Figure 6. Between-group difference in the timings of muscle activity.

The upper row represents $\overline{{\mathit{ENV}}^c}$ obtained by averaging each of the 8 envelopes over all control subjects. $\overline{{\mathit{ENV}}^c}$ were used to identify the peaks of activation of the 8 muscles. 3 peaks for FCU (Pm₁, Pm₂ and Pm₃), 2 peaks for ECR (Pm₄ and Pm₅), 3 peaks for BIC (Pm₆, Pm₇ and Pm₈), 1 peak for TRIC (Pm₉), 1 peak for AD (Pm₁₀), 2 peaks for LD (Pm₁₁ and Pm₁₂), 3 peaks for PD (Pm₁₃, Pm₁₄ and Pm₁₅), and 3 peaks for SS (Pm₁₆, Pm₁₇ and Pm₁₈) were detected. Lower rows represent, for each group separately (Dystonia: light gray; Control: dark gray) the frequency distribution of the time of occurrence of each peak (Tma_n). No statistical between-group differences were reported for any of the peaks.