Read Time: 1 hr 10 mins

Introduction

Grandmaster Ip Man once said, “A man should always think of the source of the water as he drinks”.  Although he said this in the context of passing of Wing Chun skills down to him from his predecessors, the same wisdom applies when we seek to understand the Wing Chun stance.  In this context of understanding the dynamic, relaxed, yet powerful structure of the Wing Chun Yee Gee Kim Yeung Ma stance, the ‘source of the water’ is understanding how the human body is able to maintain an upright posture in a normal standing position.  After all, it was this knowledge that was exploited by the Shaolin ancestors in creating the many forms of Kung Fu, and refining these into the simple, efficient, and effective fighting art that is Wing Chun.     

The great thing about Wing Chun as a compact form of Kung Fu, is that it does not require extraordinary flexibility or athleticism from the outset.  With a comparatively simple toolbox of fighting tools and techniques, along with its focus on natural human anatomy, Wing Chun can be practiced by people of different ages, sizes, and degrees of physical ability.  It relies on structure rather than strength, muscular relaxation rather than tension, and timing rather than speed.  The use of posture, alignment, structure, balance, and whole-body alignment takes the natural body position as a starting position and subtly, but significantly changes this – optimising the physiology and thereby allowing a smaller person to be able to defeat a larger, stronger opponent.  Through consistent practice the advanced Wing Chun student develops extraordinary balance, power, coordination, balance, sensitivity, and endurance.

It seeks to develop automatic, reflex responses to interrupt an attack, control the centre, break an attacker’s structure, and disrupt their balance – putting the fight on your terms by taking away their ability to use these fundamental elements – removing the opponent’s ability to use their balance, structure, and power to attack you.  This is achieved through training the developing student to move and control their body with great precision and economy of movement, using a minimum of effort to create the maximum effect. 

However, to the beginner student this advanced skill seems frustratingly illusive.  Even something as seemingly straightforward as the ‘basic’ Wing Chun stance, Yee Gee Kim Yeung Ma, is unnatural and awkward – far from the structural solid yet fluid, mobile platform demonstrated by their Sifu.  To the beginning student it appears completely opposite to this – it feels unnatural, tense, and immobile.    Hawkins Cheung captures this frustration that every beginning student faces:

Many joined and wanted to learn how to fight. Because of the reputation of Wing Chun, Bruce and I joined. The thing about Wing Chun is once you start the first form, you feel frustrated. We questioned, “Why do we have to learn this? How can you fight like this?”

Inside Kung Fu Interview about Bruce Lee – Hawkins Cheung

The transition between these two states – a normal standing stance and being able to be fluid and structurally solid in the Wing Chun stance – takes a significant amount of time and attention.  It requires adopting a whole new body mechanics – using our bodies (skeletal alignment, bones, muscles, sensory and nervous system) in a different way.   Just as it takes a child (or an adult who has lost the ability through illness or injury) a great deal of time to learn to stand and walk, the Wing Chun Stance (and later moving this structure around through stepping) requires an equal effort in mastering.

In order to understand the physiological challenge of transitioning from a normal standing position into the Wing Chun stance, Yee Gee Kim Yeung Ma, it is first necessary to understand what is involved in everyday standing – namely, how we maintain our balance in an upright position under the forces of gravity.  And, importantly, without having to also factor in the complexity of managing the incoming forces of an attacker. 

In this paper I will examine the mechanics of the human body in the context of a normal standing position trying to remain balanced and stable under the forces of gravity.   I will explore correct posture by looking at examples of good and bad posture from a perspective of whole-body skeletal alignment, and also how this is managed through the central nervous system and supporting sensory systems. 

Importantly, I will look at the conscious role we have in maintaining our posture and look at factors that mean that our posture is inherently a personal thing – differing from one individual to another.  Moving beyond a purely anatomical analysis, I then look at the role of sensory, and motor processing strategies that support the mechanical processes allowing for upright, normal standing.

Having established a background to the structure of posture, I then explore in more detail the role of gravity within this structure.  This includes looking at a series of terms associated with the understanding of gravity within the context of the human body – namely, the ‘centre of gravity’, ‘centre of pressure’, ‘base of support’, ‘balance sway’ and the ‘line of gravity’.

I then look at the control mechanisms employed by the brain to maintain this posture within the context of the force of gravity in the normal standing position.   I will then explore the muscles involved in maintaining the normal standing position, distinguishing between muscles engaged in movement, ‘anti-gravity’ muscles used in keeping an upright posture, and muscles used for stabilising joints or body positions.  Having understood what is involved in ‘normal standing’ and the muscles used to maintain this, I then compare this with the same elements within standing within the Wing Chun basic stance.  Key elements will be introduced in this paper but covered in detail in the second paper.

In the third paper of the series, I will explore the process of moving from the normal standing position into the Wing Chun basic stance.  This will look at the transitionary processes involved in moving between these two biomechanical stances.  As part of this I will also look at the challenge the developing student faces in moving beyond the logically separate normal and Wing Chun stance and explore the processes involved for the developing student in moving to the usage of different muscles and body mechanics, letting go of tension and finding new structural alignment.

For the purposes of posting this paper onto the website, I have divided it into two parts. We cover Part 1 – The Significance of Gravity in Human Posture here. Part 2 – Muscles Involved in Maintaining Balance, has been uploaded separately but also within the Knowledge website section.

Part 1 – The Significance of Gravity in Human Posture

Human life has evolved in the presence of gravity – a force that historically we did understand scientifically, but whose effect of pulling our bodies downwards as ‘weight’ has been felt since we first learnt to sit, crawl, and walk.   It has long been recognized, from ancient Greek time to the current day, that our posture (how we sit, stand, and hold our bodies) is maintained by tonic muscle contractions acting against gravity and stabilizing the positions of body segments.

