Interferential therapy, also known as interferential current (IFC) therapy, is a form of electrical muscle stimulation (EMS) therapy that uses low-frequency electrical impulses to contract and relax muscles. The therapy is used to relieve pain, improve muscle strength and endurance, and promote healing in conditions such as muscle strains, sprains, and injuries.
Interferential therapy has been used for decades as a form of physical therapy and pain management. The therapy was first developed in the 1940s and 1950s, and has since become a popular treatment option for a wide range of musculoskeletal conditions.
Interferential therapy works by delivering low-frequency electrical impulses to the muscles through electrodes placed on the skin near the affected muscle or muscle group. The electrical impulses are delivered in a pattern that mimics the way the brain sends signals to the muscles to contract naturally. This pattern of electrical stimulation is known as interferential current (IFC). The IFC therapy uses two electrical waves that have slightly different frequencies.
These two waves interfere with each other, creating a beat frequency that is equal to the difference between the two original frequencies. This beat frequency is the frequency that is delivered to the muscles and is what causes the muscle contraction. The IFC therapy has been shown to be effective in recruiting muscle fibers, which can help to improve muscle strength and endurance. Additionally, the IFC therapy can help to reduce muscle spasms and improve range of motion.
Indications
Interferential therapy is used to treat a variety of conditions including muscle pain and weakness, spinal cord injuries, and paralysis. It is also used to improve athletic performance, and may be used as a form of physical therapy or as an adjunct to other types of therapy. It has been used to help people with a number of conditions such as chronic pain.
Transcutaneous Electric Nerve Stimulator (TNS) is a small lightweight portable device that goes off and on from 1- 150 times per second, which is referred to as frequency or rate, pulses per second ( PPS). The tens pain machine can be worn continuously, even sleeping with it on to help the patient sleep. A Tens machine is not addictive, nor like drugs, does it affect ones mental abilities to think and reason. Often if the Tens machine is turned off the pain comes back. There is no residual pain relief generally speaking when one uses a Tens unit. For many patients the tens pain machine may be worn continuously.
Interferential machines go off and on from 8,001 to 8,150 times per second. This is also referred to as frequency, rate, PPS and there is a relationship between frequency and depth of penetration. The interferential treatments go deeper into the body and affect more nerves. When the electricity is able to penetrate deeper then the better the treatment outcome is for the pain patient.
An interferential treatment generally lasts in the clinic for 20 minutes. During the interferential treatment the pain the patient is feeling goes away and, after the treatment, the pain is gone for some time period. The time from the treatment until the pain returns is called “carryover pain relief.” The biggest difference between a Tens treatment and an interferential treatment is the carryover pain relief period. With TENS the pain often comes back shortly after the pain machine is turned off. With interferential therapy the pain is gone and stays away for longer periods of time. As Interferential therapy treatments are increased then the carryover pain relief is extended.
What is most likely is when a patient starts using an interferential unit they may need to do 3 – 5 treatments the first 2 days. After the first week or few days then the patient finds they only need to do a treatment every 2-3 days. It is not unusual for a patient who has been in chronic pain for years to do an interferential treatment upon waking in the morning and/or upon going to bed at night. With tens or interferential one can use the unit anytime there is pain present. If using tens or interferential and its difficult to sleep, due to pain, then wear the unit all night long if it helps the pain go away and one can sleep. If using interferential therapy then use the AC adaptor and plug into the wall since the unit will be on for extended time period.
What happens if one falls asleep with an interferential unit on?
Nothing other than the patient is able to sleep. First, that will not be a problem. One will not be harmed in any way. On most interferential units, and on some TENS units, there is also a timer. Most timers can be set for 15, 30, 45 minutes of stimulation, or set on Continuous mode. If 15,30 or 45 minutes of treatment occurs and the unit goes off, but the pain comes back, then switch to Continuous and wear until the pain is gone. The explanation for this is the purpose of tens or interferential is to get rid of the pain signal. Neither a tens or interferential unit is meant for the patient to “feel the unit all the time”. The purpose is for the patient to not be in pain and to not feel pain.
So if the pain machine, whether tens or interferential is not being felt, then does that mean it is not working?
