Ultrasound & Laser Modalities (PTA 1009) PDF

1 Modalities (PTA 1009) Ultrasound and Laser ©Stanbridge University 2023  2 ©Stanbridge University 2023 Objectives By the end of this section the stu...

1 Modalities (PTA 1009) Ultrasound and Laser ©Stanbridge University 2023  2 ©Stanbridge University 2023 Objectives By the end of this section the student should be able to describe: Physical principles of Ultrasound Physiological responses to Ultrasound Indications, contraindications and precautions Adverse reactions General application, dosage and frequency  3 ©Stanbridge University 2023 Ultrasound Sound- vibration of a medium Frequency- the rate at which something occurs repeated over a period  4 ©Stanbridge University 2023 A frequency of vibration that is beyond audible sound ULTRASOUND Human ear: vibrations at 20,000 cps Anything faster is Ultrasound (ultrasonic)  5 ©Stanbridge University 2023 Therapeutic ultrasound frequency 1-3 million cps 1 MHz – 3.3 MHz  6 ©Stanbridge University 2023 Ultrasound A sound wave creates pressure on a medium, thus causing compression of the molecules Each molecule transfers the energy to its neighbor until the energy runs out= Source: Behrens, 2014 chain reaction  7 ©Stanbridge University 2023 Ultrasound Sound waves can travel through Liquid Gas Solids  8 ©Stanbridge University 2023 Ultrasound (US) How is ultrasound created from a machine? Source: Behrens, 2014 Piezoelectric ceramic crystal inside a transducer delivers waves to the patient  9 ©Stanbridge University 2023 Ultrasound Waves Thermal Current is Crystal Mechanical impart and non- introduced distorts and waves are energy on thermal to a crystal vibrates produced molecules effects in in body tissue occur  10 ©Stanbridge University 2023 Ultrasound: Indications Thermal for Deep Heating: Joint contracture and scar tissue Pain & muscle spasm Subacute or chronic tissue disorders where increased tissue temperature or blood flow is required Non-thermal to Facilitate Healing: Acute injury or inflammation of soft tissue Acute injury or inflammation of peripheral nerve Open wounds  11 ©Stanbridge University 2023 Ultrasound (US) Instrumentation for delivering therapeutic US ▫ Console ▫ Coaxial cable ▫ Transducer  5 cm2 vs. 10 cm2 Source: www.pinterest.com  12 ©Stanbridge University 2023 Ultrasound (US) Coupling gel: medium for transmission of sound waves Why is a gel needed? Source: www.istockphoto.com Source: www.parkerlabs.com  13 ©Stanbridge University 2023 Ultrasound Beam nonuniformity ratio (BNR)- ratio of peak power to the average power in an ultrasound beam ▫ This is measured at.5 cm from the transducer ▫ Indicates the quality of the transducer head ▫ Acceptable BNRs in US are 2:1- 8:1 ratio; average 5-6:1  14 ©Stanbridge University 2023 Ultrasound BNR A spot in the tissue can receive ultrasound at an intensity up to 6x higher than the intended dose Hot spot Source: Bellew, 2016  15 ©Stanbridge University 2023 Ultrasound (US) Effective Radiating Area (ERA)- area of the beam that transmits clinically effective power Faceplate is usually larger than the ERA Ultrasound will ONLY be effective for delivering energy to areas less than or equal to 4x the size of the ERA due to excessively long treatment times Transducer head ERA Source: Bellew, 2016  16 ©Stanbridge University 2023 Ultrasound ERA Source: Bellew 2016  17 ©Stanbridge University 2023 Ultrasound- Biophysical Effects Thermal effects: ▫ Increased metabolism ▫ Reduction of muscle spasm ▫ Decreased joint stiffness ▫ Alteration of nerve conduction velocity ▫ Increased circulation ▫ Increased soft tissue extensibility Extent of thermal effects are dependent on the parameters  18 Ultrasound (US): Effects ©Stanbridge University 2023 Various Tissues Absorb Sound Waves Differently resulting