Gravity then is a force that impacts every activity a person does throughout their daily lives.  It plays an active role in our normal stance, although we quickly become accustomed to it and its effects as we become accomplished as young children in standing, walking, and running.   For those who have suffered injury or illness which means they have lost the use of muscles, or astronauts returning to earth having to relearn to walk or develop atrophied muscles to support our bodies consciously reminds us of the physiological process that were hard earned but quickly taken for granted.

Gravity is constantly pushing down upon us, or more specifically pulling on the mass of our bodies towards the centre of the Earth’s mass.  Our bodies have anti-gravity muscles throughout our bodies whose function is to support our bones and joints in order to maintain their alignment against this constant force.   The common term for this group of muscles is our ‘core’, but this well-known muscle grouping is supported by deep antigravity muscles which actually start down in the feet, the triceps, and all the way up into our heads.  These core / deep muscles need to be strong, flexible and be able to continuously provide this function throughout the body to maintain proper joint alignment without quickly fatiguing.  

Maintaining and strengthening these anti-gravity muscles prevents musculoskeletal pain and injury, improves balance, and makes us more powerful in sports and throughout all our other day to day activities.   The transition to the Wing Chun stance poses a unique challenge – akin to having to learn to walk again, or more precisely having to learn to walk in a new way and hold our bodies in quite a different posture.   It is no surprise then that this is something that takes time both mentally (to get our heads around) and physically (to allow our bodies to get used to the new way of standing and moving).

The Human Posture

As humans, we are bipeds (two-legged) who move through our environment with one foot in contact with the ground (when walking), no feet in contact (when running), or both feet in contact (when standing).  This creates a major challenge for our internal balance control systems.  This is especially the case because we are inherently unstable (compared to our four-legged animal friends) because two-thirds of our body mass is located two-thirds of body height above the ground.  We are effectively a top-heavy, inverted pendulum.  In order to maintain an upright position, we have had to develop a control system that is continuously acting to ensure we do not fall over.

Importantly, this control system is used to working in the context of our normal standing, walking, and running activities.  These are motor skills trained in as children learning to walk and refined further in the years thereafter.  This control system is not immediately accustomed to the new structural position of the Wing Chun stance.  It is important to recognise this as a developing student – we must appreciate that we have to relearn the most basic function of being able to stand and walk again.  Perhaps this is, in part, where the Sil Lim Tao concept of a ‘small idea’ originates from.

What is Posture?

Posture is defined as the attitude assumed by the body either with support during the course of muscular activity, or as a result of the coordinated action performed by a group of muscles working to maintain bodily alignment and stability.  This involves a series of continuously refined complex interactions between bones, joints, connective tissue, skeletal muscles, and the nervous system (central and peripheral).  The complexity of these interactions is significant when one considers the variety of motions involved in human balance, motor control and movement in relation to gravity.

There are two different types of posture:

• Dynamic posture – This is how you hold yourself when you are moving i.e., when you are walking, running, or bending over to pick up something.  This type of posture is usually required to form an efficient basis for movement.  Muscles and non-contractile structures have to work to adapt our ‘static’ posture to changing circumstances.
• Static posture – This is how you hold yourself when you are not moving i.e., when you are sitting, standing, or sleeping.  Here our body segments are aligned and maintained in fixed positions.  This is usually achieved by co-ordination and interaction of various muscle groups which are working statically to counteract gravity and other forces.

Posture refers then to an array of positions that determine the maintenance of balance with maximum stability, minimal energy consumption and, importantly, minimal stress of the anatomical structures.  In moving to the Wing Chun stance, these same principles of posture remain.

Postural Tone

The low-level muscular activity needed to maintain an upright, standing position is generally referred to as ‘postural tone’.  For the purposes of simplicity, this paper will focus on this ‘static’ posture – more specifically, the normal standing position and posture in the Wing Chun, Yee Gee Kim Yeung Ma stance.

Postural tone is the steady contraction of muscles that are necessary to hold different parts of the skeleton in proper relation to the various and constantly changing attitudes and postures of the body.  It is commonly viewed as low-level muscle tension observed in both the trunk and neck and the proximal (close to the centre of the body) and distal (distant from the centre of the body) skeletal muscles.

Postural Control Mechanisms

Having learned to stand and walk as children, our posture becomes an automatic and unconscious position which represents the body’s reaction to the force of gravity.  It is maintained through the activation, reciprocal inhibition, and co-contraction of muscles around joints, commonly through the medium of pro-prioception and spinal reflexes.  Most postural muscles span two joints, which leads to complex interactions in the biomechanical chain in response to external forces and internal automated or volitional control activity.

Good vs Bad Posture

People are often assessed in terms of having ‘good’ or bad ‘posture’.  Good posture is the result of inheritance, habit, and changes in motor and biomechanical forces.

‘Good’ posture allows movement with the least amount of strain and damage.  ‘Good’ posture is sometimes described with specific characteristics – such as, ‘back straight, shoulders back and stomach in’.  Although these characteristics fit within a context of correct posture, posture is about more than sitting or standing as straight as possible.   Our bodies adopt many different postures in order to do different tasks, not all of which involve this ‘static’ bodily position.

It is better to think of ‘good’ posture as a position in which you (1) feel well balanced, (2) are able to do everyday tasks easily, and (3) are doing the least amount of damage to your body.  All three of these elements involve the body working in a way that uses alignment of the skeletal structure and bones to achieve these tasks in a fluid, natural way.

