Lecture 7 - The Effects Of Spinal Manipulative Therapy (SMT) PDF

The Effects Of Spinal Manipulative Therapy (SMT) Lecture 7 Dr. Paul Wanlass, D.C. Professor of Chiropractic Education Certified Strength & Conditioning Specialist (CSCS) Certified Specialist in Performance Nutrition (CSPN) Cox Technic ® Parts I, II, III, IV Certified Activator Methods ® Certified Ce...

The Effects Of Spinal Manipulative Therapy (SMT) Lecture 7 Dr. Paul Wanlass, D.C. Professor of Chiropractic Education Certified Strength & Conditioning Specialist (CSCS) Certified Specialist in Performance Nutrition (CSPN) Cox Technic ® Parts I, II, III, IV Certified Activator Methods ® Certified Certification with Exemplary Badge in Teaching and Learning from the Boston University School of Medicine, 2015 Certification in the Interprofessional Clinical Learning Environment from Arizona State University, 2024 Rev. 3-6-2024 1 MODULE OBJECTIVES Upon completion of this lecture, you should understand the following: Evidence for musculoskeletal and non-musculoskeletal treatment Mechanical Components Important mechanical points on SMT Tribonucleation & its related effects Other potential noises associated with manual therapy Joint fixation hypotheses Interarticular adhesions Interarticular block due to meniscoid entrapment Interdiscal block Periarticular fibrosis & adhesions Clinical Joint Instability and Hypermobility 2 MODULE OBJECTIVES Neurobiologic Components Analgesic hypothesis Pain Gate Theory Descending Modulation of Pain Muscle spasm & hypertonicity Myofascial cycle Nerve root compression/traction Reflex dysfunction Neuroimmunology Circulatory hypothesis 3 Note: You will cover these topics in greater detail in the following course in the second year of the program: CT0610: Scientific Basis of Chiropractic 4 READING ASSIGNMENT Chapter 19 Lecture 7 5 INSTRUCTIONS This lecture is not intended to replace the required reading in your text. It is meant to highlight important concepts. Please do all of the required reading. After reading this lecture you should be able to answer the questions on the following Study Objective slides as preparation for the lecture discussion and quiz. In lecture, we will discuss key concepts and I will ask students to volunteer to answer questions that I pose to the group. Please complete all required reading prior to lecture and be prepared to participate. I look forward to discussing this topic with all of you. 6 NEURO-MUSCULOSKELETAL (NMS) Treatment of NMS dysfunction is the main reason chiropractors are consulted. Low back pain (#1 reason), neck pain (#2), and headaches (#3) are the most common. Treatment of NMS conditions are covered by insurance companies Patients are consistently happy with the quality and effectiveness of chiropractic care Patients rate chiropractic care as superior to medical care for the treatment of back pain 7 SMT AND CHRONIC LOW BACK PAIN As of 2020, low back pain affects up to 85% of the adult population imposing an economic burden of $86 billion annually or 1% of the United States gross domestic product. 16-18 Chronic low back pain (pain duration > 3 months), although only accounting for 5% of those with low back pain, represents 75% of the total treatment costs. 16,17 Present clinical practice guidelines recommend spinal manipulative therapy (SMT) as a primary intervention for low back pain. 19-21 8 SMT AND CHRONIC LOW BACK PAIN Spinal Manipulative Therapy (SMT) may reduce pain and disability in chronic low back pain patients. 22, 23 In comparison to other therapies, the practical benefits of SMT for managing chronic low back pain may include cost effectiveness, relative safety, and/or clinician or patient preferences. 24 9 SMT AND ACUTE LOW BACK PAIN A 2017 systematic review of 26 randomized control trials was conducted studying the effectiveness and harms of SMT for acute (≤6 weeks) low back pain. 25 “Among patients with acute low back pain, spinal manipulative therapy was associated with modest improvements in pain and function at up to 6 weeks, with transient minor musculoskeletal harms”. 