Along with snazzy racing outfits and sleek warm-up gear, many Olympians at the London Games have been accessorizing with athletic tape in various hues and patterns.
On the beach volleyball court, it seemed, more players than not wore lines of tape around their knees, shoulders and even in fanned strips down their abdomens. Black, blue and patterned strips appeared on gymnasts, runners, divers, discus-throwers and even table tennis players.
So, what's up with all that tape? And is it really doing anything to help?
Anecdotally, athletes and physical trainers swear by the stretchy adhesive, known as Kinesio tape or elastic therapeutic tape. If applied correctly, they say, the tape can relieve pain from tendonitis or muscle inflammation, giving competitors an athletic boost.
Scientifically, though, very few studies have been done that truly isolate the effects of the tape compared to other measures that athletes take to treat and prevent injuries.
Until better data come in, it remains possible that the tape provides more of a psychological benefit than a physical one -- its mere presence reminding athletes to be careful with a sore area or providing confidence through a sense that something is being done to help with healing.
"I've seen on the playing field and in clinics that people are getting a benefit from it," said Mary Ann Willmarth, a doctor of physical therapy at Harvard University Health Services in Cambridge, Mass. "We need the studies now to prove from an evidence-based standpoint that it's actually the tape that's doing it and not something else. I'm really curious to see what the studies will show."
Traditionally, athletes have used athletic tape like braces to prevent injuries by limiting movement in joints, particularly ankles or wrists, said Adam Knight, a sports biomechanist at Mississippi State University. And plenty of studies show that ankle taping reduces strain and helps prevent sprains.
But the stretchy tape that has noticeably adorned a large number of Olympians has different goals. The tape was developed in the mid-1970s by a Japanese chiropractor and acupuncturist named Kenzo Kase. Instead of using the rigid athletic tapes available at the time, Kase's idea was to create a product that more accurately mimicked the elastic quality of human skin.
For decades, physical trainers and therapists have been using elastic therapeutic tape (including the brand Kase developed, called Kinesio) on both athletes and on young patients with muscular dystrophy and other disorders.
Kinesio tape made its first prominently visible Olympics debut in Beijing in 2008, after the Kinesio company donated rolls of tape to 58 countries. Among other high-profile bodies, the tape appeared on women's beach volleyball champ Kerri Walsh, who sported a spider-like pattern of black strips on her shoulder.
Four years later, elastic tape is in vogue, appearing everywhere from the diving platform to the balance beam.
As for how it works, proponents offer a variety of theories. One idea is that, by pulling and stretching, the tape lifts the skin, separating it from other layers of tissue, said Jim Wallis, a certified athletic trainer at Portland State University in Oregon, who designs educational materials that explain how to apply the tape correctly.
The extra space, Wallis said, allows blood and other bodily fluids to flow better and speeds up the body's ability to clear lymphatic fluids, which reduces inflammation more quickly. Tension in the skin also reduces pressure on sensory neurons in the skin, he said, diminishing the athlete's sensation of pain.
A few studies have shown that taping with Kinesio tape might reduce the volume of fluids in the body in cancer patients, Willis said. In athletes, the most common result is that patients report feeling less pain.
Still, most of those results are preliminary and based on small case studies. Many studies lack control groups or random and blind assignments to treatment groups. Often, the tape is used in combination with other treatments, making it impossible for a study to conclude that any outcome is a result of the tape alone.
And while some studies show a performance boost, others show no benefits at all.
"Everybody makes a valid point that there's no specific research that we can point to that says this is exactly how it does it," said Wilils, who has been using the tape on patients for nearly a decade.
"I have been using it for that length of time with virtually every athlete I work with, and eight or nine out of 10 get improvement," he added. "From a clinical-application sense, I believe in it very much. From a research basis, I can't completely tell you I'm completely convinced that I understand exactly what it's doing."
Depending on the direction it is applied, elastic therapeutic tape might either take pressure off of muscles to make them more relaxed or help muscles contract so they work more, said Wilmarth, who also uses the tape in her practice with visible improvements. However, she was more skeptical about the idea that stretchy tape might help clear lymphatic fluids because of the many layers of tissue involved.
For Olympians, the tape is likely to provide a placebo effect, experts said, allowing them to focus on their performance instead of their injuries. Only better research will determine whether the benefits are physiological, too.
"The jury's out," Willmarth said. "We need more research."