The traditional Chinese exercise of Tai Chi can relieve the pain of arthritis of the knee, according to a new study. After a 12-week course of Tai Chi, people also had less difficulty with everyday tasks such as using the stairs.

What do we know already?

Osteoarthritis of the knee is very common in older adults. Among those over the age of 55, an estimated 10 percent have frequent knee pain caused by this joint disease, which can also lead to stiffness, limited movement, and a decreased quality of life.

Many people rely on painkillers to cope with the pain of osteoarthritis. Although exercise and physiotherapy can help, the improvements are often modest. However, specialists think Tai Chi is one type of exercise that might be particularly helpful.

Tai Chi features slow, rhythmic movements designed to bring about mental relaxation and enhance balance, strength, and flexibility. For people with osteoarthritis of the knee, this mind-body focus might improve their physical symptoms as well as helping them cope better mentally. Researchers have done a long-term study to learn more.

What does the new study say?

The study compared two groups of people aged 55 or older. One group met twice weekly for Tai Chi classes. The other group met twice weekly for general wellness instruction and stretching exercises. Both groups were asked to practise their exercises at home for at least 20 minutes a day.

At the end of 12 weeks, people in the Tai Chi group had a 75 percent drop in their pain, on average, and a 72 percent improvement in their ability to do everyday tasks (such as using stairs). People in the wellness and stretching group also reported improvements, but these were much lower than in the Tai Chi group.

The researchers used questionnaires to score people's symptoms, as well as their mental state, quality of life, and other indicators of wellbeing. Besides doing better on pain and physical function, the Tai Chi group also had greater improvements in depression and overall health.

The researchers followed up with participants 24 and 48 weeks after the start of the study. Less than half of the people in each group still did their exercises at 48 weeks, and much of the differences between the groups had diminished by this time. However, the Tai Chi group continued to have significantly better depression scores, suggesting these improvements might be longer lasting.

How reliable are the findings?

This study was good quality but it was very small, with only 20 people in each group. So, although it suggests that Tai Chi can help people with knee osteoarthritis, we need larger studies to know for certain.

Where does the study come from?

The study was done by researchers with Tufts University in Boston, and was funded by the National Center for Complementary and Alternative Medicine in the US. It was published in Arthritis Care and Research, a journal owned by the American College of Rheumatology.

What does this mean for me?

If you have osteoarthritis of the knee, this study's findings are quite promising. But bear in mind that the research is still at an early stage.

What should I do now?

If you'd like to try Tai Chi, be sure to tell your instructor about your osteoarthritis. An experienced instructor will help you avoid any positions that might put your knee under too much stress. In the study, for example, none of the Tai Chi positions required bending the knee more than 90 degrees.

From:

Wang C, Schmid CH, Hibberd PL, et al. Tai Chi is effective in treating knee osteoarthritis: a randomized controlled trial. Arthritis Care and Research. Published online 29 October 2009.

© BMJ Publishing Group Limited ("BMJ Group") 2009