Critical Review Static Magnet Therapy for Pain Relief

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Critical review

Static magnet therapy for pain relief: a critical review

Magneto Therapy WC Mundell*

Abstract Discussion chemical properties of magnetic Introduction Systematic reviews of the topic have potions may more likely be the Interest in magnet therapy has its reached differing conclusions by ana- reason for effect, rather than the roots from several millennia ago. lysing similar studies. The most com- attractive forces. Further cycles of Despite the lack of evidence for prehensive review and meta-analysis increasing popularity continued in found no evidence to support the the 18th Century including appli- alike, seem to want them to work. cations of electricity to paralytics Therebenefit we,are patientsnumerous and physicianshistorical research studies have, also, failed to - benefit of magnets. Subsequent referred to as ‘mesmerism’ whereby Conclusion an(Benjamin ill patient Franklin) was placed and neara technique a mag- accounts that have called into ques demonstrate a benefit. hastion been the applied benefit to of answer static magnetic whether to support the use of static magnetic which the individual would be cured. magnettherapy. therapy Recently, should scientific become rigor therapyThere is fora lack pain of whenscientific compared evidence to netic field, inducing a crisis from proven medicine that works or placebo. of its validity by a panel includ- remain unproven medicine that ingThe Antoine latter technique Lavoisier, was JI debunkedGuillotine may or may not work. This review is Introduction and Benjamin Franklin in blinded focused on the critical appraisal of Interest in Magnet Therapy has its experiments using sham-magnets the literature regarding static mag- roots from several millennia ago. as controls. It appears Franz Anton nets in the treatment of pain and Despite the lack of evidence for ben- 3 discomfort. of hypnosis (mesmerising) instead . Mesmer was describingth a technique Materials and methods seem to want them to work. This In the late 19 Century, despite PubMed, EBSCOhost, Natural Medi- canefit we,be apatients powerful and driver physicians as revealed alike, investigators in Edison’s laboratory cine Comprehensive Database and in a systematic review noting 15 of demonstrating a lack of electromag- SCOPUS database were searched 16 studies evaluated illustrated the netic effect, numerous purveyors 4 with the key words ‘static magnetic’, point that what patient’s expect has advertised their wares . Examples of 1 ‘magnet’ and ‘pain’. English language an effect on health outcomes . insoles (see Figure 1), magnetic cor- studies including randomised trials, The power of a magnet is invisible sets and bracelets are similar in con- case series, case reports, observa- but we can experience that power cept to those studied today. tional studies, systematic reviews in its attractive force. Magnets take We utilise a variety of electro- and meta-analyses were included. their name from Manges, a shep- magnetic procedures, both in the All human disease categories herd living in the area of present day therapeutic and diagnostic realms. were considered, but studies were Turkey, who described the pull of Examples include pulsed electro- excluded if the evaluation of pain iron to stone as his sandals walked - 2 or discomfort was not a primary over the lodestones . The mystical scranial magnetic stimulation, magnetic field, repetitive tran or secondary outcome. Studies not characteristics of magnets led the transcutaneous electrical nerve involving static or permanent mag- Greeks (ca. 200 A.D.) to try mag- stimulation and of course magnetic resonance imaging. This review will nets were excluded. netic rings as a treatment for arthritis and medieval practitioners to focus on static magnet therapies, but Results the public safety concerns span the Thirty-seven original research stud- purify wounds and cure arthritis and gout. Paracelsus, in the 16th Century broader spectrum of electromag- ies and 10 review articles were hypothesised the ability for magnets net applications. In the case of mag- included for discussion. to push or pull disease from the body netic resonance imaging, the Food depending on whether the north or and Drug Administration felt the 2 name change for the procedure from *Corresponding author south pole of the magnet was used . Email: [email protected] With the rise in popularity of these nuclear magnetic resonance would Division of General Internal Medicine, treatments, sceptics such as Thomas alleviate public fears about the Mayo Clinic, 200 First St. SW, Rochester, Browne, an English Physician in ‘nuclear’ term and thereby improve MN 55905, USA the 17th Century, suggested that the marketing5. Likewise, public safety

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Mundell WC Competing interests: none declared. Conflict of interests: none declared. interests: none declared. Conflict of interests: Competing the final manuscript. as well read and approved design, and preparation of the manuscript, the conception, to All authors contributed rules of disclosure. ethical Ethics (AME) for Medical the Association All authors abide by For citation purposes: . Static magnet therapy for pain relief: a critical review. OA Alternative Medicine 2013 Aug 01;1(2):19. Page 2 of 7