Posture only becomes ‘bad’ when it causes harm to your body or stops you doing everyday things. This may happen if you (1) hold one position for a long time, (2) feel unbalanced and have to use effort to stay upright, (3) find that stiff muscles make it easier to sit or stand in a bad posture, which makes the problem worse, or (4) where misalignment has occurred in the natural posture that impedes movement, causes pain or damage in the body.

Restrictions in the body’s connective tissues reduce the range of movement and add to poor posture.  These restrictions can be released through movement when working with the right muscles.  A good posture uses less energy – whether this is maintained by your muscles or by sitting in a supportive chair.  The core muscles in your abdomen work more efficiently if they are correctly aligned, which means they can support you and allow you to move your limbs more freely.

As the beginning student starts to stand in the Yee Gee Kim Yeung Ma Wing Chun stance, they initially try to use the muscles and biomechanics that is applied by the control system in the normal standing position.  In doing so, this uses more energy and results in a stiff, unbalanced position – quite the opposite of good posture.  This is the experience that Hawkins Cheung described in the quote earlier.  In order to be able to transition to the correct, ‘good’ posture of the Wing Chun stance it is important to understand how the body is held in a different way within Wing Chun than in the normal standing position. 

The starting place therefore is in first understanding how correct skeletal alignment is achieved in the normal standing stance.

Skeletal Alignment

A central key to good posture is the position of the spine.  The spine has three natural curves – at your neck, mid/upper back, and lower back.  

Correct posture in a normal standing position should maintain these curves, but not increase them.  In this alignment, the head should be above the shoulders, and the top of the shoulder should be over the hips, as shown below:

In an ideal posture, we should see gravity pass through specific points of the body – observed above like a plumb line passing through the midline of the body.  This line passes through the lobe of the ear, the shoulder joint, the hip joint, though the chest (greater trochanter of the femur), then slightly in front (anterior) of the midline of the knee joint and the lateral malleolus, which sits just above the ankle bone (talos).

When viewed from either the front or the back, the vertical line passing through the body should theoretically divide the body into two equal halves, with the bodyweight distributed evenly between the two feet.

The most common pattern of poor structural alignment is holding a posture with the head and pelvis forward of the line of gravity, knees hyper extended (locked-out) and rotated inwards (or sometimes outwards), and ankles and arches of the feet collapsed inwards, pelvis tilted forward, and the shoulders rounded, with the bodyweight resting predominantly on the balls of the feet.

Individual Differences in Normal Standing.

Posture, good or bad, is something that is quite individual – each of us have different ways of holding ourselves.   These are referred to as motor engrams, and I will explore what these are in the next section.

A wide variety of muscles in the torso engage in a combination of concentric and eccentric contractions to maintain the curves of the spine in relationship to the pull of gravity.  In each person a different combination of flexor and extensor muscles will be active in varying kinds and degrees of contractions to maintain the postural support needed.

Bodily proportions of the individual will also affect the location of the centre of gravity.  As the body has moving parts (arms, legs, head, various areas of the trunk), every time we move, the shape of our overall form varies with subtle changes in how we hold our posture.

The following factors can impact our individual posture:

• Age – Factors impacted by age include physical (motor) and neurological (brain) ones.  The degeneration of the vestibular system, including an increased loss of hearing and sight, in the elderly affects the balance control system in.  Additionally, a decrease in physical activity, painful arthritis and increased diseases of the bones and muscles associated with aging can compromise muscle strength and joint mobility. 
• Physical activity – Physical activity creates positive changes in the biomechanical functions that facilitate a healthy (dynamic) posture.  A sedentary lifestyle weakens muscle strength, creates imbalances in muscles pairs, creating a general weakness in postural muscles, and reduces joint mobility. 
• Injury -Injury and pain often result in using other muscles to prevent the use of affected muscles.   This can significantly change how are person holds their posture.
• Illness / Medical conditions – There are many factors that potentially affect the postural control system and may lead to an increased risk of falling.  These include health or medical conditions such as diabetes, peripheral neuropathy, stroke, multiple sclerosis, Parkinson’s disease, cerebral palsy, and obesity.
• Tension – Muscular tension varies greatly between individuals.  This is especially important in the ability to allow natural movement in body mechanics and plays a big part in our body posture in terms of how we hold ourselves.
• Weight – Body weight has a distinct influence on the erect posture.  The obese have the most erect posture as a result of supporting the load over the relatively small base of support.  This posture features twisting while walking with short, stiff steps.  A large abdomen requires a compensatory posterior torso leaning and acute lumbosacral angle to balance the anterior weight.  Effectively, more weight is placed on the heels with muscles and joints having to work harder to support this imbalance.
• Height – A short person may have an artificially erect posture in an attempt to appear taller. This is especially true in the short stocky person because the erect posture tends to make the physique both taller and slimmer.  Conversely, taller individuals often slouch to appear shorter with the neck leaning forwards. 
• Effects of pregnancy – During the advanced stages of pregnancy, the centre of gravity is displaced considerably forward from the normal position because of the increased anterior weight from the fetus, amniotic fluid, and enlarged uterus.  Postural compensation involves a leaning backwards which is adapted to by a slouch forwards in the upper torso. 
• Effects of footwear – As heel height is increased (especially in high-heeled shoes), the centre of gravity is moved posteriorly.  When the calcaneus is elevated about a half inch above the level of the base of the ball of the foot, its shaft is brought to a tangent with the achilles tendon.  As a result, the gastrocnemius and soleus are able to exert a greater force in plantar flexion.  When high heels are habitually worn, they tend to shorten these muscles and stretch the anterior ankle muscles.