25 10 NON-MUSCULOSKELETAL Most chiropractors have noted positive health effects outside of the musculoskeletal system Philosophically related to the relationship of structure and function and its effects on homeostatic regulation and health maintenance Unfortunately, clinical research in this area is minimal 11 NON-MUSCULOSKELETAL “At present, there have been no appropriately controlled studies that establish that spinal manipulation or any other somatic therapy represents a valid curative strategy for the treatment of any internal organ disease.” 1 “Consequently, the profession should be cautious in implying or guaranteeing a positive outcome for the manipulative treatment of visceral disease.” 1 12 NON-MUSCULOSKELETAL “At the same time, the profession should not discount the potential positive health effects noted in clinical practice.”1 “Patients without contraindications to manual therapy who have a possible somatovisceral disorder should not be refused treatment, but they should not be solicited with the implied guarantee of a positive result.”1 13 EFFECTS OF ADJUSTIVE THERAPY1 “Several hypotheses exist as to the mechanism by which chiropractic therapy affects the neuromusculoskeletal system (NMS), causes of joint dysfunction, and somatovisceral disorders.” These are broadly divided into: 1) Mechanical and 2) Neurobiologic categories. 14 MECHANICAL COMPONENTS 15 GOALS OF MANUAL THERAPY Directed toward soft tissue pathology and mechanical dysfunctions Promotes restoration of mobility and function by minimizing formation of fibrotic tissue and promoting strong, flexible, tissue repair and remodeling Most effective when coupled with exercises that increase flexibility and strength 16 ADJUSTIVE FORCES REVIEW1 The adjustive force can be expressed in terms of the kinetic energy (mass and velocity) of the clinician. And the combined mechanical resistance to deformation (stiffness and elasticity) of both clinician and the patient. 17 TRIBONUCLEATION REVIEW FROM LECTURE 6 Is the “formation of vapor and gas bubbles within fluid through the local reduction of pressure”. 1 Associated with (and not the result of) several post-adjustment phenomena: Transitory increase in Passive Range of Motion (PROM) Temporary increase in joint space Stretching of periarticular tissue Stimulation of joint mechanoreceptors and nociceptors 20-minute refractory period 18 OTHER POTENTIAL NOISES ASSOCIATED WITH MANUAL THERAPY Tearing sound – breaking of cross linkages in traumatized soft tissues (scar tissue) Snapping sound – tendon moving over bony protuberances Clunking sound – movement of impinged bony outgrowths Crackling sound – crepitus from degenerative changes 19 JOINT FIXATION HYPOTHESES Interarticular Adhesions Interarticular Block Interdiscal Block Periarticular Fibrosis and Adhesions Joint Instability 20 INTERARTICULAR ADHESIONS Theory that restrictions are due to the development of adhesions between the articular surfaces of the facet joints, inside the joint capsule Speculated to result from joint injury, inflammation, or immobilization SMT proposed to induce gapping of the facet joint leading to breaking of these adhesions 21 INTERARTICULAR BLOCK Theory that restrictions are due to the product of some derangement within the synovial joint, inside the joint capsule. Speculated to arise from poorly coordinated spinal movements or sustained stressful postures leading to entrapment of the meniscus within the posterior spinal joints SMT has the potential of reducing this entrapment Example on the next slides 22 NORMAL FACET JOINT MENISCUS 1 23 INTERARTICULAR BLOCK – ENTRAPMENT 1 24 INTERARTICULAR BLOCK – MENISCOID ENTRAPMENT 1 A. Flexion-meniscoid moves with inf. Facet B. Extension-meniscoid trapped under capsule. C. SMT/CMT- gaps joint allowing meniscoid to return to normal position= D. 25 INTERDISCAL BLOCK Theory that restrictions are due to internal derangement of the disc Postulated to result from changes associated with aging, degenerative disc disease, and trauma (we will cover this in detail in CP 4). Proposed that SMT may direct fragmented nuclear material toward a more central location or between the lamellae of the annulus. 