Pulsed Magnetic Field Therapy… How Does It Work ?
By Dr. D. C. Laycock, Ph.D. Med. Eng. MBES, MIPEM
All living cells within the body possess potentials between the inner and outer membrane of the cell, which, under normal healthy circumstances, are fixed. Different cells, e.g. Muscle cells and Nerve cells, have different potentials of about -70 mV respectively. When cells are damaged, these potentials change such that the balance across the membrane changes, causing the attraction of positive sodium ions into the cell and negative trace elements and proteins out of the cell. The net result is that liquid is attracted into the interstitial area and swelling or edema ensues. The application of pulsed magnetic fields has, through research findings, been shown to help the body to restore normal potentials at an accelerated rate, thus aiding the healing of most wounds and reducing swelling faster. The most effective frequencies found by researchers so far, are very low frequency pulses of a 50Hz base. These, if gradually increased to 25 pulses per second for time periods of 600 seconds (10 minutes), condition the damaged tissue to aid the natural healing process.
PAIN REDUCTION is another area in which pulsed electromagnetic therapy has been shown to be very effective. Pain signals are transmitted along nerve cells to pre-synaptic terminals. At these terminals, channels in the cell alter due to a movement of ions. The membrane potential changes, causing the release of a chemical transmitter from a synaptic vesicle contained within the membrane. The pain signal is chemically transferred across the synaptic gap to chemical receptors on the post synaptic nerve cell. This all happens in about 1/2000th of a second, as the synaptic gap is only 20 to 50 n.-meter wide. As the pain signal, in chemical form, approaches the post synaptic cell, the membrane changes and the signal is transferred. If we look at the voltages across the synaptic membrane then, under no pain conditions, the level is about -70 mV. When the pain signal approaches, the membrane potential increases to approximately +30 mV, allowing a sodium flow. This in turn triggers the synaptic vesicle to release the chemical transmitter and so transfer the pain signal across the synaptic gap or cleft. After the transmission, the voltage reduces back to its normal quiescent level until the next pain signal arrives.
The application of pulsed magnetism to painful sites causes the membrane to be lowered to a hyper-polarization level of about -90 mV. When a pain signal is detected, the voltage must now be raised to a relatively higher level in order to fire the synaptic vesicles.
Since the average change of potential required to reach the trigger voltage of nearly +30 mV is +100 mV, the required change is too great and only +10 mV is attained. This voltage is generally too low to cause the synaptic vesicle to release the chemical transmitter and hence the pain signal is blocked. The most effective frequencies that have been observed from research in order to cause the above changes to membrane potentials, are a base frequency of 200Hz and pulse rate settings of between 5 and 25Hz.
Source: Lecture abstract of 28-01-1995, Dr. D. C. Laycock, Ph.D. Med. Eng. MBES, MIPEM, B.Ed. (Hons Phys. Sc.). Consultant Clinical Engineer, Westville Associates and Consultants (UK).
Beneficial Effects of Pulsed Electromagnetic Fields
Bioelectric Research Center, Columbia University, Riverdale, New York 10463.
Selective control of cell function by applying specifically configured, weak, time-varying magnetic fields has added a new, exciting dimension to biology and medicine. Field parameters for therapeutic, pulsed electromagnetic field (PEMFs) were designed to induce voltages similar to those produced, normally, during dynamic mechanical deformation of connective tissues. As a result, a wide variety of challenging musculoskeletal disorders have been treated successfully over the past two decades. More than a quarter million patients with chronically ununited fractures have benefitted, worldwide, from this surgically non-invasive method, without risk, discomfort, or the high costs of operative repair. Many of the athermal bioresponses, at the cellular and subcellular levels, have been identified and found appropriate to correct or modify the pathologic processes for which PEMFs have been used. Not only is efficacy supported by these basic studies but by a number of double-blind trials. As understanding of mechanisms expands, specific requirements for field energetics are being defined and the range of treatable ills broadened. These include nerve regeneration, wound healing, graft behavior, diabetes, and myocardial and cerebral ischemia (heart attack and stroke), among other conditions. Preliminary data even suggest possible benefits in controlling malignancy.
Source: J Cell Biochem 1993 Apr;51(4):387-93
Analgesic & therapeutic effects of PEMF on cervical spondylosis or shoulder periarthritis
Treatment of osteonecrosis of the femoral head using pulsing electromagnetic fields
Double-blind trial of the clinical effects of pulsed electromagnetic fields in osteoarthritis
Treatment of experimental inflammatory synovitis with continuous magnetic field
Effects of electromagnetic fields in experimental fracture repair
Electrical stimulation of human femoral intertrochanteric osteotomies
Electrical stimulation of osteonecrosis of the femoral head
Electrical stimulation of tibial osteotomies
Electromagnetic fields for the treatment of osteoarthritis
Low frequency magnetic fields for the treatment of osteoarthritic knees
Magnetic pulse treatment for knee osteoarthritis
Modification of osteoarthritis by pulsed electromagnetic field
Pulsed magnetic field therapy for osteoarthritis of the knee
Personal experience in use of magnetotherapy in diseases of the musculoskeletal system
Comparison between the analgesic and therapeutic effects of a musically modulated electromagnetic field (TAMMEF) and those of a 100 Hz electromagnetic field: blind experiment on patients suffering from cervical spondylosis or shoulder periarthritis.
