The Journey of Interferential Therapy

The first IFT machine was designed in Austria by Dr Nemec in the late 1940’s. This Nemectrodyn was limited in frequency selection, electrode placement, output, and treatment range.

 IFT first came to Britain in 1949 (the year I was born - co-incidence or what!) and continued in popularity for the next 40 years or so, but problems with electrode placement, frequency selection, and the expansion of manual therapy techniques meant it fell from favour from all but the most ardent fans within the profession. This is the fate of virtually all electrotherapy now!

In 1978 when I was at Barts hospital, there was one of these machines sitting outside of the office. I asked my boss, the District Superintendent Physiotherapist, what it was. She told me it was an Interferential machine and that I should read the handbook that came with it. This I did and it seemed that it could treat everything from constipation to stroke! So I set about some simple trials in the Physiotherapy Department and realised that the handbook was not that far from the truth!

Unfortunately, you could only use 4 electrodes of the same size and the set up was complicated to say the least! Any variation from the “rules of application” and it wouldn’t work.

If a bus went past outside the Physiotherapy Department then it would “knock it out of tune” and we would have to set it up all over again!

Despite all of this, Professor Lilyana Nikolova, In Bulgaria, got some remarkable research results in the mid 1980s for a whole range of conditions including chronic hepatitis, gut problems and even diabetes snd inflammation of the kidneys, Her book Treatment with Interferential Current was published in 1987.

Next came a Dutch machine with a wider range of frequencies and without the need to calibrate the machine via its internal oscilloscope every time you wanted to use it!

In 1979 the first British machine was designed and developed by the Medical Electronics Department at St Bartholomew’s Hospital, London - the Medeci. This generation of equipment was also notable in that the bio-engineers actually worked in collaboration with myself, and our clinical physiotherapists at Barts in order to produce a machine with the “end user” in mind!

This is when I first really became involved with IFT and began to realise its full potential.

The bio-engineers who developed the Medeci IfT then formed their own company, SNS Bioengineering Ltd, and produced the second generation of British IfT, again with my clinical input. Even though it is now 30+ years since its development, I still use these machines in clinical practice.

There is no other machine on the market, anywhere in the world, that gives me all the features I need to treat such a wide variety of conditions.

What has been almost entirely overlooked is that during all these decades  IfT was seldom used for pain relief, whereas IfT today has now been reduced to an expensive TENS machine and if it is taught at all - then it is for pain relief!

When Physiotherapy became an all graduate entry profession in the mid 1980’s, additional areas of study were required by the BSc (Hons)course, which meant that a large section of what was once “core knowledge” has all but been removed from the curriculum. Most of the electrotherapy content was taken out and with it our ability to actively treat a wide range of conditions.

Manual therapy, rehabilitation and exercise therapy have now become the main areas of activity and the actual value and place of Physiotherapy within the healthcare professions has changed dramatically as a result.

A good deal of the old electrotherapy syllabus has, quite rightly, been consigned to the museum through lack of evidence and even clinical effectiveness. However, there are still some anomalies. I fail to understand why pulsed shortwave therapy is still being taught and used and yet IFT, ultrasound and lasers have all but fallen by the wayside.

Interferential Therapy (IfT) is viewed as an electro-analgaesic or a muscle stimulator. I have worked with IfT for over 40 years, seen the results first hand and have access to the research that was carried out in the relatively early years.

My major concern is that a valuable treatment system will be lost to our profession and our patients.

This wound was on the anterior shin and was the result of falling over a large cardboard box. This sliced the leg open and the resultant flap was removed in The Accident and Emergency Department leaving a palm sized open, full thickness wound.

The Tissue Repair unit at the hospital predicted (one week before I started the treatment) that it would take 6 months to heal. The wound was being dressed (using only Inadine) at the patient’s local GP surgery for 6 weeks prior to my starting the IFT treatment. There were no visible signs of healing and in fact was possibly worse. I thought about including that photo, but considered it might offend some readers/viewers.

All I used was IFT, simple dressings ie no pharmaceutical impregnated dressings, just plain ones, and sterile wound care. Ultimately, the wound was healed in 3 months and not 6 as predicted by the hospital.

Consider this Wikipedia entry dated 2011:

 “Interferential Therapy (IFT) is one of the various types of Physical Therapy. It uses a mid-frequency current for treating muscular spasms and strains. The current produces a massaging effect over the affected area at periodic intervals, and this stimulates the secretion of endorphins, the body's natural pain relievers, thus relaxing the strained muscles and promoting soft-tissue healing. Use is contraindicated if the affected area has wounds, cuts or infections”!

Since that time, there have been a number of different perspectives put forward, but I would like to offer a different viewpoint for consideration and even further research based on my work with IfT.

The picture of the wound above shows that IfT in fact has a beneficial effect on wounds and is not contraindicated.