in heat production: ▫ Heat absorption is greatest in tissues with high proportion of protein and in dense tissues ▫ Heat is greatest at tissue interfaces: synovial tissues, capsule, periosteum  19 ©Stanbridge University 2023 Ultrasound (US): Effects Fluid elements have low resistance and absorption Bone: High impedance and absorption= heats quickly ▫ If overheating occurs, patient may describe a prickling sensation ▫ Intensity is too high, turn down  20 ©Stanbridge University 2023 Ultrasound- Biophysical Effects Heat is generated via CONVERSION Heat is generated by: ▫ Increased molecular vibration from absorption of the energy ▫ Release of energy from unstable cavitation More heat is released by 3.3 MHz than 1 MHz due to the higher frequency (Increased freq=shorter wavelength=increased energy=increased absorption)  21 ©Stanbridge University 2023 Ultrasound- Biophysical Effects Why is it harder to heat muscles? particularly postural muscles The high capillary density and blood flow creates constant cooling of the area quickly dissipating the heat  22 ©Stanbridge University 2023 Ultrasound- Biophysical Effects Absorption is affected by: ▫ Frequency of sound waves  The deeper the penetration = the longer the wave = the lower the frequency ▫ Density of tissue The denser the tissue the greater the absorption ▫ Scar tissue ▫ Ligaments ▫ Tendons ▫ Structures within the joint capsule ▫ Branches of peripheral nerves  23 ©Stanbridge University 2023 Ultrasound Cavitation: Gas bubbles in fluids shrink and expand during compression and rarefaction phases  24 ©Stanbridge University 2023 Ultrasound Stable cavitation- small changes in bubble radius Unstable cavitation- Bubbles can grow large and collapse under pressure Frequency and cycle duration are inversely related Lower frequency waves allow for larger bubble growth Unstable cavitation occurs more frequently at 1 MHz and with improper application technique  25 ©Stanbridge University 2023 Ultrasound- Biophysical Effects Thermal effects are dependent on temperature change in tissue vs the type of modality used to create the change Tissue temp change 104°-113°F up to 3-5 cm More temperature change is usually associated with continuous ultrasound Stretching must occur within 8-10 min after US to benefit from thermal effects.  26 ©Stanbridge University 2023 Ultrasound- Biophysical Effects Non-thermal effects (usually associated with pulsed ultrasound) ▫ Increased cell membrane permeability ▫ Increased intracellular calcium levels ▫ Facilitation of tissue repair ▫ Promotion of normal cell function  27 ©Stanbridge University 2023 Ultrasound- Biophysical Effects Non-thermal effects are a result of stable cavitation (mechanical vibration) and microstreaming ▫ Acoustic microstreaming- Unidirectional movement of fluids along cell membranes ▫ Cavitation around a vibrating bubble create eddy currents and subject cell membranes and intracellular organelles to rotational forces and stresses ▫ The cell membranes become destabilized and more permeable  28 ©Stanbridge University 2023 Ultrasound (US): Purpose & Effects Non-Thermal Effects: ▫ Increased membrane permeability= increased facilitation of metabolites, promotion of protein and collagen synthesis ▫ Up-regulation (increase) of Prostaglandins and Leukotrienes during acute phase of injury, especially with high doses: may exacerbate acute inflammation  29 ©Stanbridge University 2023 Ultrasound (US) Characteristics of the US wave: Frequency: 1 MHz vs. 3.3 MHz -Sound waves at 1 MHz: penetrate 3 - 5 cm -Sound waves at 3.3 MHz: penetrate 1 - 3 cm Absorbed in superficial →waves absorbed more easily tissue layers →waves raise temperatures more quickly Absorbed in deeper tissue layers  30 Ultrasound (US) ©Stanbridge University 2023 Characteristics of