Therapeutic Kinesiology:Musculoskeletal Systems, Palpation, and Body Mechanics

Therapeutic Kinesiology Instructor Manual: Ch05 p.1 TK INSTRUCTOR MANUAL: CHAPTER 5 The Neuromuscular System Chapter manuals include: Objectives Lecture Notes Suggested Classroom and Student Development Activities For other chapter-by-chapter resources, see: Key Term Quizzes Muscle Origin and Insertion Worksheets Muscle OIAs List by Chapter MyTest Test Bank For additional resources see “Teaching Tips and Tools”: 7 research-based learning principles for kinesiology courses in massage 5-step self-directed learning cycle for body mechanics courses Tools that build metacognitive skills: e.g., concept (mind) maps, grading rubrics, and self-assessments inventories OBJECTIVES Describe and compare the major divisions of the nervous system. Define a neuron, list and describe three types of neurons in the neuromuscular system. List and describe the peripheral nerves and associated connective tissues. Define neural tension and explain its implications in movement and bodywork. Define a sensorimotor loop and describe how it works in faulty movement patterns. Define and compare proprioception and perception. Describe the stretch reflex and a reflex arc. Describe the proprioceptor in tendons and two proprioceptors in joint capsules. Describe specialized proprioceptive organs in the labyrinth of the inner ear. Define the law of reciprocal inhibition and describe how it works in reflex movements. List three types of movement assessments and three conditions they are used to assess. Describe how to make a general assessment about whether a client’s pain pattern is generated by contractile or noncontractile tissues. List the reasons for using resisted motion during a session, then describe the steps for performing resisted motion with a client. Define a trigger point and its effects and describe the process of trigger point therapy. List two muscle energy techniques and describe the steps for each. Describe the dynamics of a stretch injury. LECTURE NOTES NEUROMUSCULAR (NM) SYSTEM Introduction Not actual body system: NS + muscular system System that coordinates movement Overview of nervous system Central nervous system (CNS) = brain and spinal cord Peripheral nervous system (PNS) Autonomic nervous system (ANS): involuntary Parasympathetic Sympathetic Somatic nervous system (SNS): voluntary Neuron: nerve cell Three parts: cell body, axons, dendrites Three types: sensory, interneuron, motor Synapse: Where nerves connect to nerves or end organs Neuromuscular junction Synapse between motor nerve and muscle Also called motor end plate. Motor points: Junction between motor nerve and muscle In belly of muscle, area of greater electrical activity Correspond with trigger points c. Nerves: Groups of nerve fibers bundled into cords Tracts: Nerves in brain or spinal cord Peripheral nerves: Nerves in body Extend out from brain and spine at nerve roots Include cranial and spinal nerves Include nerve plexus: intersecting nerve roots Fascicles: Bundles of nerves d. Function of CTs around peripheral nerves CT makes nerves flexible and elastic Help nerves slide and bend during motion Pads nerves to withstand compression Three layers Epineurium: Wraps a single nerve Perineurium: Wraps a nerve fascicle Endoneurium: Wraps a single nerve fiber Neural tension Nerves can elongate 820% of resting length Neural tension equalizes tension along nerve Loss of extensibility in one area increases in another Neural tension test Example: slump test checks gliding motion of peripheral nerves Entrapment restricts gliding, can cause symptoms Neuromuscular patterns: Organization of movement pathways NM patterns are stored in motor cortex Myelin speeds conduction of impulses Well-used NM pathways have thicker myelin Sensorimotor loop: Continuous loop in NM system Sensory input (feedback) ? motor output (responses) 95% of SM processes are subcortical NM patterning method to change faulty habits SENSORY RECEPTORS Three types Interoceptors (proprioceptors): Pick up sensory information from muscles Are the "eyes and ears of body" Embedded in musculoskeletal tissues Exteroceptors: Pick up sensory information from five senses Visceroceptors: Pick up sensory impulses from organs Proprioception Awareness of posture and movement Awareness of location of body in space Proprioceptive organs found in muscles, tendons, joints Perception How the brain interprets proprioceptive input Influences how brain coordinates motor responses Can be subjective Not always accurate, can become habitual. Example: habitual off-center posture feels straight Muscle cells: Two types Motor cells: extrafusal fibers Contractile fibers in muscles Larger, more abundant muscle cells Innervated by large-diameter alpha motor neurons Sensory cells: intrafusal fibers Smaller, less abundant muscle fibers Innervate by small-diameter gamma motor neurons Two types First type registers muscle length changes Second type registers rate of length change Muscle approximation technique Mechanical shortening and lengthening of muscle Triggers relaxation and lengthening response Thought to reset muscle spindles REFLEXES AND MOVEMENT PATHWAYS Reflex: Automatic movement response to stimuli Reflex arc The circuitry for simple reflexes Example: knee-jerk test Stretch reflex Protective reflex that prevents overstretching Stretch triggers muscle contraction Regulated by muscle spindle Two types Tonic stretch reflex Results in slow contraction Activates postural response/”antigravity reflex” Phasic stretch reflex Elicited by quick stretch of muscle Results in quick, protective contraction Stretch injuries Occur in two different ways Muscle put on stretch while contracting Example: punting hamstring strain Muscle contracts while being elongated Example: biceps pull when dropping heavy object Golgi tendon organs (GTOs): Proprioceptive organ in tendons Embedded along musculotendinous junction Register increased tension on tendon Triggers inhibitory relaxation response Spindles and GTOs control rate/degree of motion Joint proprioceptors: three