In addition, I have successfully treated animals – surely questioning the placebo effect? I was a founder member  of the Association of Chartered Physiotherapists in Animal Therapy (ACPAT), and I used to treat the occasional animal including dogs and horses.

 I have treated horses with tendon injuries and dogs with arthritis and spinal issues. The most notable was a greyhound that had been chasing a Labrador and slipped over. This dog, named Alice, had 3 lumbar disc lesions that was confirmed by the vet. Unfortunately, it was so bad that Alice had become paraplegic and the vet was saying that there was nothing that could be done. The owners knew that I treated musculo-skeletal problems in humans and came to ask if there was anything that I could do as the dog was only 3 years old.

With not much hope, I went to see the dog that had become incontinent and had a full-thickness pressure sore on one hip. I thought that all I could do was to try IfT. The technique I used was to put one electrode over the lumbar spine and one electrode on each leg. The frequencies I used was 45 – 90Hz to try and increase the blood supply to the spine and to see if I could get any muscle contraction out of the legs. After only 3 sessions of 15 minutes in a week, Alice got up and walked off! In short - she made a full recovery.

The owners moved away from the area, but I met them again some 15 years later and they said that Alice had lived a full and fit life until she was about 13 years old. This could not have been a placebo response, neither was it down to natural progression of the condition given the very short treatment and resolution time.

I have since used this technique on people with low back problems with good results, and the treatment protocol has become known as the “Alice technique”. This must be a possible area of research as I don’t see human paraplegic patients in my private practice.

I am certainly not saying that here is a cure for paraplegia, but it may well prove useful in affecting the inflammation around a spinal cord injury thereby minimising the ongoing damage following the injury. There is also the consideration that laboratory animal research in the 1980s (Nikolova) showed that using IfT at certain frequencies will stimulate nerve regeneration.

IfT is very definitely not new and neither is it some old, physiotherapy “snake oil” electrotherapy treatment!

 The clinical results I have seen first hand, are remarkable and cannot be ignored any longer.

With very little electrotherapy being taught in the universities, we now have generations of physiotherapists who are completely unaware of how, why, when, and when not to treat using almost any electrotherapeutic device – let alone IfT. Couple that with the apparent lack of recent research of any note, we are now in the situation where nearly all electrotherapy has been consigned to the museum. Some may say good riddance, but I certainly would not!

The majority of physiotherapists these days don’t have a problem with this state of affairs. However, there are still enough of us who qualified before the mid 1980’s who have the knowledge, the training, the experience and the enthusiasm to keep using certain modalities that we know work from long clinical experience.

During my training in the late 1960s and early 1970s, Physiotherapy was divided into Primary Care and Rehabilitation. Of course, the Primary Care element was principally the province of musculo-skeletal conditions and rehabilitation was the majority of just about every other specialty.

Electrotherapy gave us many and various effective treatments, but nowadays nearly all the work of the Physiotherapy profession, in any speciality, is rehabilitation.

We have lost along the way the treatment of skin diseases; wounds and ulcers; pressure sores; a good proportion of medical chest conditions and even gut problems such as IBS, spastic colon and colitis. In other words, we have dropped from the syllabus/profession a whole range of conditions that used to respond to actual physical/electrophysical treatment that have very few, if any, side effects.

It is interesting that these days the few remaining electrotherapy companies in the UK only sell about 30% of their devices to the home market. So, it would appear that Europe and most of the rest of the world still see a value and a place for electrotherapy.

I am not saying that all the treatments we used to have were effective, but there are some that have proven themselves over the years – both clinically and in the research.

I really don’t know why pulsed shortwave diathermy is still used!

There is an irony when you really start to look at some of the “new” electrotherapies such as Extracorporeal Shock Wave Therapy. Apparently, it started in the 1970s  as a non invasive treatment for kidney stones and it was in the 1980s when it was considered as a possible therapeutic treatment.

“The full details of physiological and therapeutic mechanisms are yet to be identified, though a range of effects have been confirmed and several others postulated.” Professor Tim Watson www.electrotherapy.org

Shockwave therapy has less “research and clinical credentials” than IfT and yet practitioners are prepared to pay many thousands of pounds for the machines and they charge anything from £45 to £250 per session! What is equally amazing is that patients are apparently more than happy to pay the fees as it is essentially being marketed as an alternative to surgery, which is the far more costly option! It also has NICE approval. (National Institute for Health and Care Excellence for those outside the UK)

Just because something is new does not make it better. Just because something is old does not make it better either, but not to acknowledge nearly 70 years of clinical experience by thousands of physiotherapists, together with many hundreds of research papers is not the work of a logical, progressive, serious and analytical profession.

The following is the Foreword from Prof Nikolova’s textbook on IFT (May 1987) written by Jeanne-Marie Ganne[1] and I have included it here because I am amazed how relevant it is to today.

