Table of Contents
1 Introduction 3
1.1 Purpose of Study 3
1.2 Somatic Movement Education 3
2 Structures and Functions of the Nervous System 4
2.1 The Nervous System 4
2.2 The Brain 9
3 Sensory-Motor Learning 14
3.1 SMA 14
3.2 The Reflexes 15
3.3 The Techniques 16
4 Concluding Discussion 18
5 Bibliography 19
5.1 Literature 19
5.2 Articles, Lecture Notes & Handouts 20
1.1 Purpose of Study
In this paper we will look into the structure and function of the human nervous system related to Somatic Movement Education (SME). The overall purpose of this paper is to shed light on the science behind SME, to enhance understanding of the healing modality amongst clients, practitioners, other health related professionals and anybody else who has an interest in SME. In order to do so the following questions will be addressed:
- Why is the knowledge of neurophysiology important for the practice of SME?
- What structures and functions of the brain and the nervous system, central and peripheral, are involved in SME?
- How do you, or might you, use this information in the practice of SME?
The principles, background and techniques of SME will also be presented to promote a broader understanding of the nature of this work.
1.2 Somatic Movement Education
SME is the use of sensory-motor learning to improve the function of the neuromuscular system of the body. SME is a re-education of the nervous system. A Somatic Movement Educator helps the client regain voluntary control over muscles; improve functional movement and greater freedom of movement through slow mindful movements.
The word somatics comes from the Greek word soma, which means the living body in its wholeness. The soma is a process rather than something solid and static, constantly changing and adapting to its environment. It is the combined mind-body as one functional unit experienced from within.
SME is based on principles that the soma is self-healing, self-regulatory and self-correcting. It puts importance on the first person experience; what the individual, client is experiencing inside him/ her self. Unwinding any holding patterns within the soma through using neuromuscular re-education, SME focuses on releasing through the somatic centre. This is the area between the lower ribs, hip bones and the pubic bone; front, sides and back. The principles of SME are to move slowly and with awareness and to always move within a comfortable range of motion.
2. Structures and Functions of the Nervous System
2.1 The Nervous System
The human nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is lying within the cranium and the vertebral column and consists of the brain and the spinal cord. The PNS consists of nerves that are outside of the CNS, nerves joined to the spinal cord and the brain; spinal and cranial nerves.
The nervous system can also be categorised into the somatic nervous system, which can be controlled voluntarily, and into the autonomic nervous system (ANS), which is working involuntarily. The ANS consists of neurons that detect changes in, and control the activity of the viscera, such as smooth muscle, cardiac muscle and secretory glands. The ANS is divided into the sympathetic and the parasympathetic division. The sympathetic nervous system (SNS) is concerned with fight, flight and survival. The parasympathetic nervous system (PNS) is concerned with rest and repair and about finding comfort. When one does somatic movements one is more in PNS.
The nervous system consists of two kinds of cells: neurones and neuroglia. "Neurones make up the nervous tissue that forms the structural and functional portion of the system. Neuroglia or glia cells serve as support and protection". The function of the neurone is to receive incoming information from sensory receptors and to transmit information to other neurones or effector organs. Neurons vary in shape and size but they all have a single cell body. From the cell body a variable number of branching processes emerge, most of them are receptive in their function and called dendrites. All neurons have one axon; an axon can vary in length from two meters to a tenth of a millimetre. On one end of the axon are the axon terminals and at the other end of the axon are the dendrites. You can think of the neuron as shaped like a tree. The axon terminal is the roots, the axon the trunk and the dendrites the branches or twigs. Dendrites terminate in granular bumps called dendrite spines. They are the dendrites receivers of information, which makes them important in the learning process. Neurons communicate by the axon sending electrochemical information to another neurons dendrites that receives the message and may pass the message on to other neurons. Neurons never actually touch each other, there is always a space about one-millionth of a centimetre, called the synaps. Transmission of information between neurons often occur by chemical means.
