SAN FRANCISCO — The gentle martial art tai chi significantly improved pain and physical function in a randomized, controlled trial in 40 patients with knee osteoarthritis.
Participants were randomly selected to attend hour-long classes twice a week for 12 weeks to learn and practice 10 modified forms of classical Yang style tai chi or to receive wellness education and engage in stretching in a control group. Patient characteristics were similar between groups, with baseline pain scores of 209 in the tai chi group and 220 in the control group on the Western Ontario and McMaster Osteoarthritis (WOMAC) Index, which was the main outcome measure.
After 12 weeks, WOMAC pain scores decreased by 157 points in the tai chi group and 39 points in the control group, a significant difference between groups (P = .004), Dr. Chenchen Wang reported at the annual meeting of the American College of Rheumatology.
She and her associates repeated the pain assessment at 24 and 48 weeks to gauge the durability of the effects. Although the WOMAC pain scores remained significantly different between groups at 24 weeks, they did not at 48 weeks as some patients stopped practicing tai chi once the 12-week intervention had ended. Those who continued their tai chi practice, however, continued to show significant improvements in pain and secondary measures of function, compared with the control group, added Dr. Wang of Tufts University, Boston.
The tai chi group showed significant improvements, compared with the control group, in the WOMAC physical function score; the patient and physician global assessment scores (on visual analog scales); a timed chair-stand test; an assessment of knee proprioception; and in depression scores on the Center for Epidemiology Studies Depression (CES-D) Index.
“This is a very promising study,” Dr. Wang said. “However, these results should be confirmed by future large studies.”
Tai chi is an ancient Chinese exercise that combines meditation with slow, gentle, graceful movements; deep breathing; and relaxation. It uses an integrated mind-body approach to enhance muscle function, balance, and flexibility. Findings from a previous review by Dr. Wang and her associates of 47 studies of tai chi for various chronic medical problems suggested benefits in physical and mental health and function (Arch. Intern. Med.2004;164:493-501), but a dearth of high-quality studies left these conclusions in doubt and led to the current study, she said.
Sessions in the current trial included a warm-up, review of technique, and practice of the meditative movements, some of which were modified for the osteoarthritic cohort by incorporating chairs or other accommodations. The mind-body interaction of tai chi makes it difficult to compare it to a sham intervention, so the investigators used a control of conventional stretching and education about osteoarthritis, diet, nutrition, and more.
The patients were obese, with a baseline body mass index of 30 kg/m
Some patients used nonsteroidal anti-inflammatory drugs or other analgesics during the study, but medication use did not differ significantly between groups.
Pain scores decreased 157 points after 12 weeks of tai chi, compared with a 39-point decrease in the control group. ©Anne