BIOMECHANICS IN SPORT: Erle Montaigue 
For Level two Sports Accreditation Essay
Sports Specific Component


1/. BODY MECHANICS OF TAI CHI PUSH HANDS

More and more of the so called 'hard styles' are now discovering the benefits of the tai chi training tool push hands. Some karate schools are adopting the Taiji way of pushing into their own systems such as Shotokan while others have their own style of push hands such as 'kakie' from the Higoana style of Goju.


TAI CHI PUSH HANDS: WHAT IS IT

Tai Chi Push hands is a part of the training schedule from the so called internal martial art of Taijiquan (T'ai chi ch'uan). I say 'so called' when referring to internal or external because I do not believe that these expressions are exactly true. The 'so called' hard styles of karate also have so called, soft elements while the so called soft style also have hard elements. After all, it's not easy to punch someone in the mouth, softly! I prefer to use centrifugal force, using the power derived from the whole body rather than just one or two muscle groups as being representative of the 'soft styles'. Rather than rely upon the old mysticism of some form of magical internal power where-by one is able to knock people down from a distance etc. for a definition of the internal styles.

Tai Chi Push hands is a tool in just the same way that push ups on the knuckles etc is for the 'hard styles'. Now we are not going to see the 'hard stylists' going into competition to see how good they are at push ups! Neither should we see people going into competition to see how good they are at push hands.

Good common sense body mechanics is learnt from performing push hands. How to evade while not losing balance, how to gain the maximum amount of power from your particular body type, attacking while defending and most importantly, timing.


TAI CHI PUSH HANDS: ABSTRACTS

In performing tai chi push hands we are actually doing and abstract form of attack and defence. Although the four main movements of P'eng (ward off slantingly upwards), Lu (roll back to the rear), Chee (squeezing power forward) and Arn (press the opponent) are all martial applications individually, they should only be regarded as being representative of a myriad of applications which can come from these basics. Every small seemingly insignificant movement has a sub-conscious meaning. Just placing one's palm onto the opponent's elbow is significant of so many applications in defence and attack.

In stopping one's partner from pushing you over, or at least trying, we learn about timing and body mechanics. We learn about force and vectors, how to gain the greatest leverage using the least amount of energy. In stopping your partner from pulling your arm down and pulling you off balance, or trying, we are learning about adding to his force to once again gain the upper footing.

Many applications are able to be put into tai chi push hands and they all teach us about applications but these should be regarded as secondary to the ultimate goal of balance, timing and co-ordination. It should not be regarded as a competition as anyone is able to strike someone from this distance. We rather use other techniques such as punching, palm attacks, leg sweeps etc to teach us how to do these techniques and not to beat out partner. For instance, if I am performing push hands with my partner and I know that if I throw a hook punch to his/her head h/she will block it successfully, I am still going to do that technique because with ever attack I make, I am using the right muscle groups for that job. And in a good push hands work out I might throw 100 hook punches against a solid object. I am gaining the practice at throwing that type of attack while my partner is gaining experience in blocking that type of attack. The only reason that I will try and get in with an attack is to help my partner up the ladder on quicker responses, not to try and beat him!

When tai chi push hands is placed into the competition arena we see some quite damaging techniques creeping in. Not damaging physically but to one's overall training. This is when push hands no longer acts as a learning aid but becomes a hindrance to our training. for instance, if I wish to stop a strong push and I am only doing push hands for the sake of doing push hands, I will lean backwards greatly to avoid the push. I have seen many people doing this technique and saying how great they are at evading an attack and how great their flexibility is. But take a look at how open the groin is to an attack, this is just bad martial arts and creates bad habits. We should never lose sight of the initial goal of doing push hands to teach us something about the fighting arts and not just to win competitions.

In tai chi push hands as with all of Taiji (as stated in the classics) the back should remain plumb and erect. This is the only way that we are able to maintain the upper hand balance wise and martial wise. we us the twisting of the waist and hips to turn the opponent away rather than lean backward or forward. By the same token, we do not lean forward at the waist when we are pulled downward this might win a push hands competition but exposes the head to attack in a real situation. We should rather use the pulling force to take a step in and attack with a shoulder or elbow.


