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Asthma Interferential Therapy and Chartered Physiotherapy

by Wendy Emberson(more info)

listed in asthma, originally published in issue 36 - January 1999

A five-year-old boy developed asthma at six months old after being prescribed antibiotics for an ear infection. Up to that point, he was a normal healthy child. After a short course of Interferential Therapy [IFT] and chest physiotherapy, this child had no signs and symptoms of the asthma and no longer needed the ventolin or becotide. He has remained healthy and symptom free for four years. After his last session, he stood by a field and watched the farmers cut the hay. Despite the clouds of dust all around him, he only had a slightly runny nose.

Unfortunately, no interest was shown by any of the medical practitioners concerned, despite the obvious benefits.

Wendy Emberson demonstrating pad positioning during her I.F.T. Workshop

Wendy Emberson demonstrating pad positioning during her I.F.T. Workshop


What is Interferential Therapy (IFT)?

IFT is a system of getting a low frequency current into the body. Two medium frequency currents are applied to the skin in such a way that they "interfere" with each other to produce a "beat" frequency. This beat frequency is the difference between the medium frequency currents. The body recognises it as the required low frequency current. The reason for using medium frequencies in this way is that the lower the frequency the higher the resistance of the skin to the current, i.e. the lower the frequency the more the sensation you feel. Low frequencies can actually be painful.

The importance of using low frequencies is that it has been shown that the body itself produces low frequency currents between 1 and 256 Hz. Different systems in the body produce different frequencies and these can be picked up by ECGs, EMGs and EEGs. By using specific frequencies and frequency ranges, then different systems can be stimulated and activated. In short, IFT stimulates the body to heal itself. One of the commonest uses of IFT is to increase the rate of inflammation, thereby speeding up the healing process. For example, IFT can shorten the time it takes for ligaments, tendons and even bone, to heal.

Dr Nemec was an Austrian doctor, and in the late 1940s he invented IFT as a method of getting low frequency currents into the body. Although good results were achieved with these early machines, they were very limited in the possible applications and the frequencies produced. It was in 1949 that IFT came into this country, and it has been used by physiotherapists ever since. But it was not until 1979 that the first British machine was made by the research department at St Bartholomew's Hospital London. That collaboration between the Medical Electronics and the Physiotherapy Departments produced the "Medeci" machine that revolutionised IFT as a therapy. The frequency range was increased from 1-100Hz to 1-250Hz, and the possible applications were only limited by the imagination of the physiotherapist. This has since led to a world-wide re-emergence of IFT as possibly the most comprehensive and versatile physical treatment system.

Chest Physiotherapy

In these days of drugs and surgery, few people are aware of the benefits and place of physiotherapy in the treatment of asthma.

20 years ago, physiotherapy was given to asthma patients alongside the drug regime. This involved re-education and training of lung function and correct breathing patterns to give the patient the control over the condition. It also took away a significant proportion of the fear associated with an asthma attack, which could increase the severity of the breathing difficulties. Chest physiotherapy worked very well, but as more drugs came on to the market these tended to take priority over the rehabilitation of these patients, and while this "physical treatment" is still available it is not generally provided in conjunction with the drugs.

The recent "revolutionary" Russian system for treating asthma is only a more regimented version of the chest physiotherapy of 20 years ago in the UK! The only difference is that in Russia they have continued to develop a technique that has been shown to work, and not limit the treatment offered to the patient by only considering drugs. They have not thrown the baby out with the bath water.

If a patient is diagnosed as having asthma, very often the doctor will tell them, "Take some exercise. Go swimming!" What is not understood by either the doctor or the patient, is that the physiotherapist will assess the patient in terms of breathing patterns, lung function, their general fitness and even their psychological make-up and attitudes in order to devise a graded training programme.

This is not an "off the peg" programme, it is "tailor-made" for the individual patient and their particular condition. The specialised physiotherapist has many skills and techniques to draw on.

Maybe this is another problem. Physiotherapy cannot be standardised and churned out as a "universal pill".

