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  • Or goes away as soon as turn off machine
  • It’s a bridge. Move into active exercise and movement as soon as possible. Then resistive. Get them moving again.
  • Direct Current
  • Tens 1

    1. 1. Electrical Stimulation Goals and Treatment Adapted from Therapeutic Modalities: Art & Science, Knight & Draper (2008) for KIN 195
    2. 2. Competencies for Therapeutic Modalities TM-C2 Explain the principles of physics, including basic concepts associated with the electromagnetic and acoustic spectra (e.g., frequency, wavelength) associated with therapeutic modalities. TM-C3 Explain the terminology, principles, basic concepts, and properties of electric currents as they relate to therapeutic modalities. TM-C4 Describe contemporary pain-control theories.
    3. 3. Competencies for Therapeutic Modalities, cont. TM-C6 Explain the body's physiological responses during and following the application of therapeutic modalities. TM-C7 Describe the electrophysics, physical properties, biophysics, patient preparation and modality set-up (parameters), indications, contraindications, and specific physiological effects associated with commonly used therapeutic modalities. TM-C8 Identify appropriate therapeutic modalities for the treatment and rehabilitation of injuries and illness.
    4. 4. Basics of Electricity • Must understand why as well as how to use electrical stimulation. Or • You’ll be a knobologist.
    5. 5. Review: Requirements for Ion Migration: Chemical Effects • Must have continuous monophasic DC electron flow to cause ion migration. • Moving electrons against gradient – Like pushing a car uphill – When you pause, it rolls back down. • Why does a twin-pulse high-volt current not produce a chemical effect?
    6. 6. Review: Polarization & Action Potentials • Stimulation requires a polarized membrane (between inside and outside of nerve membrane). – – More positive ions than negative ions outside nerve and more negative ions than positive ions inside membrane When polarized, membranes have a potential of −70 to −90 mV between inside and outside of membrane
    7. 7. Review: Polarization and Action Potentials (cont.) • Nerve action potential eventually causes – An ascending sensory impulse to the brain Or – A descending muscle action potential • Muscle action potential causes muscle contraction.
    8. 8. Review: Polarization and Action Potentials (cont.) • Nerve repolarizes quickly. • Absolute refractory periods vary from 0.4 to 2 msec – Depends on specific nerve
    9. 9. Review Excitability: Nerve Size and Depth • The larger the nerve, the easier it can be stimulated. • The more superficial the nerve, the easier it can be stimulated. • In a practical sense: – – Large sensory nerves are more excitable than motor nerves. Motor nerves are more excitable than pain fibers.
    10. 10. Review Excitability: Rate or Frequency • Doesn’t effect individual threshold – Effects torque as it approaches tetany – Increased rate means increased fatigue rate. fati gu tetany 5/sec e
    11. 11. Review Electrodes: Physical Dimensions • Shape is unimportant – Most are round or square or rectangular. • Size and placement determine the number of motor units stimulated.
    12. 12. Review Electrode Function • Active electrode – Electrode under which the current density is great enough to elicit the desired response • Indifferent (dispersive) electrode – Electrode under which the current density is not great enough to elicit the desired response
    13. 13. Most Commonly Used Wave Forms DC: DC IF: Polyphasic HV: Twin pulse LV: Biphasic and polyphasic burst (Russian) TENS: Biphasic
    14. 14. Review: Pulse and Cycle Characteristics • Pulse: finite period of charged particle movement, separated from other pulses by a finite time during which no current flows • Made up of one or more phases
    15. 15. Review: Pulse and Cycle Characteristics (cont.) • Pulse named by number of phases – Monophasic • One phase • Current flows in one direction only. – Biphasic • Two phases • Current flows in both directions. – Polyphasic • Many phases
    16. 16. Review: Burst Characteristics • Burst – Finite series of pulses flowing for a finite time period followed by no current flow • Think of it as turning a pulse train or AC current on and off. – Burst interval • Time during which burst occurs – Interburst interval • Time between bursts, usually in milliseconds
    17. 17. Review: Current Timing & Modulation • Pulse width (pulse duration) – – Time required for each pulse to complete its cycle Reported in microseconds or milliseconds • Short pulse duration: <150 µsec • Long pulse duration: >200 µsec • Interpulse interval – Time between successive pulses
