Is Tai Chi effective in improving postural control among patients with idiopathic Parkinson's disease as compared to resistance training or stretching, respectively?
Date of publication of the randomized controlled trial: February 2012
Design
Randomized controlled trial (RCT).
Participants
195 patients (age range: 40 to 85 years, mean age range: 68 to 69 years in 3 groups, female % range: 30.8 to 41.5% in 3 groups) with idiopathic Parkinson's disease. A total of 164 persons (84%) were at stage 2 or higher on the Hoehn and Yahr staging system (range: 1 to 4; median: 2.5). The Hoehn and Yahr staging system ranges from 1 to 5, with higher scores indicating more severe disease.
Intervention
A 60-minute Tai Chi class provided twice weekly for 24 weeks. The protocol consisted of 6 tai chi movements integrated into an eight-form routine, and was specifically designed to tax balance and gait by having participants perform symmetric and diagonal movements, such as weight shifting, controlled displacement of the center of mass over the base of support, ankle sways, and anterior–posterior and lateral stepping.
Comparator
Comparison 1: Tai Chi versus resistance training;
Comparison 2: Tai Chi versus stretching.
Resistance Training—The protocol focused on strengthening the muscles that are important for posture, balance, and gait. Resistance (with weighted vests and ankle weights) was introduced at week 10. Weighted-vest resistance was initially set at 1% of body weight and was increased by approximately 1 to 2% of body weight, every fifth week until 5% of body weight was achieved. Ankle weights started at 0.45 kg (1 lb) per limb and were gradually increased to 1.36 kg (3 lb). The routine involved 8 to 10 exercises, including forward and side steps, squats, forward and side lunges, and heel and toe raises, performed in 1 to 3 sets of 10 to 15 repetitions.
Stretching—This control condition was designed to provide a low-intensity exercise program with the social interaction and enjoyment inherent in the two other interventions but without similar training benefits in lower-extremity weight bearing, strength, or balance. The core activities encompassed a variety of seated and standing stretches involving the upper body and lower extremities, with the use of gentle joint extension and flexion and trunk rotation. Abdominal breathing, with an emphasis on inhaling and exhaling to maximum capacity, and relaxation of major muscles were also included.
Major Outcomes
Outcome 1: Maximum excursion from baseline to 6 months;
Outcome 2: Directional control from baseline to 6 months;
Outcome 3: Stride length from baseline to 6 months;
Outcome 4: Walking velocity from baseline to 6 months.
Both of the maximum excursion and directional control were measured by computerized dynamic posturography (Balance Master System, NeuroCom). Scores on both measures range from 0 to 100%, with higher percentages indicating better balance or control.
Gait (stride length and walking velocity) was quantified with the use of a computerized 4.3m (14 ft) walkway (GAITRite, CIR Systems). Participants were instructed to walk at their normal pace for four times; the results were averaged to derive a score for each measure, with higher scores indicating better gait ability.
Settings
This study was conducted in an outpatient setting.
Comparison    Tai Chi versus resistance training
Main Results
Compared to resistance training, Tai Chi showed significant effects on improving maximum excursion (mean difference (MD): 5.55, 95% CI: 1.12 to 9.97), directional control (MD: 10.45, 95% CI: 3.89 to 17.00) and stride length (MD: 5.9, 95% CI: 1.5 to 10.4) from baseline to 6 months. However, Tai Chi did not show significant effect on the improvement of walking velocity from baseline to 6 months (MD: 0.5, 95% CI: −6.2 to 7.1).
Comparison 1: Tai Chi versus resistance training among patients with idiopathic Parkinson's disease
Outcomes (units) No. of studies (Total number of participants) Mean/ No. of participants Heterogeneity test (I2) MD (95% CI) Overall quality of evidence*
Intervention Comparator
1 (%) 1 (130) 9.56/ 65 4.02/ 65 Not applicable as there is only one study. 5.55 (1.12 to 9.97) High
2 (%) 1 (130) 8.02/ 65 -2.43/ 65 Not applicable as there is only one study. 10.45 (3.89 to 17.00) High
3 (cm) 1 (130) 10.3/ 65 4.3/ 65 Not applicable as there is only one study. 5.9 (1.5 to 10.4) High
4 (cm/sec) 1 (130) 10.4/ 65 10.0/ 65 Not applicable as there is only one study. 0.5 (−6.2 to 7.1) Moderate
Keys: MD = mean difference; CI = confidence interval.
Comparison    Tai Chi versus stretching
Main Results
Compared to stretching, Tai Chi showed significant effects on improving maximum excursion (MD: 11.98, 95% CI: 7.21 to 16.74), directional control (MD: 11.38, 95% CI: 5.50 to 17.27), stride length (MD: 12.3, 95% CI: 8.3 to 16.4), and walking velocity (MD: 14.9, 95% CI: 9.8 to 20.1) from baseline to 6 months.