It is important to recognise, both developing Wing Chun student and teacher alike, that all of these above factors can affect posture.   Continual good practice of posture can help realign and move towards correct posture, but this takes time.  Certain musculoskeletal structural alignment issues may only be possible to correct with surgery.  As such, when seeking to get into the Wing Chum Yee Gee Kim Yeung Ma stance it is important to understand the principles of alignment and relaxed movement in creating a correct structure for you as an individual – rather than artificially trying to recreate a ‘perfect’ position that is not right for you and will likely result in long-term damage.

Muscle / Motor Engrams

Motor engrams (also known as muscle engrams) are specific pathways that the nervous system uses to minimize the work of the brain and spinal cord.  As your body performs a certain movement or activity over and over, your body automatically creates one of these pathways, or engrams.  Once an engram is created, your body will be able to perform that specific activity without nearly as much input from the brain.  Your brain will tell your body to perform the movement and the engram will take over.

These are memorized motor patterns that used to perform a movement or skill.  Motor skill acquisition occurs through modification and organization of muscle synergies into effective movement sequences.  These engrams are desirable in sports and martial arts because they allow patterns of movement to be expressed more quickly and efficiently than when your brain has to be involved.  This is often referred to as muscle memory, but importantly these engrams coordinate memory across a range of muscles to perform specific movements.  In performing our forms and through sparring training we are actively creating desirable motor engrams that we can then quickly express as patterns of learned movement.

A good simple example of motor engram behaviour can be seen in brushing your teeth.   For most people when brushing their teeth, they perform the same procedure every time, starting on one side and systematically moving throughout your mouth without thinking about it.  Here the brain calls upon the embedded motor engram and the learned behaviours takes over.  You are able to brush your teeth without thinking about it by utilizing the very specific motor feedback loops in your body that you have created through training and repetition.

Importantly, postural habits also involve formed patterns of motor behaviour in engrams.  In general, most postural habits and characteristic movement patterns would have been developed in childhood.  Often these involve instinctively copying the way your parents move.  Biologists call this phenomenon ‘imprinting’.  Through the process of the evolution of a species this is a valuable survival tool.  However, poor posture habits can also be learned from your parents and imprinted into your engrams.

Thankfully, the brain is ‘plastic’ – the hardwired neurological connections that it makes to create these engrams in the motor area of the brain can be re-written.  But this is not an easy process and engrams are very hard to change.  This involves reprogramming your brain (motor cortex) over time.  Research has shown that to change an existing motor engram to a new one, you need to do 4000 to 5000 repetitions of the new pattern.  This is why it is so important when learning a new skill to make sure you do it attentively, correctly, and precisely. 

Sensory Systems

So, I have shown that for proper movement to occur, and in order to perform the wide spectrum of functions and activities involved in movement stability under the effects of gravity is required.  I have also covered that this is a complex process, even in normal standing, and this is a continuous process of adjustment to remain balanced.  It is provided in a co-ordinated manner by the active structures (muscles), passive structures (lumbar spine), and control by neurological systems.

Balance control also depends on healthy brain function across many brain areas.  The brain needs to process and interpret sensory information, select appropriate balance strategies, and adapt and learn new strategies with practice.  Balance is also dependent on muscle strength, joint mobility, and healthy feet.

Good balance requires reliable sensory input from the individual’s vision, vestibular system (the balance system of the inner ear), and proprioceptors (sensors of position and movement in the feet and legs).  Maintaining balance requires coordination of input from multiple sensory systems including the vestibular, somatosensory, and visual systems.

Three major sensory systems are involved in balance and posture:

• Vision – This is the system primarily involved in planning our locomotion (walking around) and in avoiding obstacles along the way.  However, it is also importantly used as a reference frame for feedback for the vestibular system.   Here senses are used for reference to verticality of body and head motion.  Spatial location relative to objects is also used – think of the feeling you get off moving despite being on a stationary train when you watch another train moving off besides you in the station.
• Vestibular system – This is our inner ‘gyroscope’, which senses linear and angular accelerations.  It includes sense organs that regulate equilibrium (equilibrioception); directional information as it relates to head position (internal gravitational, linear, and angular acceleration).
• Somatosensory system – This includes a multitude of sensors that sense the position and velocity of all body segments, their contact (impact) with external objects (including the ground), and the orientation of gravity.  It includes senses of proprioception and kinaesthesia of joints; information from skin and joints (pressure and vibratory senses); spatial position and movement relative to the support surface; movement and position of different body parts relative to each other.

The senses must detect changes of spatial orientation with respect to the stability of our posture in respect to gravity, regardless of whether the body moves (dynamic) or our posture is stationary (static).

In addition to the above three major sensory systems, environmental factors can affect balance – such as light conditions, floor surface changes, alcohol, drugs, and ear infection.

Balance Function and The Role of The Vestibular System

In understanding how motor engrams are formed it is important to briefly explore in a little more detail the vestibular system.  It is constructed from a nexus of peripheral sensory organs and a complex network of central neurons.

The vestibular system is a complex structure of fluid-filled tubes and chambers that constitutes part of the inner ear.  Specialized nerve endings inside these structures detect the position and movement of the head and also detect the direction of gravity.  Signals sent from the nerves of the vestibular system are critically important to the brain’s ability to control balance in standing and walking.

The peripheral anatomy and physiology are responsible for sensing the degree and direction of acceleration, as well as providing a sense of orientation of the head with respect to gravity.  The accurate perception of movement and self-orientation occurs, in part, because of a healthy vestibular system.  

This perception is both subconscious and autonomic in that it occurs without intent or self-control, as a learned activity embedded in our motor processes.  On its most basic level, the vestibular system is both a sensory system as well as a motor system. 

