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Seeing the Light
Monday May 9, 2011
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Low-energy lasers play a role in treating pain and repairing tissue in combination with other standard modalities. So why are lasers still misunderstood and overlooked by physical therapists?

A self-described skeptic of new modalities, Todd Forman, PT, president of Integrative Therapeutics, Natick, Mass., embraced laser technology only after he experienced the benefits firsthand. During a course on lasers, a presenter asked for a volunteer with musculoskeletal issues. Forman raised his hand because he had persistent hip pain, despite a full course of therapy and some acupuncture. “Within 15 minutes of laser treatment, my hip pain was gone, and it has not returned,” Forman says. “I did not become a ‘believer’ at that point, but the experience sure got my attention.”

Forman is part of a small but growing group of therapists using low-level laser therapy, or phototherapy, for reducing pain and inflammation, and healing wounds, muscles and nerves. Even though low-energy lasers have been around for more than 40 years, they have not been widely integrated into physical therapy curriculums and rarely are covered in the field’s literature.

Skepticism about the therapeutic value of LLLT still persists. Some studies report inconclusive research or conflicting evidence, with many primary studies having poor design and controls, says Joseph Kleinkort, PT, MA, PhD, past president of the pain management special interest group of the American Physical Therapy Association’s orthopedics section.

“There remains a tremendous amount of confusion ... because there are so many different kinds of lasers, which often get mistaken with LEDs, which are far less effective,” Kleinkort says.

Low-energy lasers have gained interest since the U.S. Food and Drug Administration approved several systems. In 2002, the FDA cleared the first laser for treatment of pain associated with carpal tunnel syndrome (MicroLight), and chronic neck and shoulder pain (Erchonia).

“Frankly, PTs have not taken the time to review and study all the current literature that provides the evidence for phototherapy,” says Peter Douris, DPT, EdD, associate professor at New York Institute of Technology. “It will take more continuing education emphasizing the current evidence and the proper way to use them before they are widely adopted.”

Cold Lasers

Unlike hot lasers, used mostly for cutting or burning, LLLT or cold lasers do not emit heat, sound or vibration. The technology generates light from a single wavelength to create a nonthermal, photochemical reaction. Cold lasers enhance cellular repair and healing by stimulating collagen production and altering DNA synthesis.

Several theories have been put forth as to the underlying biological mechanism of LLLT. One suggested reaction is enhancement of adenosine triphosphate production in the mitochondria. Other theories include increased oxygen consumption on the cellular level that results in muscle relaxation and greater anti-inflammatory effects through reduced prostaglandin synthesis.

Despite many success stories of patients miraculously responding to laser treatment and overcoming years of pain and suffering, there still are many patients who do not respond to the therapy.

“There are many potential reasons for nonresponse to lasers, such as nutrition, lifestyle and other medical conditions, but we don’t really know for sure why some patients don’t respond,” says Chukuka Enwemeka, PT, PhD, dean, college of health sciences, University of Wisconsin, Milwaukee.

If LLLT doesn’t work in two to three treatments, then move to another modality, Kleinkort suggests. Rather than being used by itself, lasers should be combined with other manual therapies and regimens, he says.

Anne Ingard, PT, of Natick, Mass., agrees lasers are not a panacea, but she says lasers have been the most helpful modality in accelerating healing and decreasing pain quickly. “I felt that I was competent using the laser after three seminars, watching videos and treating patients for about six months,” she says.

Ingard was trained by Kleinkort, who has tested nearly 50 lasers, including light-emitting diodes and superluminous diodes. He admits it can be bewildering to know which laser to choose based on wavelength, fluence, power density, pulse structure and treatment timing. However, he recommends using a dual-diode, 5-milliwatt laser with a wavelength of 635 nanometers that can be pulsed. Low-energy lasers can cost as much as $50,000 to $80,000, but the majority are less than $15,000. The biggest risk with lasers is eye exposure to the light, which can be avoided with proper eye protection, Kleinkort says.

Best Targets

Lasers are being used for conditions and injuries such as Achilles tendinopathy, arthropathies, burns, bursitis, carpal tunnel syndrome, cervical and lumbar radiculopathies, fractures, headache, lymphedema, neuromuscular dysfunction, strains and sprains, scar tissue, tendonitis, TMJ, and wound healing.

A meta-analysis led by Enwemeka examined the literature for effect of LLLT on both tissue repair and pain. The study found positive results and reported that a laser with a wavelength of 632.8 nm had the best treatment effect.

Researchers have spent a great deal of time studying LLLT for pain management, which might be the greatest benefit of low-energy lasers. A study in the December 2009 Lancet showed LLLT reduces pain immediately after treatment in acute neck pain and up to 22 weeks after completion of treatment. And the International Association for the Study of Pain found solid evidence for LLLT on myofascial pain syndrome.

Enwemeka and his colleagues examined 22 articles and published the results in the October 2010 Clinical Journal of Pain. The authors concluded: “Phototherapy effectively relieves pain of various etiologies; making it a valuable addition to contemporary pain management armamentarium.”

One randomized study, reported in the September 2010 Journal of Orthopaedic & Sports Physical Therapy, found that patients treated with LLLT in combination with exercise versus a placebo group noted less perceived pain during a 12-week period. The intervention group also reported reductions in tenderness to palpation, crepitation, morning stiffness and improvement in active dorsiflexion ROM.

APTA’s clinical practice guidelines recommend LLLT for decreasing pain and stiffness in Achilles tendinopathy. However, the association noted more research is needed. •

Paul Wynn is a freelance writer.

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Monday May 9, 2011
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