August 17, 2021 nilebratcher

Phantom limbs & lessons for healing.

By Nile Bratcher

INTRODUCTION

Many people today suffer from movement related problems that limit them in their daily activities. Some of those pain sufferers have tried traditional methods of treatment such as massage, and physical therapy, but many haven’t been able to gain lasting relief. Why is this? Could it be perhaps the status quo of injury rehabilitation and movement therapy are missing the mark with some of the population? Traditionally, discussions surrounding performance, health, and recovery have left out the significance of the brain. I’d like to take a brain-based view to a problem that affects many individuals, pain. What physiological and biochemical mechanisms are involved in the injury process and how does the brain change in response to acute insults and more devastating insults. I’ll also discuss the anatomical and physiological structures involved with producing movement and how dysfunction can contribute to overall decreased movement quality.

BACKGROUND

 For clarity, in this excerpt, I’m referring to stress relating to events or stressors that are threatening to an individual and that induce physiological and behavioral responses. Allostasis is the extension of homeostasis and represents the adaptation process of complex physiological systems to physical, psychosocial and environmental challenges (Karlamangla et al.2002). This is important to understand because many physiologic responses including hormones, temperature, blood pressure, sleep quality and nutrition always vary in response to perceived challenges (Sterling & Eyer 1988). Acute and chronic tension within muscles could be the sign of a symptom that’s overlaying a deeper adaptive mechanism within the nervous system and its response to external and internal stress. Therefore, attempts to release discomfort could be exacerbated or prolonged if an incorrect approach is taken to treat the problem.

In our normal experience within our bodies somatosensory receptors are proprioceptors, visceral sensory receptor located within blood vessels and viscera, are all quickly sent to the spinal cord and higher brain centers, integrated by the primary motor cortex, and relaying efferent motor impulses by way of motor pathways to target effectors which produce movement. Conduction pathway is an inclusive term that refers to all the series of neurons and their related structures that relay signals between the brain and the body. Sensory pathways include the sensory neurons that relay sensory input to the brain. Sensory pathways are also called ascending pathways because the nerve signals are relayed from the sensory receptors superiorly to the brain. Motor pathways include the series of motor neurons that relay motor output from the brain. Motor pathways are also called descending pathways because the nerve signals are relayed from the brain inferiorly to the body’s muscles and glands (McGraw Hill, 2019).

The axons of neurons located within the primary cortex are responsible for voluntary skeletal muscle activity, these axons decussate and project contralaterally (to the opposite side) within either the brainstem or spinal cord. Thus, the left primary cortex controls the skeletal muscles on the right side of the body and the right primary motor cortex controls the left side of the body. (McGraw Hill, 2019).

Body maps called the motor homunculus, and the sensory homunculus is a distribution of the primary motor cortex innervation to various body parts. Homunculus is for ‘little man’ located on the precentral gyrus. The figure of the body depicts the nerve distributions; the size and location of each body region indicate relative innervation (McGraw Hill, 2019). A pioneer in Neuroscientist stated it well “We don’t see with our eyes; we see with our brains. The ears, eyes, nose, tongue, and skin are just inputs that provide information. When the brain processes this data, we experience the five senses, but where the data come from may not be so important” (Bach-y-Rita, Paul, 2003).

PHANTOMS BETWEEN THE EARS

Throughout our lives and neurocognitive development, acute and chronic stresses can disrupt somatic and motor function within the somatosensory cortex of the brain (Bach-y-Rita, P. (1992). Injuries we experience can disrupt that synchrony of the nervous system and ultimately affect movement altogether. Some individuals who were born blind have been shown to develop adaptations due to the visual deficits they experienced. “Tactile vision substitution systems deliver visual information to the brain via the skin. Blind persons not only develop the ability to perceive visual information but also learn to use visual means of analysis (parallax, looming and zooming, monocular cues of depth and perspective, and subjective spatial localization) and subjectively locate the visual information correctly in the three-dimensional space. This model has provided considerable information on brain plasticity, perceptual mechanisms, and the coordination of sensory and motor factors in the development of a perceptual organ.” (Bach-y-Rita, P 1992). Could neuroplastic exercise be the frontier of rehabilitation and injury prevention? Many neuroscientists have embarked on that path and have helped many chronic pain sufferers’ live life again without sensations of agonizing pain.