• As a sensory system – It not only provides an accurate representation of self-motion, but is also integral in constructing an “internal map” of our centre of mass in space with respect to gravity.  It is this that gives us our internal awareness of our balance and allows us to ‘feel’ our centre of gravity.
• As a motor system – It coordinates effective postural and ocular motor reflexes to ensure static and dynamic equilibrium with respect to our centre of gravity as well as maintaining clarity of vision during head movement.  It is this that controls the muscular responses in maintain normal standing from the central control centre fed by the sensory system.

Although balance and equilibrium are heavily dependent upon other central nervous system processes, especially the visual and somatosensory systems, the contribution of the vestibular system is significant.  Understanding the relaxation between sensory systems and motor systems is also critical in understanding how a normal standing position is achieved.  For the developing student looking to ‘learn’ the biomechanics of the Wing Chun stance, understanding this relationship also plays an important role.

Posture Control and the Somatosensory System

The effectiveness of the postural control system depends on the availability and reliability of the information from the somatosensory system, in addition to the vestibular system.  Posture is achieved from a large number of sense-motors, at different levels of the central nervous system, with an automatic and extremely precise adjustment.

The postural control is regulated by a complex system called the tonic postural system.  This is composed by an afferent system (sensory pathways) that transmits information to a central processor (central nervous system).  The information coming from the environment are received from the sensory systems, such as the visual system (by the retina), skin system (due to receptors situated under the feet), vestibular system, the golgi tendon organs and muscle spindles.

The input information is provided by the somatosensory system, which includes exteroceptive and proprioceptive receptors, and by the vestibular and visual systems.

The somatosensory input is generated by the sense organs localized at different levels:

• Muscular – Information is supplied information by the muscle (sensitive to changes in length of the muscle bundles) and golgi tendon organs (sensitive to changes in muscle tension).
• Postural fluctuations – These cause light muscle strains and subsequent activation and response of the muscle spindles.  Muscle proprioceptive information is particularly precise and discriminating.
• Visual / Retina – Paracentral and peripheral vision transmits information relating to the movement of the visual field and detect the orientation of the head according to the perceived vision.
• Skin – Skin receptors detect changes in the bending of the foot related to the support surface.

These stimuli are transmitted to the higher centres, which include the brain, the cerebellum, and the brain stem, through interneurons and motor neurons in the spinal cord.  Upon reaching the central nervous system, the information is processed and recorded in the form of the motor engram body image (the knowledge you have of your body in a static situation and dynamic).  They are then transmitted to the muscles, where it takes the contraction of the muscles causing the displacement of skeletal levers and a stabilisation of the posture.

The human body has special sensors in the joints and muscles called sensory receptors which detect that the joints are being disturbed by gravitation forces and are being subjecting to slipping disturbances.   These disturbances and the signals created are known as gravity sensory information.

The main concentrations of these sensory receptors are located within the lumbo-pelvic region, including the deep core muscles and where the deep anti-gravity muscles hold up the arches of the feet, as shown in the diagram below.  These play a vital role in the feedback mechanisms used for ankle and hip strategies in managing balance – something I will explore in more detail later in the paper.

Information from these receptors is passed through to the central nervous system through sensory system relays.    Where corrective action is identified to counteract disturbances and maintain balance the central nervous system sends messages wo increase tone (or stiffness) to the anti-gravity muscles within the different anti-gravity kinetic chains to stabilise the relevant joints, and to increase the co-contraction of these muscles to stop joints slipping and sliding.  This is also used to correct the balance between movement muscles and anti-gravity muscles.  It does so by a reduction in activity (relaxation) of the movement muscles.

An explanation of movement versus anti-gravity muscles and kinetic chain muscle groups is given later.

It is important to note that all of these sensory inputs are taken for granted in our normal standing.   Furthermore, the kinetic chain systems used to sense and correct balance are generally something most people are not cognizant of.   When attempting to re-learn these processes, or when attempting to learn new advanced motor skills – such as the Wing Chun stance or stepping, these usually sub-conscious processes become necessitate conscious scrutiny and control.  It also requires re-programming the system process, sensory receptors, and pathways.  

This explains why developing Wing Chun students will actively look down at their feet or limbs to understand where they are positioned.  Of course, in looking down the whole dynamic of the weight distribution of good posture is broken causing the centre of gravity to shift and the body to lose stability.  This also explains why it takes a considerable amount of practice and, most importantly time, for the mind and body to reprogramme the internal biomechanical systems and processes involved in achieving and maintaining the new postural positions.   

Concepts of Gravity in Stabilisation

When seeking to actively control the use of gravity within our normal standing position (static) or whilst moving around (dynamic) to get greater stability the concepts of centre of gravity and centre of pressure are important to understand.

Centre of Gravity

We have seen in the context of the force of gravity that this is the downward pull or force that the earth exerts on your body.  Your centre of gravity is the point where the mass of the body is concentrated and in equilibrium (balance).

When we define the centre of gravity, we often do so from the reference of a static, normal standing position.  It is important to remember that the body is continuously in motion, which means we change positions often.  Our centre of gravity shifts as we move and bend.  With each new position we have a new location for the centre of gravity.  It is the point around which all the parts (segments) balance.  This point of balance may be located inside or outside your body, depending on its position.  The act of balancing requires the maintenance of the centre of gravity above the feet in the normal standing position.  You will fall over when your centre of gravity is displaced beyond the position of the feet.

