Laser Therapy A guide for chiropractors Dr. Rick Ruegg BSc,PhD,DC, is the Associate Dean of Clinics at the Canadian Memorial Chiropractic College. He can be reached at [email protected]. BioFlex: the probe (LDI 200) has a 180 mW, 830nm GaAlAs LD. The cluster has 179 840nm SLDs delivering 1500 mW over 75 cm². M Jessica Wong is a second-year student at CMCC. Having studied radiation therapy at the University of Toronto and the Michener Insti- tute, she greatly understands the importance of interprofessional health care. She may be contacted at [email protected]. any health-care professionals are investigating the use of laser therapy on their patients, as they recognize its untapped potential in the treatment of musculo- skeletal conditions. It has been more than 30 years since the initial reports on this form of therapy appeared, and, over time, studies have suggested its biological effects on injured tissue. With increasing research, as well as clinical utilization of laser therapy, chiropractors and students alike are curious about the effi cacy of this treatment modality. However, questions regarding how laser therapy works, on a biological level, the indications for its use, and instrumentation parameters continue to be asked. There are many elements of laser therapy that need to be explored before chiropractors and students can make an informed decision about this modality. BACKGROUND INFORMATION Low-level laser therapy (LLLT), commonly known as laser therapy or phototherapy, in- volves the application of light energy at specifi c wavelengths and power densities to pen- etrate into tissues and be absorbed by cells. The effect is not thermal, but instead related to photochemical reactions in the cells. These cumulative cellular benefi ts result in progres- sive improvements and sustained results. In comparison to other modalities, laser falls into the high-frequency (i.e., >10 000 Hz) range of modalities, much like ultrasound. Low-to- medium-frequency (<10 000 Hz) modalities include TENS, EMS, microcurrent and IFC. A number of research studies demonstrate the benefi ts of LLLT at a multitude of cellular levels. For instance, LLLT may play a role in stimulating growth factors and promoting an- giogenesis at the vascular level, while helping stimulate T-cells and lymph nodes at the im- mune level. Also, early studies are showing the effects of decreased edema in the lymphatic system and increased stimulation of osteoclasts in bone. Overall, these cellular changes, induced by laser, provide temporary relief of muscle and joint pain and increase tissue healing. To appreciate why this occurs, an understanding of the physics and mechanisms of laser is necessary. PERFICIAL LASER PHYSICS AND MECHANISM OF ACTION Laser therapy uses a form of electromagnetic radiation, which is energy that consists of photons travelling at the speed of light. Each photon carries energy in the form of a wave 16 • CANADIAN CHIROPRACTOR |FEBRUARY 2008 www.canadianchiropractor.ca Jessica Wong Rick Ruegg feature
Chiropractic + Naturopathic Doctor March 20008: Page 16
