Checking Pain Options

In the constant quest to get athletes back on the court, field, or rink more quickly after a punishing hit, a new player has entered the arena. Called infrared light therapy, several teams are experimenting with this new treatment option.

By David Hill

David Hill is an Assistant Editor at Training & Conditioning.

Training & Conditioning, 12.7, October 2002,

When members of the Phoenix Coyotes are suffering from contusions, strains, and sprains and feel like they can’t make the next game, they get ice just like any other player coping with life in the National Hockey League. But if that doesn’t ease the pain enough, they may also get treated with light.

Since September 2001, the Coyotes’ athletic training staff has added infrared light to the modalities it calls upon for treating soft-tissue wounds, muscle soreness, and stiffness. The treatments, conducted with devices that produce a steady flow of invisible infrared light through a light-emitting diode, haven’t replaced more traditional and established modalities. But the players like infrared, and it seems to work, says Head Athletic Trainer Gord Hart, ATC.

“We feel we saved numerous man-games because players have been able to get back and play a little bit faster than what we initially anticipated,” Hart says. “We’ve gone from players being very uncomfortable to coming in the next day being able to skate right away. We don’t know whether that’s from the athlete overplaying the severity of the injury or not, but we’ve had some pretty good results.”

Since it was approved by the Food and Drug Administration for the treatment of musculoskeletal pain in 1999, diode infrared therapy has taken off in the United States. Research, much of it from Europe and Asia, has suggested that light at certain frequencies in the infrared spectrum can hasten the healing of many types of wounds. The technology has showed promise in soft-tissue wounds that are common in athletics, including contusions, lacerations, muscle tears, and chronic conditions, such as soreness and tendinitis. Manufacturers, coupling that with developments in semiconductor diode technology, have sought and received approval from the FDA to market their devices, developed protocols, and brought a variety of products to the market.

Many companies first targeted certain allied health professionals, particularly physical therapists. But they have begun turning to athletic trainers with the promise of a relatively simple, efficient modality that can help get athletes back in action quickly.

The word “infrared” is hardly foreign to athletic trainers. It’s in most modalities texts and course syllabuses. But the term usually refers to a source of heat, as in the high school physics description of infrared energy as “heat waves,” typically delivered by electric lamps. The new crop of devices, also called photonic stim, is instead based on harnessing the effects of the light waves themselves and grew out of research from the early 1970s on the effects of infrared lasers.

Lasers were coming into their own as a way of surgically cutting and cauterizing, but many scientists noticed that if the power were greatly reduced, laser light seemed to benefit tissue rather than burn it. Light in the infrared spectrum seemed to have the most positive effects, and the field of low-level laser therapy was born. There’s even an international association for it, the World Association of Laser Therapy.

Lasers are expensive and, even at low power, must be used carefully. As a result, researchers turned to less-expensive light-emitting diodes as an alternative to lasers. NASA, interested in any potentially effective, simple, and compact therapy for use during space flight, sponsored studies. One participating scientist was Harry Whelan, MD, of the Medical College of Wisconsin. Whelan noted that diodes are less expensive, can more easily produce a wide range of wavelengths, and can radiate light on larger wounds than lasers can. Whelan and his colleagues studied the effects of treating Navy SEALS with infrared light from semiconductor diodes and found the devices promising. In addition, lacerations to submarine crews treated with infrared diode therapy healed up to 50 percent faster than without it, according to papers Whelan and colleagues have published.

As for the mechanism behind infrared action, explanations abound. In promotional materials, manufacturers point out that light-triggered biological phenomena are ubiquitous, from photosynthesis in plants to tanning and vitamin D synthesis in humans. Whelan, among other scientists, has written that infrared and near-infrared light penetrates skin more deeply than visible light, and that its energy is absorbed by mitochondria to stimulate metabolism.

Other studies have indicated infrared also increases ATP levels, vascularity, white blood cell activity, collagen production, and blood capillary circulation, says Rick Breden, Executive Vice President of BioScan, a New Mexico company that sells infrared-treatment equipment. “Those are the main effects that we know about and there are other things going on because the science is still pretty new in the understanding of light energy. Basically, the light gets into the cell and creates a photochemical response that leads to all these great things.”

Whatever the mechanism, infrared therapy seems to help athletes in sports from ice hockey to baseball, and track and field to skiing. Bob Toth, ATC, Assistant Athletic Trainer at the University of Utah responsible for skiing and baseball, says a regimen of treatments with an infrared diode device appears to have made the difference for two Utes skiers who had left their national teams because of knee pain. “One fellow was diagnosed as having a partial patellar tendon tear, and the other as having quadriceps tendinitis.

“I have a feeling that this modality had a positive effect on them,” Toth says. “I know what they went through with all their rehab, and almost all the variables were the same. The only difference was that I added the photonic stim.”

In the case of the skier with the partial patellar tendon tear, Toth theorizes that infrared stimulation increased blood flow to the tissue. “We know that when you get a partial tear, one of the problems is you get a little bit of ischemia, but after the photonic stim, the fellow’s up skiing with the U.S. national team at Mount Hood.”

Hart’s hockey players, too, have gotten back into training and competition more quickly than he’d have expected using other modalities. “Most kinds of injuries are contusions—being hit in the foot with the puck, getting a charley horse on the outside of their thigh, or getting cross-checked in the ribs,” says Hart. “In the past, they’d come out of the game, and we treat them, knowing that they might not be able to skate or play tomorrow. Now, they come in the next day and they’re able to go. They really feel that improvement is directly attributed to the initial infrared application.”