The centre of gravity of a person standing in a normal upright position with their arms at the side is at approximately 56% of the height of the person.  This being measured from the soles of the feet (plantar surfaces) to the apex of the head in an erect position.   The general approximation figure is given in recognition that this figure varies subject to other factors.  For example, it is on average 55% of the distance for women compared with 57% for men.   It is important to understand that its precise location will vary somewhat according to body type, age, and sex.

As mentioned earlier, an individual’s posture may be affected by a number of factors – the build-up of fat and the loss of soft tissue tone are common factors in changing one’s centre of gravity.  The centre of gravity shifts with each change in body alignment, and the amount of weight on the joints and the pull on the muscles. 

Generally, we are not aware of our centre of gravity.  We have made it second nature from the time we learned to stand and walk.  However, when you are engaged in activities that require balance and stability (such as gymnastics, or Wing Chun) an awareness of it becomes crucial.

As this is very much an individual thing, you will need to ‘feel’ where yours is and get used to feeling it changing location as you shift, rotate and step around.  Importantly, get used to feeling it in the normal standing position and how it changes when you are in the Wing Chun stance.   This becomes very important when we move beyond the normal standing position into dynamic movement to keep it on a horizontal level rather than bouncing up and down.  This bouncing action is a clear indication of holding muscle tension and results in a loss of the ‘sink’ of natural weight under the force of gravity.  This in turn then destroys the forwarding/spring action of the whole body and means that the possibility of whole-body application of energy and power is lost.

Segments

Just as motor engrams are a sequence of muscle movements controlled centrally by the brain to perform complex movements, it is important to understand that the individual limbs involved in movement are controlled by a series of muscles across different parts of the body.  This is referred to as segmentation, which makes a distinction between a specific limb (such as the arm) and the component parts of that limb (the shoulder, elbow, and hand).

The use of segments has mainly been driven by a requirement in biomechanics to determine the body’s centre of mass (centre of gravity).   Finding the centre of mass of a simple, rigid object with a uniform density is easy in comparison with the challenge of establishing this in the human body.   This is because the human body is a dynamic, flexible, complex object with varied density.  For example, as a person bends forward to pick up an object from a table, different parts of their body will be used in this complex movement and, importantly, changes how the whole structure is stabilised under the pressure of gravity.  Through the segmentation approach, the overall mass distribution within the body is understood as a function of the mass distribution within the individual segments and the body posture.

In 1990, Zatsiorsky divided the body into a series of segments in the article Methods of determining mass-inertial characteristics of human body segments, Contemporary Problems of Biomechanics.  These segments are shown in the figure below.

This allowed for a scientific level of understanding to calculate the centre of mass of the human body based on the different segments in relation to each other during normal standing and movement.  The body was divided into several segments – (1) the head and neck, (2) the trunk, (3) upper arm(s), (4) forearm, (5) hand, (6) thigh, (7) shank / calf and (8) foot.

For our purposes as martial artists we do not need to have a scientific level understanding of the precise location of centre of mass at any given point.  However, understanding the force of gravity and being able to maintain balance and structure through our stance and movement is something that is very important, especially within Wing Chun.  To this end I will explore the role of gravity in stabilisation and balance, and the base of support concept later in this paper.  

Our brain, however, does need to constantly monitor and maintain this complex relationship of body parts and segments in maintaining our balance.  This is not something that we are generally aware of on a daily basis, but when we seek to deviate from our learned, normal standing position and move into a completely different one (in the Wing Chun stance) this becomes important to understand.

Correct postural alignment is essential to maintain normal length-tension relationships of muscles, especially during dynamic posture.  This also determines the ease with which the body segments align themselves through the action of movement.  Any disruption to this alignment throws the kinetic chain of the body off balance, leaning the person susceptible to injury and also reducing the effectiveness of structural positions in movement.

As mentioned earlier, a common mistake in the beginner Wing Chun student is to look down at their feet, knees, or hands whilst they are getting used to the positions of the limbs and the individual techniques within the forms.   As an inverted pendulum we have already established that the normal standing position requires coordinated effort to remain balanced.  When the significant weight of the head is tipped forward to look down, this greatly impacts posture and skeletal alignment – critical elements that are the foundation of Wing Chun structure.  This is why it is important to be able to ‘feel’ from ‘within’ that you are in the correct position.  I always recommend using a mirror to developing students so they can benefit from visual cues, whilst still (crucially) getting used to maintaining structural integrity.

Understanding the basic principle of segmentation is important in understanding normal standing, but it is important to move beyond this limited concept of segmentation of how the limbs are positioned relative to each other and their collective centre of mass to extend our understanding to how limb movements are performed using muscles that extend outside of these segments with the dynamic Wing Chun stance, and later in dynamic Wing Chun turning and stepping movement.

I have shown that posture is the alignment of body parts in relationship to one another at any given moment.  Posture involves complex interactions between bones, joints, connective tissue, skeletal muscles, and the nervous system, both central and peripheral.  The axial musculature involved in maintaining the normal standing position is architecturally complex.  Axial muscles have broad anatomical origins with insertions linked to several structures—the spine, pelvis, rib cage, and shoulder girdle.  These often span long distances and have multiple attachments to multiple bones.  They are also oriented at different angles to the longitudinal axis of the spine.

Because the axis links all parts of the body together, activity from these diverse structures must be considerate of the actions of all parts of the body during the maintenance of posture and during movement.  During movement, for example, action in one part of the body disturbs other parts of the body, creating a disequilibrium.  As such, maintaining alignment can be realized only by stabilizing multiple segments.  Such combinations of stability and mobility in everyday motor activities depend on the precise regulation of axial and proximal tonic activity.

