Figure 1

Original handwriting movements and writing parameters (vertical pressure and NIV). Upper panel: original data of handwriting movement during writing of the highly automated word "Wellen" from the sentence "Die Wellen schlagen hoch" for control subject S7 (left part) and writer's cramp patient P4 (right part). The upper plots represent the X/Y coordinate plot of the tip of the writing pen on the digitizing tablet. The lower plots are the respective time courses on Z-axis for the vertical pressure. Under each the number of inversions of vertical pressure is given (NI). The continuous line denotes the pen trace on the tablet and the dotted one – the pen trace lifted. Note in the pen trace that the patient has a longer stroke length and trajectory on the paper with longer pen lift. Note also that the time course pattern of the vertical pressure for the patient is characterized by larger number of segments with more NI and lower vertical pressure. Lower panel: mean group values and standard deviations (error bars) for 7 controls (grey column) and 7 patients (black column) for vertical pressure and number of inversions in velocity per stroke (NIV). The asterisk denotes a statistically significant difference between both groups (p < 0.05). Note the statistically significant lower vertical pressure for the patients.