Electronic vibrations in ski poles

Two weeks ago, I was skiing in the Vosges mountains. The ski resort Lac Blanc is crossed by 400 kV high tension transmission lines which run over the ski trails at a height about 8 - 10 m. While waiting under them, I had the surprise to "feel" electronic vibrations in the ski pole with the tip of my fingers, as if bunches of electrons were running back and forth on the surface of the pole. Experimenting a bit with them, I noticed that the ski pole had to be planted in the ground (or the snow in this case) to set up these vibrations. For ski poles where the tip was isolated with a plastic material, there were no such vibrations. Also, this worked whatever the orientation of the pole, parallel or perpendicular to the transmission lines, which I found quite surprising. Whatever, I tried not to dwell too long under those lines, not sure to which extent these transmission lines affected my neuronal electrons ;-)