This is a very interesting article found in The New England Journal of Medicine about the benefits of Tai Chi in the management of fibromyalgia. It even considers that Tai Chi could be a treatment for this condition. Apparently the randomly assigned group that undertook the Tai Chi practice had significant improvements in the Fibromyalgia Impact Questionnaire (FIQ).
A Randomized Trial of Tai Chi for Fibromyalgia. Article by Wang C. et al.