26 INTERDISCAL BLOCK 1 27 ADJUSTING FOR INTERDISCAL BLOCK For example, an SP Push Bergmann, Fig. 4-18 1 28 ADJUSTING FOR INTERDISCAL BLOCK For example, a Mammillary Push Bergmann, Fig. 4-19 1 29 ADJUSTING FOR INTERDISCAL BLOCK 15 For example, the evidence-based Cox Flexion Distraction Technic: Drops intradiscal pressure to as low as -192mm Hg Widens the spinal canal foraminal area by 28% Reduces pressure on the spinal nerves Returns motion to the spinal joints Latest Research: Changes in Intradiscal Pressure During Flexion-Distraction Type of Chiropractic Procedure: A Pilot Cadaveric Study; R. Gudavalli, et al., Integrative Medicine Reports 2022 1:1, 209-214 30 PERIARTICULAR FIBROSIS & ADHESIONS Theory that restrictions are due to development of adhesions & fibrotic repair of tissue damage outside of the joint capsule. Usually related to acute or repetitive trauma. Distractive SMT proposed to stretch the affected tissue, break adhesions, and promote mobility without triggering an inflammatory reaction. 31 CLINICAL JOINT INSTABILITY AND HYPERMOBILITY1 Defined as a painful disorder of the spine resulting from poor segmental motor control or a loss of stiffness in the joint ligaments leading to abnormal movements. Common causes are acute trauma, repetitive-use injuries, compensation for adjacent motion segment hypomobility, ineffective neural control, degenerative disc disease, and muscle weakness. Clinical joint instability is not to be confused with gross orthopedic instability resulting from marked degeneration, traumatic fracture, or dislocation. 32 CLINICAL JOINT INSTABILITY AND HYPERMOBILITY1 Joint instability may cause recurring episodes of acute joint locking. Adjustive therapy is commonly applied to the motion segments above or below the hypermobile joint to help restore normal biomechanics in the region, to reduce episodic pain, temporary joint locking, joint subluxation, and muscle spasm that are commonly encountered in patients with unstable spinal joints. The treatment should also incorporate active rehabilitation exercises and lifestyle modification to improve stability of the joint. You will cover this in the Functional Rehab Strategies (FRS) course. 33 10 MINUTE BREAK 34 NEUROBIOLOGIC COMPONENTS 35 ANALGESIC HYPOTHESIS Pain Gate Theory Descending Modulation of Pain 36 PAIN GATE THEORY EVOLUTION The Gate Theory of Pain, was published by Ronald Melzack and Patrick Wall in Science in 1965.9 When Wyke published his work on the detailed neurology and feedback coming from the mechanoreceptors in the ligaments around joints in cats in 1967, this reinforced the “Theory” of the pain gate.10 This was discussed further in 2014 by Mendell LM. Constructing And Deconstructing The Gate Theory Of Pain.11 37 PAIN GATE THEORY Simultaneous activation of superficial and deep mechanoreceptors and proprioceptors alters input to the CNS inhibiting central transmission of pain. In the dorsal horn of the spinal cord “Gate control is often triggered by touch or non-threatening sensory input, which activates low-threshold Type II sensory A Beta (Aβ) fibers that inhibit nociceptive input from A Delta (Aδ) and C afferent fibers.” 13 A fibers are myelinated and have a higher conduction velocity than C fibers which are unmyelinated. At the same time there is a descending modulation of pain in the Central Nervous System (CNS) [next slide] 38 DESCENDING MODULATION OF PAIN These include “manipulation-induced effect through the descending inhibitory pathways from the Rostral Ventral Medulla via the release of serotonin and noradrenaline.” 12, 13 “Taken together, we hypothesize that joint manipulation produces a nonopioid form of analgesia” through the receptors for these neurotransmitters. 12 Plasma levels of endogenous opioids such as β-endorphins have increased after manipulation and have an analgesic effect 18-33 times stronger than morphine. 