Effect of Exercise on Parkinson's Disease Tremor: A Meta-analysis Study

Prior studies suggest that exercise may prevent movement disorders in Parkinson's disease (PD) patients. In this meta-analysis, the pooled effect of exercise on PD-induced tremor was investigated.

Relevant published studies (n = 7) were retrieved by searching major databases, including Scopus, Web of Science and PubMed from 1985 to November 2020. Studies were eligible if the effect of exercise on PD-induced tremor was studied and sufficient information for calculating the effect size was reported. Furthermore, non-English manuscripts and studies related to non-human species were excluded. The quality of studies was evaluated using the improved Newcastle-Ottawa scale (NOS). In this study, variables such as participant's age and gender, type of exercise, intervention duration and tremor indices were extracted for each study. Between-study heterogeneity and publication bias were calculated using I² statistic and funnel plot, respectively.

Results showed that hand movement and cycling exercises were effective for reducing tremor amplitude or frequency. When all types of exercises (upper, lower or whole-body movement) were considered, an odds ratio (OR) greater than 1 was obtained (log(OR) = 2, 95% CI: 0.88-3.12), while between-study heterogeneity was high (I² = 78%). By restricting the studies to hand-movement exercises, a lower odds ratio (log(OR) = 1, 95% CI: 0.24-1.77) with small between-study heterogeneity (I² = 0.0%, p = 0.502) was obtained. Statistical analysis based on Egger's and Begg's tests revealed no significant publication bias.

Outcomes of this study suggested that exercises as inexpensive, non-invasive and easy-to-implement strategies could be applied for PD patients alongside medical interventions for reducing tremors.

Exercises reduce tremors in Parkinson's disease patients significantly.Hand movement exercises are beneficial for reducing tremors in PD patients.