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Neurophysiology Exam - Jim Ross Why is knowledge of neurophysiology important for the practice of Clinical Somatic Education? Brain controls muscle. Muscle moves bone. This simple, but profound understanding separates us as Clinical Somatic Educators from “body-workers”. We further understand that the root cause of most of the complaints our clients present with is what Thomas Hanna called Sensory-Motor Amnesia – when the conscious brain has temporarily forgotten how to accurately sense what the muscle is doing, and to fully control it. The brain is still controlling the muscle, but in SMA it’s the unconscious brain that is doing so, and the frequent result is a chronic contraction, which, as we know, leads to a myriad of further symptoms and problems. So, as CSE’s we recognize that the fundamental issue we are dealing with is not muscular but neurophysiological. We need to put the right part of our brain back in the driver’s seat, and as the root cause of the problem is neurophysiological, so must be the solution. We recognize that the ONLY way to permanently relax the chronic muscular contractions caused by SMA is to re-teach the conscious brain how to sense and control the muscle. In sum, it’s important to always keep in mind that we are not “body-workers” but “brainworkers”. I think it’s important to understand how SMA occurs. For clients, you want to be able to explain in basic terms how they got the way they are – if they are interested. You also want to be able to coach them how to avoid triggering further episodes. It may be that a few sessions with a practitioner and regularly doing Somatics exercises on their own will be all they need. But for those whose SMA is caused by repetitive motion or bad postural habits, they need to understand that if they keep doing what they’ve been doing, they may keep triggering the same results. For practitioners, understanding the origins of SMA helps in interpreting what is going on with your client. It puts into context what the client tells you of their history, and what you can see and feel in their body. Understanding that chronic contractions usually occur in patterns rather than in single muscles helps us recognize what is happening with a client and therefore how to address it. Next, knowledge of neurophysiology helps us create an optimal learning environment for sessions, and teach clients to do the same for their home exercises. CSE is largely about focusing our awareness. To that end we want to eliminate distractions as much as possible. This means we do the following things: We don’t play music during sessions. We talk only as much as needed to instruct the client what to do. If they have questions about what we’re doing, we can either talk between movements or hold the questions until the end of the session. What we don’t want is for the intellect to interfere when the awareness should be on what is going on in the muscle. We use touch judiciously. We may tap a muscle to bring greater awareness to it, but generally we want the client to be focused internally, on what their muscles are doing. We don’t want to be holding the client either too tightly, which may cause discomfort, or too loosely, which may cause them to feel unsupported. We maintain a comfortable temperature in the room. We take the client out of gravity so that the parts of the brain involved in balance are quiet. We use bolsters as needed to make the client comfortable. We may ask the client to close their eyes to better focus internally. In general, we try to minimize any intrusions on the client’s internal focus. Knowledge of neurophysiology helps us understand why we are doing what we are doing in a session and to explain it to a client should they ask. Not all clients will want to know, but being able to give a confident, scientific answer helps build trust with your client. The same applies with whomever you are may be discussing CSE. The more you understand the science of what you do, the more professional you appear. What structures and functions of the brain and nervous system (central and peripheral) are involved in Clinical Somatic Education? How do you, or might you, use this information in the practice of Clinical Somatic Education? In CSE we are concerned with the parts of the nervous system involved with movement and sensing of movement. Or, put another way, the parts of the brain and nervous system that control muscles (motor control) and the parts that sense what the muscles are doing (proprioception). To begin, let’s cover some basic neuroanatomy. The basic unit of the nervous system is the neuron. Each neuron has a cell body, numerous dendrites - branching processes that carry incoming nerve impulses from sense organs and other neurons toward the cell body - and a single axon, which may also branch, which carries outgoing messages to other neurons, glands and muscles. Many axons are covered with myelin, which acts as an insulator and improves the transmission of signals. The nervous system is comprised of two parts, the central nervous system, consisting of the brain and spinal cord, and the peripheral nervous system, which is everything else. Bundles of neurons (actually their axons) are organized by similar function into tracts in the spinal cord. In the peripheral nervous system bundles of axons are called nerves. The neuron that carries the signal from the spinal cord to the muscle is called the lower motor neuron. The muscle cells it connects to comprise a motor unit. All the neurons that control a given muscle are called a motor pool, and the motor area associated with any given nerve is called its myotome. On the sensory side, the area of skin associated with a particular nerve is called its dermatome. When we speak in CSE of the conscious brain we refer to the cerebral cortex, which is the topmost, surface layer of the cerebrum. The most important areas of the cerebral cortex for our purposes are the motor cortex and the sensory cortex. Other parts of the brain, including the cerebellum are discussed in more detail below. Sensory- Motor Amnesia The key issue we are dealing with in CSE is Sensory-Motor Amnesia (SMA). What is it? What causes it? What do we do to correct it? Proprioception is our ability to sense ourselves from within, specifically, where our body parts are in