LASER

Terminology:o LASER (Light Amplification by Stimulated Emission of Radiation(o LLLT( Low Level Laser Therapy)o LILT ( Low Intensity Laser Therapy).

Def.: laser light is a form of electromagnetic wave having : wave length, frequency and velocity.Characters of laser radiation: • Unidirectional• Coherence ( temporal and special)• Monochromaticity ( same color).• Highly polarized.

it’s medical use is relatively recent.

Types: according to depth of penetration & heat production:1. High power laser: use for destructive or surgical

purposes (cautery), produce significant heating of tissues e.g. (co2 laser)

2. Soft ( low power laser): used for treating the skin (upper layer of dermis), produce very superficial effect e.g. ( helium laser).

3. Mid laser: used for deeper tissue effect, produce deeper effect than IR without producing significant heating of the superficial layers of the skin e.g.( infra red laser), used by physiotherapist as their depth of penetration sufficient to produce their effect on deeper tissues ( ≈ 30 – 35mm for IR laser)

How a laser beam is produced:Stimulation of atoms of certain elements by electromagnetic radiation produce electromagnetic radiation themselves of (particular freq. & wave length).Characters of any radiation depend on • Direction• Wave length • Frequency.• Color.Differ according to medium used

Mode of action of mild laser:Benefits of mild laser are due to :o Heat production:ᴥ- relief pain by ↘ ncv and ++ endorphin release.ᴥ- ↗ blood & lymph flow ( remove waste products).o Chemical effects:ᴥ- by ++ of mitochondria → transformation of laser energy into chemical energy in the form of ATP which is used by mitochondria.o Biological effects:ᴥ- anti-inflammatory effect.acceleration of tissue repair ( stim. Collagen healing).o Physical effect:ᴥ- physical chondroprotection by chondrocytes stimulation

Nerve conduction velocity

Mode of applic:• Direct contact with the pt. skin: each point

( 3 – 5 cm), as in tennis elbow.• At distance, for large area, as LBP (30 cm), open

skin wounds, keloid “precaution of hazard of reflection”.

Indications:1) Pain relief.2) MSK & Rheum dis. (painful condition).3) Wound healing, in various type of open wounds.4) Laser acupuncture Laser acupuncture

precution: Wearing of protective glasses by therapist & the pt.Avoiding reflecting surfaces with the beam (mirrors, polished floors). Risk of retinal injury.Be sure that the pt. doesn't have pacemaker. Side effects:Sever erythema & eruption may occurs. Contraindication:Photosensitivity - Infection – tumor - hemorrhage susceptibility - pregnancy - non cooperative pt.