We can now tell you, having recently attended a mind boggling day listening to the latest research by world leaders in the field at the Brain and Mind Research Institute at Sydney University.
The one sentence answer is that low level laser has an anaesthetic effect on nerve fibres that transmit pain, reduces inflammation and stimulates the lymphatic and circulatory systems that assist in the healing process. If you want to know more please read on.
Light therapy (phototherapy) has historically been used in medicine, with blue light to treat jaundice and staph infection, ultraviolet light to treat the skin condition psoriasis and visible light to treat seasonal affective disorder. Phototherapy using Low level laser therapy (LLLT) is used in the treatment non-healing ulcers, lymphedema (diffuse tissue swelling) and painful musculoskeletal disorders and offers a safe alternative to anti-inflammatory and analgesic medication.
LASER is an acronym for Light Amplification by Stimulated Emission of Radiation and is generated by simulating a medium with high intensity electrical stimulation such as a crystal, gas or diode to generate photons (light particles and waves). Laser is emitted as a single coherent (aligned) wavelength which enables it to penetrate the skin and gives it its unique therapeutic effects.
The term cold laser is used to describe low level laser that does not produce heat. This is very different to high powered laser used in surgery and for laser eye surgery where therapeutically managed destruction of tissue occurs.
There are a variety of different types of cold lasers from visible to invisible and including infrared and helium-neon lasers, some with continuous wavelengths and some are pulsed. The wavelengths typically in use in physiotherapy range from 520nm to 904 nm. Each type has its specific therapeutic effects depending on its power and wavelength and how it is applied. Laser can have a stimulatory and inhibitory effect on the tissues depending on the wavelength used. Laser has a variety of therapeutic effects including reduction of pain and inflammation, stimulation of the circulatory and lymphatic systems and increased speed of wound healing in skin and bone.
To be effective Laser needs to be absorbed in the tissues and cells. The mitochondria, which are the power house of our cells that drive energy production, emit biophotons (naturally occurring light waves and particles) in a similar range of wavelengths to that of the therapeutic wavelengths of cold lasers. Mitochondria absorb light via chromophores in the cell membrane and are the primary site of laser absorption. When the mitochondria are under stress from illness or injury they can be stimulated with laser to enhance their function. In this way we are treating a light emitting cell with light of a similar wavelength to restore normal function.
Laser has an anaesthetic effect on the pain sensitive nerve fibres that transmit pain sensation. Laser specifically inhibits nerve impulses generated by harmful stimuli, such as heat, mechanical force or chemical irritation from inflammation, via specific nerve fibres at the nerve pain receptors. We now know that laser can slow nerve conduction for between 10 min and 24 hours, and that this has a cumulative effect as the cells regain their normal function. Increased levels of the neurotransmitters serotonin and β-endorphins associated with pain relief, have been shown with trigger point treatment using laser. Trigger Points are sensitive nerve endings in muscle and can be a source of referred pain remote to the site of the trigger point. The International Association for the Study of Pain Myofascial Pain fact sheet (IASP, 2009) states that laser therapy is an evidence based treatment for painful trigger point.
There is a growing body of evidence to show how laser in the range of 830nm -904nm can effectively treat both acute and chronic painful conditions. Laser applied to the skin not only affects the peripheral nerve in the injured body part, but also affects the nerve at the spinal cord level, which is important for long term pain and stress reduction. Laser in the 1064nm wavelength is now used in dentistry for drug free anaesthesia and can last for up to 45 minutes. The longer term pain relieving effects of laser are associated with a reduction in inflammation and swelling. Stimulation of tissue healing and may occur in days to weeks of intervention and last months to years. Managing acute pain well is critical to avoiding the development of chronic pain and the subsequent sensitisation that occurs within the peripheral and central nervous systems that perpetuate pain perception.
The anti-inflammatory effects of laser are a significant contributor to pain relief achieved with LLLT. Reduction in inflammatory markers, such as PGE₂, substance P that sensitise peripheral nerves, have been shown in animal and human studies using LLLT as well as the stimulation of the healing response with increased levels of neutrophils and macrophages necessary for tissue healing. The latter part of this process is the final stage of healing necessary for long term pain relief.
The lymphatic system works with our circulatory systems and its function is critical in the healing response and to reduce swelling which causes pain and limits mobility. Congestion in the lymphatic system via muscle spasm or damage to the delicate lymphatic vessels can cause widespread pain in the body. Studies show the efficacy of 904 nm laser in the treatment of lymphedema in the arm in breast cancer patients in reducing swelling with continued benefit several weeks after the intervention.
Use of the Handycure Laser at Joint Health
At Joint Health the laser is used predominantly to treat trigger points, which are sensitised nerve endings in a taut area of muscle, and nerve entrapments in soft tissue.
The Handycure laser incorporates three different types of photherapeutic light with variable and continuous frequencies to cover a range of therapeutic wavelengths, and is coupled with a magnetic field which enhances these effects. Because of the combination of multiple laser types in the one device the Handycure laser is suitable for the treatment of arthritis, wound healing, inflammatory conditions, and pain relief in acute and chronic conditions. Settings can be altered to target tissues at a range of depths.
Side effects and warnings
The only danger of LLLT is to the eye and great care must be taken in ensuring the beam does not reach the eye directly or via reflection on a surface. The laser should only be turned on when in contact with the skin. Goggles may be worn for added protection of therapist and patient however this is not necessary in the class 1 laser we use.
Extra care should be used when using laser over dark hair or skin as a heating effect can occur.
While there is no evidence that laser is harmful during pregnancy the old adage “if in doubt leave it out” should probably apply here as a precaution.
The Handycure laser has a magnetic therapy modality and can’t be used on people with cardiac pacemakers. Other lasers without this modality can be used safely in these people.
The Handy Pulse laser has approval in Australia for personal use and retails for approximately $500. Some of our clients with chronic pain issues have found this a helpful was of managing their symptoms with guidance from their physiotherapist. The Handy Pulse laser can be purchased from Pulse Laser Relief
- Chow, R (2013) Low level laser therapy in the treatment of pain. Chapter 51 in Hamblin MR and Huang Y.Y . Handbook of Photomedicine . CRC Press.
- Myofascial Pain Fact Sheet The International Association for the Study of Pain (IASP, 2009)
- Laser therapy making light of hidden pain Financial Review, July 23, 2014