Action potential (AP) is an electrochemical current that travels down the axon, AP is created when a nerve cell gets excited. "Meaning that it reaches a certain threshold of electrical charge, a quick exchange of charged particles takes place, which will flow all the way along its membrane to the axon terminals." Specific chemical agents that are stored in the presynaptic ending are known as neurotransmitter in the CNS and as transmitter in the PNS. Some of the neurotransmitters are noradrenalin, dopamine and serotonin. Glutamic acid and gamma-aminobutyric acid (GABA) are the principal excitatory and inhibitory transmitters. When the action potential has been triggered, it then conducts along the nerve cell in a wavelike, cascading effect, named a nerve impulse.
"A nerve is made up of bundles of neurones. Then a whole bundle of bundles make up the nerve." The body is constantly gathering information/ impulses. Nerves that carry information from the peripheral receptors to the CNS are called afferent neurones. Some of these nerves that carry the information are called sensory neurones. Efferent neurones carry information/ impulses away from the CNS and are also called motor neurons if they innervate skeletal muscles to cause movement.
An upper motor neuron is coming from the cortex down to the brainstem and spinal cord. A lower motor neuron is coming from the spinal segment to the muscle. Functional disorders that are examples of upper motor neuron lesion are Parkinson's disease, stroke and spinal cord injury. Within these conditions there are often spastic paralyzes, which means that the muscles often go into an involuntary spastic contraction. My experience from working with spinal cord injury clients is that when this happens it is often useful to assist the involuntary tightening, to go with and to maybe even exaggerate this pattern. Followed by allowing and waiting for the slow release out of the contracture. With clients who have compression of the peripheral nerves, i.e. lower motor neuron lesion they may have flaccid paralyzes. This may be caused by a hyper contracted muscle pressing on a nerve, such as piriformis pressing on the sciatic nerve.
Extrafusal and intrafusal muscle fibres (cells) run parallel to the main axis of the muscle. Extrafusal muscle fibres are innervated by alpha motor neurons. The cell bodies of an alpha motor neuron lie in the motor cranial nerve nuclei of the brain stem or in the ventral horn of the spinal cord. An alpha motor neuron often branches within the muscle to innervate a number of muscles at the same time. Alpha motor neurons innervate extrafusal muscle fibres and gamma motor neurons innervate intrafusal muscle fibres (within muscle fibres). Intrafusal muscle fibres act as tension and stretch receptors and occur in groups know as muscle spindles. When the "corticospinal tract allows an activation of the alpha motor neuron, there is also an activation of the gamma motor neuron, both of them at the same time. That is the alpha-gamma co activation." The combination of a neuron, its axon and the muscle fibres that it innervates is known as a motor unit.
There are different kinds of sensory receptors that have the function of gathering information about the body's inner environment (interoceptors) and about the body's outer environment (exteroceptors). Proprioception occurs in muscles, tendons and joints and provide awareness about position and movement of the body or the extremities (posture). Proprioceptors is Latin and means self-sensation and in SME we are very interested in this. With SME people learn how to listen to their own body again, how to sense them selves.
The quality of our motor output is determined by our sensory input and how perceptive we are to those sensations. This means that the quality of our movement depends on our ability to sense what we are doing. In doing so we make use of different kinds of proprioceptors; Free nerve endings: lying freely in the innervated tissue. They respond to painful or mediate thermal sensations. Pacinian corpuscle: surrounds joints and respond to mechanical distortion. Meissner's corpuscles: responds with great sensitivity to touch and pressure and occur mostly on the tip of the fingers. Muscle spindles: respond to muscle stretch. Golgi tendon organs: occur in tendons and respond to tension. So when you are asking your client to contract a muscle voluntarily, one thing they are doing is pulling on their tendons, this because their muscles have gotten shorter stimulating the Golgi tendon organs.