TAI CHI PUSH HANDS: SUPERMEN

We, all of us have seen photos of Taiji experts uprooting their opponents some feet off the ground and throwing them backwards in push hands practice, ( I have been guilty of this myself in my younger days). So what! we do not need to apply that much pressure when we are learning about push hands and what it can give us. Master Fu Zhongwen, the 86? (it is now 1989) year old master and nephew of the famous Yang style master Yang Cheng-fu is known in China as 'Mr. Push Hands' because he is just so good at it. But never does he throw people up against walls or lift them up several feet. He just pushes until the centre has gone and the opponent is off balance and then stops to tell them what they have done wrong.


TAI CHI PUSH HANDS: THE MECHANICS

In changing our weight from front foot to rear foot in a normal 'bow stance' (i.e.; a shoulder width stance laterally with a slightly longer width length wise) we are actually shifting our centre about six inches, we are not moving straight back or straight forward but rather moving on a diagonal line. So if someone attacks your centre, all you do is to move back onto your rear foot thus shifting your centre and the force has then gone out to your side. IF we then place an almost immoveable object in the path of the force in the shape of a wheel, we are able to further shift the oncoming force by turning the waist slightly so that the 'wheel' turns with our centre to cause the force to rotate out to our side.

This also works in reverse in that is someone is attacking our centre while we are sitting on the rear foot, we move forward so that our centre is again in a different position thus putting the attacker's timing off. If, once again we are able to combine this shift with a step to the side and a technique which further forces the attack to the side, we are able to re-attack while maintaining the upper footing.

This is the basis upon which tai chi push hands is structured. Of course it all becomes much more complicated than this but the basics remain.


TAI CHI PUSH HANDS: DOUBLE PUSHING

IN this exercise we have the above four mentioned techniques to stick to and now the mechanics become a little more complicated. The mechanics now depend upon which footing you are on, 'open or closed'. For instance; if I am pushed unto my right 'peng' arm (an arm held in front of the chest with an elbow angle of no less than 90 degrees) with my right foot forward, I will be eventually pulling down onto my 'closed side' i.e.; I am pulling down to my right with my right leg forward. But before I do this, I will try and confuse the attacker by turning my right forearm to my left for a brief moment. However, if I were to shift my centre right away, I would be taking the opponent onto my centre as it goes backwards. So I keep my weight essentially on my front foot while I turn. Then, as he thinks that the force is going to my left, I immediately turn my waist to my right and sit back onto my rear leg, thus shifting my centre and also attacking him with pull down.

However, if I have my right peng arm being attacked as before but no my left foot is forward, I must sit back by 50 % as I use P'eng thus shifting my centre and causing him to think again that he is going out to my left. Now, as I sit back fully, I am in a small amount of danger because I must now pull him across my centre in order to get him to my right. IN this case I use a slightly harder bumping and pulling and as it is easier to pull onto the open side, I am still able to gain the upper hand and not lose my centre. I am also able to change the direction of the pulling and pull him down onto my left side thus losing any disadvantage.


TAI CHI PUSH HANDS: DA-LU (The Great Repulse)

Da-Lu is an exercise which is like tai chi push hands but rather uses the four corner directions rather than the four cardinal points. It is said of da-lu that if one has to make use of it, one's technique is not fully mastered. This is a counter exercise to poor technique where-by we are able to use diagonal stepping to stop from being attacked with pulling or pushing.

For instance; if my technique is not good enough to avoid a grab and pull down and the opponent actually takes my hand. I will step to my left with my left foot thus going with the force. Then I will use my left foot to power in diagonally to his centre with another step with my right foot to attack him with shoulder or elbow. To stop me from attacking with shoulder, he shifts his weight, steps to near my front foot and attacks me with palm. To avoid this, I should use P'eng to block his attack while stepping around behind him with my left foot and then take another step diagonally and attack him with pull down Now, he attacks with shoulder press as I did before and the whole process has now repeated itself and we continue covering the four corners. This is of course only basic da-lu and this too becomes quite complicated at an advanced stage with direction changes and other attacking and defensive techniques.


TAI CHI PUSH HANDS: CONCLUSION

Tai Chi Push hands will enhance anyone's martial art. IT is based purely upon body mechanics and biomechanics, there is nothing mystical about it, just good common physics. You do not necessarily have to be studying Taiji to take the great benefits from push hands. Just keep it in perspective as only a training tool. A good push hands person does not a great martial artist make. It only gives hi,/her the tools to become a better martial artist. Put it into the competition area and we you will only be doing tai chi push hands for the sake of winning that competition. Use it to teach you something with no thought of competition and you will gain greatly.

