Effect of 8-form Tai Chi vs health education on mobility in older adults with sarcopenic knee osteoarthritis: A randomized clinical trial

OBJECTIVE: To evaluate whether a 12-week simplified 8-form Tai Chi program improves mobility in older adults with sarcopenic knee osteoarthritis (SPKOA) compared with health education plus progressive home exercise. METHOD: This assessor-masked, 2-site trial randomized 96 adults aged 65-85 years with SPKOA 1:1 to Tai Chi or health education plus home exercise. The primary outcome was change in Timed Up and Go (TUG) time at week 12. Site-adjusted categorical-time linear mixed-effects models were used. A TUG improvement of at least 2.8 s defined individual response. RESULTS: At week 12, the adjusted between-group difference in TUG change was -2.52 s (95% CI, -3.43 to -1.61; p < 0.001), favoring Tai Chi but slightly below the prespecified individual improvement threshold. TUG responders were more frequent with Tai Chi (28/48 [58.3%] vs 6/48 [12.5%]; adjusted risk ratio, 4.81 [95% CI, 2.29-10.07]). At week 26, the TUG difference was -1.46 s (95% CI, -2.41 to -0.52). Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain favored Tai Chi, whereas visual analog scale pain showed no clear between-group separation. No intervention-related serious adverse events occurred. CONCLUSION: Simplified 8-form Tai Chi improved mobility compared with an active health education and home-exercise program in older adults with SPKOA. The average week-12 TUG advantage was slightly below the prespecified individual improvement threshold, but clinically important TUG responses were more frequent with Tai Chi and a smaller mean benefit persisted at week 26. TRIAL REGISTRATION: International Traditional Medicine Clinical Trial Registry: ITMCTR2025001324.