Critical review

Figure 1: Newspaper advertisements for magnetic appliances in the 1880’s32,33. issues surrounding magnetic therapy coincided with calls from articles studies were being published on the in 1998 by Fontanarosa and Angell effects of magnets to treat medical 20th Century. Currently, it is generally stating, ‘There is no alternative ailments9. This review is focused on acceptedsurfaced inthat the exposure latter quarter to therapeu of the- the critical appraisal of the literature tic magnets do not impart harmful proven, evidence-based medicine regarding static magnets in the treat- effects with the exceptions of the supportedmedicine. Thereby solid is onlydata scientificallyor unproven ment of pain and discomfort. contraindications for use in patients - with implantable devices such as dence is lacking7.’ and that ‘It is time Materials and methods pacemakers or insulin pumps6. medicine, for which scientific evi In order to survey the scope of the Entering into legitimate scien- giving alternative medicine a free existing literature evaluating the ride.for the There scientific cannot community be two kinds to stop of effects of magnets may have been medicine—conventional and alter- the relief of pain, a search of multi- heldtific investigationback by the inertia of the of therapeutic these two native. There is only medicine that pleefficacy databases of static (PubMed, magnet EBSCOhost,therapy for - Natural Medicine Comprehensive ery and safety concerns3. This began medicine that has not, medicine that Database and SCOPUS) through the toforces; change the in association the 1990s with with calls quack to workshas been and medicine adequately that testedmay or may and end of July 2013 was performed. investigate the merits or lack thereof not work8.’ Excitement was building In addition, reference lists of pub- for complimentary medicine. This lished reviews were evaluated. The

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Critical review

key words employed in the search a non-magnet, which in some cases the UK and the USA. Conditions were ‘static magnetic’, ‘magnet’ and was copper. studied included back pain; joint ‘pain’. English language studies were One single-study article was pub- pain (rheumatoid arthritis [RA], included if the experimental design lished prior to 1997. Thereafter, shoulder, hip, knee); myofascial was a randomised trial, case series, through 2012, the number of pub- pain; pelvic pain and dysmenor- case report or observational study. rhea; diabetic neuropathy and In addition, systematic reviews and one to four per year. The excep- plantar fasciitis. The strength of meta-analyses were included. All tionlications was 2006 identified, for which ranged no articles from individual magnets in the experi- human disease categories were con- were published (see Figure 2). Ten mental arms ranged from 150 to sidered, but studies were excluded 2700 gauss (note some studies used if the evaluation of pain or discom- nine systematic reviews. One meta- multiples of the single magnets for fort was not a primary or second- analysisreviews werewas includedidentified within and included one of treatment). The magnet location ary outcome. Studies not involving the systematic reviews. Seven of the in all but four studies was placed static or permanent magnets were 10 systematic reviews were pub- directly over the site of pain. The excluded. lished in 2007 or later. remaining studies utilised whole Data were extracted from each The countries where studies body exposure such as a mattress article to include: year of publica- were performed were Columbia, pad or a remote body location such tion, country of subject participants, Germany, Hungary, Japan, Taiwan, as a bracelet (see Figure 3). disease entity, magnet location and strength, study design and outcome.

Results The search yielded 731 potential articles for review (719 from databases and 12 from reference lists). Six hun- dred and thirty-nine did not meet inclusion criteria and the remaining 92 were evaluated in detail. Follow- ing initial review an additional 45 were excluded for various reasons (acupressure, electromagnetic, non- pain, duplicate or incomplete studies). The remaining 47 were included for discussion in this review. Thirty-seven original research randomised trials, two case stud- Figure 3: Examples of magnet placement (clockwise from the upper left): iesstudies and weretwo identifiedobservational including studies. 33 Magnet attached to underwear for treatment of pelvic pain; Magnets embed- In the randomised trials; 31 studies ded in a Mattress pad34; Magnets surrounding the lower lumbar, sacroiliac joints utilised sham magnets as the control; and sacrum; Magnets surrounding a surgical scar; Magnets overlying vertebral four used lower dose magnets in the vertebrae and sacrum; Magnet placed in a wrist band23 control group; and three employed with SmithMicro’s Poser 10 software). (human figures created

Figure 2: Publishing timeline of trials included in this review (number per year).

