did not understand or that they thought others did not understand.

No. 9 Can Martial Arts Falling Techniques Prevent Injuries?

In this blog I introduced the readers and the martial arts world to the work of Brenda Groen whose PhD thesis was on the use of martial arts falling techniques to prevent injury when landing from a fall. This technique has been included in a broader fall prevention program that has been rolled out in Holland, and which has recorded success according to various studies.

No. 8 Domestic Violence

Given statistics generally suggest that one if four women experience abuse or violence, it comes as no surprise that there is a great deal of interest in this issue.

No. 7 Jan de Jong Pt 3 - The War Years

Jan de Jong and myself would walk the streets of Rotterdam and Amsterdam when we were visiting Europe for his annual seminars. He would point to various buildings or locations and tell me this happened or that happened there during the war years. Standing in the same place he stood 50 years before made it all the more poignant.

No. 6 Women Self Defence Courses: Effective or Not? Pt 2.

My interest in WSD was increased after becoming involved with a woman who has recently emerged from a long-term abusive relationship. My work over the past few years in researching for my various books and articles provided me with the tools to understand, explain, and help this survivor. I suppose another project to add to my already existing projects is a WSD book and course. This book and course would be different than most others in that it would be based on knowledge of the problem.

No. 5 FOOSH Injuries

My first blog. Fall On OutStretched Hand injuries. I introduced the martial arts world to the concept of FOOSH injuries. Over 85% of all injuries to the upper limb are produced by falling on an outstretched hand. One consequence arising out of this fact is that there is very little information available concerning the physiological explanation of injuries that may be produced when executing kansetsu waza (joint-locking techniques) because the forces are applied in the upper limb in completely different directions in each case.

No. 4 The All or Nothing Law of Strangulation

I recently obtained a copy of another study on shime waza (strangulation techniques) or the more politically correct term neck restraints. There is a bit of controversy over the actual mechanism that causes unconsciousness or death in the case of these techniques or strangles generally. Four mechanisms are often cited, even in the coroners reports I've read which include reports by forensic pathologists or medical personnel. It's often a choice of one of the four mechanisms. I need to do more work on this issue because I am tending towards a combination of two. Stay tuned.

No. 3 Jan de Jong Pt 19 - What Does a Black Belt Mean?

It is interesting there is so much interest in this blog. This might reflect a general confusion about what the black belt qualification signifies. In some striking based martial arts you can obtain a black belt in 1 1/2 to 2 years. Does that imply a lowering of standards? Not necessarily. If you only have a few blocks, kicks, and punches to learn, and if black belt simply signifies proficiency, then not necessarily. For Jan de Jong, a black belt tended toward the teaching side of things rather than proficiency. For myself, anyone who I grade black will most definitely be a world class instructor. They may not be the world's best exponent, but they will most definitely be a world class instructor.

No. 2 O Mae Ukemi aka Bridgefall

This was the first blog I included YouTube vision. The YouTube vision came from a demonstration Greg Palmer put on as part of his 2nd dan gradings. I'm fascinated this polled so well.

I recall a seminar in Stockholm where Jan de Jong was teaching a hip turn which is a technique where the partner/opponent is dragged over your hips and made to fall to the ground. In a previous seminar, a participant shattered both radius and ulna when landing on an outstretched hand. I saw in the Stockholm seminar that people did not know how to land safely from this technique. I asked some of the instructors who were hosting the seminar why they were not using o mae ukemi or bridgefall technique to land safely. They didn't know the technique. I suggested to De Jong that we teach this falling technique, to which he agreed reflecting a certain open mindedness. However, he was reluctant to spend too much time on teaching this technique as he thought the participants wouldn't think they had got value for money from the seminar. In the mid-time break I had half a dozen of the senior instructors come up to me and ask for more instruction on this falling technique, not on any of the defences we were instructing.

This is what I found throughout my national and international teaching experience. It is the fundamentals that are lacking; the fundamentals that are of greatest interest to senior students and instructors.

No 1 'Shorter People Have Certain Advantages in Fighting and Warfare'

Sadly, I suspect the number 1 spot reflects the insecurities shorter people may have rather than an interest in strategy or tactics. I would suggest that shorter people embrace their height challenged status and stand tall, but they can't.

