Pain Management - magnet therapy

[Guest guest]

BioMechanics March 2004 Pain Management

Magnets attract a variety of opinions

Data on magnets may be lacking, but even skeptics find it difficult to

discourage patients from using them.

By: Jerry Karp

When it comes to research into magnet therapy and its efficacy in

reducing or eliminating pain, significant segments of the American

public have developed strong convictions, pro and con. One has only to

consider the half billion dollars Americans reportedly spend each year

on magnet products, or view the furious denunciations of magnet therapy

on Web sites like Quackwatch.org, to understand that opinions on magnet

therapy aren't hard to come by.

National media coverage of published scientific studies, both negative

and positive, keep the pot boiling. And high-profile athletes like

former NFL quarterback Dan Marino and baseball Hall of Famer Hank ,

whether being paid to endorse magnet products or just using them in

public, add to the mix. It seems patients and practitioners have

everything they need to form an opinion about magnets except definitive

proof that they are effective.

Belief in the power of magnets for pain relief has been around for

millennia. The current theory cited most often is that magnets react

with iron in the blood to increase blood flow, thereby promoting

healing. Researchers have also begun speculating that static magnetic

stimulation can influence small C-fibers and desensitize sensory

neurons, reducing pain in the treated area. Magnet products are

available as insoles, bracelets, braces, and pads for the back and just

about every joint on the body, plus pillows and mattresses. These

products make use of static magnetic fields from " permanent " magnets.

Many devices use bipolar fields-magnets arrayed in patterns of

alternating north and south polarity-which their manufacturers claim

enhance the products' effectiveness.

In response to the sales figures, public interest, and, in many cases,

questions from their own patients, medical researchers have produced a

steady, if moderately paced, stream of studies on magnet therapy.

Studies conducted in the past few years have been something of a mixed

bag, in terms both of what they have examined and what they have found.

Recent published reports have investigated the effect of magnetic

devices on pain from plantar fasciitis, lower back pain, carpal tunnel

syndrome, and symptomatic diabetic neuropathy, among other conditions.

In several studies, a measurable decrease in pain was reported by

subjects wearing magnetic devices, but the decrease was not

statistically significant compared to improvements reported by a placebo

group. And therein lie the chief obstacles to documenting the efficacy

of therapeutic magnets: use of patient rating scales to quantify pain

levels is by definition subjective, and a patient's perception of his or

her pain level can be susceptible to a placebo effect.

A recent and widely reported double-blinded, placebo-controlled study

found no greater improvement in plantar fasciitis pain with magnetic

insoles than with placebo insoles. Mark H. Winemiller, MD, a physiatrist

with the department of physical medicine and rehabilitation at the Mayo

Clinic in Rochester, MN, and colleagues, in a study published in the

Sept. 17 issue of the Journal of the American Medical Association,

enrolled 101 subjects who had reported pain in the plantar area of the

foot for at least 30 days prior to the study. Half the study subjects

wore " Active Comfort " bipolar magnetic insoles from Spenco Medical of

Waco, TX, and half wore placebo insoles specially made for the study by

Spenco (who also funded the research). Participants wore the insoles at

least four hours a day, four days a week for eight weeks, and kept

diaries to record their pain intensities using a 10-point visual analog

scale for a series of criteria including morning, evening, and mean

daily pain.

Winemiller reported that both groups indicated significant improvement

in their pain levels, particularly morning foot pain intensity, but that

there were no significant differences in the levels of relief

experienced by the two groups. Mean VAS scores improved from 6.9 in the

nonmagnetic group and 6.7 in the magnetic group at baseline to 3.9 for

each group at eight weeks. By the eighth week, 33% of the nonmagnetic

group and 35% of the magnetic group also reported being all or mostly

better.

" Although many claims have been made regarding the therapeutic use of

magnets, our outcomes showed static magnets to be ineffective in the

treatment of plantar heel pain, " the authors wrote.