    18. 18. Review: Surge Characteristics • Ramp up – Time during which the intensity increases • Plateau – Time during which pulses remain at maximum preset intensity • Ramp down – Time during which the intensity decreases
    19. 19. Commonly Used Wave Forms (p.142) • Direct (galvanic) wave form – Pure DC current, used for iontophoresis
    20. 20. Commonly Used Wave Forms (p. 142, cont.) – Monophasic, rectangular, pulsed • Also called a modified square wave • Similar to DC but modulated from AC input current • On and off times are not necessarily equal
    21. 21. Commonly Used Wave Forms (p. 142, cont.) – Polyphasic, symmetrical, balanced, sinusoidal • Wave form generated and sold by utility companies
    22. 22. Commonly Used Wave Forms (p. 142, cont.) • Faradic wave form – – – – Induced asymmetrical AC current Biphasic, asymmetric, unbalanced, spiked Positive portion: short duration, high amplitude, and spiked Negative portion: long duration, low amplitude, and curved
    23. 23. Commonly Used Wave Forms (p. 142, cont.) • Biphasic wave form – Symmetrical, balanced, rectangular, pulsed
    24. 24. Commonly Used Wave Forms (p. 142, cont.) • Russian wave form – Polyphasic, symmetrical, sinusoidal, burst – Developed by Russian scientist Kots; thus the name – Initially a 2500 Hz AC current burst, modulated every 10 msec, now many frequency choices
    25. 25. Commonly Used Wave Forms (p. 142, cont.) • Twin pulse wave form – Monophasic, pulsed, twin spiked – Common wave form of high-volt muscle simulators – Has been called high-volt galvanic and pulsed direct current – However, not direct or galvanic current – Result of misunderstanding physiology
    26. 26. Commonly Used Wave Forms (p. 142, cont.) • Interferential wave form – Symmetrical, sinusoidal, high frequency (2000–5000 Hz) AC – – Two channels, with different frequencies, used simultaneously Two currents cause a tissue current amplitude modulation
    27. 27. Commonly Used Wave Forms (p. 142, cont.) • Two identical currents Interferential wave form: current amplitude modulation Two offset currents Two opposite currents Usually accomplished with two different frequency currents
    28. 28. Use of Electrical Current Stimulation for Pain Relief • Transcutaneous electrical nerve stimulation (TENS) • Interferential current therapy (IFC) • Iontophoresis • Neuromuscular electrical stimulation (NMES)
    29. 29. For all modalities… • Know the effects, indications, contraindications, & precautions • Verify the modality is set up correctly before treatment begins • Prepare the patient psychologically & physically for the treatment • Begin treatment conservatively and ask for patient feedback • At the end of treatment, clean up the modality and instruct the patient about next treatment and activity level until then • Maintain the machines appropriately
    30. 30. TENS • TENS – Transcutaneous: through the skin – Electrical – Nerve: sensory – Stimulation: depolarize • Stimulate sensory nerves with pulsed current via surface electrodes
    31. 31. TENS: Physiological Aspects • Electrode placement – Usually at the site of pain • Clinician can change the patient’s perception of acute and chronic pain. • Selective depolarization of afferent nerves
    32. 32. How does TENS work? • Many theories • Gate system and sensory TENS – 80-150 pps • Endogenous Opiate system stimulated – Motor TENS and brief-intense TENS • Low beat frequency 1–5 pps • Slight muscle twitch
    33. 33. Brief Research Findings on TENS • Research is difficult. • TENS has relieved pain associated with – – – – Osteoarthritis Rheumatoid arthritis Dysmenorrhea Low back pain • Postoperative TENS
    34. 34. TENS Advantages 1. Portable a. Can be used during activity 2. Self-treatment 3. Alternative to cold during cryokinetics Disadvantages 1. Eliminates pain; not cause of pain 2. May mask more serious problems 3. We don't know enough about it yet 4. May become a panacea (too reliant on it, maybe even after healthy)
    35. 35. TENS: Indications & Contraindications Indications 1. Pain of peripheral origin 2. Acute pain 3. Chronic pain Contraindications 1. Do not use on person with: a. An implanted pacemaker b. History of heart disease 2. Do not treat transthoracic area 3. Discontinue use if a skin irritation develops
    36. 36. TENS: Precautions G. Precautions 1. Treatment over an area with: a. Impaired sensation b. Skin lesions (cuts, abrasions, new skin, recent scar tissue) 2. While driving or operating heavy machinery 3. Temporary decrease in pain does not mean cause of pain has gone. 4. Delicate unit, not a cheap radio a. Treat it kindly.