Tuesday, May 15, 2012

Injury Science - Full Metal Jacket Bullets

I've been working on using the concepts and theories of injury science to gain insights into striking and kicking techniques taught in the martial arts or used in violence generally that would facilitate their study in a practical way. I came across this situation which I thought I'd share.

Injury is defined as the exposure to energy in excess of the tissues tolerance levels. In the case of impacts with moving bodies and objects, kinetic energy is the form of energy that is of interest.

A moving body or object possesses kinetic energy. On impact, when a force is applied, that kinetic energy may be transferred to the impacted body or object causing a change in motion or shape of that body or object. A change in shape refers to deformation, and in the case of a body, if the tissues are deformed beyond their tolerance limits an injury is produced.

If the moving body or object that impacts another body or object continues its motion after impact, not all of its kinetic energy has been transferred to the impacted body or object. For instance, a glancing blow or an exiting bullet is continuing its motion and has not transferred all of its kinetic energy to the target. This reduces the risk of injury or the severity of the injury.

The Hague Convention of 1899 prohibits the use of ammunition on the battlefield which is designed to increase the severity of injury or suffering of the wounded. The full metal jacket bullet is commonly used by the military in compliance with the Hague Convention prohibition. It is a bullet whose lead core is encased in a hard metal which resists deformation and fragmentation on impact. Stewart (2005) explains that this type of bullet will often completely pass through the body of the targeted person 'which means that they do not transfer all of their high energy into the tissues' (Stewart 2005: 188).

On the other hand, domestic law enforcement agencies tend to use bullets which expand on impact. Two reasons for this choice of ammunition are often given, both of which revolve around the tendency of this type of bullet to remain in the body of the targeted person. Firstly, it lessens the risk to innocent bystanders of being injured by an exiting bullet. Secondly, all of the kinetic energy is transferred to the tissues of the targeted person which 'cause such severe wounds that anybody shot by these bullets would be immediately incapacitated' (Gunn 193).

Interestingly, I have read that certain law enforcement agencies are adopting the use of full metal jacket bullets because they are considered more humane.

Standard military issue full metal jacket bullets are designed to reduce the severity of injury or suffering of a wounded combatant in a war zone. Standard domestic law enforcement issue soft nose jacket bullets are designed to cause severe wounds which incapacitate a civilian subject immediately. Am I alone is seeing the irony in this?

Saturday, May 12, 2012

Banished - 'Why Didn't You Leave?'

In previous blogs I've discussed the most insidious of questions which is often asked of abused women: Why didn't you leave? During my research I came across 'Treating Survivors of Intimate Partner Abuse: Forensic Identification and Documentation' by Daniel Sheridan in Forensic Emergency Medicine, 2nd edn, Olshaker, Jackson, and Smock.
It is common for health care providers who treat severely abused women to wonder why a woman would stay in an abusive relationship. Why would she return time and time again? Why does she stay? When one questions why a woman stays in an abusive relationship, in essence, the health care provider is holding the battered woman accountable for her abuser's behavioural choices. Unfortunately, health care providers rarely say to the abusive male, 'Why do you abuse?' Instead of questioning why she stays, it is better to reframe the question as, 'What are her barriers to leaving?'
'Why didn't you leave?' is holding the abused woman accountable for her abuser's behavioural choices.What are your barriers to leaving? What were your barriers to leaving? Change the why to what. Change the are to were.

"Why do you abuse?' She provoked me. Sheriden explains that so often are the women blamed for causing the violent behaviours by their male abusers that the women begin to self-blame.

Sheridan refers to research which has compared psychological abuse in domestic violence with brainwashing of war and political prisoners. He includes in his list of barriers to leaving, Stockholm syndrome (bonding with your captor), traumatic bonding (intermittent good-bad behaviour), finances, father of their children, religious faith, forgiveness, fantasies she can fix the problem, extended family reasons, friends, etc. The point is there are many barriers to leaving, many of them based on societal and familial expectations and norms.

