The particles will move side to side over small areas.
When Marcus plucks an outstretched coil, the coli sets into wave like motion that is oscillates to and from. The particles of the medium do not move along the wave but just vibrate sideways about a fixed position. The particles would move side to side over very small areas. Such type of wave is known as mechanical wave. Sound wave is a mechanical wave. The particles vibrate in the direction of the motion of the wave. The wave carries forward the energy.