No again the purpose is to not feel pain. Many times after the interferential machine goes off the patient will not feel any stimulation but that is fine and expected. What the treatment goal is for the patient is to not feel pain, not to feel the stimulation. Second, the main goal with interferential is to extend the time periods when the patient is pain free, which is referred to as carryover or residual pain relief.
Why is that?
Unlike pain medications the goal with interferential is to not have to use the unit, to extend the carryover pain period and not be in pain. With medications it can be the opposite and the patient is increasing the frequency of taking pills, or asking for more or stronger drugs.
So its successful to not need to use the interferential unit?
Yes. The best outcome is when the use of the interferential unit has resulted in fewer treatments because there is less pain and it is not needed.. Third and last, but not necessarily least, is due to some chemical changes that occur in the body, as well as a patient being able to become more active, the real possibility that permanent change is occurring in the body and the unnatural pain impulse is being modified or simply goes away for good may be occurring.
The explanation for that is we know for sure that positive and negative charges affect our cell and tissue structures which includes nerves. Now that a patient can self treat as needed the ability to do such is opening up new possibilities of permanent structural change and the pain impulse is thwarted.
O.K. so how might we tell if this is being successful?
With an interferential treatment the pain will lessen or go away during the first 5 minutes of the treatment for most people. The results will be there within the first 20 minute treatment session. Remember that inferential treatments have been used successfully since the 1950’s and with utmost success. The big difference now is the treatments can be done by the patient at home, work or where needed, and not have to go to a clinic or hospital for treatments.
This new innovation in portable interferential is also much less expensive and does not involve taking off work, scheduling, and having to drive to a hospital or clinic for treatment.
How does one try tens and interferential to see which works best?
Either a tens unit can be tried or an interferential unit and one can see which helps most. Often the combination of using tens sometimes and interferential at other times is best for the patient. Also seek a pain machine that combines tens and interferential together in one unit so both tens and interferential can be tried using the same machine. Switch the treatment between tens and interferential as needed. Tens and interferential units use the same electrode pads, cables etc. so two sets of supplies are not needed, although interferential treatments because of more electrical energy, work best when larger electrodes are used than what is customarily used with only a tens unit. Interferential therapy has been used by physical therapists, chiropractors, pain clinics, physicians since 1953 with the same carryover pain relief results. It has been the mainstay of those medical professionals in treating patients suffering from chronic pain diseases. Some of the best results have been obtained for those who have been unable to find adequate treatments and they are successfully treated by “alternate”, non-drug methods and interferential treatments are the mainstay for those treatments. These are the typical diagnoses that have been treated by interferential therapy:
• Osteoarthritis
• Trigeminal Neuralgia
• Shingles
• RSD – Reflex Sympathetic Dystrophy
• Fibromyalgia
• Sciatica
• Chronic Low Back Pain
• Post Herpetic Neuralgia
• Neuralgia pain
• Phantom Limb Pain
• Headache pain
• Muscle pain
• Neck and Shoulder pain
• Inflammatory pain
• Multiple Sclerosis Pain
Many other pain conditions where the patient has been doped out on drugs or told “there is nothing else we can do”. Often the processes of rehabilitation, such as you see where one has suffered a “frozen shoulder”, are enhanced and healing increased by using interferential therapy in conjunction with doing the painful exercises. The interferential helps to overcome the pain created by the exercises and shortens the pain that follows after the exercises are over. None of this is new though.
Let me describe the process that has been going on and on for decades and is totally dependent upon interferential providing carryover pain relief.
The patient enters the Chiropractic, Physical Therapy, Pain Clinic or Physician office. Generally at the time of entry the patient has been very uncomfortable due to pain. It has reached the point the patient needs help or it has reached the point the patient is tired of using drugs and not being able to live life due to the masking in the brain. The patient is not going to keep using the drugs but is now hurting and it’s to the point of being unbearable.
The health care practitioner will normally greet the patient and begin to either, if chiropractic, do a manipulation if indicated, or if Physical Therapy, apply warm moist heat and soft tissue massage or stretching. Most chronic pain patients have already tried surgery, injections, pills, and conventional treatments to no avail. They are looking for something that just might work.
