QST raw data compared across different stimulation frequencies.

<p>Following conditioning stimulation with the matrix array electrode, all mechanical perception and pain thresholds (except the windup ratio) were significantly increased. This effect was pronounced after 4 Hz rather than 30 Hz stimulation, when compared to baseline condition. Stimulation using a 30 Hz frequency was an optimal sham condition, when assessing deep pain thresholds. However, this frequency still was effective in reducing superficial mechanical sensitivity. Stars or crosses denote the level of significance with *p<0.05; **p<0.01; ***p<0.001 for the comparison to the baseline condition.