14 Endogenous opioids include: enkephalins, endorphins, and dynorphins found in the pituitary and adrenal glands. Additional details on the biochemistry and neurology involved can be found here: https://www.hindawi.com/journals/ecam/2019/2878352/ 39 PAIN GATE THEORY Bergmann TF, Peterson DH. Chiropractic technique: Principles and procedures, 3rd ed., Fig 4-20. 40 RECAP OF THE ANALGESIC HYPOTHESIS Together, the Pain Gate Theory and the Descending Modulation of Pain are hypothesized to cause an analgesic effect (decreasing pain). Pain Gate through stimulation of the mechanoreceptors over-riding the pain fibers in the dorsal horn of the spinal cord at the level of the adjustment. The Descending Modulation of Pain through the release of endogenous opioids and neurotransmitters. 41 OTHER NEUROBIOLOGIC COMPONENTS Muscle Spasm Myofascial Cycle Nerve Root Compression/Traction Reflex Dysfunction Neuroimmunology Circulatory Hypothesis 42 MUSCLE SPASM AND HYPERTONICITY Unguarded and uncoordinated movements may affect muscle spindle activity leading to muscle spasm. 3,4 Abnormal sustained postures, or poorly judged movements, induce intersegmental muscle overstretching and reactive hypertonicity. This can be alleviated with SMT. 5 43 MUSCLE SPASM AND HYPERTONICITY In a study presented at the March 2017 Assoc. of Chiropractic Colleges Research Agenda Conference (ACC-RAC), high velocity low amplitude (HVLA) manipulation produces significant reduction in motor neuron excitability in both asymptomatic and LBP groups that is unique and specific compared to non-thrust techniques. 6 This means that the HVLA thrust provides more afferentation to the CNS and is better than mobilization grades 1 through 4 at reducing pain. 44 45 MYOFASCIAL CYCLE Self-perpetuating cycle that may be interrupted by High Velocity Low Amplitude (HVLA) adjustments SMT may stimulate low and high threshold mechanoreceptors and nociceptors leading to an inhibitory effect on segmental motor activity 46 NERVE ROOT COMPRESSION/TRACTION 2 Types: Nerve root and Dorsal Root Ganglion (DRG) Spinal cord compression or traction 47 NERVE ROOT COMPRESSION/TRACTION Compression of the spinal nerves within the intervertebral foramen (IVF). May become compressed by edema, blood vessels, lymphatic vessels, fat, scar tissue, disc nuclear material, osteophytes, or connective tissue. Alters function of nerve root’s axoplasmic transport (a cellular process responsible for movement of mitochondria, lipids, synaptic vesicles, proteins, and other organelles to and from a neuron's cell body). D.D. Palmer and others believed that traction on the nerve root can alter the normal tone and frequency of the nerve, even though currently there is no literature to support this hypothesis. 48 DORSAL ROOT GANGLION COMPRESSION The DRG is very sensitive to small pressures and tension and is affected even with an injury distal to the DRG. The DRG can produce the neuropeptide Substance P by itself.7 Substance P acts as a neurotransmitter and neuromodulator causing vasodilation, inflammation, pain, and angiogenesis. 49 SPINAL CORD COMPRESSION B.J. Palmer was the biggest proponent of this model of subluxation. The basis for B.J.’s upper cervical, Hole in One Toggle Recoil technique. 50 REFLEX DYSFUNCTION Vertebral subluxation complex (VSC) induces persistent nociceptive activity and altered proprioceptive input triggering a segmental cord response leading to pathologic Somato-Somatic or Somato-Visceral reflexes. There are four major types (on the next slides). Proposed that SMT normalizes joint mechanics and stops the cause for the reflex dysfunction Another theory is that irritation to sympathetic chain ganglia leads to altered autonomic regulation and function (Viscero-Somatic and Viscero-Visceral reflexes). Sato and Swenson demonstrated sympathetic discharge in rats by placing mechanical stresses into the spinal joints 51 SOMATO-SOMATIC REFLEXES Reflexes whose afferent and efferent pathways are somatic nerve fibers. A vertebral subluxation can cause muscle hypertonicity, pain, swelling, etc. in other somatic (of the body) structures. Somatic Dysfunction can involve structures such as muscles, ligaments, and tendons. For example, leg length checks work through this reflex. 