Rigato M, Battisti E, Fortunato M, Giordano N.
Department of Physics, Section of Medical Physics University of Sienna, Italy. firstname.lastname@example.org
The analgesic-therapeutic efficacy and tolerability of a low-frequency electromagnetic field (ELF), modulated at a frequency of 100 Hz with a sinusoidal waveform and mean induction of a few gauss, has been demonstrated by the authors in numerous previous studies of various hyperalgic pathologies, particularly of the locomotor apparatus. In the present study, the authors tested a new type of all-inclusive field, denoted TAMMEF, whose parameters (frequency, intensity, waveform) are modified in time, randomly varying within the respective ranges, so that all the possible codes can occur during a single application. For the comparison, 150 subjects (118 women and 32 men, between 37 and 66 years of age) were enrolled. They were affected by cervical spondylosis (101 cases) or shoulder periarthritis (49 cases). Unbeknownst to them, they were randomly divided into three groups of 50 subjects. One group was exposed to the new TAMMEF, another group to the usual ELF, and the third group to simulated treatment. The results show that the effects of the new TAMMEF therapy are equivalent to those obtained with the ELF.
J Med Eng Technol. 2002 Nov-Dec;26(6):253-8.
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The conservative treatment of osteonecrosis of the femoral head. A comparison of core decompression and pulsing electromagnetic fields.
Aaron RK, Lennox D, Bunce GE, Ebert T.
University of Rhode Island, Kingston.
Once roentgenographic changes are apparent, osteonecrosis of the femoral head in the adult generally progresses to osteoarthritis within two to three years. A variety of conservative surgical procedures have been devised to conserve the femoral head with varying success. This study examines the effectiveness of pulsing electromagnetic fields and core decompression in the treatment of osteonecrosis of the femoral head. Both techniques reduce the incidence of clinical and roentgenographic progression. Exposure to pulsing electromagnetic fields appears to be more effective in hips with Ficat II lesions than in hips with more advanced lesions.
Clin Orthop. 1989 Dec;(249):209-18.
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A double-blind trial of the clinical effects of pulsed electromagnetic fields in osteoarthritis.
Trock DH, Bollet AJ, Dyer RH Jr, Fielding LP, Miner WK, Markoll R.
Department of Medicine (Rheumatology), Danbury Hospital, CT 06810.
OBJECTIVE: Further evaluation of pulsed electromagnetic fields (PEMF), which have been observed to produce numerous biological effects, and have been used to treat delayed union fractures for over a decade.
METHODS: In a pilot, double-blind randomized trial, 27 patients with osteoarthritis (OA), primarily of the knee, were treated with PEMF. Treatment consisted of 18 half-hour periods of exposure over about 1 month in a specially designed noncontact, air-coil device. Observations were made on 6 clinical variables at baseline, midpoint of therapy, end of treatment and one month later; 25 patients completed treatment.
RESULTS: An average improvement of 23-61% occurred in the clinical variables observed with active treatment, while 2 to 18% improvement was observed in these variables in placebo treated control patients. No toxicity was observed.
CONCLUSION: The decreased pain and improved functional performance of treated patients suggests that this configuration of PEMF has potential as an effective method of improving symptoms in patients with OA. This method warrants further clinical investigation.
J Rheumatol. 1993 Mar;20(3):456-60.
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Treatment of experimental inflammatory synovitis with continuous magnetic field.
Weinberger A, Nyska A, Giler S.
Department of Medicine B, Rabin Medical Center, Petah Tikva, Israel.
The effect of a magnetic field on synovitis in rats was studied. Synovitis was induced by bilateral intraarticular injection of zymosan to the hind joints. One group of rats was held in a cage with a magnet of 3,800 Gauss on the bottom of the cage (treated), while another group was held in a cage without a magnet (control). Three weeks following intraarticular zymosan injection all rats were killed and the hind joints tissues were examined histologically. The pathologic process was noted and graded according to the involvement of various tissue components, number of inflammatory foci, and size of the lesion. The histologic findings of the tissues from the control group consisted of marked articular infiltrate, composed of lymphocytes and plasma cells with some histocytes in 80% of the animals. A small articular infiltration of the same nature was observed in 20% of the treated rats. The inflammatory score was 3.4 +/- 1.1 in the treated animals and 6.8 +/- 2.6 in the control group (P = 0.002). These data showed that synovitis and the inflammatory process are significantly suppressed by a magnetic field.
Isr J Med Sci. 1996 Dec;32(12):1197-201.
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Effects of electromagnetic fields in experimental fracture repair.
Otter MW, McLeod KJ, Rubin CT.
Program in Biomedical Engineering, State University of New York at Stony Brook 11794-8181, USA.