the US wave: Mode: Continuous or Pulsed -Continuous: Thermal effects -Pulsed: Thermal and Non-thermal effects Source: Bellew 2016  31 ©Stanbridge University 2023 Ultrasound (US): Dosage Commonly used Duty Cycles: Continuous mode: the duty cycle is 100% Pulsed mode the duty cycle is 20% or 50% Duty cycle = (On time/ total treatment time) x 100 ▫ 50% 1:1 ratio ▫ 20% 1:4 ratio Source: Behrens 2014  32 ©Stanbridge University 2023 Ultrasound Duty Cycle (Cont)  33 ©Stanbridge University 2023 Ultrasound (US): Dosage Intensity: Quantity of energy per unit area Ranges include: 0.5 – 3.0 W/cm2 Frequency (of sound waves): 1MHz (deeper tissues up to 3 - 5 cm) 3.3MHz (more superficial tissues 1 - 1040F= vigorous heating)  35 ©Stanbridge University 2023 Ultrasound (US): Dosage Treatment Frequency: Dependent on acuity and goal ▫ Pulsed (non-thermal) US Acute- daily ▫ Pulsed or Continuous (thermal) US Subacute/Chronic- 2-3x/wk Duration of total treatments: Results should be seen in 3 sessions No more than 14 sessions due to effects on red and white blood cell count  36 ©Stanbridge University 2023 Ultrasound Dosage Treatment parameters will be based on these 2 things: Treatment area: size and depth of the target tissue ✓Determines treatment ime ✓Determines transducer size ✓Determines frequency setting in machine (pps or Hz) Stage of healing the tissue is currently in ✓Determines duty cycle ✓Determines intensity ✓Determines treatment frequency (times per week)  37 ©Stanbridge University 2023 US Dose Based on Tissue Healing Phases Phase of healing Acute Settings Sub-acute Settings Chronic Settings Duty Cycle 20% 50% 100% Intensity 0.5- 1.0 w/cm2 1.0 w/cm2 1.0-1.5 w/cm2 Dose should be started around these baselines and may be altered according to goals First treatment: recommend using the lower intensity level listed at the phase of healing  38 ©Stanbridge University 2023 US Parameter Based on the Tissue to be treated Tx Area Smaller area Tissue Depth Small transducer (2 cm2) 2-3 x ERA max Superficial: 3.3 Hz Time: 5’ minimum Larger area: Deep: 1.0 Hz Large transducer (5 cm2) 3-4 x ERA Tx time: 10’ minimum  39 ©Stanbridge University 2023 Ultrasound- Biophysical Effects Ultrasound under water Use in still water (minimal air bubbles) Wipe air bubbles off skin ▫ Effectiveness under water is reduced ▫ Reflection of sounds waves in the water ▫ Some heat is transferred to body through water (if warm) via conduction vs conversion in the tissue ▫ Wounds (practitioner wears gloves) ▫ Can be used for poor uniformity of transducer on treatment area  40 ©Stanbridge University 2023 Ultrasound (US)- Water Application Intensity of US should be increased by 50% Example: US at 1.0 W/cm2 should be performed at 1.5 W/cm2 Transducer should be 0.5-3.0 cm away from skin with water application  41 ©Stanbridge University 2023 Ultrasound: Contraindications Anesthetic areas Pregnancy: over pelvis, abdomen, L/S Impaired arterial circulation Malignancy and Infection Over epiphyseal plates of growing Over carotid sinus, heart, stellate, bones cervical ganglia, pacemaker Active bleeding or Hemorrhage Over region of Thrombophlebitis or Over eyes, testes, spinal cord after DVT laminectomy: may cause Cavitation Abscesses (enclosed infection)  42 ©Stanbridge University 2023 Ultrasound: Precautions Maintain consistent energy transfer: KEEP TRANSDUCER MOVING (even contact, remove air bubbles: otherwise, may burn the tissue) Increased absorption at periosteum: can produce burns→ Keep off bony prominences Acute inflammatory pathologies: can increase inflammatory response (use low doses; 20% Duty) Epiphyses of growing bones: (administered at.8MHz- BUT CONSIDER A CONTRAINDICATION)  43 ©Stanbridge University 2023 Ultrasound (US) General instructions for US application ▫ Check