If a muscle is stretched it will respond by contracting, this is known as the stretch reflex, or the myotatic reflex. When a muscle is stretched a message goes from the muscle spindles in the muscle via the afferent fibres to the spinal cord and motor neurons and then another message is sent back to the muscle to recontract. This is called the monosynaptic reflex. In SME we are conscious not to activate the stretch reflex as this is counterproductive in lowering the tension level of a muscle.
2.2 The Brain
Paul MacLean developed the Triune theory of the brain. This theory states that the human brain consists of three separate sub-brains. Each possesses its own intelligence, sense of time and space, and its own individual subjectivity.
1st brain: the reptilian brain includes the brain stem and the cerebellum. It supports basic life functions and maintains and controls heart rate and breathing.
2nd brain: the old mammalian brain maintains and controls body temperature, blood sugar levels, blood pressure, digestion and hormonal levels. It is also responsible for fighting, fleeing, feeding, fornication. The mammalian brain, also known as the emotional brain, is located directly in the middle of the brain. This area is most highly developed in mammals. It is the size of an apricot in an adult human and is situated just above the brainstem. The most important structures of the mammalian brain are the thalamus, hypothalamus, hippocampus, pituitary, pineal gland, amygdala, and basal ganglia.
3rd brain: the neocortex/ new brain. The neocortex is in the cerebral cortex of the brain. Is the seat of our awareness and creativity, it is where we learn and remember everything from our external world. The neocortex is said to be the seat of the executing mind, identity, personality and higher brain functions. Performs higher brain functions such as reasoning, intellectualizing, learning, remembering, planning and verbally communicating.
The brain consists of about 100 billion neurons that are linked together and make up a neural network. The neurons are firing in unique sequences, in the neocortex each nerve cell can link with 40,000 to 50,000 other nerve cells. The cerebral cortex is the outer layer of the brain, 3 to 5 mm thick (/7 to ¼ of an inch). It is so rich in neurons that it has more nerve cells than any other brain structure.
There are two cerebral hemispheres, the left and the right. The two hemispheres are joined together by a bridge of millions of neurons, called the corpus callosum. This bridge is actually axons of the neurones, also called the fibrous bridge. Each hemisphere is controlling the opposite side of the body. The cerebral hemispheres are further divided into four lobes. Each hemisphere has a frontal lobe, parietal lobe, temporal lobe and occipital lobe. The anterior part of the cerebral hemisphere is called the frontal lobe and is the most resent achievement of our evolution. It is the seat of intentional actions, focused attention, coordinates almost nearly all the functions of the brain and has one of the language centres. It is also responsible for higher mental activities. The posterior boundary of the frontal lobe is the central sulcus. Posterior to the central sulcus lies the parietal lobe, which has to do with sensations related to touch and feeling (sensory perception), body orientation and coordinates language function. The temporal lobe is separated from the parietal lobe below by the lateral fissure. It is involved as you associate the image with what you remember. The temporal lobe process sound and smell and is responsible for learning, memory, language and perception. The occipital lobe is situated in the posterior part of the hemisphere and has to do with seeing. This is where visual information is processed.
The brainstem contains the medulla oblongata, pons and midbrain. It is a small part of the brain but is of crucial importance. There are four nerve tracts that originate in the brain stem, connecting the brain and the spinal cord. It also contains the site of origin and termination of many of the 12 cranial nerves, through which the brain innervates the head region and many other parts of the body.
The cerebellum, also called the little brain, is attached to the brain stem by a large mass of nerve fibres. It does coordination, proprioception and body movement. Simple actions and responses that are learned, coordinated and memorized are stored in the cerebellum, such as bicycling and walking. The cerebellum does things quickly. It does pre-programmed movements and helps smooth movements.