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Critical review

The results in most studies were therapy inclusive of multiple painful - determined using a pain scoring sys- conditions. In these reviews, there tion in pain in treatment and control tem such as the Visual Analog Scale are heterogeneous variations in the results, five with significant reduc (VAS) or the Western Ontario and reduction in the treatment group McMaster Universities Osteoarthri- - comparedgroups and to seventhe control with group. significant The tis Index. Only a few studies utilised sions,study groupsbut they that do make allow it for difficult a more to alternate interpretation would then physiology parameters as their pri- thoroughdraw more analysis than qualitativeof magnet therapy. conclu be that the magnet groups did have mary endpoints. Nearly two thirds of Eccles’17 review from 2005 a decrease in pain but in a large the studies reported non-statistically included 21 studies from which the minority of the studies this was not author concludes that static mag- the result was not always stated. Four- control group; only seven of 15 stud- teensignificant studies results reported but statisticallythe direction sig of- iessignificant favoured when magnet compared therapy towhen the excluded.netic fields The can author’s induce conclusion analgesia compared to placebo (see Figure 4). were no negative studies reported. noteswhen that lesser analgesia quality was studies obtained were in The 2011 review of Salomonowitz nificant results and in this group there 11 of 15 studies. Breaking down the et al.18 concluded that ‘static magnetic Discussion studies in a different manner could Interest in static magnet therapy for lead to an alternate conclusion, how- pain therapy’. The complete review pain, based on publications, seems ever. When looking at all 21 studies, (publishedfields are ineffective in German) with respectwas not to to be waning after peaks in 2002 and six results were found to be non-sig- examined for inclusion or exclusion 2004 (see Figure 2). Explanations criteria, but the references listed for this could include less interest in contained eleven studies in common conducting trials following the pub- andnificant; control six groups, results but were not reportedbetween with Eccles’ review. The remaining lication of Pittler, Brown and Ernst’s groups;as significant and 11for resultsboth the reported treatment a articles were reviewed and six of the systematic review and the lone meta- seven reported non-statistically sig- analysis regarding the treatment of magnet treatment groups over the pain with static magnets in 2007. controlsignificant groups benefit (note favouring two stud the- included in both reviews were the This review suggested there was no ies reported two outcomes each). nificant results. Nine of the studies - Eccles. Only three of the studies that pain6. Interest continues, however, ies are considered, the distribution overlappedhigher quality reported studies results considered suggest by- inbenefit the way to staticof systematic magnet therapyreviews foron When only the higher quality stud ing no change with magnet therapy, the topic. This may be in an attempt to better understand the parameters reveals three with non-significant on which to focus future study, such attempt to shed light on the continued popularityas on specific of diseaseuse in the entities face ofor weakin an

The systematic reviews fall into twoscientific main evidence categories. to support One them.including studies involving static magnets in the greater context of review- ing complementary and alternative medicine therapies for a particular entity. These may cover the broad topic of pain10 or be more focused 11, Figure 4: Distribution of studies in three meta-analyses: Pittler6 (blue), osteoarthritis of the knee12, plantar Salomonowitz18 (red) and Eccles17 fasciitison specific13,14, conditionsdiabetic suchneuropathy as RA 15 Eccles are depicted by the inner yellow oval, bordered in black. Non-statistically or pelvic pain16. These reviews con- (yellow). Higher quality studies described by- tain few articles relating to magnet tion in pain in both magnet-treated and control arms are represented by a therapy, which limits the types of significant studies are represented by a ‘–’ sign. Studies with significant reduc conclusions that can be drawn. The when compared to the control arm are represented by a ‘+’ sign. The circled other category focused on magnet individual-studies‘×’ sign. Studies where represent the those magnet included arm resultin the meta-analysis was statistically by Pittler. significant