Pad positioning

Pad positioning

Interferential Therapy

IFT was originally developed by an Austrian doctor in the late 1940s, and very soon after it came into use in the UK. It is a treatment that uses the same electrical frequencies as those produced by the body. Two medium frequency currents are made to "interfere" with each other to produce a beat frequency that the body recognises as a low frequency current. But it was not until the late 1970s that the first British machine was made at St Bartholomew's Hospital, London. This revolutionised the technique and allowed Chartered Physiotherapists to treat many more conditions even more effectively. Unfortunately there has been very little "scientific research" carried out until recently, but the clinically-observed effects are based on nearly 50 years of work by many chartered physiotherapists for a whole range of conditions.

But it would appear that IFT, and the physiotherapists involved directly with its use, are in a "no-win" situation. Medicine today expects there to be proven, research evidence of the effects, side effects and contraindications of any therapy, be it drug or electrotherapy – even surgical techniques are coming under scrutiny.

There is no problem with this much more "scientific" approach, except that research papers can be misleading and ill conceived. They should not be regarded as proof positive, merely because they are designated as research.

No account has been taken of the work, knowledge and experience of the chartered physiotherapist, who has been trained extensively in the use of electrotherapy modalities, and possibly more importantly, knows when NOT to treat. For instance, it is expected that no chartered physiotherapist would carry out IFT across the chest of a patient with a known heart disease.

IFT in the hands of physiotherapists who have no recognised qualifications, or indeed other professions where electrotherapy is not included in their core knowledge, may indeed be putting the patient at risk through ignorance.

There are no legal restrictions over who gives the treatment, and therefore no safeguards for the patient. The general public should be aware of these facts.

Interferential Therapy and Asthma

Treatment of asthma, using Interferential Therapy (IFT) has been shown to be a valuable treatment system for many years. The technique was first described as far back as 1965, and in 3 successive physiotherapy textbooks the authors describe the value of IFT in the treatment of asthma. In 1988, there was a study carried out in Japan, which demonstrated the benefits of IFT in asthma.

In 1996, a physiotherapy university student in his final year demonstrated that IFT had a measurable beneficial effect on bronchodilation in people who smoke cigarettes. As an undergraduate student, he was not allowed to carry out the research with asthmatic patients, but he did manage to show using accepted research techniques that IFT causes bronchodilation, or opening of the airways. This was a highly significant finding and should have generated many more research projects and trials. Unfortunately it has yet to be published in any journals, so very few people are aware of his work.

1 in 7 children and 1 in 25 adults in the UK suffer from asthma. That is a total of 3.4 million people.

The "Orthodox Alternative"

Why is it that a treatment regime of IFT and routine chest physiotherapy is almost universally ignored, even though it is carried out by an orthodox, recognised medical profession?

Could it be that like the Russian technique it will not be taken seriously until the mechanism of the treatment is fully understood, despite years of clinical evidence? Or is it just that doctors can't do it, therefore it must be ineffective? Maybe it is because our society has been conditioned to think that for a treatment to be effective it must also have potentially serious side effects? IFT and chest physiotherapy either works or it doesn't, provided the treatment is given by a chartered physiotherapist who will be aware of the few contraindications.

We do not fully understand how IFT works, but we do have many years of clinical observations that suggest a number of possible mechanisms. I suspect that one of those mechanisms is on the immune system. An initial university study in the late 1980s showed just such an effect. Perhaps the effect is to "help the body" to correct the defect in the immune system that causes the asthma? Perhaps treating the symptoms with drugs is attacking the problem from the wrong end? Treatment of related conditions like hayfever and sinusitis are easy with IFT. Asthma takes a little longer!

In the late 1970s, when I was working at St Bartholomew's Hospital, London, the research engineers who built the first British IFT equipment, found a reference in the archives that went back to the days of Faraday. He worked with electricity and electromagnetism in the first half of the 19th century, and was quoted as saying that he could see a use for electricity in medicine, but not for anything else. As he actually invented the first dynamo he proved himself wrong. It is such a pity that the medical profession in favour of drugs and the drug companies has largely ignored the medical uses he predicted.

Chartered Physiotherapy is over 100 years old. It is the only state recognised qualification which involves a three year honours degree course in physiotherapy. Electrotherapy in its many forms has been a major part of our core training for most of that time. Almost every form of energy, short of nuclear energy, has been applied to the patients for a whole range of conditions – from alopoecia to piles, from sports injuries to Raynaud's disease, and from irritable bowel syndrome to asthma. Couple the electrotherapy with a whole range of manual therapies, manipulation and all the rehabilitation techniques and you have a profession that has moved a long way from the old days of heat, massage and exercises.

