lasers in physiotherapy

Question 1

laser stands for

Answer 1

Light Amplification by Stimulated Emission of Radiation

Question 2

Characteristics

Answer 2

⦁ monochromatic
⦁ polarized
⦁ coherent
⦁ collimnation (minimal divergance)

Question 3

Types of laser according to power

Answer 3

low energy and high energy.
⦁ up to 10 mW - for laser puncture
⦁ up to 25-75 mW - for laser therapy

Question 4

types of laser according to regime

Answer 4

pulse mode and continuous mode

Question 5

how do lasers stimulate cells

Answer 5

⦁ light is absorbed
⦁ if sufficient energy is absobed there is a change in cell membrane permiability for calcium uptake
⦁ ATP synthesis is increased
⦁ cells are mobilised and energised

Question 6

how do certain wavelengths stimulate certain cells?

Answer 6

⦁ red light: is absorbed by mitochondria therefore red light seems to stimulate all healing cells (growth factor)
⦁ invisible light: is absorbed diectly through the cell wall. for invisible light to be absorbed the cell must have the correct receptors (chromophores).

Question 7

Laser effects on tissues

Answer 7

⦁ biostimulation- acceleration of healing
⦁ anti-inflam and anti-edematous effect- strong importance in acute conditions
⦁ analgesia
⦁ thermal effects- local microcirculation is increased

Question 8

how does laser light cause biostimulation

Answer 8

⦁ mitochondria RNA replication
⦁ replicatoin of mitochondria
⦁ increased ATP prodcution
⦁ nuclear DNA synthesis (couldnt make out the last word because a picture covered it on the lecture slide

Question 9

process of biostimulation by laser light

Answer 9

⦁	mitochondria RNA replication
⦁	replicatoin of mitochondria
⦁	increased ATP prodcution
⦁	nuclear DNA synthesis (couldnt make out the last word because a picture covered it on the lecture slide
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Question 10

how does laser light cause antiinflamm effect

Answer 10

⦁ stimulation of immune cells: polymorphonuclear neutrophils proliferation and monocyte activation
⦁ reduction of prostaglandin E2 (PGE2)
⦁ support prostacyclin (PCI2) secretion

Question 11

how does laser light cause analgesia

Answer 11

⦁ inhibit nociceptor - C fibers

⦁ elevate beta endorphin levels

Question 12

Physiologic effect of lasers

Answer 12

⦁	increased growth factor response
⦁	increased ATP synthesis
⦁	increased cell prliferation/motility
⦁	increased angiogensesis
⦁	matrix remodelling enhanced:
⦁	modulation of metabolism of neurochemicals i.e. serotonin and endorphins
⦁	reduced nociceptor activity

Question 13

how does high intensity laser- produce an analgesic effect with the photochemical wave

Answer 13

⦁ wavelength near to 1000 nm + power over 5W in pulsed mode with very short pulses = creation of photochemical wave in tissue
photochemical wave in tissue:
⦁ reaches subcutaneous pain receptors
⦁ mechanically stimulates A-fibers
⦁ activation of A-fiber path inhibits nociception via gate control “melzack” mechanism
⦁ supported with endogenous opioid release
⦁ immediate and long lasting pain suppresion

Question 14

what are the thermal effects of high intensity laser

Answer 14

⦁ thermally induced micro circulation increase
⦁ local vasodialation =
⦁ edema reduction
⦁ metabolism support

Question 15

indications (7)

Answer 15

⦁	wounds
⦁	degenerative and inflam disorders
⦁	traumatic injuries- especially with delayed fracture healing
⦁	neuritis, herpes zoster
⦁	skin- neurodermatitis, herpes simplex
⦁	inflam gynecological diseases
⦁	dental disorders

Question 16

contraindications

absoloute

Answer 16

⦁ eye area- possible retinal damage
⦁ tumourous diseases
⦁ irradiation of endocrine gl.
⦁ tattoos, freckels

Question 17

relative contraindications

Answer 17

⦁	epilepsy
⦁	patients with febrile conditions
⦁	pregnancy
⦁	photosensitive medication
⦁	cortisone injection
⦁	metalic implants

Question 18

special precautions (3)

Answer 18

⦁ all patients must be evaluated according to the Fitzpatrick scale
⦁ the more pigment in the skin the more aborption/heating
⦁ grade V, VI must be treated with special precauriuons