equipment: calibration ▫ Instruct patient about the treatment and what is to be expected ▫ Check the patient’s skin sensation and integrity ▫ Position and drape patient appropriately ▫ Identify the area to be treated; palpate; consider depth of tissue ▫ If necessary, position the patient to move the target tissue out from under overlying tissue- i.e. joint position ▫ Select appropriate frequency range (i.e. 1 MHz or 3.3 MHz)  44 ©Stanbridge University 2023 Ultrasound (US) General instructions for US application ▫ Select appropriate transducer size (i.e. 5 cm2 or 10 cm2) ▫ Apply US gel to head of transducer ▫ Maintain contact of the transducer to the gel/skin (parallel to skin) ▫ Select and establish appropriate dosage (see POC) ▫ Set the duty cycle and intensity and quickly apply transducer to body surface ▫ KEEP THE TRANSDUCER MOVING- ~4 cm/sec  45 ©Stanbridge University 2023 Ultrasound (US) General instructions for US application ▫ The patient’s subjective tolerance is the ultimate determinant of continuance of immediate treatment ▫ To conclude treatment, turn off power ▫ Clean or dry patient ▫ Clean and dry transducer; use alcohol wipe to sanitize the transducer prior to returning it to its cradle ▫ Perform post-treatment evaluations, including skin inspection; stretch immediately if heating is goal  46 ©Stanbridge University 2023 Ultrasound (US): Responses Normal response: warmth (thermal effects) Abnormal response: sharp pain- periosteum may be receiving too much energy Pause machine, remove sound head from skin, and decrease intensity 1st before changing frequency  47 ©Stanbridge University 2023 Ultrasound (US) Assessment of US intervention ▫ Outcome measures Documentation of US treatment ▫ Frequency of US ▫ Size of transducer ▫ Mode ▫ Duty cycle (if applicable) ▫ Intensity ▫ Duration ▫ Frequency of intervention ▫ Size and location of treatment area ▫ All patient responses  48 ©Stanbridge University 2023 Ultrasound- Evidence C Martin et al, Heel Pain- Plantar fasciitis: Clinical Practice Guidelines; JOSPT 2014; 44(11): a1-a33 ▫ - There is no recommendation for use of US on heel pain plantar fasciitis A Martin et al.; Ankle Ligament Sprain: Clinical Practice Guidelines; JOSPT 2013; 43(9): a1-a40 ▫ -Clinicians should not use ultrasound on acute ankle sprains C Kelley et al.; Adhesive Capsulitis: Clinical Practice Guidelines; JOSPT 2013; 43(5): a1-a31 ▫ - Clinicians may use US on patients with Adhesive capsulitis of the shoulder  49 ©Stanbridge University 2023 Ultrasound- Evidence I Dingemanse et al; Evidence for the effectiveness of electrophysical modalities for the treatment of medial and lateral epicondylitis: a systematic review; Br J Sports Med; 2014; 48: 957-965 C ▫ - There is moderate evidence to use ultrasound for the treatment of lateral epicondylitis I Zhang et al, Effects of therapeutic ultrasound on pain, physical functions and safety outcomes in patients with knee osteoarthritis: A systematic review and meta-analysis; Clin Rehabil; 2015 -Ultrasound is beneficial for reducing pain and improving function in patients suffering from knee osteoarthritis  50 ©Stanbridge University 2023 Ultrasound- Evidence II Larsson et al, Treatment of patellar tendinopathy- systematic review of randomized control trials. Knee Surg Sports Traumol Arthrosc, 2012, 20:1632-1646 ▫ - Ultrasound can be ruled out as a treatment for patellar tendinopathy  51 ©Stanbridge University 2023 Phonophoresis Application of US through a medicated couplant Common anti-inflammatory medications include: ▫ Dexamethasone and fluocinolone acetonide (12-fold enhancement) ▫ Hydrocortisone and domethacin (3-5 fold enhancement)  52 ©Stanbridge University 2023 Phonophoresis Local application with Systemic effects Clear for anti-inflammatory allergies Make