What is interferential current therapy (IFC)?

Updated: Nov 12, 2019
  • Author: Vladimir Kaye, MD; Chief Editor: Milton J Klein, DO, MBA  more...
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A variety of newer transcutaneous or percutaneous electrical stimulation modalities have emerged. They include the following:

  • Interferential current therapy (IFC) is based on summation of 2 alternating current signals of slightly different frequency. The resultant current consists of a cyclical modulation of amplitude, based on the difference in frequency between the 2 signals. When the signals are in phase, they summate to an amplitude sufficient to stimulate, but no stimulation occurs when they are out of phase. The beat frequency of IFC is equal to the difference in the frequencies of the 2 signals. For example, the beat frequency and, hence, the stimulation rate of a dual channel IFC unit with signals set at 4200 and 4100 Hz is 100 Hz.

  • IFC therapy can deliver higher currents than TENS can. IFC can use 2, 4, or 6 applicators, arranged in either the same plane, for use on such regions as the back, or in different planes in complex regions (eg, the shoulder).

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