The thalamus is above the midbrain and is mainly a switching station for both sensory and motor input and output. Neurons come into it, synapse and then goes somewhere else in the brain. The hippocampus is an important structure because it does short term memory and it helps us to put things into long term memory. The amygdala, which is a part of the limbic system, is helping with long term memory and learning. As the amygdala gets "activated" clients frequently feel happier and more expressive. The basal ganglia facilitates purposeful movements and inhibit unwanted movements. It receives motor and sensory information from the cerebral cortex, brain stem and spinal cord.
The area immediately in front of the central sulcus, in front of the sensory cortex is the primary motor cortex. In the motor cortex you are mapped upside down, which is called the homunculus of the motor cortex, with a disproportionate representation of how much you use an area. About 1/3 is devoted to face and lips, 1/3 to hands and 1/3 to the rest of the body. This is why SMA occurs easily in the somatic centre and legs.
The motor cortex is in charge of and activates all of the voluntary muscles in the body and participates in all our voluntary movements and actions. The impulses from the motor cortex coming down are largely inhibitory. It synapses on little neurons inhibiting the alpha motor neurons. The motor cortex is responsible for conscious, slow and inhibiting movements. This is why two of the SME principles are to move slowly and to move with awareness.
In the parietal lobe, just behind the central sulcus lies the primary somatosensory cortex. Also, in your sensory cortex you are mapped upside down. The representation is a little different from the motor cortex homunculus because you do not move everything you feel. So we have sensory representation of parts of our body that we will not move. The sensory cortex senses movement and receives sensory information from different proprioceptors, such as the Golgi tendon organs and the muscle spindles.
Besides the primary areas there are association areas. They are of importance to us in SME because "the first step in deciding to move is using the association cortex and the limbic system."
If you use a part of your body more, the representation of this area in your homunculus will increase. In the same way if you do not exercise sensing or moving an area of your body, this area will fall into disuse. If used it will stay functional, if we don't use it, we will lose it. That is often what has happen to clients when they come in with pain; they have given over their conscious control over muscles to the brainstem. The brainstem has to do with unconscious fast movement and the sensory- motor cortex has to do with voluntary control of a movement. The sensory-motor cortex has the unique ability to reset the resting level of the muscle and does refined slow movement.
The premotor cortex, the area just in front of the motor cortex, is responsible for mentally rehearsing intentional action. In this area of the brain programming and preparation of movement takes place. The supplementary cortex is a part of the premotor cortex and this area is activated while visualizing a movement before doing it.
The reticular activating system (RAS) contributes to muscle tone and muscle contractions. Doing somatic movements, the contraction level of muscles will decrease and at the same time the activity in the RAS will tune down inhibiting the level of alertness.
There are five descending spinal tracts that originate from the brain stem and the cerebral cortex. The brain stem spinal tracts are: the Vestibularspinal tract that is involved in standing up and it contracts the extensor muscles. The Rubrospinal tract flexes joints and is excitatory. The Reticulospinal tract has to do with the arousal response. It influences voluntary movement, reflex activity and muscle tone by activating both the alpha and gamma motor neurons. According to Tom Hanna it is the tract for the Red Light Reflex. The Tectospinal tract has to do with movements of the neck muscles, in response to visual stimuli. The Corticalspinal tract originate from the cerebral cortex and is mainly concerned with voluntary, inhibitory, discrete and skilled movements. This is the spinal tract that we are the most interested in working with SME.
3. Sensory-Motor Learning
As we move through life our sensory-motor system responds to incoming stimuli and adapt to function to its best ability. Sometimes we are trapped in this adaptation and end up being run by our own unconscious patterns, created by the brain trying it's best to respond to the input it is given from the colleting nerves trough out the body. We are being run by sensory motor amnesia (SMA) and stress responses.
SMA is a loss of voluntary control of a muscle and can be sudden or gradual. When SMA occurs we have forgotten how to move and how to sense a muscle. When doing a somatic movement you may sometimes find that the movement is not fully smooth but with bits and pieces that are jerky or jumpy, this is SMA. It is an adaptive response of the nervous system and because SMA is a learned it can be unlearned. You can further reverse and avoid SMA by re-educating your sensory motor system.