The clinical benefits of electromagnetic fields have been claimed for 20 centuries, yet it still is not clear how they work or in what circumstances they should be used. There is a large body of evidence that steady direct current and time varying electric fields are generated in living bone by metabolic activity and mechanical deformation, respectively. Externally supplied direct currents have been used to treat nonunions, appearing to trigger mitosis and recruitment of osteogenic cells, possibly via electrochemical reactions at the electrode-tissue interface. Time varying electromagnetic fields also have been used to heal nonunions and to stabilize hip implants, fuse spines, and treat osteonecrosis and osteoarthritis. Recent research into the mechanism(s) of action of these time varying fields has concentrated on small, extremely low frequency sinusoidal electric fields. The osteogenic capacity of these fields does not appear to involve changes in the transmembrane electric potential, but instead requires coupling to the cell interior via transmembrane receptors or by mechanical coupling to the membrane itself.
Clin Orthop. 1998 Oct;(355 Suppl):S90-104.
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Electrical stimulation of human femoral intertrochanteric osteotomies. Double-blind study.
Borsalino G, Bagnacani M, Bettati E, Fornaciari F, Rocchi R, Uluhogian S, Ceccherelli G, Cadossi R, Traina GC.
Department of Orthopaedics and Traumatology, Montecchio Hospital, Reggio Emilia, Italy.
Low-frequency pulsing electromagnetic fields (PEMF) are being used in nonunion healing at several centers around the world. Much debate exists about quantification of PEMF effects, especially in humans where no randomized studies have been performed. The results of a double-blind treatment of 32 consecutive patients treated with femoral intertrochanteric osteotomy for hip degenerative arthritis are reported. Roentgenographic evaluation and callus density measurements performed with an image analyzer showed a statistically significant difference between controls and stimulated patients (p less than 0.01). In this extremely homogeneous patient population, PEMF stimulation favored osteotomy healing.
Clin Orthop. 1988 Dec;(237):256-63.
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Electrical stimulation of osteonecrosis of the femoral head.
Aaron RK, Steinberg ME.
Department of Orthopaedics, Brown University, Providence, RI.
Osteonecrosis of the femoral head in the adult is a progressive condition that, if untreated, usually results in femoral head collapse and secondary osteoarthritis. The experimental application of electrical and electromagnetic fields has been shown to favorably affect a number of biological processes pertinent to osteonecrosis of the femoral head and has led to several clinical trials. The condition has been treated by the application of electrical fields invasively by the surgical implantation of electrodes within the femoral head and noninvasively by capacitative or inductive coupling. This review describes results in osteonecrosis of the femoral head with these therapeutic techniques. Stimulation by means of inductive coupling with pulsed magnetic fields seems to be the most promising technique studied so far, but the optimal signal characteristics and device design are not yet known.
Semin Arthroplasty. 1991 Jul;2(3):214-21.
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The electrical stimulation of tibial osteotomies. Double-blind study.
Mammi GI, Rocchi R, Cadossi R, Massari L, Traina GC.
Department of Orthopaedics and Traumatology, Ospedale Civile C. Magati, Scandiano (RE), Italy.
The effect of electromagnetic field stimulation was investigated in a group of 40 consecutive patients treated valgus tibial osteotomy for degenerative arthrosis of the knee. All patients were operated on by the same author and followed the same postoperative program. After surgery, patients were randomly assigned to a control group (dummy stimulators) or to a stimulated one (active stimulators). Four orthopedic surgeons, unaware of the experimental conditions, were asked to evaluate the roentgenograms taken 60 days postoperatively and to rate the osteotomy healing according to four categories (the fourth category being the most advanced stage of healing). In the control group, 73.6% of the patients were included in the first and second category. In the stimulated group, 72.2% of the patients were included in the third and fourth category. On a homogeneous group of patients, electromagnetic field stimulation had positive effects on the healing of tibial osteotomies.
Clin Orthop. 1993 Mar;(288):246-53.
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Electromagnetic fields for the treatment of osteoarthritis.
Hulme J, Robinson V, DeBie R, Wells G, Judd M, Tugwell P.
Cochrane Collaborating Center, Center for Global Health, Institute of Population Health - University of Ottawa, 1 Stewart Street, Ottawa, Ontario, Canada, K1N 6N5. email@example.com
BACKGROUND: As the focus for osteoarthritis (OA) treatment shifts away from drug therapy, we consider the effectiveness of pulsed electric stimulation which is proven to stimulate cartilage growth on the cellular level.
OBJECTIVES: 1)To assess the effectiveness of pulsed electric stimulation for the treatment of osteoarthritis (OA). 2) To assess the most effective and efficient method of applying an electromagnetic field, through pulsed electromagnetic fields (PEMF) or electric stimulation, as well as the consideration of length of treatment, dosage, and the frequency of the applications.
SEARCH STRATEGY: We searched PREMEDLINE, MEDLINE, HealthSTAR, CINAHL, PEDro, and the Cochrane Controlled Trials Register (CCTR) up to and including 2001. This included searches through the coordinating offices of the trials registries of the Cochrane Field of Physical and Related Therapies and the Cochrane Musculoskeletal Group for further published and unpublished articles. The electronic search was complemented by hand searches and experts in the area.
