Peng Jing (pronounced 'pung gin' and sometimes spelt as peng jin) is considered the core principle or skill of Taiji by the leading proponents of all the major Taiji styles. (Incidentally this can also be said to be true in all other internal arts where it is known as neijing.) 'Peng Jing' can be translated many ways but for ease of comprehension I am going to use the term 'Loose Strength'. Simply put, without loose strength (Pengjing) there can be no Taiji. The strategies and techniques of Taiji rely on this underpinning strength. It is assumed to be in every movement and in every direction. Trying to understand this principle and gain this core skill is the central part of the initial training in Taiji. Once it is understood then the techniques and martial applications can then be practiced as desired.
My preferred description of this strength is as a relaxed, loose or elastic strength from the ground, through the middle of my body, to that part of body being used. Sometimes it is known as "ground strength." Another way of thinking of it is as a supportive strength. Where ever my body makes contact with something pengjing should be manifest. Whenever a force imposes on me pengjing should meet that force and through my pengjing I read that force's strength and direction. The development and maintenance of pengjing is a discrete, physical skill.
How can a student set about understanding what this strength is and gain some skill in it by studying Taiji? My suggestion would be to pay most attention to learning "How to Move" as opposed to "Where to Move."
At the heart of Taiji are its moving jing skills. Jing skills are the manipulation of pengjing in application to produce a smooth, seamless, mind-led strength without loss of balance (or centre.) Unfortunately to understand what this means is not easy.
Simply to understand this requires that my body is capable of producing a loose strength. In my opinion trying to understand what Taiji is intellectually without bodily feedback is a waste of time. In my experience a physical understanding of what Pengjing or Neijing is mandatory before an intellectual understanding of the next stage can be achieved. The reason for this is very practical: I need to be able to do a less complex action before I try and learn about a more complex one that relies on it. For example I need to learn sounds before I learn words and I need to learn words before I speak sentences. While it is possible to teach someone sentences without understanding the words (it is done in movies frequently when actors do not speak the language the film is being made in), I can see this is pretty meaningless. It only produces an appearance, not an understanding. The same is true for Taiji without pengjing.
One of the problem when learning Taiji is that, in the hands of an accomplished master, the type of motion used is very similar in appearance to normal movement. Many people spend many years trying to duplicate the "where to move the body" of Taiji as accurately as they can. They fail to understand that without learning "how to move the body", "where to move the body" is wasted time. "Where to move the body" I will call choreography. "How to move the body" I call the essence of Internal Strength and Taiji.
This different way to move the body is not very difficult to understand. However, if my body is stiff it is next to impossible to do. Loosening and relaxing my body is, in my opinion, a major part of beginning Taiji.
I could simplify the definition of "How to Move" by saying that the body must stay loose or relaxed. This is not to say that the body is limp or that my muscles are not being used. It does mean that my joints must not stiffen when I move. Learning to move the body without stiffening certain joints (i.e. the back, the hips, the waist and the shoulder,) are the emphasis of the initial exercises I teach. Once a basic looseness is achieved then more complex movement can be considered and trained. The name given to these more complex exercises in Chen Taiji is Reeling Silk Exercises or Chan Si Gong. In Yang Style Taiji these type of exercises are known as Pulling Silk or Taiji Qigong. These exercises are designed to train a "mind led loose strength" or neijing (Internal Skill or Strength.)
The nature of internal strength (neijing) is such that the body does not stiffen in response to incoming pressure or in generating strength. Although I had been studying Taiji for 12 years by the time I was exposed to this idea, it was revolutionary to me. It was clear to me that high level practitioners did not stiffen in movement or in producing strength, although it was only possible for me to see when they moved slowly. More recently it has been particularly instructive when Wang Haijun demonstrated to me various strengths in use. Watching high level practitioners move and feeling the nature of their strength is a component of understanding in my opinion.
The idea of producing strength without stiffening changed my understanding. It changed how my body is held in stationary position. It changes how my body moves (Six Harmonies motion.) It changes how and what strength is built (neijing) and how it is released (fajing.) It is a functional requirement in reading or listening to strength in others. Understanding that this relaxed strength was at the core of internal movement, I realised that I had to start all over again.
