Online tai chi improves knee pain, function

A free, self-guided online tai chi program reduced walking knee pain and improved daily function more than online education alone after 12 weeks.
*Randomized clinical trial; Level 1b (OCEBM).

Citation

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. Published online October 27, 2025. doi:10.1001/jamainternmed.2025.5723

Background

Tai chi is recommended for knee osteoarthritis, but in-person classes can be hard to access. This trial tested whether a fully self-guided online program can improve symptoms.

Patients

178 adults in Australia (average age ~62 years) with clinical knee osteoarthritis, knee pain for at least 3 months, and walking pain at least 4/10; required internet access. Key exclusions included regular exercise in the prior 3 months, recent knee surgery, inflammatory arthritis, or inability to walk unaided.

Intervention

Online program: education plus a 12-week video-based tai chi course (3 sessions/week) and encouragement to use a phone app that supports exercise habits.

Control

Education-only website about osteoarthritis and benefits of exercise.

Outcome

(Primary) Change in walking knee pain (0–10 scale) and difficulty with physical function (0–68 questionnaire).

Follow-up Period

12 weeks.

Results

Outcome (12 weeks) Difference vs control (95% confidence interval)
Walking knee pain (primary) −1.4 points (−2.1 to −0.7)
Physical function difficulty (primary) −5.6 points (−9.0 to −2.3)

Clinically noticeable improvement occurred more often with tai chi for pain (73% vs 47%; number needed to treat 4) and function (72% vs 52%; number needed to treat 6). No serious related harms were reported. Most participants met the program’s adherence target (82%).

Limitations

Participants reported their own outcomes and knew their group assignment, which can inflate perceived benefit. Follow-up was short (12 weeks). Average benefits were modest and slightly below the study’s prespecified “noticeable change” thresholds, although many more people reached those thresholds. The app and tai chi were tested together, so their separate effects are unclear. Results may not apply to people without reliable internet access.

Funding

Australian government medical research funding; no industry support reported.

Clinical Application

For knee osteoarthritis, consider prescribing this free online tai chi program when supervised classes are unavailable; it provides modest but meaningful 12-week symptom improvement.