SELECTION CRITERIA: Randomized controlled trials and controlled clinical trials that compared PEMF or direct electric stimulation against placebo in patients with OA.
DATA COLLECTION AND ANALYSIS: Two reviewers determined the studies to be included in the review based on inclusion and exclusion criteria (JH,VR) and extracted the data using pre-developed extraction forms for the Cochrane Musculoskeletal Group. The methodological quality of the trials was assessed by the same reviewers using a validated scale (Jadad 1996). Osteoarthritis outcome measures were extracted from the publications according to OMERACT guidelines (Bellamy 1997) and additional secondary outcomes considered.
MAIN RESULTS: Only three studies with a total of 259 OA patients were included in the review. Electrical stimulation therapy had a small to moderate effect on outcomes for knee OA, all statistically significant with clinical benefit ranging from 13-23% greater with active treatment than with placebo. Only 2 outcomes for cervical OA were significantly different with PEMF treatment and no clinical benefit can be reported with changes of 12% or less.
REVIEWER'S CONCLUSIONS: Current evidence suggests that electrical stimulation therapy may provide significant improvements for knee OA, but further studies are required to confirm whether the statistically significant results shown in these trials confer to important benefits.
Cochrane Database Syst Rev. 2002;(1):CD003523.
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Low-amplitude, extremely low frequency magnetic fields for the treatment of osteoarthritic knees: a double-blind clinical study.
Jacobson JI, Gorman R, Yamanashi WS, Saxena BB, Clayton L.
Institute of Theoretical Physics and Advanced Studies for Biophysical Research, Perspectivism Foundation
CONTEXT: Noninvasive magnetotherapeutic approaches to bone healing have been successful in past clinical studies.
OBJECTIVE: To determine the effectiveness of low-amplitude, extremely low frequency magnetic fields on patients with knee pain due to osteoarthritis.
DESIGN: Placebo-controlled, randomized, double-blind clinical study.
SETTING: 4 outpatient clinics.
PARTICIPANTS: 176 patients were randomly assigned to 1 of 2 groups, the placebo group (magnet off) or the active group (magnet on).
INTERVENTION: 6-minute exposure to each magnetic field signal using 8 exposure sessions for each treatment session, the number of treatment sessions totaling 8 during a 2-week period, yielded patients being exposed to uniform magnetic fields for 48 minutes per treatment session 8 times in 2 weeks. The magnetic fields used in this study were generated by a Jacobson Resonator, which consists of two 18-inch diameter (46-cm diameter) coils connected in series, in turn connected to a function generator via an attenuator to obtain the specific amplitude and frequency. The range of magnetic field amplitudes used was from 2.74 x 10(-7) to 3.4 x 10(-8) G, with corresponding frequencies of 7.7 to 0.976 Hz.
OUTCOME MEASURES: Each subject rated his or her pain level from 1 (minimal) to 10 (maximal) before and after each treatment and 2 weeks after treatment. Subjects also recorded their pain intensity in a diary while outside the treatment environment for 2 weeks after the last treatment session (session 8) twice daily: upon awakening (within 15 minutes) and upon retiring (just before going to bed at night).
RESULTS: Reduction in pain after a treatment session was significantly (P < .001) greater in the magnet-on group (46%) compared to the magnet-off group (8%).
CONCLUSION: Low-amplitude, extremely low frequency magnetic fields are safe and effective for treating patients with chronic knee pain due to osteoarthritis.
Altern Ther Health Med 2001 Sep-Oct;7(5):54-64, 66-9
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Magnetic pulse treatment for knee osteoarthritis: a randomized, double-blind, placebo-controlled study.
Pipitone N, Scott DL.
Rheumatology Department, King's College Hospital (Dulwich), London, UK.
We assessed the efficacy and tolerability of low-frequency pulsed electromagnetic fields (PEMF) therapy in patients with clinically symptomatic knee osteoarthritis (OA) in a randomised, placebo-controlled, double-blind study of six weeks' duration. Patients with radiographic evidence and symptoms of OA (incompletely relieved by conventional treatments), according to the criteria of the American College of Rheumatology, were recruited from a single tertiary referral centre. 75 patients fulfilling the above criteria were randomised to receive active PEMF treatment by unipolar magnetic devices (Medicur) manufactured by Snowden Healthcare (Nottingham, UK) or placebo. Six patients failed to attend after the screening and were excluded from analysis. The primary outcome measure was reduction in overall pain assessed on a four-point Likert scale ranging from nil to severe. Secondary outcome measures included the WOMAC Osteoarthritis Index (Likert scale) and the EuroQol (Euro-Quality of Life, EQ-5D). Baseline assessments showed that the treatment groups were equally matched. Although there were no significant differences between active and sham treatment groups in respect of any outcome measure after treatment, paired analysis of the follow-up observations on each patient showed significant improvements in the actively treated group in the WOMAC global score (p = 0.018), WOMAC pain score (p = 0.065), WOMAC disability score (p = 0.019) and EuroQol score (p = 0.001) at study end compared to baseline. In contrast, there were no improvements in any variable in the placebo-treated group. There were no clinically relevant adverse effects attributable to active treatment. These results suggest that the Medicur unipolar magnetic devices are beneficial in reducing pain and disability in patients with knee OA resistant to conventional treatment in the absence of significant side-effects. Further studies using different types of magnetic devices, treatment protocols and patient populations are warranted to confirm the general efficacy of PEMF therapy in OA and other conditions.