In the 1990’s neuroscientist Vilayanur S. Ramachandran, director of San Diego center for Brain Cognition, had been researching phantom limbs and had developed a “mirror box” to ‘resurrect’ phantom limbs and thereby ridding patients of pain accompanied by phantom limbs. This discovery led Ramachandran to use mirrors as a useful model that explains brain function. One patient mentioned within the literature titled ‘D.S.’, suffered a brachial avulsion and required him a year later to undergo amputation of the injured arm 6 inches above the elbow. He developed intense pain several times a day in his phantom arm, which was “stuck’ in a clenched position. Anytime D.S. would try and open his hand he would get jolted with pain in his phantom arm. “A relatively common phenomenon was a ‘clenching spasm’, an involuntary contraction of the phantom hand, which patients to their great annoyance could usually only unclench with difficulty. The spasm could be painful because patients would often feel their phantom ‘fingernails digging into the palm’ (Guenther, Katja, 2016)

To help rid D.S of his agonizingly painful phantom arm, V.S Ramachandran developed what was called a “mirror box”, which created a ‘virtual reality’ that related to the material world, reproducing a form of psycho-physical parallelism. Patients would sit in a chair and place their physical hands within a box that had mirrors on the right and left side of each respective box for each hand. With difficulty D.S. got his physical and phantom limbs with the mirror box. He could then “see” his phantom hand and could then freely move it without pain signals. In other words, physically seeing the phantom limb inside the “mirror box”, allowed the somatosensory cortex once again to integrate with the primary motor cortex, thereby reducing pain signals. The neurophysiology of phantom limb pain can teach us valuable lessons about how the central nervous system can rewire itself following cataphoretic injury and methods we can use to aid in the healing process.

 Persons with phantom limb pain can sense sensations with specific areas of the phantom limb, by gently stroking specific areas on the face.  It turns out, The Wilder Penfield’s somatic-sensory homunculus located on a strip of the cortex helps explain this phenomenon. Brain maps for the face are adjacent to the arms on the somatic sensory homunculus.  When the arm is amputated, sensory input signals are also lost as lost stimuli within that region of the brain map. Therefore, when these points are touched, the sensations are felt to arise from the missing hand but also felt in the maps in the face (Phantoms in the Brain, Ramachandran V.S, M.D., PH.D. 1998, pages 30).

The co-existence of these two bodies, the internal dynamic body image and the external physical body provided a framework for explaining phantom limbs. Could this model be used to further the advancement of treatment for individuals needing rehabilitation and movement dysfunction? According to Ramachandran, “when ‘a central representation of the limb survives after amputation’, the mismatch between the body image and the real body was ‘largely responsible for the illusion of a phantom” (V.S. Ramachandran and William Hirstein, 1998). “The lack of signals to that part of the brain made it particularly sensitive to signals passing through proximate areas. For that reason, stimuli sent to the neighboring part of the cortex (dedicated to the face) might now be felt by the otherwise inactive part dedicated to the arm and hand; the patient would experience sensations on the face as sensations on the arm and hand. In this way the parietal lobe continued to receive evidence that the arm still existed, and thus refused to abandon or modify the pre-existing body image” ( Katja Guenther, Princeton university, 2014).

 KINETIC DYSFUNCTION

Pain is synonymous with clients I’ve worked with throughout my career as a Health and Performance coach. Assisting my clients to achieve their goals requires me being able to help them in the most efficient way possible. What seems to be widely misunderstood is changes in tissue length and extensibility are governed by the central nervous system. Newton’s third law tells us that for every action, there is an equal and opposite reaction. That means when forces are applied to the body, equal and opposite forces are being applied as well. Ground reaction force directly influences joints, which in-turn influences muscle tonus. Muscles should always when at rest have muscle tonus. Muscle tone is the resting tension in skeletal muscles generated by involuntary somatic nervous stimulation of muscle. Motor units within muscle can be stimulated at any time to maintain constant tension called resting muscle tone. This tension is found within muscle tendons, thus stabilizing the position of the bones and joints. Muscle tone primes the muscle for contraction, so that movement responses can be generated quicker to sensory responses.

Muscle tone plays another role in the many reflexes that our bodies have. generated by alpha motor neurons within the anterior grey horn of the spinal cord that innervate extrafusal muscle fibers and generate muscle contraction. Interneurons synapse with alpha motor neurons to antagonist muscles, inhibiting muscle contraction also called reciprocal inhibition.  Muscle spindles are composed of intrafusal muscle fibers and are innervated by gamma motor neurons within the posterior and anterior root grey horn of the spinal cord that innervate motor units within muscle fibers (McGraw Hill,2019). Areas of the body that have altered joint positioning can alter muscle tone and length-tension relationships between agonist, antagonist, and synergistic muscles. Mechanical dysregulation of reduces proper deceleration and dissipation of ground forces that travel up and through the body during movement. The mechanical energy traveling through the body causes the articulation of joint surfaces otherwise known as arthrokinematics. These angular movements of bones involve a combination of roll, spin, and glide. Decreased ability of joints to roll, spin, and glide directly affect not only range of motion of the joint but also increased ‘neural threat’ due to altered arthrokinematics. The increase in ‘neural threat’ which is increased muscle tonus (hypertonic) and will cause the reduction in joint space by adduction, flexion, and internal rotation of joints capsules thereby keeping it close to the midline where it’s neurologically “safer”. Could addressing the tension without addressing the neural mechanical component hinder progress and prolong discomfort?

