The original concept of interferential therapy was developed over 57 years ago by Austrian physician, Dr. Hans Nemec. He found that by crossing two slightly different medium frequency alternating currents within the tissue; a third frequency current of greater intensity is created in the deeper tissue, effectively delivering deep therapeutic benefits for pain control and speeding up the healing process while maximizing patient comfort. Electrode placement should be in an "X" pattern, as the point of intersection provides the third stronger frequency.