During normal standing the alignment of the body is also stacked like a tower of stones through the main joints (ankles, knees, hips, shoulder) to create good posture.   Within Wing Chun these areas are grouped into 2 broad categories – creating triangular structures in the lower body (Lok Ma or ‘Lowering Horse’) and upper body (Tie Seung San or ‘Uplifting upper Body’) which is unified through whole body application (Tei Gong or ‘to make solid’) through the re-alignment of the spine. 

Understanding how the six major joints are stacked is important for the developing Wing Chun student to construct the Yee Gee Kim Yeung Ma stance as solid from the ground.   Also understanding how the individual components fit together as part of a whole-body application is also critical in being able to use the Wing Chun stance in a fluid, relaxed but structurally sound way.  I spent a couple of years working from the ground upwards ensuring that each segment was firmly ‘rooted’ and the weight of the segment above it balanced upon it and was structurally aligned.  Over the next couple of years, I was then able to mindfully have each segment as a mental focus point as I ‘set the tower structure up, getting into the Wing Chun stance. 

This becomes second nature and you no longer need to consciously focus on this, but quickly become aware if your centre of gravity or centre of pressure sensory feedback identifies a deviation – at which point you can re-check your structural positions and correct these – generally as a result of muscular tension creeping in.     

Centre of Pressure

In addition to the concept of centre of gravity, it is also important to understand the centre of pressure.  This is the point location of the vertical ground reaction force vector.  It represents a weighted average of all the pressures over the surface of the area in contact with the ground.  

In the simple example of the normal standing figure above, the centre of pressure would be felt in the centre of each foot.  However, it is important to understand that it is totally independent of the centre of gravity.  If one foot is on the ground the net centre of pressure is located within that foot. Where both feet are in contact with the ground the net centre of pressure is located somewhere between the two feet, depending on the relative weight taken by each foot.

This is important in the feedback used by the somatosensory system – proprioception pressure information from the skin and joints, in providing spatial position and movement relative to the support surface along with movement and position of different body parts (and segments) relative to each other.

As we seek to move from a normal standing position into the Wing Chun stance, having an awareness of the centre of pressure becomes very important.   The beginner student initially will have no focus on where their weight is positioned and will not mindfully ‘feel’ the centre of pressure.  As mentioned, this is a critical part of the advanced students’ tool-box – which they will use as an integral part of the sensory feedback system to feel that they have correctly set up their stance and have correctly positioned their centre of gravity. 

Balance

As a noun balance is defined as “an even distribution of weight enabling someone or something to remain upright and steady”.  As a verb it is defined as “(to) put (something) in a steady position so that it does not fall”.  As such, within the context of achieving balance as a human in a normal standing position, we see this is an action of actively distributing the weight of the body in such a way that it remains upright and steady.  

In its simplest form, balance is achieved through the relationship of the base of an object and its centre of gravity.  The narrower the base of an object is, the higher its centre of gravity will be.  This results in less stability – where the object is easier to be toppled over.  Conversely, the wider the base of an object is, the lower its centre of gravity will be.  This results in greater stability – where the object is harder to topple over.  As such, the most stable objects have wide bases and low centres of gravity.  This concept is shown in the model below.

This concept of creating a lower centre of gravity within martial arts is achieved by creating a wider, lower stance.   This is shown is the models below.

The figure on the left has a low, wide stance with a much larger distance between their feet.  Their centre of gravity (marked by the red cross) is along the lower dotted line.  The figure of the right has a high, narrow stance with a much smaller distance between their feet.  Their centre of gravity (marked by the red cross) is along the higher dotted line. 

The character on the left has a much more stable stance than the one on the right.  This character has a much lower centre of gravity.  Within the context of a martial art this means being able to have created a strong platform from which to attack an opponent, whilst also being able to receive an attack without being knocked over.

However, stability is only part of the equation when it comes to a fighting stance.  Not only do you need stability, but you also need mobility – specifically, speed of movement to be able to attack the opponent and avoid their attacks.  As such, there is a trade-off of these two elements.  With a focus on both speed of movement and stability of structure, Wing Chun’s Yee Gee Kim Yeung Ma stance is a compromise of the two. 

The exception within the Wing Chun system is the long, deeply sunk Gwun Ma stance used in the Luk Dim Boon Kwun (Long Pole) form.  Having to manage the weight of the pole and as a result of the advantage of being able to attack the opponent at a distance, the need for speed to avoid close range, fast attacks is reduced, and in changing the balance of this equation it allows for the widening of the base of support.   

Base of Support

The base of support is the area around the outside edge of the sections of your body in contact with the ground/surface.  This is shown in the models below:

Widening your base of support gives you more stability, but it also makes you less mobile.  Additionally, having a long narrow base of support gives you stability against a force coming at you head on, but leaves you vulnerable to an attack from the side.  The character on the left would be able to resist a significant amount of pressure onto their fist, without losing balance.  However, they would topple quite easily if pressure were applied into the centre of their chest, at a right angle to the base of support.   One solution is to create a side-facing stance, as shown in the right diagram, which although not as long provides a greater, more even area.

In order to increase mobility and improve acceleration you need to reduce your base of support.  However, this comes at the cost of reduced stability.  This is why the Wing Chun stance is a compromise – recognising the need for increased stability, but at the same time a need for mobility.  Yee Gee Kim Yeung Ma as a front-facing stance involves widening the stance to slightly wider than the shoulders.  The Wing Chun stance is extremely mobile and allows the Wing Chun exponent to move quickly from their centre of mass in any direction.

Given the relatively narrow base of support this basic stance can only take so much stress before it breaks down.  But this is a recognised, intentional feature of the basic stance – Importantly, the structure of Yee Gee Kim Yeung Ma with the centre line of gravity passing directly down the centre of the body allows body to rotate around this and move into the side-facing stance which has a much larger base of support.