relation to each other and in space, and what our muscles are doing. The sensory aspect of SMA reflects our forgotten ability to fully sense (or sometimes sense at all) our muscles. Our muscles may be contracted but we can’t feel it. The motor aspect of SMA reflects our forgotten ability to fully control (or sometimes control at all) our muscles. Our muscles may be contracted but we can’t let go of that contraction. Movements fall into two categories: voluntary and involuntary. Voluntary movements originate in the motor planning area of the cerebral cortex with a conscious decision to perform a certain action. Involuntary movements originate in the sub-cortical brain or spinal cord without a conscious decision. Both voluntary and involuntary movements can become habituated. Tom Hanna believed that SMA was the result of the habituation of three reflexes: the Landau response (or Green Light reflex), the Startle (or Red Light) reflex, and the Trauma reflex. Each of these reflexes is hard-wired into humans. They are natural, normal and necessary for survival. The trouble arises when these reflexes are triggered either too often or for too long and become habits. The muscular contractions triggered in response to the reflex become chronic, never letting go. Repeatedly performing the same movement is another very common cause of habitual muscle contractions. The habituation affects both the sensory and motor systems. The Reticular Activating System (RAS) of the brain stem determines what stimuli we become aware of. It’s our attention focusing system. The brain likes novelty. Sensory messages that the RAS has received repeatedly diminish in importance and eventually fail to rise to the level of conscious awareness. The result is that a muscle that has been contracted for months or years isn’t even felt anymore. On the motor side, Long Term Potentiation (LTP) explains how any motor activity, when repeated over and over, becomes a “preferred pathway”. Neurons physically change, as do their synaptic connections to other neurons, in response to activity. The more the activity, the more the change, the deeper the groove so-to-speak, and the easier it is to trigger the activity again. In other words, it takes less to get a muscle to contract. (LTP has a positive side as we’ll see later.) Also on the motor side, once activities are learned, their execution moves from the cerebral cortex to the cerebellum, which is responsible for, among other things, coordination. The brain shifts responsibility for learned action to the cerebellum to free up the cortex for other things that require conscious engagement. It is more efficient not to be consciously aware of certain things. Unfortunately, if something goes awry we are no longer aware of that either. So what is actually happening when a muscle is chronically contracted? A “contract” signal is being continually sent from a subcortical part of the brain (likely the cerebellum) down one of the motor tracts of the spinal cord and then continuing down one of the nerves of the peripheral nervous system until finally reaching a muscle. A muscle will only “fire” when a certain threshold of “contract” messages is reached. Muscles receive both “contract” and “don’t contract” (inhibitory) signals and it is the net sum of all such signals at any given time that determines whether a motor neuron fires and causes the muscles fibers it controls to contract. In a chronically contracted muscle, we have a continuous stream of “contract” messages originating from a sub-cortical, which is to say, subconscious, part of the brain. At the same time, we are unaware sensorially of the contraction, because we have become habituated to it and have stopped noticing it. We can’t relax it because we don’t know and can’t feel that we are contracting it. Our sense of what it means to be “relaxed” is distorted. We may believe we are relaxed when we’re anything but. Our job is to reestablish communication between our sensory and motor systems so we can accurately sense what we’re doing and have conscious control over it. In a healthy sensory-motor system a decision is made to move (for example) your hand, at which point neurons in the motor cortex in the frontal lobe of the cerebrum fire, sending a message down the cortico-spinal tract of the spinal cord and then, leaving the spinal cord, down the peripheral nerve that controls the hand, terminating in and innervating one or more muscles. Because of the way neurotransmitters work, these motor pathways carry information in only one direction: from the brain to the muscles. Sensory information moves in separate pathways in the opposite direction, from the peripheral muscles, up the nerve to the spinal cord, and then up into the thalamus (which processes sensory information), ultimately reaching the sensory cortex in the parietal lobe of the cerebrum, right across the central sulcus from the motor cortex. Our sensory system and our motor system are intimately intertwined. Any given nerve carries signals in both directions. The sensory and motor areas area adjacent in both spinal cord and brain. As we make a conscious movement our sensory system senses what we are doing and sends messages back to the brain where “what we intended” is compared to “what we’re actually doing”, and if necessary, new, altered instructions are sent out. It’s a constant feedback loop. If we can no longer sense what we’re doing, the loop is broken and we lose the ability to control ourselves. Clinical Somatic Education largely consists of reminding the nervous system of how it feels to move the body in a particular way and then reminding it how to control that movement. To paraphrase Hanna, what is habitually unconscious is made conscious by means of new sensory information and this new awareness leads to greater self-control. Let’s look at some of the tools we use in CSE. In Means-whereby we begin this reeducation process with passive movement, where the client makes no effort to do anything but be aware as we move them though a range of movement that they may not have experienced in a while. We accomplish a few things with this: The client gains immediate experience of moving (albeit passively) in a way they may have forgotten was possible. And they not only know what’s possible, they know what it feels like. They can also feel where they are limited, as