Somatic Movement Education takes these unconscious patterns, slows them down, reprograms them to be more functional for us and then gives it back to the cerebellum and the brainstem, so that we do not have to think about them the whole time. Lasting improvement can more often be achieved by doing the changes from the inside, versus trying to massage, stretch or manipulate the muscle from the outside. Only by reprogramming the nerve supply to the muscle will one regain voluntary control over the muscle, i.e. replacing SMA with sensory motor remembrance (SMR).
Thomas Hanna writes that all somatic distortions reflect problems that are simultaneously problems of the person's life-style and body, i.e. soma. Therefore when we re-gain greater sensory-motor control we also receive benefits in other areas of our life.
3.2 The Reflexes
The reflexes that are connected to SMA are the Red Light Reflex, the Green Light Reflex and the Trauma Reflex. They are an important part of SMA as they may cause of, or be the result of SMA. The Red Light Reflex is an involuntary tightening of the flexor muscles – a withdrawal response. It is connected to fear and apprehension. It is also called the Stop or Startle reflex. The Green Light Reflex is the opposite in the way that it is an action response; positive or eustress. It is an involuntary tightening of the extensor muscles of the back. The Trauma reflex is an involuntary tightening of the muscles surrounding an injury or to guard against pain. It is often to do with lateral flexion and rotation. The Senile Posture is an involuntary simultaneous activation of the Green Light Reflex and the Red Light Reflex. It is also called to as the "dark vise" or the "ageing syndrome". It is a stop and go response. These reflexes all occur within the nervous system and can, therefore, be neutralised by working mindfully through the nervous system.
3.3 The Techniques
SME comes from a lineage of movement education. It started in the early 1900 century with the Alexander Technique, developed by F. Matthias Alexander who developed the method of Means- Whereby. Later Moshe Feldenkrais invented Functional Integration, developing the work further dealing directly with neuromuscular pathologies. Feldenkrais developed a technique that Thomas Hanna called Kinetic Mirroring. Thomas Hanna developed Hanna Somatics Education in the 1990s. His major contribution to the field is the understanding and application of the technique pandiculation. In the early 2000 osteopath Brian Siddhartha Ingle further developed the work to include greater understanding of how to combine and apply the techniques to enhance the effectiveness of this work. Dr Ingle created new protocol for the clinical hand on work and expanded and refined Tom Hanna's protocols. In 2007 he set up his own institute: the Ingle Institute for Somatics Movement Education and calls his work Somatic Movement Education.
SME offers a shift from reflexive (automatic physiological) programs in the CNS towards more voluntary control involving higher brain functions. In the process of doing so we use three techniques.
Means-Whereby: there is active and passive means-whereby (MWB). The focus is on the means that it takes to do certain movement, rather than getting to the end range of motion. The focus is on sensations within ones own body as one moves. The attention is not on the movements themselves, but on the internal feelings of these movements. In passive MWB a muscle is moved passively through a comfortable range. There is sensory feedback that is coming in to the sensory cortex from different sensory proprioceptors during MWB.
Kinetic mirroring: by bringing the origin and the insertion of the muscle together, the muscle relaxes. Feldenkrais described it as "If you do the work of the muscle, it ceases to do its own work". It makes use of the Golgi tendon organs and tunes down the muscle spindle.
Pandiculation: In a SME session the client is asked to voluntarily contract a muscle or set of muscles and thereafter the client is asked to slowly and voluntarily release out of this contracture, an eccentric contracture. By doing this we are letting the motor cortex check out how many neurons are needed to inhibit the motor unit.
When you are doing an unconscious movement, you are using the brain stem and the cerebellum. By working with voluntary muscle contraction, you take it up into the sensory motor cortex, i.e. higher brain functions. This has the unique ability to reset the resting level of a muscle. During the contraction of a muscle in a pandiculation, both the alpha and the gamma motor neuron increase in activity and then the activity decrease during eccentric contracture.