    37. 37. Electrode placement techniques for TENS Electrode placement a. Over acupuncture or trigger points b. Directly over the pain c. Proximal or distal to pain d. Crisscross over pain (two-channel unit) e. Over motor point (helps with spasms) f. Dermatome placement
    38. 38. Application Parameters: TENS Adjust pulse width and rate a. Go through entire range and select most comfortable settings. b. Specific settings for specific conditions. i. Acute pain: narrow pulse width (75 µsec) and high pulse rate (80–200 pps) a) Pain relief is almost immediate, but short lasting (1–60 min) ii. Chronic pain: wide pulse width (200 µsec) and low pulse rate (1–5 pps) a) Pain relief may take ½ hr but will be long lasting (6–7 hr)
    39. 39. Application Parameters: TENS (cont.) Length of application 1. Extremely variable 2. Some treat for 30–60 min, others for hours Frequency of application 1. Three or four times a day as needed for pain Duration of therapy 1. Use until TENS is no longer effective.
    40. 40. Interferential Current • Interference or superimposition of two separate medium-frequency sinusoidal currents on one another • Symmetrical, sinusoidal, medium frequency (2000–5000 Hz) AC • Invented in 1950; used in United States by 1980s • Fifth most frequently used physical agent
    41. 41. What Is IFC Therapy? (cont.) • Basic principle – Decrease tissue impedance (resistance) so simulation is less painful • Impedance at 50Hz = ~3200 Ω • Impedance at 4000 Hz = ~40 Ω • Current passes more easily through skin • Advantages of vector pattern – – – – – Surface and deep stimulation Targeted tissues for added benefit Treatment of easily localized pain Treatment of large areas Treatment of poorly defined pain
    42. 42. How Does IFC work? (cont.) • Example: One channel runs at 5000 Hz another at 5100 Hz – Use a dynamic vector (or scan for poorly defined pain) – Use target for easily localized pain – Treats most of the area bracketed by the electrodes (scan or dynamic vector)
    43. 43. Is IFC Therapy Effective? (cont.) • Those who have had success – Correctly position vector – Use appropriate size and positioning of electrodes – Use appropriate stimulation parameters – Persevere, if pain relief is not immediately obtained
    44. 44. IFC advantages & disadvantages Advantages 1. More comfortable than a TENS a. Medium-frequency currents meet with less skin resistance than low frequency currents. i. TENS uses low frequency currents 2. Stimulates tissues deeper than a TENS unit 3. Larger coverage area than TENS Disadvantages 1. Eliminates pain; doesn't deal with cause of the pain 2. May mask more serious problems 3. Few portable units available 4. Sometimes becomes a panacea
    45. 45. IFC: Indications & Contraindications Indications 1. Acute pain 2. Chronic pain 3. Muscle spasm 4. Pain that covers a large area Contraindications 1. Do not use on a person who has: a. Implanted pacemaker b. History of heart disease 2. Do not treat transthoracic area 3. Discontinue if skin irritation develops
    46. 46. IFC Precautions Precautions 1. Be cautious when using IFC over: a. Impaired sensation b. Skin lesions (cuts, abrasions, new skin, recent scar tissue, etc.) 2. Use caution when using IFC while driving or operating heavy machinery. 3. A temporary decrease in pain does not mean the cause of the pain has gone.
    47. 47. Application Parameters: IFC Adjust pulse rate settings for specific injury a. For acute pain i. Use a high pulse rate of 80–200 pps ii. Pain relief is almost immediate iii. Lasts only a few minutes to 1 hr b. For chronic pain i. Use a low pulse rate of 1–5 pps ii. Pain relief may take ½ hr iii. May last 6–7 hr Target or vector a. Pain that is easily identifiable and pinpointed i. Use target or vector buttons to move spot where current intersects to area directly over pain b. Pain that is hard to pinpoint i. Use dynamic vector
    48. 48. Application Parameters: IFC (cont.) C. Length of application 1. 20–30 min D. Frequency of application 1. Once or twice daily, as needed for pain E. Duration of therapy 1. Use until IFC is no longer effective.