Curr Med Res Opin. 2001;17(3):190-6.
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Modification of osteoarthritis by pulsed electromagnetic field--a morphological study.
Ciombor DM, Aaron RK, Wang S, Simon B.
Department of Orthopaedics, Brown Medical School, Providence, RI 02906, USA.
OBJECTIVE: Hartley guinea pigs spontaneously develop arthritis that bears morphological, biochemical, and immunohistochemical similarities to human osteoarthritis. It is characterized by the appearance of superficial fibrillation by 12 months of age and severe cartilage lesions and eburnation by 18 months of age. This study examines the effect of treatment with a pulsed electromagnetic field (PEMF) upon the morphological progression of osteoarthritis in this animal model.
DESIGN: Hartley guinea pigs were exposed to a specific PEMF for 1h/day for 6 months, beginning at 12 months of age. Control animals were treated identically, but without PEMF exposure. Tibial articular cartilage was examined with histological/histochemical grading of the severity of arthritis, by immunohistochemistry for cartilage neoepitopes, 3B3(-) and BC-13, reflecting enzymatic cleavage of aggrecan, and by immunoreactivity to collagenase (MMP-13) and stromelysin (MMP-3). Immunoreactivity to TGFbeta, interleukin (IL)-1beta, and IL receptor antagonist protein (IRAP) antibodies was examined to suggest possible mechanisms of PEMF activity.
RESULTS: PEMF treatment preserves the morphology of articular cartilage and retards the development of osteoarthritic lesions. This observation is supported by a reduction in the cartilage neoepitopes, 3B3(-) and BC-13, and suppression of the matrix-degrading enzymes, collagenase and stromelysin. Cells immunopositive to IL-1 are decreased in number, while IRAP-positive cells are increased in response to treatment. PEMF treatment markedly increases the number of cells immunopositive to TGFbeta.
CONCLUSIONS: Treatment with PEMF appears to be disease-modifying in this model of osteoarthritis. Since TGFbeta is believed to upregulate gene expression for aggrecan, downregulate matrix metalloprotease and IL-1 activity, and upregulate inhibitors of matrix metalloprotease, the stimulation of TGFbeta may be a mechanism through which PEMF favorably affects cartilage homeostasis.
Osteoarthritis Cartilage. 2003 Jun;11(6):455-62.
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Pulsed magnetic field therapy for osteoarthritis of the knee--a double-blind sham-controlled trial.
Nicolakis P, Kollmitzer J, Crevenna R, Bittner C, Erdogmus CB, Nicolakis J.
Department of Physical Medicine and Rehabilitation, AKH Wien, University of Vienna, Vienna, Austria. Peter.firstname.lastname@example.org
BACKGROUND AND METHODS: Pulsed magnetic field therapy is frequently used to treat the symptoms of osteoarthritis, although its efficacy has not been proven. We conducted a randomized, double-blind comparison of pulsed magnetic field and sham therapy in patients with symptomatic osteoarthritis of the knee. Patients were assigned to receive 84 sessions, each with a duration of 30 minutes, of either pulsed magnetic field or sham treatment. Patients administered the treatment on their own at home, twice a day for six weeks.
RESULTS: According to a sample size estimation, 36 consecutive patients were enrolled. 34 patients completed the study, two of whom had to be excluded from the statistical analysis, as they had not applied the PMF sufficiently. Thus, 15 verum and 17 sham-treated patients were enrolled in the statistical analysis. After six weeks of treatment the WOMAC Osteoarthritis Index was reduced in the pulsed magnetic field-group from 84.1 (+/- 45.1) to 49.7 (+/- 31.6), and from 73.7 (+/- 43.3) to 66.9 (+/- 52.9) in the sham-treated group (p = 0.03). The following secondary parameters improved in the pulsed magnetic field group more than they did in the sham group: gait speed at fast walking [+6.0 meters per minute (1.6 to 10.4) vs. -3.2 (-8.5 to 2.2)], stride length at fast walking [+6.9 cm (0.2 to 13.7) vs. -2.9 (-8.8 to 2.9)], and acceleration time in the isokinetic dynamometry strength tests [-7.0% (-15.2 to 1.3) vs. 10.1% (-0.3 to 20.6)].
CONCLUSION: In patients with symptomatic osteoarthritis of the knee, PMF treatment can reduce impairment in activities of daily life and improve knee function.
Wien Klin Wochenschr 2002 Aug 30;114(15-16):678-84
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Personal experience in the use of magnetotherapy in diseases of the musculoskeletal system.
Sadlonova J, Korpas J.
