Exercise as it relates to Disease/Can Tai Chi improve balance in people suffering from Parkinson's Disease?

Based on:

Tai Chi and Postural Stability in Patients with Parkinson’s Disease

By Li, Harmer, Fitzgerald, Eckstrom, Stock, Galver, Maddalozzo, & Batya (2012)

What is the background to this research?
Parkinson’s disease (PD) is a progressive neurological condition that effects approximately 80,000 Australians. It is categorised as a movement disorder, which has no known cause, and gets increasingly worse over time. Given the prevalence of this condition, the debilitating symptoms that sufferers experience, and the fact it is still not well understood, research in this field is very important.

Poor balance is a common impairment of PD sufferers. This results in an increased risk of falling, and decreased functional ability. Health professionals routinely prescribe exercise to assist in the management of such impairments, but few exercise protocols have been demonstrated to be effective. With this gap in literature in mind, Li et al. (2012) decided to investigate the effectiveness Tai Chi training on balance in PD patients.

Tai Chi is a balance based exercise regime, which has been demonstrated to improve strength, balance, physical function, and prevent falls. It emphasizes rhythmic weight shifting, symmetrical foot stepping, and controlled movements near the limits of stability. Li et al. (2012) hypothesised that Tai Chi may be more effective at improving balance than resistance based exercise and stretching in patients with PD; they therefore conducted a study to test this idea.

Where is the research from?
Li et al. (2012) conducted this research at various medical centres across the state of Oregon, in the United States of America. Funding for this research was aided by a grant from the National Institute of Neurological Disorders and Stroke.

Results were subsequently outlined in the article “Tai Chi and Postural Stability in Patients with Parkinson’s Disease”, which was published by The New England Journal of Medicine, in 2012.

What kind of research was this?
Randomized Control Trial

What did the research involve?
One hundred and ninety-five patients with stages 1–4 (mild-moderate) of PD, according to the Hoehn and Yahr staging scale (see further readings for details), were randomly assigned to one of three training intervention groups:


 * 1) Tai Chi
 * 2) Resistance
 * 3) Stretching

Each group did 60 minute exercise sessions in their assigned intervention style, twice per week, for 24 weeks.

The main outcome that was measured was changes in balance and stability, based on measures of maximum excursion and directional control.

The researchers also measured changes in secondary outcomes:


 * Walking technique
 * Strength
 * Reaching distance
 * Timed Up and Go Test: Time to stand up from sitting, walk 5 meters, turn around and return to sitting in the chair
 * Number of falls

What were the basic results?
The Tai Chi group showed:


 * Greater maximum excursion and directional control than both groups
 * Better secondary outcomes than the stretching group
 * Greater stride length and functional reach than the resistance group
 * Lowered incidence of falls compared to stretching group, but not the resistance group
 * Tai Chi training resulted in no serious adverse effects

Importantly, these effects were maintained at three months follow up.

How did the researchers interpret the results?
The researchers concluded, that when compared to a resistance or stretching based training program, Tai Chi, had numerous advantages.

Based on their results, Li et al. (2012) established that Tai Chi was effective at improving postural stability and functional outcomes in patients with mild-moderate PD. Tai Chi was found to improve balance whilst reaching forward, transitioning from sitting to standing, and walking. Increased stride length and walking speed were also observed, demonstrating that Tai Chi is also effective in regards to treating other symptoms of PD, such as slowed movements.

It was suggested that the inherent training features of Tai Chi may be the causal factor for Tai Chi also being effective in reducing the probability of falls, when compared to a stretching intervention.

Furthermore, due to the fact that there were no serious adverse effects in Tai Chi training, and that improvements were maintained at three months post intervention, the researchers concluded that Tai Chi is both a safe and effective treatment for improving balance in patients with mild-moderate PD.

What conclusions should be taken away from this research?
Tai Chi training, two times per week, for 24 weeks, appears to be effective in improving balance, stride length, walking speed, and lowering the incidence of falls, in patients with mild-moderate PD. It was shown to be a safe intervention, and results maintained at three months follow up.

When examining the results of this research, multiple limitations, as acknowledged by the authors, must be taken in to account, before the conclusions can be trusted.


 * Participants were aware of their intervention, which may have created bias due to potential preferences and preconceptions.
 * There was no non-exercise control group, so the net total improvement as a result of Tai Chi training cannot be clearly established.
 * All participants were tested during the most effective period of their symptom controlling medication, which may have concealed the improvements that were induced solely by the training interventions.

The authors further highlighted that the mechanisms behind the physiological improvements that were observed are not well understood and warrant further research. Given the prevalence of this issue, this study will hopefully spark interest for further study in the area.

What are the implications of this research?
PD patients commonly have impaired balance, and therefore are at increased risk of falls, which at times, can be life threatening.

The research by Li et al. (2012), suggests that Tai Chi can be more effective than resistance and stretching based training programs at improving both balance and functional ability, in people with mild-moderate PD. Results also demonstrate that it is safe, and that benefits are maintained at three months post intervention.

The mechanisms behind such improvements are not well understood and should be investigated further, in order to fully appreciate the benefits that can be gained through Tai Chi training.

Further readings/information sources
Parkinson's Australia

Tai Chi and Postural Stability in Patients with Parkinson’s Disease

Supplementary Material for Tai Chi and Postural Stability in Patients with Parkinson’s Disease

Hoehn and Yahr Staging of Parkinson's Disease