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Critical review

either alone or compared to control. in pain (~2 on a VAS) compared to designed a study to further mask The differing conclusions appear to the sham magnet group (~0.5 on a the identity of the active magnet be related to the method of catego- VAS) those subjects with stomati- group using an active, weak and risation of the studies that showed tis (alveolitis or aphta) did not26. In deactivated magnetic bracelet along the aphta group both treatment and with a copper bracelet in four dif- and control groups (see Figure 4). sham groups reported pain reduc- ferent study groups. This design similarPittler’s benefit 2007 in bothreview the treatmentcontains tion in a similar range of the tempo- - two additional studies that were not ralmandibular joint treatment group nition of the placebo. Interestingly, referenced in either of the two pre- (~2.1 and 1.75, respectively). The decreaseswas intended in painto confound were described the defi viously mentioned reviews. It does authors suggest that anecdotal obser- similarly in each of the three ‘magnet- not include four studies present in vations have demonstrated less reli- bracelet’ groups with neither group one or the other of those reviews. In able results when infection or fever being statistically better than the addition, Pittler’s review contains a is involved26. However, this does not other, whereas the copper bracelet meta-analysis of nine studies (see seem to explain the apparent ben- group noted an increase in pain. By narrowing their study to to the literature reported a trend In two studies, though the results participants with osteoarthritis, minimallyFigure 4). Thisfavouring quantitative magnet additiontherapy, efit of the sham treatment of aphta. Richmond et al.23 were building which did not reach statistical signif- control group reported slightly more on the recommendation of Pittler icance. Only one of the nine studies were not statistically significant, the- that further study in subjects with was reported to have statistical sig- net treatment group19,25. osteoarthritis may be helpful since benefit when compared to the mag was a study in patients with osteoar- as problematic in static magnet 6. thritisnificance leading in the the meta-analysis. authors to suggest This studies.Blinding Several is frequently recent studies described have Theprevious negative studies study were results insufficient led the attempted to address this creatively. authorsto exclude to recommend benefit in that that patients group this condition. For all other condi- End-of-study surveys give some should be informed that magnetic there may be possible benefits for insight into the patient’s views bracelets may not be helpful23. This whether further study is warranted on blinding. Some raise concerns study design tested the principle of giventions, thethe convincing question was lack raised of evidence as to - remote placement of the magnets 6. ing. A survey of the active treat- from the site of pain, leaving open Several main themes exist in the mentregarding group the in adequacyone study ofrevealed blind designfor benefit development of magnet ther- that 45% of the participants either testing local placement of magnets apy studies. There is a lack of stand- deliberately or inadvertently dis- inthe osteoarthritis question for patients. further Of studies inter- covered the magnetic properties of est, Richmond’s group did a similar and polarity. Location of the magnets the bracelet. In another, when two study in RA patients28, and results isardisation also varied. in magnetic Most studies field place strength the strengths of magnetic belts were are anticipated soon. magnet over the site of pain. The compared to sham, 60% correctly It has been suggested that there proximity to the target tissue varies, seems to be an active effect of however, when placement of a mag- assigned to based on pain relief placebo or expectation that may net is over a joint compared to deeper identified which group they were - tissues when treating pelvic pain. their treatment20. Good study design rounding magnet therapy29. Recent Other studies attempt to demon- regardingwhile 32% blinding incorrectly was suggested identified surveysconfound have the shown final conclusions that physicians sur strate a more general enrichment in in other studies. In a study using have some acceptance of the use of the body by testing magnets remote magnet-embedded mattresses, 80% placebo30 and a recent study demon- to the painful site. Mattresses, brace- of participants felt they were not strated that a placebo may be effec- lets and necklaces are the predomi- able to determine which was the tive even when it is fully disclosed as nate locations (see Figure 3). test or sham mattress. This included a placebo31. Future study should be In the nine randomised controlled an inability to detect a difference in designed to help in appreciating the trials published since Pittler’s texture27. In a study of magnetic knee poorly understood placebo effect. review,19–26 only one reported statistically wraps, a large majority was unable to determine whether their knee Conclusion three patient sub-groups and while wrap was active or not and 26% in Without evidence that there is a thesignificant temporalmandibular results. This trial joint included sub- the sham group believed they had active magnets21. Richmond et al.23 it should be considered whether benefit to static magnets for pain, group had a significant reduction Licensee OA Publishing London 2013. Creative Commons Attribution License (CC-BY)

Critical review

future resources should be devoted to the topic. Which side of this debate Fontanarosa and Angell when the physical interventions in osteoarthritic one is on will likely be grounded in to the composite question posed by kneeLjunggren pain. A AE.systematic Short-term review efficacy and meta- of how one views uncertainty. On one of static magnets unproven; they analysis of randomised placebo-con- maycurrent or may analysis not work. leaves the benefits trolled trials. BMC Musculoskelet Disord. 2007 Jun;8:51. supported by the many studies fail- hand, the certainty of benefit is not ing to prove the hypothesis of pain References Interventions for treating plantar heel being reduced. At some level of pain.13. Crawford Cochrane F,Database Atkins D,Syst Edwards Rev. 2000 J. certainty, scientists will accept the how you do depend on how you think Jul;(3):CD000416. evidence available and determine you’ll1. Mondloch do? 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