Introduction (hereafter) Was first developed as a technology around the middle of the 20th century in Europe, and has been an established clinical practice in physiotherapy since the 1970s (Kitchen & Bazin, 2002). IFT has not been precisely defined in medical literature, but may be described as a system of medium and varying frequency alternating currents of moderated amplitude, transmitted through the skin, with the objective of interrupting nerve transmission for therapeutic purposes (Kitchen & Bazin, 2002).
IFT is not used alone, but is designed for use in conjunction with other strategies to manage pain and to promote healing. It is therefore to validate in terms of efficacy, by modern scientific principles (Kinchin, 2004). IFT is in widespread use in the U. K. and Australia (Kitchen & Bazin, 2002); much of this is based on anecdotal conventions, rather than on scientific evidence (Strong et al, 2001). However, some patients report so much relief, that the technology cannot be dismissed out of hand.
This document reviews representative literature on the use and limitations of IFT, and concludes on how it can be developed in future. Critical Literature Review of Interferential Therapy of Soft Tissue Injuries IFT is similar to TENS (Transcutaneous Electrical Nerve Stimulation), but a distinct form of electrotherapy. IFT uses various permutations of frequencies and amplitudes to interrupt normal nerve transmission over specified locations of the body. Such interruption may be either by way of stimulation or inhibition (Strong et al, 2001).
The actual administration of IFT has therefore to be precisely balanced to replicate reported results, because even minor changes of frequency and amplitude may produce contradictory results. IFT is a technology which is better established as a conventional practice of physiotherapy, than a proven algorithm of formal medicine. IFT suffers from strong opposition in certain medical circles because of the absence of strong support in scientific literature, and seems to survive in clinical settings based on strong patient support.
This is why IFT finds widespread mention in standard texts on pain relief and rehabilitation from injuries, though it does not have incontrovertible support from clinical trials. IFT is reported to have significant effects on a variety of soft tissues. Apart from nerves, IFT can also influence blood supply, stimulate muscle contraction, and promote wound healing (Strong et al, 2001). IFT has even reported as being effective against edema (Street, 2002): this may be because of its effects on blood vessels. It has to be said that evidence in support of such broad based claims is lacking, and even contradictory.
However, it does appear that IFT can be integrated in to the treatment of injuries and wounds, as well as for relief from pain. It seems to be crucial to position the electrodes exactly, so that the interference and beat frequency occurs over a precise spot in the body, and to ensure the correct wave pattern for targeted and specific action on soft tissues. It may be that experiments in which IFT has not produced significant benefits, included variations in terms of interference patterns, and location of such interferences, which affected efficacy.
IFT is distinct from other forms of electrotherapy, including the more extensively researched TENS. These distinctive features highlight much of the literature on the technology (Strong et al, 2001). IFT can be used directly above the site of pain. This includes following a superficial nerve from its root in the spinal column, to the course over which it runs. This feature makes it superior for pain control in certain circumstances. IFT can also be used with large electrodes and follow the quad polar technique for effect on deep-seated sites (Strong et al, 2001).
Thus, IFT is a flexible technique, capable of treating superficial soft tissue, as well as organs deep in the body cavities. This feature also explains the broad range of medical conditions for which IFT has been used. Physiotherapy clinics which invest in an IFT system can expect a wide range of applications for the equipment. A second major advantage of IFT is that it works with amplitudes and frequencies which cause no damage to the skin, and consequently, it can be administered without undue discomfort for the patients.
Most patients even report a pleasant sensation on being given IFT (Kitchen & Bazin, 2002). IFT reduces skin resistance, which is responsible for the quality of reaching underlying tissues without any superficial harm. Another crucial difference between IFT and other forms of electrotherapy such as TENS is the use of suction pads. The latter add to the sensory stimulation (Strong et al, 2001). Rhythmic alternation of negative pressure can be used to simulate a massage when IFT is used in areas such as the spinal column.