Comparison 2: Tai Chi versus stretching among patients with idiopathic Parkinson's disease
Outcomes (units) No. of studies (Total number of participants) Mean/ No. of participants Heterogeneity test (I2) MD (95% CI) Overall quality of evidence*
Intervention Comparator
1 (%) 1 (130) 9.56/ 65 -2.42/ 65 Not applicable as there is only 1 study. 11.98 (7.21 to 16.74) High
1 (%) 1 (130) 8.02/ 65 -3.36/ 65 Not applicable as there is only 1 study. 11.38 (5.50 to 17.27) High
3 (cm) 1 (130) 10.3/ 65 -2.0/ 65 Not applicable as there is only 1 study. 12.3 (8.3 to 16.4) High
4 (cm/sec) 1 (130) 10.4/ 65 -4.5/ 65 Not applicable as there is only 1 study. 14.9 (9.8 to 20.1) High
Keys: MD = mean difference; CI = confidence interval.
Comparison    Tai Chi versus resistance training
Main Results
Compared to resistance training, Tai Chi showed significant effects on improving maximum excursion (mean difference (MD): 5.55, 95% CI: 1.12 to 9.97), directional control (MD: 10.45, 95% CI: 3.89 to 17.00) and stride length (MD: 5.9, 95% CI: 1.5 to 10.4) from baseline to 6 months. However, Tai Chi did not show significant effect on the improvement of walking velocity from baseline to 6 months (MD: 0.5, 95% CI: −6.2 to 7.1).
Comparison 1: Tai Chi versus resistance training among patients with idiopathic Parkinson's disease
Outcomes (units) 1 (%) 2 (%) 3 (cm) 4 (cm/sec)
No. of studies (Total number of participants) 1 (130) 1 (130) 1 (130) 1 (130)
Mean/ No. of participants Intervention 9.56/ 65 8.02/ 65 10.3/ 65 10.4/ 65
Comparator 4.02/ 65 -2.43/ 65 4.3/ 65 10.0/ 65
MD (95% CI) 5.55 (1.12 to 9.97) 10.45 (3.89 to 17.00) 5.9 (1.5 to 10.4) 0.5 (−6.2 to 7.1)
Overall quality of evidence* High High High Moderate
Keys: MD = mean difference; CI = confidence interval.
Comparison    Tai Chi versus stretching
Main Results
Compared to stretching, Tai Chi showed significant effects on improving maximum excursion (MD: 11.98, 95% CI: 7.21 to 16.74), directional control (MD: 11.38, 95% CI: 5.50 to 17.27), stride length (MD: 12.3, 95% CI: 8.3 to 16.4), and walking velocity (MD: 14.9, 95% CI: 9.8 to 20.1) from baseline to 6 months.
Comparison 2: Tai Chi versus stretching among patients with idiopathic Parkinson's disease
Outcomes (units) 1 (%) 1 (%) 3 (cm) 4 (cm/sec)
No. of studies (Total number of participants) 1 (130) 1 (130) 1 (130) 1 (130)
Mean/ No. of participants Intervention 9.56/ 65 8.02/ 65 10.3/ 65 10.4/ 65
Comparator -2.42/ 65 -3.36/ 65 -2.0/ 65 -4.5/ 65
MD (95% CI) 11.98 (7.21 to 16.74) 11.38 (5.50 to 17.27) 12.3 (8.3 to 16.4) 14.9 (9.8 to 20.1)
Overall quality of evidence* High High High High
Keys: MD = mean difference; CI = confidence interval.
Conclusion
Benefits
Compared to resistance training or stretching respectively, Tai Chi showed significant benefits for patients with idiopathic Parkinson's disease by improving maximum excursion, directional control and stride length from baseline to 6 months. However, Tai Chi only showed beneficial effect on improving walking velocity from baseline to 6 months when compared to stretching. Similar benefit was not observed when compared to resistance training. Compared to resistance training, the overall quality of evidence is high for outcomes 1 to 3. Further research is unlikely to have an important impact on our confidence in this estimate of effect. For outcome 4 in this comparison, the overall quality of evidence is moderate. Further research is fairly likely to have an important impact on our confidence in this estimate of effect. Compared to stretching, the overall quality of evidence is high for all outcomes. Further research is unlikely to have an important impact on our confidence in this estimate of effect.
Harms
No serious adverse events were observed.
Link to Original Article
http://www.ncbi.nlm.nih.gov/pubmed/22316445
The synopsis is based on the following article:
Li F, Harmer P, Fitzgerald K, Eckstrom E, Stock R, Galver J, Maddalozzo G, Batya SS. Tai chi and postural stability in patients with Parkinson's disease. The New England Journal of Medicine. 2012 Feb 9;366(6):511-9.


* Interpretation of quality assessment results:
• Very low: Further research is most likely to have an important impact on our confidence in this estimate of effect.
• Low: Further research is likely to have an important impact on our confidence in this estimate of effect.
• Moderate: Further research is fairly likely to have an important impact on our confidence in this estimate of effect.
• High: Further research is unlikely to have an important impact on our confidence in this estimate of effect.
• Very high: Further research is most unlikely to have an important impact on our confidence in this estimate of effect.

Details of assessment method can be found at Chung VC, Wu XY, Ziea ET, Ng BF, Wong SY, Wu JC. Assessing internal validity of clinical evidence on effectiveness of CHinese and integrative medicine: Proposed framework for a CHinese and Integrative Medicine Evidence RAting System (CHIMERAS). European Journal of Integrative Medicine. 2015 Aug 31;7(4):332-41.