Without reviewing the entire chapter, a few items are of interest to increase our understanding of this most common of abusive and violent experiences.
The first form of domestic violence is a combination of verbal and emotional abuse. These include name-calling, public embarrassment, veiled and explicit threats of harm, harassment, lies, 'mind games,' and other psychological manipulations.
I liken this to the boiled frog analogy. If you put a frog into a pot of boiling water it will jump out to protect itself. If you put a frog in a pot of water and slowly turn up the heat the frog will slowly boil to death.
For many women, the forms of abuse change and escalate when the attempt to leave the abusive relationship. For thousands of battered women, leaving the abusive relationship is marked by increased harassment and danger. Tragically, for more than 2,000 women every year, leaving an abusive relationship results in their death and sometimes in the deaths of their children at the hands of their abusive male partners. ... These data support the assertion that the first year out of an abusive relationship is the most deadly for battered women.
Another barrier to leaving. This supports the fear some women express concerning the risks to their and their children's well-being and lives if they left the abusive relationship.

When discussing the 'father' barrier to leaving, Sheridan explains that a motivator to leave the abusive relationship is when the children begin to mimic his abusive language or abusive physical behaviour. Another barrier to leaving is 'familiarity' where the woman has been brought up in an abusive home and accepts that being beaten by a man is a necessary part of being a woman. This demonstrates the generational effects of domestic abuse.

Possessing a better understanding of this phenomenon increases our chances of being part of the solution rather than part of the problem. If we are fortunate enough not to experience domestic violence personally, we can be damn sure that we will know someone who has or currently is. As instructors, it is our responsibility to have an informed understanding of the problem if we are even to offer an opinion let alone attempt to help.

Tuesday, May 8, 2012

Straight Arm Lock/Arm Bar/Ude Kujiki - Take Two

I originally posted this blog using a particular image of what appeared to be the defender stepping toward the attacker when executing the technique. I used this image as it highlighted a particular issue I wanted to explore, however, it was pointed out to me that the technique in question, while looking similar to the straight arm lock under review, was actually different and is the applied forces are intended to produce a different affect. I take that comment on board and apologise unreservedly for taking licence with that image. This blog recasts the previous with a more appropriate image. For those who have already read this blog (and there have been quite a few of you) the amendments are contained in the end part of this blog. This has also given me the opportunity of including a little more information which I neglected to include in the original of this blog.

I've recently been contacted by a group of fellow martial artists who are interested in the biomechanics of the martial arts. The interaction reminded me of the work I commenced on understanding joint-locking techniques (kansetsu waza).

The photograph to the right is of a straight arm lock, also commonly known as an 'arm bar', and in Japanese as ude kujiki. The photograph is not the greatest, but it was taken at the late Greg Palmer's dojo with two of his former junior students. Greg was a senior instructor of Jan de Jong, was one of my instructors, had a depth of understanding and love of jujutsu possibly second to none at the Jan de Jong Self Defence School, and became a friend and training partner of mine. Out of respect and in memory of Sensei Palmer, I'll use this photograph for illustration purposes.

The straight arm lock is a technique taught by many, if not most, martial arts. It is one of the few kansetsu waza which is permitted in judo competition, and is often seen in mixed martial arts competitions. It can be applied using the arm, as in the photograph above, or the hip while lying on your back, as in the photo to the right. It can also be applied with the leg, hip while standing, stomach, hand, forearm, shoulder, neck, head, and with weapons.

Jan de Jong included theory gradings in his dan (black belt) grades. These are oral gradings which examine the candidates knowledge of techniques and tactics, the proficiency being taken as given. If a black belt represents a teaching qualification, as it most definitely does in Jan de Jong jujutsu, the candidate's theoretical knowledge should most definitely be examined.

How do you study for this theory grading? Unfortunately biomechanics in biomechanical or martial arts texts will not be of much help. Vieten (2008) provides an overview of the English-language martial arts literature related to biomechanics. He found the percentage of biomechanics papers among the literature in martial arts is very low compared to some popular sports and suggests ‘the biomechanics of the martial arts is still in its infancy’ (562). Too true. My work is about growing that infant. This blog is about growing that infant, and possibly encouraging others more qualified than myself to take up the challenge.

Welcome to your theory grading, or part thereof. A typical question De Jong would ask, and which Palmer often referred to when explaining the theory examination, was: What are the forces involved in ude gatame ude kujiki (arm set arm breaking; the first techique illustrated above)? This, as it turns out, was a very insightful question. The problem was that De Jong and the candidates only had a layperson's understanding of 'forces'. If they'd have had a mechanical/biomechanical understanding of forces, the answers would have not be so convoluted.