sure couplant and medication is not “whipped” to avoid air bubbles Dose Same as US parameters Very limited supportive research  53 ©Stanbridge University 2023 Phonophoresis- Evidence I Martin et al, Heel Pain- Plantar fasciitis: Clinical Practice Guidelines; JOSPT, 2014; 44(11): a1-a33 ▫ - There is no recommendation for use of phonophoresis on heel pain plantar fasciitis Kim et al, Assessing the Effectiveness of Phonophoresis on Chronic II Injuries: An Evidence-based Approach: A Systematic Review; Athletic Training and Sports Health Care; 2013 ▫ - There is no support for the use of phonophoresis over the use of other modalities such as ultrasound or iontophoresis in the treatment of chronic musculoskeletal injuries  54 ©Stanbridge University 2023 Laser Therapy  55 ©Stanbridge University 2023 Objectives By the end of this section the student should be able to describe: ▫ Types of Laser ▫ Affects of light ▫ Physiological responses ▫ Indications, contraindications and precautions ▫ Advantages and Disadvantages ▫ General technique/application, Dosage and Frequency  56 ©Stanbridge University 2023 Light Therapy Devices- Subcategories Advance for Physical Therapy and Rehab Medicine- The use of Laser therapy in Rehabilitation 1. Low level laser (≤500mW of peak power) 2. High intensity laser (>500mW of peak power) For: ▫ Reduction of pain and inflammation/swelling of musculoskeletal origin ▫ Nerve repair ▫ Promotion of healing for chronic skin wounds  57 ©Stanbridge University 2023 Laser Therapy Laser Acronym: Light Amplification by Stimulated Emission of Radiation Description: Photons of light move in the same direction at the same frequency and the same wavelength FDA: Approval of Low Level Laser Therapy (LLLT) & High Intensity Laser Therapy (HILT)  58 ©Stanbridge University 2023 Laser Therapy A contained chamber or environment houses an active medium of excitable atoms Electrical energy travels through the medium resulting in unstable molecules Unstable molecules shed energy (photons) Photons travel through the medium again and emit from the chamber as “Laser” beams Source: www.commons.Wikimedia.org  59 ©Stanbridge University 2023 Laser Therapy Monochromatic and coherent light- Low beam divergence unlike white light (Radiant energy) One specific wavelength= one color (monochromatic) Coherent parallel beam profile which remains tightly focused for long distances Enormous energy density in an area of focus  60 ©Stanbridge University 2023 Laser Therapy Monochromatic light Radiant light Source: Bellew, 2016 Source: Behrens, 2014  61 ©Stanbridge University 2023 Laser Classification Class 1: ≤0.5 mW- safe for any exposure time with intended use of device Class 2: ≤1 mW- limited visible light, safe due to blink reflex Class 3a: 1-5 mW- momentary viewing without eye damage (laser pointers) Class 3b: 5-500 mW- hazardous to eye if viewed directly Class 4: >500 mW- Can cause skin burns and permanent eye injury from direct and indirect viewing  62 ©Stanbridge University 2023 Laser Therapy: Purpose & Effects Produces physiologic responses in the target tissue- growth of tissues on a cellular level without the use of heat (biostimulative) Wavelength of: 400-700 nm stimulates myoglobin and hemoglobin 700-1200 nm stimulates mitochondrial cytochromes Light is absorbed into the cell’s mitochondria, setting off a cascade of biochemical reactions & physiological responses in the cells  63 ©Stanbridge University 2023 Laser Effects https://lightforcemedical.com/photobiomodulation-therapy-pbm Stimulates Cytochrome C ▫ Helps transport electrons Increases ATP production ▫ Energy Increases nitric oxide (NO) ▫ vasodilator Restores cellular energy balance ▫ Prevents cell death  64 ©Stanbridge University 2023 Light Force Laser- How it works  65 ©Stanbridge