After the practitioner has completed the initial treatment the chances are excellent the patient will then lay on a treatment table and begin a 12 to 20 minute interferential treatment. There is a large clinical machine beside the table and the practitioner will apply 2 to 4 self-adhering electrodes to the patient. The machine is turned on with the instructions to the patient to tell the practitioner when the patient “feels the sensation”. The interferential machine is turned up till the patient declares it is feeling good to the patient and the pain has diminished. At this point the practitioner sets the timer on the interferential unit and will leave the room. The patient quietly lies on the table until the interferential machine stops treating. Once the machine stops then the patient in almost all cases actually feels better and the pain is either gone or severely diminished.
Now the “guessing game” begins. The patient, especially in the Chiropractic field, goes to the payment window and is asked to pay the bill. This is a crucial step in determining the efficacy of the interferential treatment. For many Chiropractic Physicians the service may not have been covered by insurance and the patient is paying out of pocket for the treatment.
If the treatment did not help the patient the patient will be:
• Reluctant to pay the bill or,
• Not come back for any future treatments
This is a critical moment for the patient and practitioner. In most cases due to the chronicity of the pain there will be follow up visits for care. The next appointment is also a guessing game. The guess is “when will the pain return” and a guess is made to have a return visit prior to the onset of pain, prevention is always the best course of action, or when will the patient be in so much pain an interferential treatment is needed. This isn’t something to ignore.
It will help to understand the patient now feels much better but the key is how long the treatment will last and the pain stay away. That is the carryover or residual pain relief period that interferential is famous for. That is also the guessing part of when to reschedule the return. This protocol is based on carryover pain relief and has been such for the last 60+ years clinically. It is also the proof of interferential therapy efficacy. The pain free period has to last at least till the patient pays the bill, and hopefully much longer so the patient will return!!!
It’s not only science but also patient success that matters. Did the interferential treatment work? If so the patient returns, if not, then good by or the next appointment is missed or not scheduled at all. That is the strength of interferential therapy over the decades. It has worked and worked well on the most difficult pain patients. The newness now is not that there is carryover pain relief, but with a patient being able to treat when needed with a portable interferential pain machine, then the carryover pain relief is getting extended over time. The newness of extended pain relief is what is and has emerged in the past 18 months. It’s the advent of self-treatment with interferential, without drugs, that is now challenging the understanding of the medical community.
Is there a physiological answer as to why longer periods of no, or reduced pain, is occurring?
It’s my contention there is. As stated there is no surprise that interferential provides immediate and long lasting pain relief. What is surprising is how, with self-treatments, the pain is prevented or treated and the treatments become less frequent.
There is an answer to the physiological side of electrical charges being used to heal. Nothing new as it’s well known anytime positive and negative charges of electricity are applied to the body there are very distinct chemical changes occurring. These charges have been used beneficially therapeutically for decades. For years positive and negative charges have been used to promote bone healing, non-union fractures, so the chemical and physiological changes are known. For many patients suffering with crush injuries amputation was the normal course until it was learned to electrically stimulate for unionization. The use of electricity would restart the process of the bones merging together and effecting a functionally stable reunion. Equally impressive is the continuing use of electricity for healing bed sores, decubitus ulcers, which started with the use of the form of electricity known as pulsed galvanic stimulation.
In the physical therapy profession small, portable electrical devices have been used to make bed sores fill in with tissue and eventually to close and heal completely. Of course with bones and soft tissue repair the body must have the necessary nutrients to effect the changes electricity can do. Electrical charges alone will not suffice since the electricity initiates the body’s response to heal and the body requires the necessary nutrients and hydration to accomplish the task.
There is no doubt with the pain patient that there exists a chemical process that is causing the pain sensation to be created and transmitted to the brain. That process is indicative of sickness, since chronic pain of unsubstantiated cause, is unnatural and requires therapeutic healing to stop the injurious processes. Possibly the use of interferential with the positive and negative charges is chemically altering the pain stimulus area and the repeated usage of the interferential unit to stop and prevent pain, is altering the chemistry of the area. That alteration may become permanent and it is that permanency which is stopping the unnatural pain impulses. With preventive treatment the body is stopping the chemical changes before they can cause pain.