Lower Intensity Laser Treatment for Plantar Faciitis


BY:
Linda Jones, Ph.D., Department of Physics, College of Charleston, JonesL@cofc.edu

.R. Basford and coworkers from the Department of Physical Medicine and Rehabilitation at the Mayo Clinic in Rochester, MN conducted a randomized, double blind, placebo-controlled clinical study to determine the effectiveness of low intensity laser treatment for plantar fasciitis. The results were published in the Archives of Physical Medicine and Rehabilitation in March 1998 (see: abstract). Thirty two patients suffering from plantar fasciitis for at least one month were given dummy treatment or irradiated with a 30-mW 830-nm laser three times per week for four weeks. There were no significant differences between the groups during the treatment or at the one-month follow-up.

More recently, Melanie McManus described her personal four-week treatment for plantar fasciitis in the August, 2007 issue of Runner’s World (see: article). She reported that after just one laser treatment, she was able to use an elliptical machine and run without pain. The article does not give the wavelength, power, or energy of the laser treatment so it is not possible to compare her experience with the results of the peer-reviewed article mentioned above. Although the author credits her dramatic improvement to the laser treatments, it is not possible to know whether her improvement was due to the placebo effect, from her four month layoff from running, or from the laser treatment.

Some LLLT devices have been approved by the FDA. The approvals cover both safety and efficacy. The Microlight 830, which emits near infrared radiation at 830 nm, was approved in 2002 for treatment of carpal tunnel syndrome. Other approvals followed for similar devices that emit near infrared radiation. Each approval is for treatment of a specific medical condition. Unlike an infrared heat lamp, these lasers do not cause tissue heating. They work through a photochemical reaction.

Why are LLLT devices considered experimental if they have been approved by the FDA? The studies that were used by the companies to obtain FDA approval sometimes do not demonstrate results that are convincing to insurance companies. The supporting study for the Microlight 830, for example, reported the following:
Treatment was considered successful if a patient showed a 30% or more reduction in
VAS pain score at the 12-week follow-up point. The MicroLight laser successfully
treated 55.8% of the patients in the active group, compared to 40.0% success for
patients in the placebo group.
Insurance companies review the FDA approval studies and other reports in the peer-reviewed literature and then decide whether the treatment is valid for specific medical conditions. For example, see these reports from: Washington State Dept of Labor and Industries and Cigna Healthcare.

The field of LLLT has been controversial. The scientists and physicians who carry out LLLT research are learning to control variables and design better studies so that their results will be acceptable to the medical community.

A number of reputable research groups have demonstrated significant biological effects from LLLT. Scientific studies generally include control groups as well as information about the wavelength, power, and energy of the laser. Scientific studies have a measurable outcome in addition to a subjective outcome such as pain perception. You can search for peer-reviewed articles on the National Library of Medicine website. For example, you can enter the search terms “plantar fasciitis and laser”. The site will provide abstracts of related articles at no charge. You can usually go to the website of the individual journals to order the full text of the articles.

Nature published an article in October 2006 describing a potential mechanism of interaction that could explain the biological effects of LLLT (Lane N, 2006, Cell biology: Power games, Nature 443:901-3.) in which the author says “Light has long been known to promote wound healing, but the detailed molecular mechanisms have only recently been studied.” Evidence is presented that red or near infrared light may be able to relieve chronic inflammatory conditions. Studies may eventually show that LLLT is effective for some sports injuries. This will be an interesting area to watch in the coming years.