University 2023 Laser Therapy Wavelength shorter Wavelength longer Frequency higher Frequency lower More effective in superficial tissue More effective in deeper tissue Source: Bellew, 2016  66 ©Stanbridge University 2023 Laser Therapy (Wavelengths)  67 ©Stanbridge University 2023 How Does LASER Work? How does a laser work - Basics of laser technology - YouTube  68 ©Stanbridge University 2023 Laser Therapy Therapeutic use (Classes 3b-LLLT & 4- HILT) Helium Neon (HeNe)- red (632.8 nm) - LLLT ▫ Wound healing ▫ Absorbed.8mm and affects tissue up to 1 cm Gallium Arsenide (GaAs)- infrared (780-860→904 nm) –LLLT ▫ Great for RC tendonitis, lateral epicondylitis, carpal tunnel syndrome ▫ Absorbed 2-5 cm Neodymium-doped yttrium aluminum garnet (Nd:YAG) –HILT ▫ Arthrosis, cartilage, peri-articular tissue of joint, hematomas, tendinitis, bursitis, etc. ▫ 1-3kW  69 ©Stanbridge University 2023 Laser Therapy Advance for Physical Therapy and Rehabilitation- The Use of Laser Therapy in Rehabilitation, Michlovitz et al- Modalities for Therapeutic Intervention, 5th edition Low power cold lasers- maximum power cannot create a thermal response (Radiation) Low level lasers- max peak output ≤500mW ▫ Class 3 b High intensity lasers- max peak output >500mW (Radiation) ▫ Class 4 (10-15 W) ▫ Surgical cutting (300W)  70 ©Stanbridge University 2023 Laser Therapy: Physiological Responses of LLLT & HILT Increased production of ATP leads to increased cellular energy -i.e. increased fibroblast activity Increased cell proliferation (improved tissue healing- fibroblasts, endothelial cells, keratinocytes, macrophages, mast cells) Increased local blood circulation Muscle relaxation  71 ©Stanbridge University 2023 Laser Therapy: Physiological Responses of LLLT & HILT Improved cell membrane stabilization: alteration in flow of ions across cell membrane i.e. increased synthesis of endorphins, decreased C pain fiber activity, increased serotonin activity (enhances mood and helps with blood clotting), decreased bradykinin (inflammatory mediator, vasodilator) Leads to anti-inflammatory response Decreased pain  72 ©Stanbridge University 2023 Laser Therapy: Physiological Responses of LLLT & HILT Increased immune response increased activation of macrophages mast cells (wound healing) Increased DNA and RNA synthesis rate Reduced Prostaglandin E2 concentrations (PGE2 contributes to the inflammatory cascade)  73 HIT Laser Therapy: ©Stanbridge University 2023 Physiologic Responses and Special Considerations Michlovitz et al- Modalities for Therapeutic Intervention, 5th edition HILT benefits: heating of tissue + photostimulatory effects of LLLT Heat benefits (See thermal effects week 2) ▫ Dehydration of tissue ▫ Coagulation of protein ▫ Thermolysis ▫ Evaporation Application- Must always sweep the diode Must have intact sensation for hot/cold Research supported pathologies ▫ Trigger points for fibromyalgia ▫ Low back pain ▫ Subacromial pain  74 ©Stanbridge University 2023 LASER- Evidence HILT combined with exercise is effective in increasing II ROM and function and decreasing pain than exercise or sham HILT alone. Salaheldein et al., Laser Med Sci, 2014 I There was an improvement in upper extremity flexibility and pain with the use of HILT vs sham heat therapy. Panton et al., The J of Alt and Comp Med, 2013  75 ©Stanbridge University 2023 LASER- Evidence APTA Guidelines D Acute ankle sprains B Achilles tendinopathy C Plantar fasciitis Most of the APTA guidelines are older than Source: Bellew, 2016 the LASER research  76 ©Stanbridge University 2023 Laser Therapy: Indications Reduce Pain (acute, chronic) Decrease inflammatory response Improve healing time Stimulate immune system Improve wound healing Stimulate collagen production Increase tensile strength of the tissue