“It is a pleasure to have the opportunity of acknowledging Professor Nikolova’s major contribution to interferential therapy.

English-speaking physiotherapists will welcome this book, which is a record of the author’s vast experience of the use of interference currents over a period of 23 years.

Twenty years ago, few physiotherapists had heard of interferential therapy in Great Britain and Australia, and very few had used it clinically. There was at the time in the United Kingdom a phase of diminishing interest in the therapeutic use of direct and low frequency electrical currents, apart from faradic or faradic equivalent currents to produce motor stimulation. In the United States Interferential Therapy was virtually unknown. Although the original work of Dr H Nemec was  followed up on the European continent, and early reports of treatment and clinical investigations were presented at conferences and published in European journals, it was difficult to obtain information on the subject in the English language.

Professor Nikolova became a generous source of information to any physiotherapist who sort her assistance from abroad. Her early recognition of the advantages and potential value of interferential therapy and her extensive experience of its use for a wide variety of inflammatory and traumatic conditions have effectively contributed to its development in many treatment centres.

Interferential therapy was introduced in physiotherapy teaching units and clinical departments in Adelaide in 1971. Professor Nikolova’s work on fractures also stimulated the introduction of this treatment for delayed union in Adelaide in 1974. She was an early pioneer in drawing attention to the effects of these currents in hastening resolution of inflammation and tissue regeneration, in addition to their analgaesic effect. This prompted her early use of interference currents in the treatment of fracture complications and to promote repair of bone, showing the advantages of a non-invasive technique which stimulates both soft tissue and bone. This was in contrast to the numerous experiments carried out by various research workers which led, in the 1970s, to surgical implantation of electrodes at fracture sites in order to stimulate callus formation with small amounts of direct or pulsed currents, given continuously.

Professor Nikolova’s clinical observations of the results of treatment prompted her to undertake the experimental studies detailed in the second chapter of this book. Results of those histochemical studies showing the effects of interferential therapy on capillaries and on the activity of certain enzymes should be of special interest to those who have presumed that metabolic changes must occur at cellular levels.

The author does not set out to present the complex physics of the currents, and she also recognises that the effects of different frequencies require further investigations. The major value of this book is in the reports of clinical treatment, in the physiological test used to determine results objectively and in some comparisons of the effects of various treatments. As a Professor of Physiotherapy and Rehabilitation, Doctor of Science and medical practitioner, the author points out the importance of a combined approach in treatment, where indicated, and how interferential therapy can supplement or be supplemented by additional therapy, including chemotherapy.

Whereas there has been a tendency to use interferential therapy principally in the treatment of musculo-skeletal problems, the author stresses its value for vascular abnormalities such as Sudeck’s atrophy, for pelvic inflammatory disease and sterility, in the treatment of nerve lesions and some visceral chronic conditions. Because of the basic metabolic effects described in the chapter on histochemical research, the effects on pain and sympathetic control, the penetration of the currents, the absence of any unpleasant sensation and few contra-indications, it is to be expected that these currents can have a wide application.

Although the clinical reports frequently refer to treatment  of chronic complications and cases whose early management proved inadequate, the author emphasizes the importance of early application of the currents which shortens the total number of treatments  required and obtains the best results. She recommends that an adequate trial of treatment with interferential therapy therapy should be completed, in many cases, before resorting to surgery.

With renewed interest in the effects and uses of electrical currents and electro-magnetic fields in medicine and in view of the constantly rising costs of health services, it is important for the medical profession to be aware of the value of therapy which can play a part in preventing prolonged disability and the need for very costly procedures. It is equally important for physiotherapists to use these currents with appropriate understanding and careful skill and to evaluate different techniques themselves.

There is no doubt that this book will be a valuable source of clinical information to readers, and I am indebted to the author for her extensive contribution in this area.”

I hope you see my point!

May 2022: I have just read this paper that really sums up all my complaints! This paper was published in 2022, which at least shows that there are some people out there actually doing current research, but this is looking at using IfT for pain relief only!

When reading through this paper, the focus of attention was mainly on the variations of the carrier MEDIUM frequencies used by different people over the years. They have missed the fact that IfT is a way of generating a LOW frequency current within the body. This is the WHOLE POINT!

And this is before I repeat the fact that IfT is NOT an “electrical painkiller”. It’s major effect is on inflammation - let alone the circulatory system, immune system and nervous system etc. I totally agree that there needs to be more research to support the observed clinical effects, but once the precise mechanism of individual frequencies has been established then IfT, as part of the wole care package, will become the treatment of choice.

[1] Jeanne-Marie Ganne, M.C.S.P., Dip. T.P., F.A.C.P., recently retired as Senior Lecturer in Physiotherapy at the South Australian Institute of Technology, Adelaide. She is a Fellow of the Australian College of Physiotherapists and President of the Australian College of Physiotherapists.