Meanwhile, at the opposite pole

But Weintraub, MD, a clinical professor of neurology at New York

Medical College, who in May published a study with conclusions

supporting the efficacy of magnet therapy for treating pain accompanying

symptomatic diabetic neuropathy, was critical of the Winemiller

research. Weintraub noted that in the JAMA study, chronic

conditions-some of up to 14 years' duration-were treated for a few hours

a day, a few days a week.

" You can't get anything better that way, " he said. " Also, they didn't

use the magnets through the night, even though plantar fasciitis

patients have pain through the night, and morning pain is a

characteristic. They did a poor study. "

Winemiller could not be reached for comment.

According to Weintraub, larger studies are needed for real answers to

emerge about the efficacy of magnets for pain management.

" You need to get larger cohorts, " he said. " I don't think the final

answer is out there right now. We're just breaking the surface. But you

can't treat a chronic condition over a short amount of time with a

magnet. You've got to treat people consistently for 24-hour periods for

months, because static magnets are weak devices. "

Even that assessment is not exactly good news for the throngs of people

hoping that magnets will bring them instant relief, or for the growing

number of manufacturers promising speedy alleviation of everything from

foot pain to migraines.

Weintraub's randomized, double-blinded, placebo-controlled study,

published in the Archives of Physical Medicine and Rehabilitation,

attained final data from 141 subjects who wore magnetic insoles and 118

patients who wore placebo insoles. All wore the devices for four months.

Clinicians in 48 facilities (11 university-based centers and 37 private

practices), spread over 27 states, took part in the research. All

subjects suffered from symptomatic diabetic peripheral neuropathy, with

constant symptoms present for at least six months.

The active group members were assigned to constantly wear 450 Gauss

multipolar insoles called Magsteps from Nikken of Irvine, CA, who also

funded the study. Daily VAS scores were tabulated over four months.

Separate VAS scales were tabulated for burning, numbness, tingling, foot

pain, and sleep interruption. During the third and fourth months, the

treatment group reported a 12% reduction in burning versus 3% for the

placebo group. For numbness and tingling the treatment group reported a

mean 10.5% reduction versus a 1% increase for the placebo group. For a

subset of patients with baseline severe pain, those in the experimental

group reported a 32% reduction of numbness and tingling against 14% for

the placebo group and a 41% reduction in foot pain against 21% in the

placebo group. There were no significant differences measured in sleep

interruption between the treatment group and sham group.

These figures have statistical significance within the context of the

study. Weintraub, who has also produced several smaller magnet studies,

believes they have broader significance, as well. And, significant or

not, all three TV networks reported his findings.

Weintraub said that despite funding the project, Nikken had no influence

on the results.

" They were lucky, " he said. " It could have come out poorly for them. "

A pair of smaller studies looked into magnet use with mixed results.

Collacott, MD, of the VA Medical Center in Prescott, AZ, tested

20 patients with chronic back pain and published his results in the

March 8, 2000, issue of JAMA. The patients, who all had stable low back

pain of at least six months' duration, wore 300 G bipolar magnet pads

for six hours per day, three days per week, then wore sham pads for a

similar schedule, with a week off in between. Their VAS scores declined

by 0.49 for the real magnet treatment and 0.44 for the sham treatment.

Although this difference was not statistically significant, Collacott

stresses that it was only a pilot study. A larger study with stronger

magnets that he had begun was short-circuited when his institution

discontinued all research projects.

In a study published in the Journal of Family Practice in January 2002,

researchers from the Oklahoma College of Medicine found no added benefit

associated with magnet therapy for treatment of carpal tunnel syndrome.

Fifteen participants wore 1000 G magnetic disks applied to the carpal

tunnel area for 45 minutes, and 15 wore placebo disks. The two groups

reported almost identical lessening of VAS pain scores after the

45-minute trials (both -2.4 VAS). At a two-week post-treatment follow-up

the two groups reported their pain at an identical 4.3 on the VAS scale.

