Modalities Ch. 20 Light Therapy Flashcards
how does laser work
light at specific wavelengths cause specific physiological responses in the body
lasers used as a therapeutic modality in physical medicine have a low power, typically 1 milliwatts (mW)
laser effects
photobiomodulation
stimulated tissue repair
decreased pain
photobiomodulation
the act of stimulating or inhibiting biological processes with light
mechanisms of action for photobiomodulation
excitation of electrical bonds to change molecular structure
excitation of atoms, creating greater movement and generation of heat
rotation of atoms, resulting in the generation of heat
stimulated tissue repair
numerous intracellular effects
enhanced ATP synthesis
decreased pain
decreased nociceptor response
what does the research say
still a “young” modality
not entirely decisive regarding mechanisms of action and effects
delivery technique
single vs cluster probe
laser probe should be in contact with the skin throughout the treatment
in cases of open wounds, the probe should be held <1 cm. away from the wound
single probe options
-grid application
-scanning
advantage of cluster probe
treat a larger area
disadvantage of scanning method
hard to know dosage each treatment area receives
wavelength determinant
-infrared
determines how deep the beam penetrates
-infrared lasers have the best penetration, thus achieving deeper absorption which is of great importance in treating muscle and joint pain types
tissue penetration and lasers
issue with the therapeutic use of lasers
light does not penetrate deeper than 5 mm into the tissue
dosage =
dosage = (average power x treatment time) / treatment area
dosage measure
j/cm2
average power
power output of the machine (in mW)
power output
fixed in the machine
the altered variable is time
new formula as a result of altering time
treatment time = (dosage x treatment area) / power
current recommended parameters for tissue repair
frequency: 630 nm
wounds: begin with 4 J/cm2; increase if not responding
soft tissue injury: 4-8 J/cm2 up to 3x/day
chronic: up to 30 J/cm2
current recommended parameters for pain control
frequency: 830 nm
treat from nerve root to site of pain to trigger points
10-12 J/cm2
trigger points: 10-20 J/cm2
other current recommended parameters
lower doses for acute, higher for chronic
lower doses for superficial, higher for deep