ch 16 1020

Objectives

• Definition Understanding:

  • Define lasers, light, and photobiomodulation (PBM).

  • Describe the effects of PBM on rehabilitation.

• Comparative Knowledge:

  • Compare and contrast different types of laser therapy.

• Adverse Effects:

  • Explain the adverse effects associated with PBM treatments.

• Technique Selection:

  • Choose the best treatment technique for PBM; list advantages and disadvantages of each.

• Equipment Selection:

  • Select appropriate equipment and treatment parameters for PBM.

• Documentation:

  • Accurately document treatment processes involving PBM.

Types of Electromagnetic Radiation

• **Sources of Electromagnetic Radiation:

  • Used for:**

  • Cooking, communication (radio, telephone), and various medical applications (e.g., cancer treatment).

• Classification:

  • Nonionizing (most types) vs. ionizing radiation (e.g., X-rays, Gamma rays).

Evolution of Terminology

• Terminology Change:

  • Low-level laser therapy (LLLT) is now termed Photobiomodulation (PBM).

  • PBM includes both laser and other light forms used in rehabilitation.

Photobiomodulation (PBM) Overview

• Nature of Light Used in PBM:

  • Electromagnetic radiation primarily in and around visible light spectrum:

  • Types of Light:

  • Polychromatic Light: Multiple colors, incoherent, non-directional.

  • Laser Light: Monochromatic, coherent, collimated (directional).

Historical Context

• FDA Approval:

  • 2002: FDA approves laser therapy for carpal tunnel syndrome (CTS).

• Other Approved Uses:

  • Sunlight therapy prior to PBM; ophthalmologists using lasers for retinal repairs.

Light Sources in PBM

• Types of Light Sources:

  • LEDs (Light Emitting Diodes): Multiple colors and lower power.

  • SLDs (Supraluminous Diodes): Higher power and narrower frequency compared to LEDs.

  • Lasers: More concentrated light, well-studied within PBM.

  • Cluster Probes: Contain multiple diodes (Laser, LED, SLD).

Properties of Electromagnetic Radiation

• Frequency and Wavelength:

  • Inverse relationship; essential for understanding the depth of penetration and therapeutic effects in rehabilitation.

• Intensity Considerations:

  • Nonthermally applied light aids in tissue healing, inflammation reduction, and pain control.

Wavelength and Biological Effects

• Chromophores:

  • Molecules in cells that absorb specific wavelengths of light; linked to cellular function and depth of tissue absorption.

• Diathermy and Light Types:

  • Different light types (e.g., Infrared (IR), red light) penetrate tissue at varying depths.

Power and Power Density in PBM

• Definitions:

  • Power: Rate of energy flow (measured in Watts).

  • Power Density: Power per unit area (measured in mW/cm²) during PBM treatment.

  • Laser Classifications: 1-4 based on safety and therapeutic application levels.

Energy and Energy Density

• Energy Measurement:

  • Total energy = Power x Time (Joules, J);

  • Energy density is crucial for determining treatment efficacy and dosage (J/cm²).

Physiological Effects of PBM

• Major Goals of PBM:

  • Facilitate healing through:

  • Enhanced ATP production.

  • Increased collagen synthesis.

  • Bromoglyphic effect on cell membranes and tissue regeneration.

• Mechanisms of Action:

  • Chromophores react to light; primarily affects mitochondria's cytochrome-C oxidase function.

Clinical Applications of PBM

• Indications:

  • Soft tissue healing, wound healing, and tendon recovery.

  • Bone healing (no changes in radiographs observed).

  • Pain management, arthritis therapy, and treatment of lymphedema.

Contraindications and Precautions

• Common Contraindications:

  • Eye irradiation, malignancy, radiotherapy history, burns, and thyroid conditions.

• Precautions:

  • Wait for epiphyseal plate closure in youth; impaired sensation could increase burn risk.

Adverse Effects

• Notable Adverse Effects:

  • Eye irradiation, burns (despite aiming for non-thermal effects).

Application Techniques for PBM

• Standard Application Steps:

  1. Assess appropriateness for condition.

  2. Confirm contraindications.

  3. Select proper diode and wavelength.

  4. Apply treatment with documented parameters.

  5. Goggles when using lasers.

Documentation Components

• Essential Elements to Document:

  • Type of diode, wavelength, total power, body area treated, and energy density.

Summary of Evidence in PBM

• Clinical Evidence Findings:

  • Significant effects noted in diabetic ulcers and rheumatoid arthritis, among endocrine indications.

  • Research to be expanded to validate long-term efficacy and establish treatment protocols.

Recommended Resources

• Resources for Further Study:

  • Includes videos, case studies, and relevant training materials related to laser and PBM applications for rehabilitation.