Ist Dpt of Internal Medicine, Jessenius Faculty of Medicine, Comenius University, Martin, Slovakia. email@example.com
Therapeutic application of pulsatile electromagnetic field in disorders of motility is recently becoming more frequent. Despite this fact information about the effectiveness of this therapy in the literature are rare. The aim of this study was therefore the treatment of 576 patients who suffered from vertebral syndrome, gonarthritis and coxarthritis. For application of pulsatile electromagnetic field MTU 500H Therapy System was used. Pulsatile electromagnetic field had a frequency value of 4.5 mT in all studied groups and magnetic induction value 12.5-18.75 mT in the 1st group. In the 2nd group the intensity was 5.8-7.3 mT and in the 3rd group it was 7.6-11.4 mT. The time of inclination/declination in the 1st group was 20/60 ms, in the 2nd group 40/80 ms and in the 3rd group 40/90 ms. The electromagnetic field was applied during 10 days. In the 1st-3rd day during 20 minutes and in the 4th-10th day during 30 minutes. The therapy was repeated in every patient after 3 months with values of intensity higher by 50%. In the time of pulsatile electro-magnetotherapy the patients were without pharmacotherapy or other physiotherapy. The application of pulsatile electromagnetic field is a very effective therapy of vertebral syndrome, gonarthritis and coxarthritis. The results have shown that the therapy was more effective in patients suffering from gonarthrosis, than in patients with vertebral syndrome and least effective in patients with coxarthosis. Owing to regression of oedema and pain relief the motility of patients improved. (Tab. 3, Ref. 19.)
Bratisl Lek Listy. 1999 Dec;100(12):678-81.
Exposure to pulsed electromagnetic fields had beneficial effects in the treatment of patients suffering from painful osteo arthritis of the knee or cervical spine. PEMF therapy consisted of 18 exposures lasting 30 minutes and administered 3-5 times per week.Electromagnetic fields produced significant favorable effects in patients suffering from osteoarthritis.
The effects of changeable magnetic fields (Polus-101 device) coupled with more conventional therapies in the treatment of patients suffering from osteoarthrosis. Magnetic therapy consisted of daily 20 minute exposures for a total of 12 sessions. Results showed more rapid improvements of immunological indices and alleviation of symptoms associated with the disease among patients receiving the combination therapy compared to those treated only conventionally.
D.H. Trock, The Effect of Pulsed Electromagnetic Fields in the Treatment of Osteoarthritis of the Knee and Cervical Spine. D.H. Trock, Treatment of Osteoarthritis with Pulsed Electromagnetic Fields," Bioelectric Repair and Growth Society, Vol. XIII, 13th Annual Meeting, 10-13 October 1993, Dana Point, CA, p. 14. L. Yurkiv, The Use of Changeable Magnetic Field in Treatment of Osteoarthrosis.
Three hours of exposure to a 50-Hz magnetic field revealed that experimentally i nduced inflammation and suppressed arthritis was significantly inhibited as a result.
Treatment of patients with psoriatic arthritis with magnetic fields, an alternating low-frequency magnetic field (30-40 mT) from such generators as "Polius-1" and "Polius-101" improves the clinical state of afflicted joints. Such treatments are normally carried out for 30 minutes per day over a period of 15 to 20 days.
The effects of magnetolaser therapy alone or combined with conventional drugs in rheumatoid arthritis patients. This treatment utilized a AMLT-01 device for magnetolaser therapy and consisted of 14 days with 6 minute exposures daily. An obvious improvement was seen after 3 days of treatment, with greater improvement by patients suffering from mild to moderate levels of the disease. End results computed into a 90 percent patient improvement rate.
Ref Y. Mizushima, et al., "Effects of Magnetic Field on Inflammation," J.C. Reynolds, "The Use of Implantable Direct Current Stimulation in Bone Grafted Foot and Ankle Arthrodeses: V.D. Grigor'eva, et al., "Therapeutic Use of Physical Factors in Complex Therapy of Patients with Psoriatic Arthritis,"B.Y. Drozdovski, et al., "Use of Magnetolaser Therapy with an AMLT-01 Apparatus in Complex Therapy for Rheumatoid Arthritis,"
Pulsating Magnetic Therapy For Treating Soft Tissue Rheumatism
Alternative therapy in treatment of rheumatic and arthritic disorders has gained widespread popularity over the past few years as it has for treating a broad range of medical conditions. There is a growing financial impact on the health care market as billions of dollars spent yearly on alternative and complementary medical treatments. In an article published in The Annals of Internal Medicine in 1999, it was estimated that in 1997, 4 out of 10 Americans with chronic conditions made 629 million visits to practitioners of alternative medicine. In a survey by Arthritis Today, in 1999, it was determined that 19% of patients polled chose magnets as a form of therapy. Other modalities included prayer, meditation, glucosamine, massage therapy, chiropractic, metal jewelry and yoga. In the same survey, 85% of the primary care and rheumatologists polled indicated that they believe some alternative therapies may be effective.