The diversity of conditions that can be treated by a chartered physiotherapist has inevitably led to specialisation. For almost every speciality in medicine there is a corresponding speciality in physiotherapy. In the same way that you wouldn't take your broken leg to a gynaecologist, don't ask a neurophysiotherapist to treat asthma. It takes many years of post graduate study to specialise in a particular area, but unfortunately we do not yet have the same recognition as consultants.

Although there are more than 20,000 chartered physiotherapists in the NHS, there is almost always a waiting list. The 2800 chartered physiotherapists who belong to the Organisation of Chartered Physiotherapists in Private Practice [OCPPP] can usually see patients within 48 hours. The trading name for OCPPP is PhysioFirst. You can find your local member in the Yellow Pages in the OCPPP block advert, or you can ring the Administration Office at Southend 01702 392124, or even visit their website at


IFT Textbooks
Emberson, M W (1996) Interferential Therapy Workbook Allied Mouse
Savage, B. (1984) Interferential Therapy Faber and Faber
Nikolova, L (1987) Interferential Therapy Churchill Livingstone

Relevant papers

1. Charman, R.A. "Bioelectricity and Electrotherapy – Towards a new Paradigm?" Physiotherapy, Vol 76, No 9 September 1990 to February 1991, vol 77, No 2.
2. Fernandes, Hubbard and Undem. "Release of inflammatory mediators from guinea pig trachea by electrical field stimulation: lack of neuronal involvement" Division of Allergy and Clinical Immunology, The John Hopkins Asthma and Allergy Center, Baltimore, Maryland USA 1994
3. Green RJ, Laycock J "Objective Methods For Evaluation of Interferential Therapy in the Treatment of Incontinence" IEE Transactions on Biomedical Engineering, Vol. 37, No. 6. June 1990
4. Hon-Chi Lee, John J, Cai and Hongwe Y U. Effect of Protein Kinase C on Cyclic 3', 5' – Adenosine Monophosphate-Dependent Phosphodiesterase in Hypertrophic Cardiomyopathic Hamster Hearts. The Journal of Pharmacology and Experimental Therapeutics Vol. 270 No. 3 1171-1176 1994
5. Kok-Swang Tan, Johnson David L. Ventricular fibrillation caused by interferential versus alternating currents. IRCS Medical Science: Biochemistry; Biomedical Technology; Cardiovascular System; Cell and Molecular Biology; Connective Tissue, Skin and Bone; Experimental Animals; Nervous System; Physiology IRCS MED. Sci., 14, 307-308 1986.
6. Meyer-Waarden, K, Hansjurgens, A, Friedman, B. "Demonstration of Interferential Current in Deep Biological Structures" Biomedizinische Technik, Vol. 25 Sept 1980
7. Shafshak T S, El-Sheshai A M, Soltan H E. Personality Traits in the Mechanisms of Interferential Therapy for Osteoarthritic Knee Pain. Arch Phys Med Rehabil 72 (8): 579-81 July 1991
8. Shuto, H. Nakagami, K. Suzuki, H. and Noguchi, E. "ILF therapy on Patients with Bronchial Asthma" Division of Respiratory Disease, School of Medicine, Showa University Fujigaoka Hospital, Japan.
9. Szehi E, David E. The Stereodynamic Interferential Current – a New Electrotherapeutic Technique Electromedica 1/80
10. Thom H. Stereodynamic Interferential Current Therapy – Fundamentals and Initial Results Electromedica January 1980
11. Treffene, Robert J "Interferential Fields in a fluid medium" Australian Journal of Physiotherapy, Vol. 29, No 6 1983
12. Wright G S. (1996) The effects of Interferential Therapy on bronchodilation in a smoking population with a view to establishing a standard protocol in the respiratory compromised patient. Not published.


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About Wendy Emberson

Wendy Emberson is a chartered physiotherapist who has been working in her private practice for 20 years specialising in orthopaedic medical and musculo-skeletal conditions. She can be reached at her clinic on Tel: 01279 654020.

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