Repeated measures analyses of variance (ANOVA) will be used to investigate the following three factors on the outcome variables: time (four levels: baseline, T0, T30 and T60) and muscle (two levels: APB and FDI) as within-subject factor and group (three levels: organic dystonia, psychogenic dystonia, and healthy controls) as between-subjects factor. The model of repeated measures ANOVA will include the interactions between the three factors. If the interaction between muscle and group is significant, the interaction between time and group will be evaluated for each muscle separately. If significance is found for time and/or group, then the evaluation will be followed by Tukey Kramer multiple pair-wise comparisons.