52 SOMATO-VISCERAL REFLEXES Also Known As (A.K.A.) Somato-Autonomic Reflex Reflexes whose afferents are somatic sensory fibers and whose efferents are autonomic efferent fibers The vertebral subluxation induces aberrant spinal reflex activities associated with clinical manifestations in the organs For example, relief of symptoms in a patient with Raynaud’s Phenomenon, or relief of stomach symptoms (T5-T8). 53 VISCERO-SOMATIC REFLEXES A.K.A. Autonomic-Somatic Reflex Reflexes whose afferents are visceral sensory fibers and whose efferents are somatic motor nerve fibers Visceral Dysfunction can involve organs such as kidneys, heart, diverticula, liver, etc. leading to referred pain in the body For example, a patient experiencing low back pain from a bladder or kidney pathology 54 VISCERO-VISCERAL REFLEXES A.K.A. Autonomic-Autonomic Reflex Reflexes whose afferent and efferent pathways are visceral sensory fibers and autonomic nerve fibers Body functions that are largely reflexive-heartbeat, breathing, digestive activity, and glandular secretions. Organs affecting other organs. For example, an increase in blood pressure detected by the baroreceptors will cause a reflex change in heart rate and blood pressure 55 REVIEW OF THE FOUR REFLEXES 1 56 EFFECTS OF MANIPULATION ON THE IMMUNE SYSTEM 57 GENERAL ADAPTATION SYNDROME Hans Selye, MD, PhD in the 1930’s researched the effects of stress on rats and other animals. Found that all animals display a similar sequence of reactions manifesting in 3 distinct stages. He labeled this universal response the General Adaptation Syndrome (G.A.S.). Hans Selye (1907-1982). Published 1,700 research papers, 15 monographs and 7 books. A monograph is a specialist book on a single subject written by one author. 58 THREE STAGES OF THE G.A.S. Alarm – adrenaline is produced to start the fight-or-flight response, followed by activation of the Hypothalamic–Pituitary–Adrenal axis (HPA) producing cortisol. Resistance – the body tries to adapt and cope, but as resources are depleted the person enters the Exhaustion phase. Exhaustion – the initial autonomic nervous system symptoms may reappear (sweating, increased heart rate, etc.) If this continues, it can lead to DISease (from D.D. Palmer) 59 THREE STAGES OF THE G.A.S. 60 NEUROIMMUNOLOGY 1 61 IMMUNE SYSTEM Few chiropractic studies have addressed the topic of how specific adjustments affect specific organs or systems. Most evidence draws from basic science studies that gave broad mechanistic support but did not specifically examine CMT and its effects on immune function. In 2019, Colombi, et al. studied the Effects of SMT on the Immune and Endocrine Systems and the role these systems may play in musculoskeletal (MSK) pain.26 62 EFFECTS OF SMT ON THE IMMUNE AND ENDOCRINE SYSTEMS26 The authors state: “It is suggested that low-grade inflammation may be associated with the severity of lower back (LBP) and neck pain (NP) as systemically elevated pro-inflammatory cytokines and chemokines have been found in these patients.” “These neurochemicals including but not limited to, tumor necrosis factor (TNFα), interleukin-1 (IL-1), interleukin-6 (IL-6), or interleukin-8 (IL-8), have been consistently revealed in cohorts of patients presenting with joint degeneration of the vertebral column.” 63 EFFECTS OF SMT ON THE IMMUNE AND ENDOCRINE SYSTEMS26 “low-grade inflammation may be the result of an impaired cortisol regulation, which has been found in patients with chronic low back pain, fibromyalgia, and temporomandibular disorders, among others.” “Cortisol is a hormone activated by the Hypothalamic-Pituitary-Adrenal (HPA) axis and is known to play a key role in the stress-related response and in the modulation of inflammation.” “Under normal conditions, it serves a potent anti-inflammatory function, and its circulating levels attenuate with negative feedback mechanisms. Yet, any dysfunctional response [due to a subluxation] is likely to lead to unmodulated inflammation and it has been associated with pain hypersensitivity.” 