Musculoskeletal: laser therapy
Synonym(s): Low level laser therapy, LLLT, Photobiomodulation
Podcast: Musculoskeletal: laser therapy
- Low-level laser therapy (LLLT) has been a popular modality in the physiotherapeutic management of musculoskeletal injuries and skin wounds in humans, dogs and horses, with scientific literature available in both the human and veterinary fields.
- In 2012 the World Association of Laser Therapy (WALT) and the North American Association of Light Therapy (NAALT) adopted the nomenclature Photobiomodulation (PBM) to be used as the term for LLLT.
- High-power lasers (>0.5 Watts) are used in the veterinary field for both surgical and physiotherapeutic applications.
- Low-power lasers (<0.5 Watts) are only used in superficial physiotherapeutic applications such as the management of wounds.
- Laser therapy uses light wavelengths of between 600 and 1200 nm with unique properties of a single wavelength (monochromatic), waves in phase (coherence) and collimation (waves in parallel). As a result, it can deliver large amounts of energy to a small region over a short period of time.
- Wavelength determines the depth of penetration within the tissue and the power (in Watts) determines the number of photons that reach that depth.
- The proposed theories of action include: stimulation of cytochrome and mitochondrial respiratory activity resulting increased ATP production, the release of nitric oxide and reactive oxygen species; plus numerous virtual biochemical cascades of events concluding in a state of analgesia, a modulation of the inflammatory cycle and an increase in circulation.
- The energy density that is applied (J/cm2) as well as the specific tissue upon which it is targeted is important in measuring the effect of laser treatments.
- There is literature demonstrating that He-Ne or GAA diode lasers accelerate wound healing, modulate the inflammatory reaction and provide analgesia.
- Wounds Wound: types - overview especially those healing by second intention Wound: healing - second intention. In the human field they are used in treating pressure skin sores.
- Resolution of bruising and edema.
- Tendon and ligament musculoskeletal injuries Carpus: intercarpal ligament (MPICL) - trauma Flexor tendon: trauma Tarsus: trauma - collateral ligament Common digital extensor tendon: rupture Deep digital flexor tendon: tendinitis Extensor tendon: trauma Flexor tendon: trauma SDFT: luxation SDFT: tendinitis.
- Pain relief in chronic musculoskeletal conditions such as osteoarthritis Musculoskeletal: osteoarthritis (joint disease).
- To stimulate acupuncture and trigger points avoiding the use of needles. Laser acupuncture has been described using multiple wavelengths and with settings both in continuous wave and at frequencies.
- Time-efficient, non-invasive, non-pharmacological anti-inflammatory treatment.
- The exact parameters for treating individual types of problems are not very clear.
- Repeated treatments are required to achieve long-lasting effects.
- Costs of the machine.
- Lasers can be dangerous, particularly to the eye (retina) of the operator, patient or handler. Protective eyewear is a must when using any Class III or Class IV laser!
The beam of an infrared laser is invisible making it even more potentially dangerous.
- Physiotherapist requires an understanding of the science behind LLLT (PBM) and training in proper application techniques.
- Low Level Laser: the substance which is used to generate the laser determines its wavelength and can include helium neon (HeNe) 632 nm, gallium arsenide (GaAs) 904 nm and gallium-aluminum-arsenide (GaAlAs) 820 nm. Most therapeutic lasers are diode lasers.
- Results from equine research suggest that, when applying laser to a subcutaneous structure in the horse, the area should be clipped and cleaned beforehand to improve penetration of the laser beam.
- Use of alcohol without clipping was not associated with an increase in light transmission.