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September, 2016 PEMF Therapy and Your PracticeBy Mickey Scheinowitz, PhD and Howard Fidler, DC, FICC, FICA Since low-level laser therapy, aka cold laser or laser biostimulation, was introduced more than 20 years ago, it has slowly gained acceptance and is today used in many institutional and private practices. It has had a slow adaptation curve. The same will hold true of the use of low-frequency pulsed electromagnetic field (PEMF) therapy in our field. This article introduces PEMF therapy and explains how it can be applied to treat muscular aches and pains, particularly of the lower back. The efficacy of PEMF therapy has been well-documented.1-10 PEMF is a combination of electromagnetic fields at a given frequency. There are many PEMF devices on the market today, some stationary and some portable, varying from nano (10-9) and pico (10-12) tesla to several tesla; and from a few hertz to mega (106) hertz. Devices manufactured outside the U.S. require a U.S. Food and Drug Administration (FDA) listing to be sold here. The Science Behind PEMF Therapy Magnetic fields (MFs) and electric fields (EFs) are generated by many sources and are present everywhere around us. Some sources are man-made, while others are naturally occurring – such as the static MF of the Earth and solar activity. Units of MFs are measured in tesla (T) or gauss (G), where 1T = 10,000G. For reference, the Earth's MFs range from 25µT to 65µT (0.25G to 0.65G). MF intensity is inversely proportional to the square of the distance from the source. MFs can be defined by their intensity or amplitude, wave frequency and waveform. Numerous articles have reported on studies of the effects of short and long-term exposure to environmental PEMF, mostly 50 Hz to 60 Hz. Time-varying electromagnetic fields (EMFs) used in therapy are also known as PEMFs. EMFs are non-ionizing and athermal; i.e., they produce no significant heating of the tissue. One of the common theories regarding MFs' mode of action is based on inducing small EFs on the tissue, thereby promoting certain biological effects. PEMFs are recognized as real physical entities that promote improvements in various health conditions, even when conventional treatments have failed to produce adequate clinical results. PEMF therapy provides a non-invasive, safe and easy method to directly treat the site of an injury, the source of pain and inflammation.11-12 Medical literature is abundant on the mechanisms of action and the therapeutic effects of PEMF in a variety of health conditions. Despite extensive evidence included in literature demonstrating the beneficial effects of extremely low frequency (ELF) weak magnetic fields (WMFs), there is little standardization in this area and a large variety of PEMF therapeutic devices and treatment parameters exist. In addition, there is uncertainty regarding the biological mechanisms of action taking place during EMF-tissue interaction. Proposed Mechanisms of Action for PEMF Therapy There is basic and clinical evidence that time-varying MFs can modulate cellular and tissue function in a physiologically and clinically significant manner.13-14 For example, we have seen 16 Hz MF of 80-100 nT induce a cardioprotective effect in rats following acute myocardial infraction (AMI).15 We hypothesized that 16 Hz MF would induce KATP ion channel openings to mimic the pharmacological effects of potassium ion channel openers, which are known to be cardiac protective in certain human clinical trials. This effect is achieved through shortening of myocardial action potential, followed by decreases in calcium ions entry, having an inhibitory effect on the inotropic state of the heart and serving a cardioprotective effect for the ischemic myocardium following AMI. When entry of calcium decreases, oxygen consumption of contractile elements is reduced and calcium loading during the ischemic period and the subsequent recovery is expected to be reduced. Support for our hypothesis was shown by Fixler, et al.,16 and Yitzhaki, et al., who showed an effect of 16 Hz and 40 nT MF on cardiac myocyte Ca2+ transients, via modulation of KATP channels opening. Other studies suggest MFs induce EFs and small currents on the tissue, thereby promoting certain biological effects. As alternating current flows in a treatment coil, the emitted MF penetrates the body, inducing current and EFs in the exposed tissue. The induced currents or EFs are controlled by several characteristics of PEMF therapeutic devices: the waveform, the rise / fall time and the rate of change of the MF peak-to-peak. Therefore, it is important to specify those modifiable characteristics. EFs and action potentials are produced in body cells and tissues to promote ion-channel opening and transportation of ions efflux (such as Ca2+, K+, Na+, Cl-) in and out of the cells, thus constituting the basis for physiological activity.17 EFs generated in body tissues are of magnitudes ranges 0.01-100 V/m; therefore, it can be ascertained that such induced EFs can promote physiological effects in accordance with the tissue type. With suitable intensities and appropriate time domain characteristics, it is possible to evoke action potentials using external coils. The coil produces a time-varying MF that penetrates into the body. The MF induces an EF that can depolarize cell membranes in the tissue.18 The electrical properties, such as conductivity and resistivity of each tissue, interacting with the field to which it is exposed, impose certain highly specific changes in the energy characteristics of the targeted cell / tissue. In addition, other investigators have found that the frequency of alternating current (AC) MF which causes an effect on the potassium channels also depends on the direct current (DC) component of the MF (in ranges of 40-50 µT) based on the ion cyclotron resonance frequency theory.19 In this process, a resonant transfer of energy from a time-varying MF occurs when its frequency matches the cyclotron resonance frequency (or its harmonics) of an ion moving within a static MF. Therefore, the possible mechanism for the influence of WMFs on biological systems may be the result of the combination of applied static and alternating MFs which affect the interactions between calcium ions and calcium-binding proteins.20-21 PEMF does seem to have biological effects on body tissues and organs. Further exploration of the clinical benefits and outcome measures on a variety of patient populations with different underlying diseases, as well as understanding the mechanism(s) in which PEMF produces its therapeutic effects, is certainly warranted. Clinical Applications This co-author [Dr. Fidler] has been in practice for close to 20 years, and has seen and used various therapeutic technologies. For the past 18 months, I have been using a portable PEMF unit to reduce pain and inflammation, and increase cellular regeneration and healing. Many of my patients have benefited greatly from the application of PEMF therapy. Here are a few examples describing the outcomes achieved thus far:
Summing Up A large body of evidence suggests PEMF has positive therapeutic effects on a variety of clinical indications. The mechanisms underlying such effects continue to be studied by active institutional and private-practice clinicians, in clinical trials, and in human and non-human animal experimentation. Since no single therapy is effective for all patients, the application of PEMF may be an important therapeutic enhancement for select patient populations when used as part of an overall chiropractic regimen. References
Professor Mickey Scheinowitz is the chief scientific officer of Aerotel USA, Inc., and chairman of the Department of Biomedical Engineering and director of the BioMedical Technology Innovation Program at Tel-Aviv University, Israel. He spent two years as a post-doctoral fellow at the National Institutes of Health and two years at the Washington Hospital Center in Washington, D.C., during a sabbatical from the university. Dr. Howard Fidler has treated hundreds of athletes ranging from elementary school soccer players, to high-school state champions, to Olympic medalists and professional athletes. His knowledge of functional biomechanics of the spine and extremities sets him apart in his field. Dr. Fidler received his DC degree from Cleveland Chiropractic College / Kansas City in 1997.
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