    49. 49. NeuroMuscular Electrical Stimulation • NMES is used for – Muscle reeducation and prevention of disuse atrophy – Decreasing muscle spasm – Decreasing edema
    50. 50. History of NMES • 1980 companies started manufacturing Russian current • No North American scientist has been able to duplicate Kots’s claims of 30% increase in force vs. voluntary contractions and lasting gains up to 40% in healthy athletes – Great amount of pain (as the current amplitude was increased to try to replicate a voluntary muscle contraction)
    51. 51. Why NMES? • Used on patients who cannot perform a voluntary muscle contraction – Peripheral nerve innervation is intact, yet muscle is too weak to contract from atrophy, pain, immobilization, etc. • Promotes early AROM in postsurgical and immobilized limbs • Break pain-spasm-pain cycle of muscle spasms
    52. 52. Don’t Replace Strength Training with NMES • NMES recruits fibers in the opposite order than that of a voluntary contraction. – Machine = large fibers followed by small – Voluntary = small fibers followed by large • Patient needs to move on to more traditional weight training ASAP.
    53. 53. Tetanic Contraction to break Muscle Spasm • Goals – – – – Increase local circulation Remove metabolic wastes Mechanically stimulate muscle fibers Induce some muscle spasm fatigue
    54. 54. NMES for Decreasing Edema • Produce cyclic muscle contractions to help pump chronic edema – 5–10 sec on; 5–10 sec off
    55. 55. NMES Effects Effects 1. Muscle contraction a. Increase blood flow b. Retard atrophy development c. Decrease and retard neuromuscular inhibitions d. Increase muscle relaxation; decrease spasm 2. Decrease pain a. Possibly by decreasing muscle spasm
    56. 56. NMES Advantages & Disadvantages C. Advantages 1. Can be applied to immobilized body part D. Disadvantages 1. Sometimes becomes a panacea
    57. 57. NMES Indications & Contraindications Indications 1. Residual or chronic muscle spasm 2. Any time normal neuromuscular function is not possible 3. Muscle strains 4. During cast immobilization or disuse atrophy 5. Pain owing to muscle spasm Contraindications 1. Do not use: a. On a person with a pacemaker b. Over the heart or brain c. Over recent or non-union fractures d. Over potential malignancies
    58. 58. NMES Precautions G. Precautions 1. Be cautious over an area with: a. Impaired sensation b. Skin lesions (cuts, abrasions, new skin, recent scar tissue) c. Decreased range of motion d. Extensive torn tissue
    59. 59. Application Parameters: NMES C. Length of application 1. 10–30 min 2. See individual manufacturer’s instructions. D. Frequency of Application 1. As often as twice per day if separated by 3–4 hr
    60. 60. Iontophoresis: Basic Principle  Like charges repel like charges,  Drug ions are repelled or pushed into the underlying tissue.  Two electrodes – One drug delivery – One larger dispersive electrode
    61. 61. How Does Iontophoresis Work? • When an electrical DC current is applied – Positively charged electrode delivers positively charged drug ions into skin and surrounding tissues – Negatively charged electrode delivers negatively charged drug ions into skin and surrounding tissues
    62. 62. Why Use Iontophoresis? • Delivering medicine such as antiinflammatories and pain relievers directly without the negative effects of – Painful needle injections – Risk of infection from nonsterile needle injections – Avoid the gastrointestinal side effects of NSAIDs and COX-2 inhibitors – Localized drug delivery; doesn’t travel through entire system – Machine is Portable and easy to transport
    63. 63. Common Drug Ions Used in Sports Medicine • Dexamethasone – – • Negative ion Reduces inflammation by inhibiting biosynthesis of prostaglandins and various other inflammatory substances Acetate – – Negative ion Assists in dissolving calcium deposits and scar tissue in soft tissues
    64. 64. Common Drug Ions Used in Sports Medicine (cont.) • Hydrocortisone – Positive ion – Assists in decreasing tissue inflammation by inhibiting biosynthesis of prostaglandins • Lidocaine – Positive ion – Assists in decreasing local pain by blocking nerve impulse transmission
    65. 65. Is Iontophoresis Effective? • Debate – Research has shown it to deliver medication from 6 to 20 mm below the skin • Effective in reducing pain and inflammation associated with • Plantar fasciitis • Temporomandibular disorders • Epicondylitis – When dexamethasone, lidocaine, or sodium salicylate is used
    66. 66. Ionto Advantages & Disadvantages Advantages Compared to injections:  Virtually painless  Noninvasive, minimizing…  Risk of infection  Risk of tissue necrosis, tendon rupture, etc. Compared to oral medications:  Localized drug delivery, nonsystemic  Avoid risk of systemic side effects Disadvantages 1. Eliminates pain or inflammation a. Doesn't deal with the cause of the pain/inflammation. 1. Slight risk of electrode burns 2. Some believe transdermal drug delivery is not possible.