64 EFFECTS OF SMT ON THE IMMUNE AND ENDOCRINE SYSTEMS26 “Some proponents claim that the mechanical stimulus provoked by SMT, typically associated with an audible cavitation, may trigger a cascade of neurophysiological responses orchestrated by the co-activation of the autonomic nervous system (ANS) and the HPA axis thus promoting tissue healing.” -------------------------------------------------------------------------------------- Remember……… this correlates with the Pain Gate Theory and the Descending Modulation of Pain happening at the same time immediately after SMT. 65 EFFECTS OF SMT ON THE IMMUNE AND ENDOCRINE SYSTEMS26 Conclusion from the article: “Although it has been demonstrated that SMT provides short-term benefits across different spinal MSK disorders, the available evidence supporting the capacity of SMT to trigger a significant immune-endocrine response is mixed and its clinical relevance remains to be established.” “Quality issues, small sample size, lack of studies on symptomatic subjects, and heterogeneity related to methods of biomarkers collection and sham procedures limit the interpretation of findings. Further high quality and adequately powered studies are needed to draw valid inferences on the biological plausibility of SMT and to support its consistent implementation in clinical practice.” 66 CIRCULATORY HYPOTHESIS Osteopathic research concluded that vertebral lesions in animals may affect vascular supply to glands and viscera. Sympathetic hyperactivity leads to vasoconstriction and relative ischemia in the area involved. SMT is theorized to improve circulation by restoring joint function and removing the source of sympathetic irritation. Musculoskeletal mobility and strength also influence venous, lymphatic, and CSF flow 67 OTHER EFFECTS OF SMT Psychological effects Laying on of hands Reassurance – demeanor, touch, voice Relaxation – demeanor, touch, voice, tx. environment Placebo 27, 28, 29 Today, scientists define these placebo effects as the positive outcomes that cannot be scientifically explained by the physical effects of the treatment. Research suggests that the placebo effect is caused by positive expectations, the doctor-patient relationship and the act of receiving medical care. 68 HEALING EFFECTS OF HUMOR AND LAUGHTER Physiological changes to body chemistry and brain function. For example30,31 Laughter affects heart function. It increases stroke volume and cardiac output, and it dilates blood vessels. Improves muscle tone Lowers levels of the stress hormone, cortisol. Increases serum immunoglobulins A and E. In most studies, it seems to increase natural killer cell activity as well. It raises levels of beta-endorphins and dopamine (the feel-good chemicals of the body) and increases human growth hormone Laughter increases pain tolerance.32,33 69 LECTURE 7 REVIEW 70 Treatment of musculoskeletal (MSK) conditions with SMT is well supported in the literature. Treatment of non-musculoskeletal conditions with SMT should be approached with caution and without inappropriate expectations or promises of a cure. 71 MECHANICAL COMPONENTS INCLUDE: Forces and movements during adjustive therapy Cavitation / Tribonucleation Joint Fixation Interarticular Adhesions Interarticular Block Interdiscal Block Periarticular Fibrosis and Adhesions Joint Instability 72 NEUROBIOLOGIC COMPONENTS INCLUDE: Analgesic Hypothesis Pain Gate Theory Descending Modulation of Pain Muscle spasm and hypertonicity Myofascial cycle Nerve root compression/traction Reflex dysfunctions Neuroimmunology Circulatory hypothesis 73 QUESTIONS ABOUT LECTURE 7 CONTENT? 74 REFERENCES Bergmann TF, Peterson DH. Chiropractic Technique: Principles and Procedures. 3rd ed. 2011. Kawchuk GN, Fryer J, Jaremko JL, Zeng H, Rowe L, et al. (2015) Real-Time Visualization of Joint Cavitation. PLOS ONE 10(4): e0119470.https://doi.org/10.1371/journal.pone.0119470 Korr IM. 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