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

Three grids of 8x4 electrodes and two grids of 16x2 electrodes. Non interpolated maps of the RMS distribution (epochs of 0.125ms) of the horizontal (trapezius) and vertical (erector spinae) differential signals. Electrodes: Ø=3mm, interelectrode distance = 10mm.