In orthopedics and rheumatology there are interesting applications for the use of magnets and pulsating magnetic fields. Modern bone stimulators used to treat non-union of fractures in long bones apply pulsed magnetic fields (PEMFs) to stimulate cartilage and bone growth and the fracture sites. This technology had been around for 20 yrs. and has become standard treatment.
The experimental evidence shows that an exogenous electric field can induce current through ionic solutions and affect cell behavior. An externally applied PEMF of varying frequency can induce an electric current to which cells respond. It appears that the chondrocyte (the cell responsible for cartilage growth) responds best at low frequencies, i.e. up to 15Hz (Hertz). At present, this noninvasive effective alternative to surgery shows success rates of up to 80% in the treatment of ununited fractures. Because of its affect on cartilage growth and bone repair, there may be implications for the treatment of osteoarthritis. Moreover, externally applied PEMFs may be useful in ordinary fractures, shortening the time a patient needs to wear a cast.
In rheumatology there is interest in PEMF because of its effect on cartilage growth and possibly on other connective tissues. There is experimental evidence that PEMFs can elevate one of the basic chemicals from which cartilage is produced. There also appears to be a beneficial effect on other connective tissue as well. Experiments on rat Achilles tendonitis using 17 Hz PEMF showed superior healing and reduction of inflammation when compared to diathermy. In one study using PEMF, at low frequency and very low power (10 to 50 Gauss of magnetic energy), to treat osteoarthritis of the knee, there was approximately 32% improvement in pain and function. The most commonly used magnets are static magnets which can be applied to various parts of the body or put under the mattress. These magnets are low in power, i.e., between 300 and 900 Gauss and do not pulsate and therefore do not have a frequency. They are very popular but actual effectiveness is still being questioned. One study on pain associated with the post polio pain syndrome reported superior results when compared to placebo.
A new modality to deliver a pulsating magnetic field has recently become available. It has been FDA approved for the treatment of female incontinence. Its original design was in the form of a chair but has been modified to a hand held device which can be placed almost anywhere on the body. It is extremely safe to use with almost no side effects. This device delivers a powerful magnetic field, called Extracorporeal magnetic innervation (ExMi) and can produce muscle contractions by actually inducing an action potential. An action potential is the electrical current which stimulates the nerve and causes the muscle to contract. Static magnetic fields delivered by standard magnets, have become very popular in treating a variety of aches and pains, including arthritis. They do not cause contractions and they range in magnetic power from about 300 to 5,000 Gauss. In contrast, ExMI, delivers 100,000,000 Gauss (10,000 Tesla). This is 20,000 times as powerful as the most powerful static magnet. An MRI machine uses about 1.5 Tesla to create its images. The power of this device enables it to reach 3-5 inches deep into soft tissue. At present, there are only a handful of these devices available for clinical use. I have had the opportunity to investigate the use of this new device in my clinical rheumatology practice. Both my partner, Dr. Stephen Bernstein and myself have completed a pilot study looking at treating soft tissue rheumatism with ExMI. We treated a number of patients with a variety of conditions including sciatica, tendonitis, bursitis, acute muscle spasms and muscle injuries and muscle atrophy (weakness). Patients rated there pain at the beginning and at the end of their treatment course, most patients having about three or four sessions. The results have been impressive and according to the statistician, they were statistically significant in reducing pain. Further studies must be undertaken including expansion of the original trial and additional physiologic studies to further understand how ExMI may actually work. Indeed, magnetic therapy, especially powerful pulsating magnetism may have an increasingly important role in the treatment of soft tissue rheumatism and possibly osteoarthritis in the near future.
Jacobson JI, Gorman R, Yamanashi WS, Saxena BB, Clayton L.
Institute of Theoretical Physics and Advanced Studies for Biophysical Research, Perspectivism Foundation, 2006 Mainsail Cir, Jupiter, USA.
Placebo-controlled, randomised, double blind clinical study to determine the effectiveness of low-amplitude, extremely low frequency magnetic fields on patients with knee pain due to osteoarthritis. 176 patients were randomly assigned to 1 of 2 groups, the placebo group (magnet off) or the active group (magnet on). INTERVENTION: 6-minute exposure to each magnetic field signal using 8 exposure sessions for each treatment session, the number of treatment sessions totalling 8 during a 2-week period, yielded patients being exposed to uniform magnetic fields for 48 minutes per treatment session 8 times in 2 weeks. The range of magnetic field amplitudes used was from 2.74 x 10(-7) to 3.4 x 10(-8) G, with corresponding frequencies of 7.7 to 0.976 Hz. RESULTS: Reduction in pain after a treatment session was significantly (P < .001) greater in the magnet-on group (46%) compared to the magnet-off group (8%). CONCLUSION: Low-amplitude, extremely low frequency magnetic fields are safe and effective for treating patients with chronic knee pain due to osteoarthritis. PMID: 11565402 PubMed
E. Riva Sanseverino, A. Vannini, P. Castellacci: "Therapeutic effects of pulsed electromagnetic fields on joint diseases," Panminerva Medica 34(4), October-December 1992, pp. 187196. - This study characterizes PEMF as an excellent physical measure for the treatment of joint diseases. The authors of this study report that PEMF, when used correctly and repeated periodically, can stop the disease process of the effected joints, with regard to the clinical condition. The best results are achieved in the treatment of pain.
