Modalities Ch. 20 Light Therapy

Question 1

how does laser work

Answer 1

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)

Question 2

laser effects

Answer 2

photobiomodulation
stimulated tissue repair
decreased pain

Question 3

photobiomodulation

Answer 3

the act of stimulating or inhibiting biological processes with light

Question 4

mechanisms of action for photobiomodulation

Answer 4

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

Question 5

stimulated tissue repair

Answer 5

numerous intracellular effects

enhanced ATP synthesis

Question 6

decreased pain

Answer 6

decreased nociceptor response

Question 7

what does the research say

Answer 7

still a “young” modality

not entirely decisive regarding mechanisms of action and effects

Question 8

delivery technique

Answer 8

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

Question 9

advantage of cluster probe

Answer 9

treat a larger area

Question 10

disadvantage of scanning method

Answer 10

hard to know dosage each treatment area receives

Question 11

wavelength determinant

-infrared

Answer 11

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

Question 12

tissue penetration and lasers

Answer 12

issue with the therapeutic use of lasers

light does not penetrate deeper than 5 mm into the tissue

Question 13

dosage =

Answer 13

dosage = (average power x treatment time) / treatment area

Question 14

dosage measure

Answer 14

j/cm2

Question 15

average power

Answer 15

power output of the machine (in mW)

Question 16

power output

Answer 16

fixed in the machine

the altered variable is time

Question 17

new formula as a result of altering time

Answer 17

treatment time = (dosage x treatment area) / power

Question 18

current recommended parameters for tissue repair

Answer 18

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

Question 19

current recommended parameters for pain control

Answer 19

frequency: 830 nm
treat from nerve root to site of pain to trigger points
10-12 J/cm2
trigger points: 10-20 J/cm2

Question 20

other current recommended parameters

Answer 20

lower doses for acute, higher for chronic

lower doses for superficial, higher for deep