Hart says players often ask for infrared treatment. “The way professional sports works, if one person believes in it, then generally everybody’s going to follow. And we’ve seen some pretty good results with it.”

Dean Clark, DC, a sports chiropractor in Portland, Ore., who has worked with the U.S. national track and field team and two Portland-area colleges, has found infrared diode treatment effective for chronic sore muscles, contractive muscle spasms, sprains and strains, low-back pain, and shoulder nerve and muscle pain. It’s most effective, Clark says, on conditions involving nerve irritation or inflammation.

“When you have any condition, whether it be an inflammation, an injury, a chronic problem, the nervous system is involved,” Clark says. “What this does is send a message to the nervous system to normalize. It tells it to get back to its normal function. If it’s got too much nerve flow, it’ll shut it down. If it’s got not enough nerve flow, it sends the message down the nerve pathway, ‘Hey, get this started. Let’s change this pathway. Let’s get it moving again.’”

Using the new infrared devices is comparable to using ultrasound and electrical stimulation equipment. Typically, a wand is held to the affected area, though the products of at least one manufacturer, BioScan, are designed to be strapped on. Its BioPatch consists of an array of flat diodes attached to flexible brace-like material, for example.

Protocols developed by manufacturers typically involve treatments of five to 15 minutes daily, or at least several times a week. Some devices allow the user to adjust the intensity and wavelengths, and some are programmable to simplify use and ensure consistency when used by more than one practitioner on a particular patient. But, as with most modalities, protocols may be tweaked depending on the injury and individual involved.

In the case of the Utah skiers, Toth wasn’t getting the results he wanted, so he increased the intensity slightly. “I wouldn’t say I experimented. I’d say I used the protocol that the manufacturer provided, and it didn’t necessarily give me exactly what I wanted, so I just changed the parameters within the protocol to give the effects that I wanted. I simply turned up the lamp intensity and they felt a little bit of heat in the treatment session.”

Infrared isn’t for all cases. Contraindications for diode infrared therapy include anyone with cancer, and, like traditional heat modalities, it’s not for immediate use on acute injuries. Infrared also isn’t for breaking up knots in muscles, says Curtis Turchin, scientific director for Computerized Thermal Imaging, maker of the product used by Toth at Utah.

“If you have a fibrous, tight muscle—let’s say that a football player gets hit in the quad and he develops a fibrous nodule there—you probably wouldn’t use infrared because infrared is not going to have the heat or electricity to actually break the tissue,” Turchin says. “But once you break up the tissue with, for example, ultrasound, or electrical stimulation, then you might take your elbow or your knuckles to try to break it up. You’d follow that with infrared, because infrared would stimulate the healing and make it more likely that the tissue would heal up with the proper cell forms. But for breaking up chronic fibrous tissue, it’s not as effective as ultrasound.”

There are other limitations. Toth, for instance, says infrared was tried on Utah’s basketball players without any significant effect. One reason it worked for the skiers was that they were quite conscientious about getting into the training room every day for two weeks for treatment.

“The skiers, you’re able to tell them, ‘Hey, I know that you guys have practice almost every day of the week, and if not, you’re just going to have to come in when you don’t have practice so we can do the session.’ It’s basically five to 10 minutes but you have to make sure, at least I did, that you get in 14 consecutive days.

Hart appreciates the ease of using the infrared devices he’s tried—a characteristic, he says, that can help with consistency of treatment. The Coyotes have a small, portable unit that can be taken on the plane when traveling or even given to players to take home.

“If they’re taking a TENS [transcutaneous electrical nerve stimulation] unit home, they have to apply the electrodes and stim pads, you have to set the machine for them, and hopefully they don’t change the settings on them,” he says. “If they do, they run the risk of hurting themselves or not getting the proper treatment. With this machine, all they have to know is to wrap it on and turn an ‘on’ button.”

Toth, however, says he’d be reluctant to send his unit home with an athlete. He notes that even ice can do harm if not used correctly, and while there are no indications infrared is particularly dangerous if misused, he prefers a cautious approach.

“They’re selling TENS units on TV now,” Toth says. “What are we telling people, to go home and amp up the juice on a TENS unit? What could happen with someone’s tissue if you bombarded it with infrared all the time? I don’t know what would happen, so I wouldn’t like the idea of a patient taking something like that home.”

Another drawback may be the price. Utah got its unit, which costs about $5,000, only when the manufacturer, Computerized Thermal Imaging, loaned it to the sports medicine staff to try it. Though BioScan offers a portable unit for $399, its main commercial unit lists for $3,450.

Even with the cost issue, many specialists see potential for infrared therapy. If nothing else, Hart and others say, it’s another option in the never-ending quest to get athletes healthy and playing again.

At the meeting of the Professional Hockey Athletic Trainers in June, Hart recommended infrared. “We use it in conjunction with all the other modalities. It’s just like anything else that comes on the market. We can’t just all of a sudden stop using our traditional modalities to use this modality altogether.”

Clark says infrared has all but replaced electronic stim and ultrasound in his practice, but it still is only one of many approaches he takes, along with chiropractic techniques, hot packs, range-of-motion exercises, and massage therapy.

“It’s just another bag of tricks,” Toth says. “The way that I handle my tendinitis cases is to go along with the usual protocol to manage those, and if athletes’ symptoms aren’t getting any better, then I go to a more aggressive protocol, which uses the photonic stim. But I don’t go to it every time I get a case of tendinitis.

“It’s certainly a very interesting modality,” he continues. “It’s something that I think we really need to look into some more. It certainly does some good things. This is a different type of modality than what we had when we were in school, and it does some different stuff. I think there’s a lot that has changed that we’re going to have to catch up on.”