types Pacinian corpuscles Found in joint capsules Detect rapid changes in pressure and vibration Ruffini endings Embedded in skin around joints Detect slow changes in position and angle of joint Nociceptors Sensory nerve ending that acts as pain receptor Joint proprioceptors function as nociceptors when registering extreme temperatures or pressures Labyrinth: three-part equilibrium apparatus inside inner ear Vestibule: Registers changes in position and velocity Contains saccule and utricle Inside are nerve cells, otoliths, and fluid Semicircular canals: Register angular movement Three fluid-filled canals in each plane Maintain spatial orientation Cochlea: Snail-shaped hearing apparatus Reciprocal inhibition: Sherrington's law of muscle response Describes firing pattern of opposing muscles Opposing muscles share reciprocal innervation One muscle relaxes when opposing muscle contracts Explains how muscles work in reflexes Protective reflexes Extensor thrust reflex: Extends limbs when falling Flexor withdrawal reflex: Protective flexion away from danger Crossed extensor reflex: Lifts one foot while extending other Kinetic chains: Functional series of successive joints and muscles Are predictable movement pathways (e.g., extensor chain) Can be open or closed chains Continuity of tone along chain reflects muscle balance Myofascial meridian Term coined by Rolfer Tom Meyers in "anatomy trains" Myofascial meridians originated in Rolfing recipe Assessing kinetic chains Determine three-dimensional integrity of myofascial system What part of body moves in open/closed chain? Is height, width, depth proportional/symmetrical? Where are muscles along chain shortened/overstretched? Are weight-bearing joints centered/balanced in extension? Is tone along pathways even? Is tone along bilateral pathway symmetrical? Assessing inside line: Kinetic chain along inner leg and thigh Obvious in movement of skiers and skaters Imbalances in inside line Genu valgum: knock-kneed pattern Genu varum: bow-legged pattern Three assessment channels to assess overall muscle and joint patterns Palpatory assessment Postural observation Movement observation MOVEMENT APPLICATIONS IN NM TECHNIQUES Two general applications Local applications To elicit relaxation in specific muscle To facilitate contraction in specific muscles Global applications To improve overall posture To improve overall NM and movement efficiency Active, passive, and resisted motion assessments Used to assess source of musculoskeletal pain Determine whether pain is coming from contractile or noncontractile tissues Active motion: Client actively moves Passive motion: Practitioner moves client Resisted motion: Client moves against practitioner's resistance Direct technique Moves in direction that stretches tissues Pulls tissues out of shortened position Example: myofascial release techniques Indirect technique Moves in direction of shortened tissues Takes client into pattern, creates slack in tissues Example: straincounterstrain or positional release Hold shortened position for 90 seconds Slowly return area to neutral position, then stretch Gives muscles time to reorganize resting tone Active motion skills: Elements to assess Alignment of joint in starting position Where movement initiates, occurs, or is guarded Range, pathway, and quality of motion Client's willingness/reluctance to move Where and what symptoms occur with motion Client's reaction to symptoms Reasons for using passive motion skills To assess range of movement To figure out which tissues generate pain To stretch adaptively shortened tissues To improve range of motion Reasons for using resisted motion skills To facilitate contraction of inhibited muscle To organize and improve neuromuscular patterns To perform muscle energy techniques To determine treatment effectiveness with retesting Trigger points (TrPs): Localized irritable and painful nodule in muscle Active TrPs: Cause pain even in absence of movement Latent TrPs: Only cause pain when under direct pressure Active TrPs have four cardinal features: Palpable nodular or band-like hardening in muscle Localized spot of extreme tenderness in taut band Digital pressure Reproduces symptoms Triggers jump sign: Protective reflexive movement Direct pressure on trigger point relieves pain Muscle energy techniques (MET) Post-isometric relaxation (PIR) Three steps: contractrelaxstretch Have client contract target muscle against resistance Have client relax target muscle Stretch target muscle (should stretch further due to PIR response) Reciprocal inhibition (RI) Use PIR to stretch muscle While stretching, have client contract antagonist to enhance stretch Active pin and stretch steps Have client contract target muscle against resistance Pin one end of target muscle and hold Have client stretch muscle away from pinned end As client stretches, apply linear stripping along muscle SUGGESTED CLASSROOM AND STUDENT DEVELOPMENT ACTIVITIES PROVIDE AN OVERVIEW OF THE CLASS Before class, write a short, schematic overview of the class on the board, then go over it at the beginning of class. For example: Today's class covers: Overview of the nervous system Sensory receptors Reflexes and basic movement pathways Movement applications in neuromuscular techniques Activities: Review, lecture, NM skills lab, recap, and homework GOING OVER GUIDELINES EXERCISES Elements to track while observing active movement (p. 118) Steps for using passive motion (p. 118) Steps for using resisted motion (p. 119) EXPLORING TECHNIQUE EXERCISES Muscle approximation (p. 107) Slow movement to relax head and neck muscles (p. 110) Trigger point therapy (p. 121) Muscle energy stretch techniques (p. 122) MOVEMENT EXERCISE: Post-Isometric Relaxation (PIR) and Reciprocal Inhibition in Stretching Break students into small groups of three. Have each group come up with two stretching exercises that use both PIR (contractrelaxstretch) and RI (antagonistcontract). Then have one student from each group lead the class through both stretches. © 2013 by Education, Inc. Foster, Instructor Resources for Therapeutic Kinesiology