Kreighbaum and Barthels (1996; K&B) explain that 'because forces account for the motion and changes of motion of all things in the environment, including the body and the body segments, it is important for the movement specialist to understand what forces are and how we can picture them as they are applied to or by the body' (80). Firstly, 'a force is something that causes or tends to cause a change in the motion or shape of an object or body' (80). It's not just a change in motion which forces cause; they also cause a change in shape which is referred to as 'deformation' in mechanics. If the deformation of the body's tissues is significant enough, it will lead to injury. Secondly, given the preceding explanation of forces, it is important for martial arts instructors and students to understand what forces are and how they can picture them as they are applied to or by the body. The beauty of it all is that it is so easy - 'easy peesy Japanesey.'

'A force can be thought of as a push or a pull; ... a blow or impact, or gravity' (K&B 1996: 80). Forces have four unique properties: magnitude, direction, point of application, and line of action (K&B 1996). In initially answering our theory question, all we need to do is identify all of the points of application and describe their direction and whether they are a push or a pull. That is it - easy peesy Japanesey. Forces are what makes the technique work. They are the essence of the technique.

See: http://www.kojutsukan.blogspot.com.au/2011/06/using-forces-to-understand-and-explain.html

With the ude gatame ude kujiki, there are three points of application. The right hand is applying a pushing force to the back of uke's (receiver of the technique) flexed hand back towards uke; the left hand is grasping and applying a pulling force on uke's wrist away from uke; and the elbow is applying a downward force to uke's elbow. That is it - easy peesy Japanesey. Next question.

What is the purpose of ude gatame ude kujiki, or any kansetsu waza for that matter? Kansetsu waza is a seperate class of technique. This can be seen in numerous texts and in numerous systems. For instance, the Kodokan Judo classification of techniques initially classifies all their techniques as nage waza (throwing techniques), atemi waza (striking techniques), and katame waza (grappling techniques). Katame waza is subdivided as osae komi waza (immobilisation techniques), shime waza (strangulation or choking techniques), and kansetsu waza (joint locking techniques).

The kata gatame ude kujiki (shoulder set arm breaking) illustrated to the right can be turned into a shoulder throw. In jujutsu, throws often involve initially locking up the joint in order to throw an opponent. They are also used to take an opponent to the ground without causing both the opponent's feet to leave the ground. This is my biomechancially-based definition of a takedown technique. Kansetsu waza are often used as immobilisation techniques, as is often seen in aikido. They are also used as kuzushi* (unbalancing) techniques. They are used as pain compliance techniques, and, which is probably the first explanation that would most likely be given, they are used to disable an opponent by injuring their joint. If I was examining a candidate and they gave me the last answer, I'd immediately ask them how often is the ubiquitous wrist twist used to disable an opponent by injuring their wrist. The humble wrist twist is most often used to take an opponent to the ground (takedown technique not a throwing technique as is so often described in aikido and many jujutsu systems)in order to execute another technique, a 'finishing' technique.

Firstly, it can be seen that kansetsu waza is a class of technique which overlaps with many other classes of techniques. It has multiple personalities. Secondly, so what? So what? The technique may look the same, that is to say it has the same points of application of the forces, but the direction and magnitude of the forces will differ depending on the purpose of the technique.

What is the physiological effect of applying forces to the extended elbow when executing ude kujiki? Here there is no authoritative answer. I was astounded, when researching the science behind joint locking techniques, that I could find no detailed explanation of the effects of kansetsu waza when forces are applied and the joint is moved beyond its range of motion. If any reader knows of such information, and only authoritative information is of interest, I'd appreciate it being forwarded to me and I will duly share it with the world via this blog.

Why not refer to medical or forensic texts? I did. However, between 80% and 90% of all injuries that occur to the upper limb are the result of a fall on an outstretched hand (FOOSH injuries; see http://http://www.kojutsukan.blogspot.com.au/search/label/FOOSH). Consequently, the medical and forensic literature focuses on these types of injuries. The forces are applied in a different direction when landing on an outstretched hand compared to when forces are applied at right angles to the posterior aspect of the elbow when executing an ude kujiki.