    67. 67. Iontophoresis Indications & Contraindications Indications  Used to administer water-soluble ionic medications Contraindications  Damaged or denuded skin  Recent scar tissue  Drug allergies  Transcranial  Orbital region  Electrically sensitive support systems  Pacemakers
    68. 68. Iontophoresis: Precautions Precautions  Diabetes  Pregnancy  Over external metal fixation devices  Elderly skin  TMJ  Dizziness  Metallic taste
    69. 69. Ionto: Drug Dose Calculation Dosage (mA/min) = Current (mA) × Treatment time (min) • Examples: • 40 mA/min = 4.0 mA (current) × 10 min (time) • 40 mA/min = 2.0 mA (current) × 20 min (time) • 24 mA/min = 2.0 mA (current) x 12 min (time)
    70. 70. Reported Sensation of Iontophoresis  Some patients feel little or no sensation; others describe it as a tingling or warm sensation.  The intensity of the sensation varies among patients and depends on the site being treated.  These sensations usually decrease or disappear after a few minutes.
    71. 71. Typical Skin Reactions to Ionto  DC causes capillary dilatation, leading to erythema (reddening) of the skin under one or both electrodes.  Less frequent: appearance of small fluidfilled bumps caused by the release of histamine from dermal mast cells  Note: These skin reactions disappear over the course of a few minutes but may last longer in patients with particularly sensitive skin. Also, some patients with sensitive skin may react to the adhesive on the electrode.
    72. 72. Reduce Negative Effects from Iontophoresis • To help reduce the risk of skin irritation – Clean the skin with an alcohol scrub. – After treatment, apply a lotion containing aloe vera. – Increase the size of the anode or cathode to decrease current density. – Increase the spacing between electrodes to decrease current intensity.
    73. 73. Application Parameters: Ionophoresis C. Length of application 1. Dose specific D. Frequency of application 1. Every other day E. Duration of application 1. Up to 3 weeks
    74. 74. High Voltage Pulsed Current Stimulation for Wound Healing • Electrical stimulation for the purpose of repairing tissues includes management of open wounds and edema reduction. • Production of a twin-peak, monophasic, pulsed current driven by its characteristically high electromotive force or voltage • Positive or negative polarity
    75. 75. HVPC (cont.) • Versatile and can perform several functions: – – – – Pain modulation Edema reduction Muscle reeducation and spasm reduction Wound healing
    76. 76. Characteristics of High-Volt Stimulator • • • • • • Low volt stimulators generate <150 V High volt stimulators generate >150 V HVPC uses between 150 and 500 V. High peak voltages Low average current Twin peak monophasic waveform – Resembles a double spike with a fast rise followed by a fast decline • • Short pulse widths (100–200 µsec) Pulse rates of 1–200 Hz
    77. 77. HVPC: Uses & Techniques • Monophasic current used for – – – – Pain reduction Disuse atrophy Reduction of edema Wound management • Monopolar or bipolar technique – Monopolar used when treatment is directed over a large area – Bipolar used for muscle contraction or chronic pain
    78. 78. HVPC: Advantages • Less resistance to the current by the skin Short phase duration allows for moderately high-intensity muscle contraction with little discomfort • – Other types of stimulators provide a stronger contraction • Highly variable in its functions • Can be used for – Pain modulation a. Sensory level (acute pain) b. Motor level (chronic pain) – Edema reduction – Treating muscle weakness – Wound healing
    79. 79. HPVC: Disadvantages Disadvantages 1. Cannot provide as strong of a contraction as NMES 2. Many aren’t portable. 3. Sometimes trial and error are needed to determine electrode polarity for wound healing. 4. Effects (muscle contraction) are as strong as low-volt units.