can we. We know, and can explain to them, that jerkiness or restricted movement is a sign of SMA and a guide to where there is work to be done. Moreover, we learn by contrast. Meanswhereby gives both client and practitioner a baseline to compare “before” and “after”. In Kinetic Mirroring we do the work of the contracted muscle for it, tricking it into relaxing. The muscle has been getting the message to contract at a certain rate, shortening itself in the process. When we use our hands to shorten the muscle it creates sensory feedback that says “this is being taken care of; you don’t have to contract anymore”. And so the muscle relaxes. Pandiculation begins with a strong voluntary contraction. Even a chronically contracted muscle is only partly contracted, and it’s with pandiculation that we take advantage of the muscle’s ability to contract further. As the client contracts the muscle, a strong sensory stimulus is also created, “waking up” the muscle, or more precisely, the brain’s awareness of the muscle in the sensory-motor cortex. This is a muscle that may have been contracted for years or even decades with no conscious awareness that it’s been contracting. The client has forgotten what it feels like to contract that muscle. By consciously contracting it above the level of the chronic contraction, the client immediately remembers how to control (at least part of) the muscle and experiences what it’s like to consciously contract it. The second phase of the pandiculation, the lengthening of the muscle while the client continues to contract it (albeit at a slightly reduced level), involves several neurophysiological principles, as follows: Quoting Hanna: “If this strong contraction is released very slowly, the sensory arousal of the motor neurons is such that, when the muscles are released to the point of their original contractile rate, they continue to release below that rate”. In the process of lengthening the muscle we need to be aware of the stretch reflex. If we lengthen the muscle too far, or especially, too fast, stretch receptors in the muscle spindles will send a message that the muscle is in danger of tearing and a return message is sent to shorten the muscle by contracting it. So it’s imperative we go slow. The most powerful part of the stretch reflex is related to the rate of lengthening. The Golgi Tendon Organ measures the tension on the tendon at the end of the muscle. Like the stretch reflex, its purpose is to prevent injury. If we contract too strongly we could tear a tendon. As the GTO senses tension it sends an inhibitory signal to the muscle causing it to relax. The greater the tension the stronger the inhibition. By maintaining tension in the muscle even as it lengthens we cause the GTO to send signals to the muscle to relax. The brain likes novelty. It notices that which is different. Contracting a muscle at the same time it is being lengthened is a new experience – one that draws attention, and awareness. The brain learns by contrast. In each pandiculation, rather than move through the entire range of motion in one continuous movement, two or three times we ask the client to “change your mind” or “press back up”. By requiring the client to consciously change the level of their contraction we are allowing them to contrast what different levels of effort feel like. When we do lock-ins we use the principle of reciprocal inhibition. By contracting the antagonist muscle we cause inhibitory signals to be sent to the muscle we are trying to learn to relax – exactly what we want. Ultimately, what we are trying to accomplish is to change the client’s sense of what a relaxed muscle feels like. The client has been chronically contracting a muscle without being aware of it and probably believing that the muscle was relaxed. The feedback loop was faulty. We are helping the client remember what a relaxed muscle feels like, what a normal range of motion is, and what it feels like to control a muscle consciously. As long-held contractions are released, we need to realign the brain’s internal image of the body with the body’s new reality. Someone who has been bent over to one side for a long time learns to perceive that bent over position as “straight”. So, when the contractions are released and the body straightens, the brain may now perceive the body as bent the other way. At this point we introduce visual feedback through mirror work. The point is to get the brain to match up what it feels with what it sees. Once the proprioceptive sense is calibrated to match the visual input the learning is cemented. Part of what we do in CSE is help the client overcome bad habits. We do that by making the unconscious conscious. But habits are not necessarily always bad, and we need to help build positive habits as well and that is where daily exercises come in. By repeating the movements with attention we create what Lawrence Gold calls kinesthetic memory – the memory of movement patterns. The more frequently we do the exercises the deeper the memory of them, the greater the long-term potentiation and the more they become a “preferred pathway”. One last note: As I finished my research, I came across an article in the New York Times of March 4, 2007 entitled “How to Grow a Super-Athlete”. Prior to reading the article I thought of myelin as something that surrounded many axons, insulating them and allowing faster transmission of nerve impulses. I didn’t think of it as something that was intelligently distributed. The article explains however, that the relative thickening of the myelin layer on one axon versus another is used in order to improve muscular coordination. The more the myelin the faster the transmission. Coordinated movements depend on the firing of many neurons, each at precisely the right time. By varying the thickness of the myelin on different axons, the brain controls exactly when the signal reaches the muscle. The key to taking advantage of this incredible learning ability we have is repetition. The more we do something correctly, the more we become hardwired to do it correctly again. Selected Bibliography: Neuroanatomy (Crossman and Neary) Survey of Functional Neuroanatomy (Garoutte) The Neural Basis of Motor Control (Brooks) Somatic Technique (Dreaver) Somatics.com (various articles by Lawrence Gold) Hundreds of other websites. Jim Ross Windham, ME April 2008