In a pandiculation you are voluntarily contracting the agonist, this is done through the sensory motor cortex. After doing this a few times it can be followed by a quick release, which is a ballistic movement that gives back the motor control to the brainstem and especially the cerebellum. Where after a lock-in can follow, where the antagonist muscle consciously is activated and simultaneously the agonist is inhibited by reciprocal inhibition, also called reciprocal innervation. Meaning that when one set of muscles contract, the opposite muscles automatically relax. Reciprocal inhibition is a spinal cord event. The function of the quick release and the lock-in is to give the control of the movement back to the cerebellum and the brainstem. When you have done that, the brainstem and the cerebellum have a new program.
4. Concluding discussion
SME is really brainwork, so understanding the principles on which it rests, from a neurophysiological point of view, I find is of crucial importance. The knowledge of neurophysiology I find useful when communicating with people in other health professionals, such as doctors, physical therapists, yoga teachers.
It helps me to be direct and clear in my instructions and guidance with the client so that the messages within the clients own neuromuscular system becomes as clear as possible. It is good to know the pathway of nerves and dermatomes in case there are complications with the nerve supply to a muscle. To be able to help and guide a client verbally and kinaesthetically, I find it helpful to be aware of the different neural pathways at work. I can be more precise, if I really know how and what parts of the client's sensory-motor feedback loop we are working with. To be aware of the neurophysiology behind SME also reminds me that the clients are creating the changes within their own soma and that I work with a client, versus on a patient.
Researchers have found that the human brain has the potential to be mouldable trough whole of life. "The brains plasticity is its ability to reshape, remould and reorganize itself well into adult life." Brain's plasticity is totally in the spirit of SME, which makes use of the brain's innate ability to learn and change. I believe that having some knowledge about the sensory-motor feedback loop involved in the practice of our somatic practice enhances the way we can support brain plasticity.
When I can explain to clients why and how SMA affects them, it helps them to reverse the process and become more self-autonomous. I find that it has helped me in the development of my own self-practise. I now understand why it is important to move slowly as I come out of a contracture and how I can get rid of stress that have accumulate in my soma. In short, I have found it very self-empowering to know how I can create changes within my own nervous system. Instead of becoming a slave under involuntary and unconscious events in my nervous system and muscles, I can use my understanding of the underlying neurophysiology to make use of the brilliance of my own muscular nervous system. It has empowered me to create the changes necessary for me to stay open and free in my soma to continue to enhance my life quality.
Crossman, A. R. and Neary, D., Neuroanatomy An Illustrated Colour Text, Third Edition, Churchill Livingstone Elsevier, 2005.
Dispenza, Joe D.C., Evolve Your Brain The Science of Changing Your Mind, Deerfield Beach: Health Communications, Inc. 2007.
Hanna, Thomas, The Body of Life, Creating New Pathways for Sensory Awareness and Fluid Movement, New York: Healing Art Press, 1980.
Hanna, Thomas, Somatics Reawakening the Mind's Control of Movement, Flexibility, and Health, New Ed. Edition, Cambridge: Da Capo Press, 2004.
Henriksson, Olle and Rasmusson, Margareta, Fysiologi: med relevant anatomi, Lund: Studentlitteratur, 2003.
5.2 Articles, Lecture Notes & Handouts
Criswell Hanna, Eleanor, Drafts of HSE Neurophysiology Lectures, Wave 4, 1998.
Hanna, Thomas, 'Clinical Somatics Education A New Discipline in the Field of Health Care' Autumn/ Winter Somatic Journal (1990-91) p. 4-10.
Ingle, Brian Siddhartha, Introduction to SME Science and Neurophysiology, Module 1, 2007.
Ingle, Brian Siddhartha, Neurophysiology & Biofeedback, Module 2, 2008.
Shenk, Phil and Warnock, Marilyn, Hanna Somatic Education Glossary of Terms, 2006.