PEMF Therapy and Your Practice

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:

• 41-year-old multi-sport male professional athlete who suffered from moderate LBP secondary to multiple fractures and facet syndrome. Daily pain ranged from 3/10 to 6/10; within a few weeks of applying PEMF therapy, his pain was gone.
• 35-year-old male truck driver suffering from moderate to severe plantar fasciitis with a pain level of 6-7/10. Applied PEMF therapy twice a day. Pain was reduced to 4/10 by the end of the first week of use; by the end of six weeks, pain was 1/10, measured at the end of the work day, and the patient is now fully functional.
• 40-year-old rugby player, post-ACL reconstruction, suffering from continuing edema and pain. Patient had restored ROM within two weeks of PEMF applications and pain levels have decreased from 5/10 to 1/10.
• 56-year-old female with three moderate cervical disc herniations. Limited cervical ROM and daily average pain levels of 5-6/10, with flare-ups to 8/10. NSAIDS were not helpful. Applied PEMF therapy twice daily; within one week, pain levels had reduced to an average of 2/10, with significantly increased cervical ROM.
• 23-year-old female professional mixed martial arts (MMA) fighter suffered a severe thoracolumbar sprain. Severe spasm and pain level of 7/10; severely limited ROM. Applied PEMF therapy; within one week, pain levels were down to 2/10 and the patient had returned to full workout.
• Finally, two world-champion female MMA fighters and one world-champion contender used a portable PEMF device I provided to them as prophylactic therapy during training. All three reported they recovered faster than they ever had during training.

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

1. Schnoke M, Midura RJ. Pulsed electromagnetic fields rapidly modulate intracellular signaling events in osteoblastic cells: comparison to parathyroid hormone and insulin. J Orthop Res, July 2007:933-940.
2. Yen-Patton GPA, et al. Endothelial cell response to pulsed electromagnetic fields: stimulation of growth rate and angiogenesis in vitro. J Cell Physiol, 1988;134:37-46.
3. Lin H-Y, Lin Y-J. In vitro effects of low frequency electromagnetic fields on osteoblast proliferation and maturation in an inflammatory environment. Bioelectromagnetics, 2011 Oct;32(7):552-60.
4. Lin H-Y, Lu K-H. Repairing large bone fractures with low frequency electromagnetic fields. J Orthop Res, 2010 Feb;28(2):265-70.
5. Bassett CAL, Pawluk RJ, Pilla AA. Augmentation of bone repair by inductively coupled electromagnetic fields. Science, 1974;184:575-577.
6. Marks RA. Spine fusion for discogenic low back pain: outcomes in patients treated with or without pulsed electromagnetic field stimulation. Adv Ther, 2000 Mar;17(2):57-67.
7. Dallari D, et al. Effects of pulsed electromagnetic stimulation on patients undergoing hip revision prostheses: a randomized prospective double-blind study. Bioelectromagnetics, 2009 Sep;30(6):423-30.
8. Shupak NM, et al. Exposure to a specific pulsed low-frequency magnetic field: a double-blind placebo-controlled study of effects on pain ratings in rheumatoid arthritis and fibromyalgia patients. Pain Res Manag J Can Pain Soc, 2006 Jan;11(2):85-90.
9. Lee P, et al. Efficacy of pulsed electromagnetic therapy for chronic lower back pain: a randomized, double-blind, placebo-controlled study. J Int Med Res, 2006 Mar;34(2):160-167.
10. Lyskov E. et al. Low frequency therapeutic EMF differently influences experimental muscle pain in female and male subjects. Bioelectromagnetics, 2005 May;26(4):299-304.
11. Benazzo F, et al. Cartilage repair with osteochondral autografts in sheep: effect of biophysical stimulation with pulsed electromagnetic fields. J Orthop Res Off Pub Orthop Res Soc, 2008 May;26(5):631-642.
12. Zucchini P, et al. In vivo effects of low frequency low energy pulsing electromagnetic fields on gene expression during the inflammation phase of bone repair. Electromagn Biol Med, 2002 Jan;21(3):197-208.
13. Ventura C, et al. Turning on stem cell cardiogenesis with extremely low frequency magnetic fields. FASEB J, 2005 Jan;19(1):155-157.
14. Morgado-Valle C, et al. The role of voltage-gated Ca2+ channels in neurite growth of cultured chromaffin cells induced by extremely low frequency (ELF) magnetic field stimulation. Cell Tissue Res, 1998 Feb;291(2):217-30.
15. Barzelai S, et al. Electromagnetic field at 15.95-16 Hz is cardio protective following acute myocardial infarction. Ann Biomed Eng, 2009 Oct;37(10):2093-2104.
16. Fixler D, et al. Correlation of magnetic AC field on cardiac myocyte Ca(2+) transients at different magnetic DC levels. Bioelectromagnetics, 2012 Dec;33(8):634-40.
17. Binhi VN. Amplitude and frequency dissociation spectra of ion-protein complexes rotating in magnetic fields. Bioelectromagnetics, 2000;21:34-45.
18. Harel EV, et al. H-coil repetitive transcranial magnetic stimulation for treatment resistant major depressive disorder: an 18-week continuation safety and feasibility study. World J Biol Psychiatry, 2012 Feb:1-9.
19. Lisi A, et al. Ion cyclotron resonance as a tool in regenerative medicine. Electromagnetics Biol & Med, 2008;27:127-133.
20. Smith SD, et al. Calcium cyclotron resonance and diatom motility. Bioelectromagnetics, 1987;8:215-227.
21. Halle B. On the cyclotron resonance mechanism for magnetic field effects on transmembrane ion conductivity. Bioelectromagnetics, 1988;9:381-385.