The bones of the elbow joint are the humerus, radius, and ulna. The olecranon of the head of the ulna fits into the olecranon fossa of the humerus which limits the hyperextension of the forearm and provides stability to the joint. Dislocation refers to the complete disruption of of a joint so that the articular surfaces are no longer in contact. Dislocation of the elbow results in, among other things, extreme pain and inability to move the elbow. Elbow dislocations are classified with reference to the position of the ulna relative to the humerus following injury. Dislocation of the elbow can be posterior or anterior:

  • posterior – the forearm bones are displaced posterior to the distal part of the humerusand accounts for the majority of all elbow dislocation injuries.
  • anterior - the forearm bones are displaced anterior to the distal part of the humerus and are extremely rare. Consequently the data on these types of injury are likewise rare.
In layperson terms, with a FOOSH injury more than 90% of the dislocations of the elbow involve the ulna sliding up the back of the humerus because the forces are being transferred from the hand to the forearm and to the elbow. The forces are applied in a different direction when an ude kujiki technique is executed; they are applied to the posterior aspect of the elbow, which means the injury may be different. After all, Whiting and Zernicke (2008) include in their seven factors which combine to determine the nature of an injury, the tissues injured, and the severity of an injury, 'direction (where is the force directed?)'.

Anterior dislocations are often described as occurring when the elbow is flexed and it receives a blow. The olecranon can lever the humerus and slide in front of it, or, it can be fractured. This is often referred to as a 'fracture-dislocation'.

I apologise for not being able to identify the source of the following quote. It is included in my notes without reference, and I need to go back to my notebooks to identify the reference. However for the purposes of this blog I will proceed without the reference.

Given elbow dislocations are the one joint technique allowable in judo (wrist, shoulder, and knee techniques were forbidden due to the risks of injury associated with the techniques), a sport practiced around the world for a century, and there is no reference I can find in the literature on extreme elbow injuries as in the case of a fracture-dislocation in judo, I might hypothesise that the abovementioned dislocations without fractures are not uncommon when an external force is applied to the posterior aspect of the elbow.
What type of dislocation and injury occurs when executing ude kujiki? Given they are permitted and used in judo and mixed martial arts, you might have thought there would be information published on this issue. You might have thought wrong. If I am mistaken, I'd appreciate reader's directing me to the source that would correct my misunderstanding. This blog is, as stated above, a call to arms to encourage others to study these most basic of questions: What injuries are intended to be inflicted when a joint-locking technique is executed? In the case of ude kujiki, in my mind it is the comparatively rare anterior dislocation with a possible fracture of the olecranon

The technique to the right is described as a 'step in arm lock.' Comment on the technique? This is a question which De Jong would often pose using photographs from books, etc? Firstly, a tactical issue. Stepping toward the opponent while applying this technique exposes the defender to the risks posed by the attacker's free hand. Secondly, stepping forward changes the forces applied by the hand at the wrist. Now it is pushing rather than pulling. This has the effect of 'close packing' the elbow joint increasing rather than decreasing its stability (increasing rather than decreasing its resistance to forces). Thirdly, I would hypothesise that should the combined forces result in a dislocation of the elbow, it would result in a posterior dislocation whereas when forces are applied to stretch the elbow joint and then forces applied to the posterior aspect of the elbow, they might result in an anterior dislocation and/or a disclocation-fracture.

Notes

*Interestingly, Jigoro Kano explains that 'the basis of kuzushi is pushing and pulling' (1986: 42). Kano, the originator of the use of biomechanics to understand and study the tactics and techniques of the martial arts - to a degree and possibly unwittingly.

References

Kano, J. (1986). Kodokan Judo. Tokyo: Kondansha International

Kreighbaum, E. and K.M. Barthels. (1996). Biomechanics: A qualitative approach for studying human movement. 4th edn. Boston, Massachusetts: Allyn and Bacon.

Vieten, M.M. (2008). Application of biomechanics in martial art training. In Handbook of biomechanics and human movement science, edited by Y. Hong and R. Bartlett. Abingdon, Oxon: Routledge.

Whiting, W.C. and R.F. Zernicke. (2008). Biomechanics of musculoskeletal injury.2nd edn. Champaign, Illinois: Human Kinetics.

