Tai Chi is effective in treating knee osteoarthritis: a randomized controlled trial

Abstract

Objective: To evaluate the effectiveness of Tai Chi in the treatment of knee osteoarthritis (OA) symptoms.

Methods: We conducted a prospective, single-blind, randomized controlled trial of 40 individuals with symptomatic tibiofemoral OA. Patients were randomly assigned to 60 minutes of Tai Chi (10 modified forms from classic Yang style) or attention control (wellness education and stretching) twice weekly for 12 weeks. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score at 12 weeks. Secondary outcomes included WOMAC function, patient and physician global assessments, timed chair stand, depression index, self-efficacy scale, and quality of life. We repeated these assessments at 24 and 48 weeks. Analyses were compared by intent-to-treat principles.

Results: The 40 patients had a mean age of 65 years and a mean body mass index of 30.0 kg/m(2). Compared with the controls, patients assigned to Tai Chi exhibited significantly greater improvement in WOMAC pain (mean difference at 12 weeks -118.80 mm [95% confidence interval (95% CI) -183.66, -53.94; P = 0.0005]), WOMAC physical function (-324.60 mm [95% CI -513.98, -135.22; P = 0.001]), patient global visual analog scale (VAS; -2.15 cm [95% CI -3.82, -0.49; P = 0.01]), physician global VAS (-1.71 cm [95% CI -2.75, -0.66; P = 0.002]), chair stand time (-10.88 seconds [95% CI -15.91, -5.84; P = 0.00005]), Center for Epidemiologic Studies Depression Scale (-6.70 [95% CI -11.63, -1.77; P = 0.009]), self-efficacy score (0.71 [95% CI 0.03, 1.39; P = 0.04]), and Short Form 36 physical component summary (7.43 [95% CI 2.50, 12.36; P = 0.004]). No severe adverse events were observed.

Conclusion: Tai Chi reduces pain and improves physical function, self-efficacy, depression, and health-related quality of life for knee OA.

Trial registration: ClinicalTrials.gov NCT00362453.

Figure 1

Study Flow Chart

Figure 2

WOMAC Pain Subscale over a 12 week Intervention Period by Treatment Group Values shown are unadjusted means. Measurements were obtained weekly over a 12 week period, Error bars indicate the 95% Confidence Interval (CI) but the data are slightly offset in the figure for clarity. Means with 95% CI shown at each line for each group. Linear treads between weeks indicated by connected graph. WOMAC= Western Ontario and McMaster Universities Osteoarthritis index.

Figure 3

Mean Change of Secondary Outcomes by Treatment Group at Baseline, 12, 24, and 48 Weeks Values shown are unadjusted means (SD). Error bars indicate the 95% Confidence Interval. Measurements were obtained at Baseline, 12 weeks, 24 weeks and 48 weeks, but the data are slightly offset in the figure for clarity. WOMAC= Western Ontario and McMaster Universities; VAS= Visual Analogue Scale; CES-Depression= the Center for Epidemiology Studies Depression; SF-36= Short-Form health survey; MCS= Mental Component Summary; PCS= Physical Component Summary. * Lower scores indicate improvement in outcome † Higher scores indicate improvement in outcome.