Previous research has suggested that in order for a treatment to be considered effective for fibromyalgia, it should produce at least a 14 percent improvement in the FIQ.

In this case, the average FIQ score in study participants improved by 44 percent as compared to an average 13 percent improvement in the placebo group.

Researchers aren’t sure how tai chi may be helping, but they suspect that it probably works on many fronts – movement may increase muscle strength, while meditation promotes tranquility, decreasing the stress and anxiety than can amplify pain.

Study author Chenchen Wang, MD, a research rheumatologist at Tufts University School of Medicine in Boston, has been studying the effects of tai chi on rheumatic diseases for nearly a decade. She says she was not surprised by the magnitude of improvement many people in the study achieved.

"Patients with chronic rheumatic conditions always have lots of improvements," Dr. Wang says. "Patients send flowers and cards. My office is full of flowers all the time. They just feel that it really changed their lives."

Dr. Wang says study participants were doing Yang-style tai chi, but she thinks that other kinds would work equally well.

"It seems like a well-done study," says Leigh Callahan, PhD, an epidemiologist with the Thurston Arthritis Research Center at the University of North Carolina at Chapel Hill, who is evalauting the effects of an 8-week program of sun-style tai chi, which is offered as a class and a DVD from the Arthritis Foundation, in 330 people.

"I think it just lends more credence to the fact that physical activity is good for arthritis, and I think the broader the menu we have for people, the better," she adds.

Though her results have not been fully analyzed, Callahan says participants in that study, which is being sponsored by The Arthritis Foundation and the Centers for Disease Control and Prevention, have seen improvements in pain, stiffness, sleep, self-efficacy and balance.

"We're really affirming what they found," she says.