Tuesday, May 1, 2012

Air Punches

What is an 'air punch'? The Urban Dictionary (apologies for the less then credible source) defines an air punch as: the act of throwing a punch in the air intended for someone or something, but without the physical contact.

Karate, kung fu, wing chun, taekwondo, etc., etc. all have their students standing in lines practicing their punches via air punches.

A recent blog on Japanese Jiu Jitsu: A Journey (http://japanesejiujitsu.blogspot.com.au/) raised the issue of keeping what is useful and discarding what is not, and the issue of how we decide between the two. The martial arts were developed by trail-and-error. Supposedly, those who discard the traditional techniques are doing so based on trial-and-error, although sometimes you have to question their 'trial'. That blog provided further support for my work. One way to evaluate methods we are unfamiliar with is by understanding the science behind the methods. The science is common to all methods; it is the essence of the methods and what makes them work, or not. What does science have to tell us about air punching; one of the most common ways to teach striking and kicking techniques in the martial arts.

A force is something that causes something to start, stop, speed up, slow down, or change direction. From a stationary position, a force is applied to an arm to start its journey and speed it up when punching. When the arm is extended and the punch is terminated, a force must have been applied to the arm to cause that arm to decelerate and stop. When we are talking about air punches we are talking about internal forces as no contact is made with another body or object which applies a force to that arm/fist. Internal forces start the punch and internal forces stop the punch.

All moving things possess kinetic energy. Energy can be neither created nor destroyed - it has to go somewhere. A moving air punch possesses kinetic energy. When a punch or kick stops moving it no longer possesses kinetic energy. Where did the kinetic energy go? It was absorbed by the puncher's body.

So, what are we training when we train air punches? We are training to apply a force to our arm to accelerate it in a particular direction and then to apply another force to decelerate and stop the arm, thereby doing 'work' on the arm and absorbing the kinetic energy in our own bodies.

Injury is defined by injury science as the exposure to energy in excess of the tissue's tolerance levels. Kinetic energy is transferred from one body or object to another via mechanical work. Mechanical work refers to force. A force is applied to another body or object which transfers the kinetic energy of the punch to the impacted body or object with an injury or damage resulting if the transferred kinetic energy is in excess of the impacted body or object's tolerance levels. The force applied to an impacted body is a different force to that applied to stop a punch without impacting another body.

A force is simply defined as a push or a pull. Pushing and pulling involves different muscles, as explained in Arthur Chapman's Biomechanical Analysis of Fundamental Human Movements. A force applied to stop an air punch has to be a pulling force, whereas a force applied to another body or object has to be a pushing force. By definition, the different actions have to involve different muscles.

A punch is designed to apply a force to another body or object, and to transfer the kinetic energy of the punch to the target. An air punch does not train the application of a force to another body or object. Rather, it trains the application of an internal force to decelerate and stop a punch, and thereby the absorption of the kinetic energy of the punch in the puncher's own body.

In addition, Newton's third law of motion states that for every action there is an equal and opposite reaction. Newton was referring to forces when he referred to actions and reactions. When we punch a body or object, the body or object 'punches' us back. The reaction force has to be absorbed in our own body otherwise it will cause a change in our motion or shape (the latter meaning deformation, or injury or damage). Air punching provides no experience of the reaction force exerted on us when punching.

The potentially deleterious effect of training air punching was brought home to me when I explored Bruce Lee's three-inch punch with two very experienced jujutsuka/aikidoka. One, who had trained for over 20 years, was literally rocked backwards when punching a thick text book held on his partner's chest. He had not trained, and had no appreciation of, the reaction force that accompanies a punch when impacting with another body or object.

An understanding of the science behind punching tells us that air punching is not punching.

I could leave the issue with the rather dramatic statement above. That would be the common approach. I would not abandon air punching simply based on the above argument, even as compelling as it is. Rather, I would look to air punching and ask, what is it actually training? After all, based on the traditional trial-and-error method, it appears to have some benefits. The trick is in understanding precisely what those benefits are. What the above analysis does demonstrate however, is that we have to train striking and kicking techniques by actually striking and kicking something. Otherwise, we are not training striking and kicking techniques.