2.3. Sample Size Calculation
Parkinson’s disease
The total sample size was estimated through an a priori power analysis, using the G power V 3.1.9.7 software (Heinrich-Heine-Universität, Düsseldorf, Germany). The following input parameters were applied using a repeated-measure ANOVA design: effect size f = 0.33, α = 0.05, power = 0.80, and correlation between repeated measures r = 0.50. The a priori power calculation revealed that the initial sample size required is 11. By considering a 10% dropout rate, 13 individuals with Parkinson’s disease will be recruited to voluntarily participate in this study.