Laser therapy (light amplification by stimulated emission of radiation)
Laser light is of a single wavelength and occupies a specific place on the light spectrum emitting a single colour of light. The light from a laser is said to be coherent where the components of the light are aligned enabling the laser to be focused allowing the laser beam to stay narrow over long distances. They are used in many applications from optical disc drives, fibre optics, for cutting and welding and military applications. There are also used in medicine for laser surgery and various skin treatments. Low-level laser therapy (LLLT) has been used for some time to improve tissue repair and there is an increasing body of evidence to support these claims. These include skin wounds and ulcers, muscle, tendon, nerves and bone healing. It has been shown to be effective in reducing inflammation and pain wherever the beam is applied and is usually administered by a doctor or trained therapist.
The beneficial effects of LLLT have been reported in the “BMJ Sports Medicine Journal”, the “American Physical Therapy Association Guidelines”, “The Lancet” and there are many other medical papers written in favour of the use of LLLT.
How Laser therapy works
Most people, if asked what cells in the body respond to light would immediately name the eyes, probably would mention the skin and the fact that it turns coloured with the action of sunlight however, many of the cells in the body will react to light stimulation of particular wavelengths. Research to date would seem to favour light in the red or near infrared spectrum. The mechanism involves stimulation of a protein in the cells “power supply” or mitochondria resulting in a chemical cascade that leads to improved tissue repair and reduced inflammation. Application of higher power density can result in analgesia or pain relief. The intensity of LLLT lasers is not high as in surgical lasers and there is little heating effect, however as light energy is being imparted to the tissue absorption of that energy will result in some mild heating effect.
The effects of laser may be enhanced by pulsing, (although there is debate on this point), but it is suggested that lower pulse rates are best used for acute conditions while higher pulse rates work better for chronic conditions, however when pain relief is required this would seem to favour a strong continuous beam of light. The beneficial effects of LLLT are dose dependent and the appropriate dose must be applied to achieve the desired affect, in summary low-power densities to achieve better healing and anti-inflammatory effects and higher power densities for an analgesic effect.
Further reading on the use and effectiveness of Low Level Laser Therapy (LLLT) may be found from laser equipment manufacturers or Prof Tim Watson, School of Health and Social Work, University of Hertfordshire, UK.
Contraindications
There are very few contraindications for use of LLLT, and may be viewed more as cautions and commonsense than contraindications.