The Line of Gravity

The line of gravity is an imaginary vertical line from the centre of gravity to the ground or surface the object or person is on.  It is the direction that gravity is acting upon the person or object.  In the anatomical position during normal standing the line of gravity is between the legs and feet right under the person.  In the diagram you can see the line of gravity in red going down to the ground from the centre of gravity, indicating the force of gravity. 

The closer the line of gravity is to the centre of the base of support the more balanced a person is.  If the line of gravity falls outside the base of support area the person must provide corrective muscle action or movement, otherwise they will fall over.

As I showed earlier, a lower centre of gravity means better balance and stability.  As such, a shorter line of gravity between the centre of gravity and the ground also means better balance and stability.  Lowering the centre of gravity is universally recognised as increasing balance and stability in sports and martial arts.   It also allows you to change direction faster by bending your legs and getting lower to the ground, something that is seen most noticeable in slalom skiing.  It also increases your stability, allowing you to adjust to greater force production by the legs.

The most economical use of energy in the normal standing position is when the vertical line of gravity passes through a column of supporting bones.  If the weight-bearing segments are aligned so that gravity passes directly through the centre of each joint, the least stress is placed upon the adjacent ligaments and muscles.  This is an ideal situation and not something that is achievable in the musculoskeletal system in the human body because the centres of segmental links and the movement centres between them cannot be brought to accurately meet with a common line of gravity. 

Within the Wing Chun stance in the lower body (Lok Ma) we can see the force of gravity marked in the diagram above by the dotted black line from the knee joint on the left leg down to the ground.  This marks the upper leg segment line of gravity down to the ground.  Importantly, we must align these individual segment lines of gravity, stacking these across all the segments.  Where the joints of the leg (pelvis, knee, and ankle) are aligned, as shown by the dotted line through the leg on the right side, the force of gravity is supported within the structure of the limb.  This balances out the segments and allows the force of gravity to be balanced through the limbs and joints, shared across multiple segments.  

When this gets out of balance, damage to the joints will occur.  This is because excessive weight will come to bear at the end of the chain of alignment.  For example, if the knees are artificially held ‘clamped in’ by the adductor muscles in the upper leg, this distorts this natural line and ‘freezes’ the knee joint breaking down the natural spring/forwarding action.  This also stops the use of the adductor muscles being able to raise and lower the Lok Ma structure, but this is something that we will cover in the following paper. 

In the correct position shown in the previous diagram we saw that the knee line of gravity was in alignment with the inside of the angled-in foot.  In the diagram above, we see this is now a good couple of inches away from the dotted line on the leg to the left.  The knee is showing as out of line from the natural line between the ankle and pelvis.

This makes the lower body static rather than dynamic and the Wing Chun student is left with no mobility.  Even more importantly, the weight of the upper body segments is pressing down under the force of gravity into the upper leg segments and all that weight is bearing down on the knee joints.   Without the natural line allowing this weight to be balanced and supported correctly on the lower limb segment this seeps out of the alignment position and places great pressure on the knee joint – pressure that it was not intended to support in the normal standing position – and sufficient pressure to quickly cause damage.

A correct alignment of ‘Lok Ma’ is shown in the image below, which is a sideways perspective of the lowering effect of the stance.  This shows that the line of gravity from the centre of the Pelvis segment is placed central to the foot.  The line of gravity from the knee is positioned in alignment above the toes.

This position is achieved by the advanced student through the correct relaxed musculoskeletal use of ‘Lok Ma’ through the sinking/forwarding of the dynamic use of muscles against the force of gravity.   Where the correct muscles are used, the advanced student does not need to try and achieve this position – instead, this is the position that the body automatically find with the lower spine straightened, the pelvis rotated, and the legs rotated inwards.  However, in the beginner student, where this understanding and ability has not yet been achieved, the student will do three possible alternatives:

• Artificial placement – In seeking to artificially reproduce the position their instructor has shown them the beginner student will artificially place themselves in this position.  This involves the continued use of normal standing anti-gravity muscles, with the student then looking down whilst they lower their knees over their feet.  If they persist in holding this artificially then joint damage can quickly result.
• Not sinking enough – In seeking to continue using normal standing anti-gravity muscles they will initially artificially place themselves in the correct position, but quickly fatigue will mean that they return to an almost normal standing position.  Lacking structure they are then quickly toppled and typically then try to compensate for this by increased muscle tension in the upper body.
• Sinking too far – Again, resulting where the student fails to transition from the use of normal standing structure and sinks down beyond the alignment of the knee by seeking to be ‘floppy’ assuming this equates to relaxed structure.  With the weight of the upper body segments pressing down and not correctly aligned or balanced on the knee joint damage is likely to quickly occur if not corrected.

As I mentioned previously, since the body is a segmented system, the stability of the body depends upon the stability of its individual segments.  The force of gravity acting upon each segment must be individually neutralized if the body as a whole is to be in complete gravitational balance. That part of balance contributed by an individual segment is called the segment’s partial equilibrium, as contrasted with the total equilibrium of the whole body.  Thus, each segment has its own partial centre of gravity and partial line of gravity. 

With a lack of initial understanding or insight in the beginner student it is critical that the Sifu understands this and corrects this as quickly as possible in the student to avoid joint damage.  In the developing student, it is important to give thought to each of these segments in the normal standing position and how these are changed within the Wing Chun stances as part of the refinement of relaxed structure.    

Copyright @ Craig Sands

Continue to Part 2 - Muscles Involved in Maintaining Balance, here: Link