T. Zizic et al.: "The treatment of rheumatoid arthritis of the hand with pulsed electromagnetic fields," World Congress for Electricity and Magnetism in Biology and Medicine, June 1997, Bologna, Italy. - This double blind, placebo-controlled study investigates the effects of pulsating fields for a period of four weeks in the treatment of arthritis of the hand. The results show a definite clinical improvement in patients receiving magnetic field therapy in comparison with the control group without PEMF.
V.D. Grigor'eva et al.: "Therapeutic use of physical factors in complex therapy of patients with psoriatic arthritis," Vopr Kurortol Fizioter Lech Fiz Kult (6), 1995, pp. 48-51. - This study presents a review of the treatment of patients with psoriatic arthritis with low-frequency pulsed electromagnetic fields. It demonstrates a definite improvement in the clinical condition of the effected joints.
D.H. Trock et al.: "A double blind Trial of the Clinical Effects of PEMF
in Osteoarthritis," Journal of Rheumatology, 1993:20, pp. 456-460. - This
double blind randomised study with 27 patients (primary arthrosis of the knee)
is one of the most important research studies conducted in the field of PEMF.
Six clinical parameters were investigated at different times during the treatment
and an evaluation was carried out after one month. These results show a definite
improvement in clinical parameters (such as mobility) in the group treated
with PEMF in comparison with the group treated without PEMF. An important conclusion
in this study is that for more than 17 years, more than 200,000 patients have
already been treated in Eastern Europe with pulsating electromagnetic fields
in clinical trials without any mentionable side effects. Observations in Eastern
Europe on 861 patients with painful rheumatic changes have shown an improvement
in symptoms in 70-80%.
F. Pezzetti et al.: "Effect of Pulsed Electromagnetic Field Exposure of Human Chondrocytes in Vitro," University of Ferrara, Italy, November 1998. - This study investigated the influence of pulsating electromagnetic fields on cartilage cells and demonstrated a definite increase in cartilage reconstruction under the influence of PEMF.
H. Lieu et al.: "PEMF Influences Hyaline Cartilage Extracellular Matrix Composition without Affecting Molecular structure," Osteoarthritis and Cartilage 4, 1996, pp. 63-76. - This study represents and important step in scientific research into the positive effects of magnetic fields on arthrosis. It shows that PEMF influences cartilage metabolism and can prevent the degradation of glucosamine glycans. In some individual cases, cartilage mass has been regenerated.
L. Yarkiv et al.: "The use of Changeable Magnetic Field in Treatment of Osteoarthritis," European Bioelectromagnetics Association, 3rd International Congress, February 29 - March 3, 1996, Nancy, France. - This controlled study on arthrosis patients has shown a definite improvement in the disease condition of patients treated with PEMF.
D.H. Trock et al.: "The Effect of PEMF in the Treatment of Osteoarthritis of the Knee and Cervical Spine. Report of Randomised, Double blind, Placebo-controlled Trials," Journal of Rheumatology, 1994:21, pp. 1903-1911. - This study on 86 patients with arthrosis in the knee and 81 patients with arthrosis in the cervical spine has shown a definite difference between the PEMF group and the control group. The patients treated with PEMF show an improvement with a statistically significant difference in almost all clinical parameters.
The Herder Clinic in Bremen reports of four years of experience with PEMF in diseases and injuries of the supporting system and the motor system - An evaluation of 650 cases of arthrosis of the spinal column and peripheral joints found a reduction in pain in 60-70% of the cases.
K. Konrad et al.: "Therapy with PEMF in Aseptic Loosening of Total Hip
Prostheses: A Prospective Study," Budapest, Hungary, Clin. Rheumatol.,
July 1996. - PEMF was used on 24 patients with a loosened hip prosthesis. Follow-up
examinations were performed after six months and after one year, showing that
the patients treated with PEMF had experienced pain relief and a definite improvement
in hip movements. The isotope scan and ultrasonic tests confirmed these positive
W.F. Kennedy et al.: "Use of PEMF in Treatment of Loosened Hip Prostheses. A Double blind Study," Clin Orthop., January 1993 (286), pp. 198-205. - This study with 37 patients with cemented hip prostheses demonstrates that 53% of the loosened hip prostheses had fused again after six months of PEMF, whereas only 11% in the control group had a similarly positive effect.
Studies are currently carried out at three renowned German University Clinics. The studies were initiated after extremely positive preliminary.
G. Gualtieri et al.: "The Effect of PEMF Stimulation on Patients Treated of Hip Revisions with Trans-femoral Approach," Second world Congress for Electricity and Magnetism in Biology and Medicine, June 8-13, 1997, Bologna, Italy. - This double blind study investigated the effect of PEMF on patients with loosened hip prostheses. The results demonstrate an increase in bone density with a stabilising effect on the prostheses in all patients treated with PEMF, whereas only about half those in the control group showed an increase in bone density.