Major insurance carriers don't seem impressed with either the research

or the sales figures. A 1998 JAMA study reported that 30.8% of health

insurance users received coverage for " energy healing, " most frequently

meaning magnet therapy, in 1997 (see " Magnetic therapy attracts

attention, " December 1999, page 37). However, spokespersons from Kaiser

Permanente, Pacific Mutual, and Blue Cross of California all said at the

end of last year that their companies did not reimburse for magnet

therapy because the efficacy of the therapy had not been proven.

What are practitioners to do with this conflicting information? None of

the approximately 20 orthotists, sports therapists, and podiatrists

contacted for this article said they used magnet therapy in their

practices or recommended it to their patients. Many said they simply

weren't impressed with the research they'd seen. But few were willing to

deny the possibility that magnets might in time prove useful. And none

said they would tell patients to discard magnetic devices if the

patients thought they were helping.

" Until valid studies can be produced that show a therapeutic effect, no

legitimate medical professional should advocate its use, " said Ted A.

Trower, CPO, of A-S-C Orthotics & Prosthetics in , MI. " On the

other hand, there is no evidence of harm. The placebo effect is very

real in the individual who believes, so it is difficult to hold a

position that strongly opposes its use by the consumer. "

People who believe they will find magnetic therapy helpful before they

use it, will very likely believe it was helpful after they've used it,

Trower said.

" Do I personally use them? No, " said Scherer, DPM, medical director

of ProLab USA in Napa, CA. " Am I supposed to be an expert on orthotic

therapy? Yes. Do I own an orthotics lab? Yes. Does that orthotics lab

produce any orthotics that use magnets? No. So that gives you a pretty

good indication of where I stand now. But I'm perfectly willing to be

open. "

One authoritative professional who's convinced of the efficacy of

magnetic insoles is Harry Hlavac, MEd, DPM, a past president of the

American Academy of Podiatric Sports Medicine who left podiatry practice

in April 2003 after 35 years to sell Magsteps insoles for Nikken.

" I think that we can say with confidence that magnets can help

supplement treatment, " Hlavac said, " But it's not a substitute for

medical treatment. That's been the philosophy of Nikken, too. "

The company doesn't claim it's going to cure anybody, he said.

" Magnets provide some relief, and for conditions that don't respond well

to conventional medicine-like fibromyalgia or migraine headaches or

sciatica-lots of people have had relief when they didn't have relief

with physical therapy, cortisone, or surgery, " Hlavac said.

Anecdotal evidence

Valmassy, DPM, a staff podiatrist for the Center for Sports

Medicine at St. Francis Memorial Hospital in San Francisco, tells a

story that may sum up the current attitude of most practitioners towards

magnet therapy best of all.

" One of my patients, who is a physical therapist and so a very

knowledgeable person, had had a problem with plantar fasciitis, and I

had prescribed some orthoses for her, " he said. " On one of her follow-up

visits, she said that one of her patients, who was involved with magnet

therapy promotion and sales, had given her a pair of magnetic insoles to

use. She said that, for the heck of it, she put them in her shoes

underneath her orthoses. And the residual discomfort that she'd been

having with the plantar fasciitis-which apparently was not resolved with

the orthoses or the physical therapy we'd tried-immediately went away

and was allowing her to do everything in perfect comfort. "

When Valmassy's patient took the magnetic insoles out of her shoes, her

pain returned. When she put the magnets back in, the pain went away

again. So she left them in.

" Now whether the magnetic insole made the shoe fit a little snugger,

which made the orthotic more effective, I don't know, " Valmassy said.

" It's totally anecdotal, but I always remember my conversation with her,

because my reaction was, 'Gee, that's pretty interesting. I don't know

what to make of it, but keep them in your shoes.' "

Jerry Karp is a freelance writer based in San Francisco.