Effects Of Tai Chi On The Status Of Elderly Subjects With Knee Osteoarthritis

BACKGROUND Osteoarthritis (OA) is a major cause of disability in the aging population and its management is costly. Tai Chi (TC), an ancient form of Chinese martial art that encompasses low impact, low intensity controlled movements, has been proposed as an inexpensive alternative to benefit people with knee OA. PURPOSE The purpose of this study was to compare the effects of a TC intervention program including both group and home video sessions followed by detraining session to the effects of an attention control (AC) program on knee pain, knee range of motion (ROM) and function of subjects with knee OA. METHODS Subjects >50 yrs with knee pain were recruited. Diagnosis of knee OA was based on the Classification Criteria of the American Rheumatism Association for Osteoarthritis of the Knee. Subjects were assigned to a TC or AC group using a match-paired random block design. TC group received 40 minutes of TC 3x/week for 6 weeks, followed by 6 weeks of TC home program 3x/week and 6 weeks of no TC. AC group received 6 weeks of 40-minute lectures 3x/week, followed by no activities for the following 12 weeks. Knee ROM, knee pain using Visual Analogue Scales (VAS) and the McMaster Universities Osteoarthritis Index (WOMAC) were recorded at 0, 3, 6, 9, 12, 15 and 18 weeks. Data analyses were performed using 2 (treatments) × 6 (times) mixed repeated measures analysis of covariance model, with baseline value and Body Mass Index covariates. RESULTS Forty one subjects (7M/34F, 70 ± 9.2 yrs) participated in the study, 19 in the AC group and 22 in the TC group. For the AC group, knee pain, WOMAC and knee ROM scores did not change significantly during the study. For the TC group, mean knee pain significantly decreased at weeks 3, 6 (p <0.05) and 9, 12, 15 (p <0.01) from a high of 4.67 ± 2.59 at week 0 to a low of 2.30 ± 1.43 at week 9 and then increased to 3.46 ± 2.45 at the end of the study. TC group recorded significantly less knee pain than AC group at weeks 9, 12 and 15 (p = 0.008, 0.035, 0.043, respectively). WOMAC score also significantly decreased in the TC group at weeks 9, 12 and 15 (p <0.05), from 65 at week 0 to 51 at week 9, and was significantly better for the TC group than the AC group at week 9 (p = 0.005). No significant differences were found for knee ROM between the TC and AC groups. CONCLUSION Group exercise plus home video program of TC can provide significant knee pain reduction and improvement of function in the elderly with knee OA, and it may offer a cost effective alternative to the management of knee OA. However, such effect of TC was not sustained after detraining.