Learning to hold and move the body without stiffening is the entry door into the Internal martial arts. It is the beginning and foundation. Without it the practice cannot be classed as internal. This skill can be divided into two aspects, the first skill is called "song" in Chinese and is the under pinning to the second aspect, "peng" jing, a constant supportive strength. (It should not be confused with the posture and strength direction of the same name.) Peng has more recently become more widely recognised as the primary skill of the internal arts. It is an understanding and ability in Pengjing that is generally recognised as the beginning of taiji training.
I would say that the first 12 years of my taiji was worth at best a few months of basic practice. The reason for most of this wasted time was that I did not have a clear idea of what I was looking for. I wanted to have all the benefits of taiji but that meant simply moving like my teacher and emulating what they could do. (Unfortunately they had little or no neijia skill.) It was not a taiji skills based objective. So it is hardly surprising that after 12 years I still had little taiji skill (though I didn't realise it) and was teaching choreography on the understanding that it was taiji. Some of my teachers were strong, some of them lively, some were good fighters. These traits I interpreted to be as a result of 'good taiji'. I was simply wrong. I think if I had thought more and "followed along" less I probably would have made more progress even if it was just to look for a more competent teacher. The information I needed to arrive at this understanding was available to me but I simply chose to ignore it. I knew I was supposed to stay relaxed. (Song was the first Chinese word I encountered after Taiji.) I did not appreciate exactly what this involved or how far away from loosening my body I was. Even after many years of training, frequently several hours per day.
The crux of the problem is that the body must be used in a fairly exact manner initially if the body is not to stiffen in reaction to even a light force imposed on it. (A light force could be a light push of a few kilos or simply be the weight of our limbs.) This idea is fairly easy to grasp intellectually but considerably more difficult to train the body to move and respond in this loose fashion habitually. Our movement habits are deeply ingrained from just after birth and difficult to recognise and even more difficult to change.
As an experiment try extending your arm so your hand is about head height, weight on your back leg, and get a friend to push along your extended arm lightly. Then see if your knees, hips, back shoulder etc. are loose or if they have stiffened. If they are loose you should be able to rotate these joints with little effort and without loss of strength. The friend will feel any loss of strength as a movement towards you. Another might be to have your friend hold your extended arm up at shoulder height and see if you can exert a force down without stiffening your shoulder. When you partner can feel some force exerted down check that your shoulder has not stiffened by rotating your shoulder without you friend feeling any loss of strength.
Neither of these exercises is difficult for someone with a little skill in the neijia arts. What surprises me is how many practitioners and teachers with many years of training cannot evidence these small skills. They usually see why they should be able to do them and are surprised that they cannot. Despite a decade or more of training their bodies still stiffen in response to even a light push. I would say it is very easy to fool myself in the internal martial arts and believe I'm doing something when an independent observer who knows what to look for will plainly see I am not.
It became clear to me that my body was much stiffer than I had assumed and that to loosen my body took considerable strength of mind and body (especially legs.). Habitually relying on stiffening joints, particularly in the lower spine, the hips and the shoulders is almost universally common despite its admonition in the internal arts.
Mechanically there are good reasons for this relaxation. In
an article published over ten years ago in Internal Strength Magazine,
Mike Sigman identified three in particular:
"The mechanical efficiencies … dependent upon optimum joint angles which transmit force with the least muscular effort. Training with the least strength compels the use of optimally efficient angles (if you look for results). In order to re-coordinate the body (re-pattern the muscle use) as a unit, the employment of isolated musculature (i.e., not relaxed local musculature) is deleterious. The practice of the internal arts is incomplete without adequate knowledge and practice of light-to-moderate motion using the "mind intent" to direct (neijing) through a very relaxed body. Any stiffness will hinder this necessary and differentiating ingredient which is the core of "internal strength."
I include this quote to demonstrate how long this information has been in the public domain, in English. Yet few people can actually demonstrate these fundamental, basic skill which forms and exercises are designed to train. In my opinion the most effective first step is to understand (neijing) and the use of angles in practice. People who use stiff strength and hope to append discussions of relaxation to their practice will not accomplish much. The body truly has to be loosened.
The implications of keeping the joints loose (or relaxed) extend into motion. They are defined in the internal arts by the common phrase "Six Harmonies Motion." This phrase is found to taijiquan, xingyiquan and baquaquan. It description can be found with little effort but understanding its action takes more work. Learning to move in this fashion is essentially what all the methods of training to generate internal strength aim to accomplish at one level. Although the different internal arts use different strategies and consequently some different techniques they all rely on this type of motion to utilise their trained strength.
The following YouTube video features Grand Master Chen Xiaowang