    80. 80. HPVC: Indications & Contraindications Indications 1. Wound lesions (pressure sores, scarring from incisions) 2. Edema control and reduction 3. Residual or chronic muscle spasm (when low-volt unit unavailable) 4. Pain Contraindications 1. Do not use on patient with pacemaker 2. Do not use over a. Heart or brain b. Lumbar and abdominal area of pregnant women c. Potential malignancies d. Anterior cervical area
    81. 81. HPVC Precautions G. Precautions 1. Be cautious when using HVPC over an area with: a. Impaired sensation b. Extensive torn tissue c. Hemorrhagic area 2. Patients with epilepsy should be monitored during treatment.
    82. 82. HVPC: Edema Management • Curbing edema formation – HVPC is not DC – Decreases the permeability of microvessels – Decreases the leaking of vessels, reducing the number of plasma proteins and amount of fluid that leave the vessels to enter the interstitial spaces
    83. 83. HVPC: Edema Management (cont.) • Two protocols for curbing edema Water immersion -Negative polarity -120 pps -90% of visible motor threshold -30 min treatments every 4 hr -Apply ASAP postinjury or as long as edema is still forming Resolution of edema once formed -Can be employed in a muscle pumping action to get rid of edema -Intensity increased until strong muscle contraction -Setting of 1–10 pps for muscle contraction
    84. 84. HVPC: Pain Modulation • Ineffective in reducing the pain of delayed-onset muscle soreness • Yet has been shown to help relieve pain caused by muscle spasm
    85. 85. HVPC: Wound Management • How does HVPC stimulate wound repair? – Body possesses bioelectric currents in the vascular and interstitial tissues. – Blood vessel walls, insulating tissue matrix, interstitial fluid, and intravascular plasma are capable of conducting bioelectricity. – When tissues are damaged, an electrical potential is created between injured and noninjured tissues.
    86. 86. HVPC: Wound Management (cont.) • • • • • • • DC may stimulate cellular activity when injured. Stimulating débridement of injured tissues Tissue regeneration and remodeling May speed up healing by promoting the natural healing process May develop a difference in potential between wound area and the surrounding healthy tissue Injury potential typically becomes positive 24–48 hr after injury & negative 8–9 days after injury. As the wound heals, the difference slowly returns to baseline. – Can be used to enhance the natural process of tissue recovery and healing
    87. 87. HVPC: Electrode Polarity • Negative polarity – – Increases • Vascularity • Stimulation of fibroblastic growth • Collagen production • Epidermal cell migration Inhibits bacterial growth • Positive polarity – – Increases macrophages Promotes epithelial growth
    88. 88. HVPC: Electrode Polarity (cont.) • Most treatments begin with the negative polarity – Encourages blood clots to dissolve and increases the inflammatory by products • Necrotic tissues • Positive polarity encourages clot formation around the wound and granulation tissue.
    89. 89. Application Parameters: HVPC D. Frequency of application 1. As often as three per day if separated by 3–4 hr
    90. 90. Microcurrent Electrical Nerve Stimulation • Therapeutic use of constant (DC) and pulsed (interrupted) currents where the stimulus amplitude is in the microamperage range • Proposed Uses – – – – Tissue healing Pain control Edema control Slow healing skin lesions
    91. 91. MENS Names • Many names of microcurrent – MENS does not accurately describe this device. – Current intensity is too low (<1 mA) to cause motor nerve depolarization • Other than MENS, these devices have been referred to as: – – – – – Low-voltage pulsed microamp stimulation Biostimulation Bioelectric therapy Low-intensity direct current Low-intensity electrical stimulation
    92. 92. MENS: Theory • Brief research – – No clear-cut research supporting the use of microcurrent therapy Positive effect in treating • • • Pressure ulcers Diabetic ulcers TMJ disorders • No effect in treating – DOMS – Pressure ulcers – Coracoacromial arch pain – Surgically induced wounds
    93. 93. MENS: Theory (cont.) • Might play a positive role in wound healing, an area athletic trainers typically don’t deal with • It is safe.