Long bows on string 1 and 4 of a violin. Upper, middle and lower right trapezius; upper and middle left trapezius; right and left lumbar erector spinae.

Three grids of 8x4 electrodes and two arrays of 16x1 electrodes. Non interpolated maps of the RMS distribution (epochs of 0.125ms) of the horizontal differential signals. Electrodes: Ø=3mm, interelectrode distance = 10mm.