repair Improve blood supply Improve nerve functioning  77 ©Stanbridge University 2023 Laser Therapy: Contraindications Contraindications HILT; Class 4; >5 W; 10-15W LLLT; Class 3b; ≤5W Direct eye exposure Direct eye exposure Pregnant/Over gravid uterus Pregnant/ Over Gravid uterus Malignancy/Irradiated skin last 4-6 months Malignancy/Irradiated skin last 4-6 months Active hemorrhage Active hemorrhage Over open growth plates Over open growth plates Uncontrolled epilepsy Uncontrolled epilepsy Over Thyroid/Endocrine glands Over Thyroid/Endocrine glands Photosensitive medication Photosensitive medication Infection/Fever Over vagus nerve, mediastinum, sympathetic ganglia  78 ©Stanbridge University 2023 Laser Therapy: Precautions Dark pigmented skin: will absorb energy more and has decreased depth of beam penetration Impaired sensation Impaired mentation Photophobia: increased sensitivity to light- watch for skin rash Diabetes- check sensation Over tattoos (absorb the light and heat more)  79 ©Stanbridge University 2023 Laser Therapy ADVANTAGES DISADVANTAGES Short treatment times Potentially hazardous to the eyes Can treat very small areas Equipment is expensive Non-contact method decreases Dosage guidelines are unclear risk of wound infection Not likely to be effective on devitalized tissue  80 ©Stanbridge University 2023 Laser Therapy: General Technique & Application Direct Contact Approach (LLLT) Indirect/Non-Contact Approach (LLLT & HILT) Sweeping Technique (LLLT & HILT)  81 ©Stanbridge University 2023 Laser Therapy: Light https://youtu.be/qd8iiqqGNE8  82 ©Stanbridge University 2023 Laser Therapy: Dosage & Frequency Most lasers on the market have a built-in menu that provides the appropriate treatment program Variable parameters documented in the current research WALT- recommended doses for LLLT (online) Pulse Frequency: Generally (Hz = Hertz = pulses/ second) : -Low frequencies (1-100 Hz): pain inhibition -Medium frequencies (500-1000 Hz): edema reduction -High frequencies (2500-5000 Hz): anti-inflammatory  83 ©Stanbridge University 2023 Laser Dosage and Frequency Dosage is reported in Joules Joule=1W/sec To calculate dosage, you must know: 1) The actual power of the machine 2) Is output continuous or pulsed 3) Number of laser diodes in the applicator 4) Area of each diode aperture 5) Time of irradiation per point **Lasers are typically preset for a safe intensity and time**  84 ©Stanbridge University 2023 Laser Therapy: Frequency Acute conditions: more frequent at lower doses Sub-acute conditions: every other day, 3x/week Chronic conditions: less frequent at higher doses; every 2nd day If no response after 2 weeks: re-evaluate use  85 ©Stanbridge University 2023 Light Force application with Roller ball  86 ©Stanbridge University 2023 Light Force Therapy Machine  87 ©Stanbridge University 2023 Light Force Application Additional videos can be found on the Chattanooga YouTube channel https://www.youtube.com/c/Chattanooga-RehabUSA/search?query=laser  88 ©Stanbridge University 2023 Laser Therapy: Response to Intervention & Modification Patient’s typically will not feel anything (LLLT) May experience mild warmth from the laser diode Rarely: tingling, buzzing sensation, pain, burning, nausea, fatigue  89 ©Stanbridge University 2023 Laser Documentation: Location Surface area treated Dosage (expressed in joules/cm2) Laser power (watts) multiplied by the treatment duration (seconds) Frequency and type of laser (i.e. HeNe 633 nm) Use mode (continuous or pulsed) Patient response to the tx  90 ©Stanbridge University 2023 Objectives At this point the student should be able to describe: Types of Laser Affects of light Physiological responses Indications, contraindications and precautions Advantages and Disadvantages Dosage and frequency