Biomechanics involves the knowing of action and forces in the human body and the effects which they produce in terms of body movement.

This area is quite important in my own field of kung-fu as we must find the way to gain the maximum amount of power through the least amount of energy used with the greatest amount of speed. The way in which we use our muscles, bones and tendons and limbs is of the greatest importance here.

Balance is one of the most important factors in kung-fu as we have to maintain the best possible stance in order to not be attacked and put down. Whether we are stationery or moving balance must be taught. We have to look at how low the stances are to improve balance, how the feet are placed on the ground and how much energy is in the upper and lower portions of the body. We must look at ways to increase endurance when standing in the one position for some time and also endurance when moving around in quick spurts for some time and greater balance plays an important part in evenly distributing the weight and balance.

Balance is related to the position of the centre of gravity. In kung-fu we try to maintain the lowest possible centre of gravity not only physically but also mentally, we have training methods to teach the student to 'think down and under'. Quick movement is attained in the lower position by shifting he weight onto the balls of the feet so that centre of gravity is now positioned close to the perimeter. A person's centre of gravity can be upset by either pulling at their upper body to upset the stability or by attacking the lower body to pull their base away.

Motion is a combination of both linear and angular movement, i.e.; movement in a straight line or movement about an axis respectively. Quite often we will see both linear and angular movement interrelated and in particular in kung-fu. For instance we will not only punch using a forward motion pushing from the rear to front foot but also at the last millisecond twist the waist so that the arm is shot out at great speed adding to the linear thrust.

We are able to calculate the linear velocity V, by multiplying the radius of rotation r', by the angular velocity. The initial velocity of a fist can be increased by the addition of angular movement prior to the fist being released. This also applies to kicking techniques, we not only use the leg in a linear way but also use the hips to add angular movement to the kick just before impact to gain the maximum amount of power and speed. So in my sport, biomechanics can be used to show how to increase power and speed.

Even projectile motion can be used in kung-fu in that there are many weapons which require that we actually throw them at the opponent such as spear or stick. So we must know about the path that this object will take and we are able to use biomechanics to help determine this factor. There are three factors which determine the path that the object will take.

1. The initial velocity

2. The trajectory angle made with the ground

3. The height of release



The two main factors which will affect the object while it is in the air are air resistance (drag and lift) and gravity. These will alter the projectile's flight in two ways.


1. Linear motion in line with the ground is reduced by air resistance

2. The body is forced back to the ground by gravity



In order to gain the most distance (horizontal travel) we must have a take off angle of less than 45 degrees.


Force

We use force more than any other biomechanics in kung-fu and this can be in it's simplest form, a push or a pull. Everything that we do in kung-fu is either a push (punch, kick) or a pull (take down etc.)


Law 1:
A body remains in a state of rest unless acted upon by a force.

The fist or foot is at rest until the muscles cause it to move by exerting a force of pulling upon it.


Law 2:
The total force on a body is the product of the
mass of the body and its acceleration.

If an equal force is applied to two different bodies for the same time, the lighter will be accelerated to a higher velocity than the heavier. Which means that if two people have the same leg muscle power but their bodies are different in weight then the smaller person will be able to move faster.


Law 3:
For every action there is an equal and opposite reaction.

This law is used in kung-fu all the time in that we must not only count on our own attacking motion but also look out for the equal reaction (rebound) from the strike.

Rotation of body segments is caused by muscles acting in conjunction with the 
skeletal system as a series of levers. When a muscle contracts to cause motion 
at a joint, the resulting rotary effect (torque) is a product of the force and 
the shortest distance between the force and the axis of rotation. In levers where 
the force arm is constant as it is in the human body, the shorter the resistance
arm, the grater will be the working capacity. This idea is also greatly used in
my sport as the whole biomechanics of a simple punch relies upon the levers of 
the arm being at their maximum angle and direction for the greatest amount of 
force to be delivered to the point of impact. Biomechanics is indeed of great 
importance to the art/sport of kung-fu/ martial arts as this is how our bodies 
work and an understanding of these principles will only help to increase our performance in the sort.


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