A DIFFERENT APPROACH

Traditionally the widely accepted idea when dealing with movement dysfunction, is stretch what’s tight and strengthen what’s weak. However, a question worth asking is the source of the tissue restriction due to fascia layers not sliding properly and thus needed manual manipulation and release? Or is the source of the restriction due to the brain creating the restriction all together? Well turns out I’m not the only person who’s wrestled with these questions. Robert Schleip, head of the fascia research group at Ulm university in Germany also had frequent debates with Feldenkrais somatic education and the Rolfing method of structural integration.  Structural integration practitioners claimed that restrictions were due to mechanical adhesion within fascia and myofascial lines, whereas the somatic awareness group claimed that restriction was due to dysregulation of sensory motor integration or “it’s all in the brain”. (Schleip, Robert, 2015).

Researchers cited a story of a man who was very stiff and rigid in the hospital. When placed under anesthesia the stiffness and rigidness transformed into being limber and soft, under anesthesia his muscle tonus lowered. However, as soon as he gained consciousness his rigidness returned, and muscle tonus increased. After conducting a small study of patients who prior to surgery presented observable restriction and high muscle tonus in a particular area of the body, typically a shoulder. Robert went on to say “I must say that I was quite shocked by the result of my tests. From my Rolfer’s point of view I had expected that remaining fascial restrictions would prevent the arms dropping all the way under anesthesia. Given the limited scientific rigor of this preliminary investigation, the result nevertheless convinced me that what had been perceived as mechanical tissue fixation may at least be partially due to neuromuscular regulation (Schleip, Robert, 2015)

In many cases, reduced range of motion caused by immobilization or injury can affect arthrokinematics and result in decrease in performance. In those cases, proper assessment of joint range of motion and mobilization can improve range of motion resulting in improved arthrokinematics (Loudon, Janice, K, 1996). In fact, the provoking event for ACL injury is a delayed coactivation of the hamstrings and quadriceps and that this lack of muscular protection makes inherent knee laxity a critical factor in anterior tibial translation (Hashemi, 2011)

How can we blend neuroplastic exercise and traditional methods to help clients even further?  Looking at things through the brain is always a sure bet. “Unmasking of relatively inactive pathways, the taking over of functional representation by undamaged brain tissue, and neuronal group selection are among the mechanisms that are being explored.” (Bach-y-Rita, Paul,1990). Looking through this complex topic from a neural perspective I believe can help improve the way health and fitness professionals care for their clients at a profound level. Increased research and awareness about biofeedback and the neuroplastic nature of the brain, could result in huge paradigm shifts in the realm of post-operative rehabilitation (Queen, Robin M). An integrative mechanical model for multidisciplinary treatment that includes sensory-motor integration, movement reeducation, psychosocial intervention, and lifestyle can address many common and debilitating conditions. To achieve this, a shift in approach must occur in the rehabilitation and human performance industry that aims to address mechanical movement dysfunctions with the brain at the forefront of intervention.

WORKS CITED:

“Gauenther, Katja, “It’s all done with mirrors: V.S. Ramachandran and the material culture of phantom limb research, Princeton University, 2016.

“Helene M. Langevin, Karen J. Sherman”, Pathophysiological model for chronic low back pain integrating connective tissue and nervous system mechanisms, Medical Hypotheses, Pages 74-80.

www.discovermagazine.com/mind/can-you-see-with-your-tongue

“Javad Hashemi”, Hip extension, knee flexion paradox: A new mechanism for non-contact ACL injury, Journal of Biomechanics, Pages 577-585,

“Karlamangla AS, Singer BH, McEwen BS, Rowe JW & Seeman TE” Allostatic load as a predictor of functional decline. MacArthur studies of successful aging. Journal of Clinical Epidemiology 55, 696–710, 2002.

“McGraw- Hill Education”, Nervous system: Spinal Cord & Spinal Nerves, Pages 548-549, 552.

“McGraw-Hill Education”, Nervous system: Brain and Cranial nerves, Pages 504,508.

“Loudon JK, Bell SL”, The foot and ankle: an overview of arthrokinematics and selected joint techniques,1996.

“Paul Bach-y-Rita”, Recovery from Brain Damage. Journal of Neurologic

Rehabilitation, 1992.

“Paul Bach-y-Rita”, Brain plasticity as a basis for recovery of function in humans, Neuropsychologia, Pages 547-554, 1990). www.fascialfitness.net.au/articles/fascia-as-an-organ-of-communication/

“Sterling P & Eyer J”, (1988). Allostasis: a new paradigm to explain arousal pathology. In: Handbook of Life Stress, Pages 629–649.

“V.S. Ramachandran and D. Rogers-Ramachandran”, Synesthesia in Phantom Limbs Induced with Mirrors, 1996.

“V.S. Ramachandran and William Hirstein”, The Perception of Phantom Limbs,

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