CATEGORY: MOBILITY, BONES & JOINTS
If you have knee osteoarthritis — the common “wear-and-tear” joint condition in which the smooth cartilage cushioning your knee gradually breaks down, causing pain and stiffness — a gentle form of exercise you can follow at home may ease it. In a 2026 randomized trial, people who did unsupervised tai chi guided only by online videos saw their knee pain while walking fall about twice as much over 12 weeks as those in a comparison group.1
What Osteoarthritis Does to the Knee
In a healthy knee, cartilage lets the bones glide smoothly. In osteoarthritis, that cushion thins and roughens over time, so the joint aches, stiffens, and can swell — often making walking and stairs harder. It’s one of the leading causes of pain and reduced mobility in older adults, and while there’s no cure, movement-based approaches are a mainstay of easing symptoms.
How the Trial Worked
The study, called the RETREAT trial, enrolled 178 adults who met the clinical criteria for knee osteoarthritis. Half were randomly assigned to a 12-week program of tai chi — a slow, flowing “moving meditation” of gentle postures and controlled breathing — which they followed entirely on their own using online videos, with no in-person instructor. The other half formed a comparison group. Because participants were assigned by chance, this design can point more directly to cause and effect than an observational study. Nearly all — 96% — completed the trial.1
What Improved
Knee pain while walking was measured on a 0-to-10 scale. The tai chi group’s pain fell by 2.7 points on average, compared with 1.3 points in the comparison group — roughly double the improvement. A measure of physical function, covering everyday tasks like climbing stairs and rising from a chair, also improved more in the tai chi group. Both differences were statistically significant, meaning they were unlikely to be due to chance.
Why Tai Chi May Help
Tai chi is low-impact, so it’s gentle on sore joints while still strengthening the muscles that support the knee and improving balance and flexibility. Its slow, mindful pace may also change how the brain registers pain. Because this version needed no class, equipment, or instructor, it offers a low-cost, accessible option — though a video program isn’t right for everyone, especially with balance problems or other health conditions.
Key Takeaways
- In a randomized trial, unsupervised online tai chi was linked to about double the reduction in knee-osteoarthritis walking pain over 12 weeks versus a comparison group.
- Physical function — everyday movements like stairs and standing up — also improved more with tai chi.
- The program used only online videos at home, suggesting a low-cost, accessible approach for some people.
- Before starting a new exercise routine, especially if you have joint pain or balance concerns, check with your healthcare provider about what’s safe for you.
References
- Zhu SJ, Hinman RS, Nelligan RK, et al. Online Unsupervised Tai Chi Intervention for Knee Pain and Function in People With Knee Osteoarthritis: The RETREAT Randomized Clinical Trial. JAMA Internal Medicine. 2026;186(1):15–25. link