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ORIGINAL ARTICLE| Volume 80, ISSUE 9, P1138-1145, September 2005

Effect of Magnetic vs Sham-Magnetic Insoles on Nonspecific Foot Pain in the Workplace: A Randomized, Double-Blind, Placebo-Controlled Trial


      To determine whether magnetic insoles are effective for relieving nonspecific subjective foot pain in the workplace, resulting in improved job satisfaction.


      A prospective, randomized, double-blind, placebo-controlled study of health care employees who experienced nonspecific foot pain for at least 30 days, which occurred more days than not, was conducted between February 2001 and January 2002 at the Mayo Clinic in Rochester, Minn. Participants were asked to wear either magnetic or sham-magnetic cushioned insoles for at least 4 hours daily, 4 days per week for 8 weeks. The primary outcome variable was reported foot pain (by categorical response of change from baseline and by visual analog scale) at 4 and 8 weeks. Secondary outcome variables included graded intensity of pain experienced during various daily activities and the effect of insoles on job performance and enjoyment.


      Among 89 enrolled participants, 6 either withdrew before wearing insoles or were noncompliant with follow-up questionnaires; 83 participants remained for full statistical analysis. Participants in both treatment groups reported improvements in foot pain during the study period. No significant differences in categorical response to pain or pain intensity were seen with use of magnetic vs sham-magnetic insoles.


      The magnetic insoles used in this study by a heterogeneous population with chronic nonspecific foot pain were not clinically effective. Findings confirmed that nonspecific foot pain significantly interferes with some employees' ability to enjoy their jobs and that treatment of that pain improves job satisfaction.
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        • Weintraub MI
        Magnetotherapy: a new intervention? [letter].
        Arch Phys Med Rehabil. 1998; 79: 469-470
        • Eisenberg DM
        • Kessler RC
        • Foster C
        • Norlock FE
        • Calkins DR
        • Delbanco TL
        Unconventional medicine in the United States: prevalence, costs, and patterns of use.
        N Engl J Med. 1993; 328: 246-252
        • Eisenberg DM
        • Davis RB
        • Ettner SL
        • et al.
        Trends in alternative medicine use in the United States, 1990-1997: results of a follow-up national survey.
        JAMA. 1998; 280: 1569-1575
        • Barker AT
        • Dixon RA
        • Sharrard WJ
        • Sutcliffe ML
        Pulsed magnetic field therapy for tibial non-union: interim results of a double-blind trial.
        Lancet. 1984; 1: 994-996
        • Sharrard WJ
        A double-blind trial of pulsed electromagnetic fields for delayed union of tibial fractures.
        J Bone Joint Surg Br. 1990; 72: 347-355
        • Pujol J
        • Pascual-Leone A
        • Dolz C
        • Delgado E
        • Dolz JL
        • Aldoma J
        The effect of repetitive magnetic stimulation on localized musculoskeletal pain.
        Neuroreport. 1998; 9: 1745-1748
        • Ellis WV
        Pain control using high-intensity pulsed magnetic stimulation.
        Bioelectromagnetics. 1993; 14: 553-556
        • Binder A
        • Parr G
        • Hazleman B
        • Fitton-Jackson S
        Pulsed electromagnetic field therapy of persistent rotator cuff tendinitis: a double-blind controlled assessment.
        Lancet. 1984; 1: 695-698
        • Trock DH
        • Bollet AJ
        • Markoll R
        The effect of pulsed electromagnetic fields in the treatment of osteoarthritis of the knee and cervical spine: report of randomized, double blind, placebo controlled trials.
        J Rheumatol. 1994; 21: 1903-1911
        • Zizic TM
        • Hoffman KC
        • Holt PA
        • et al.
        The treatment of osteoarthritis of the knee with pulsed electrical stimulation.
        J Rheumatol. 1995; 22: 1757-1761
        • Pennington GM
        • Danley DL
        • Sumko MH
        • Bucknell A
        • Nelson JH
        Pulsed, non-thermal, high-frequency electromagnetic energy (Diapulse) in the treatment of grade I and grade II ankle sprains.
        Mil Med. 1993; 158: 101-104
        • Leclaire R
        • Bourgouin J
        Electromagnetic treatment of shoulder periarthritis: a randomized controlled trial of the efficiency and tolerance of magnetotherapy.
        Arch Phys Med Rehabil. 1991; 72: 284-287
        • Devereaux MD
        • Hazleman BL
        • Thomas PP
        Chronic lateral humeral epicondylitis—a double-blind controlled assessment of pulsed electromagnetic field therapy.
        Clin Exp Rheumatol. 1985; 3: 333-336
        • Rosch PJ
        Stress, pain, fatigue, depression—and magnets [editorial].
        Stress Med. 1998; 14: 69-74
        • Finegold L
        Magnet therapy.
        Sci Rev Altern Med. Spring-Summer 1999; 3 (33.): 26-31
        • Repacholi MH
        • Greenebaum B
        Interaction of static and extremely low frequency electric and magnetic fields with living systems: health effects and research needs.
        Bioelectromagnetics. 1999; 20: 133-160
        • Lednev VV
        Possible mechanism for the influence of weak magnetic fields on biological systems.
        Bioelectromagnetics. 1991; 12: 71-75
        • Olney RK
        • So YT
        • Goodin DS
        • Aminoff MJ
        A comparison of magnetic and electrical stimulation of peripheral nerves.
        Muscle Nerve. 1990; 13: 957-963
        • Weintraub MI
        Primary findings: alternative medicine: chronic sub-maximal magnetic stimulation in peripheral neuropathy: is there a beneficial therapeutic relationship?.
        Am J Pain Manage. 1998; 8: 12-16
        • Trock DH
        Electromagnetic fields and magnets: investigational treatment for musculoskeletal disorders.
        Rheum Dis Clin North Am. 2000; 26: 51-62
        • Vogl TJ
        • Paulus W
        • Fuchs A
        • Krafczyk S
        • Lissner J
        Influence of magnetic resonance imaging on evoked potentials and nerve conduction velocities in humans.
        Invest Radiol. 1991; 26: 432-437
        • Hong CZ
        Static magnetic field influence on human nerve function.
        Arch Phys Med Rehabil. 1987; 68: 162-164
        • Zablotsky TJ
        The application of permanent magnets in musculoskeletal injuries [manufacturer's handout]. BIOflex Medical Magnets, Inc, Oakland Park, Fla1998
      1. Pratt GW Jr, Misra L. The effect of the BIOflex magnetic pad on the flow rate of 5% aqueous saline solution. Presented at: International Symposium on Biomagnetology, Magnetotherapy and Postural Activity; Newport, RI; May 29, 1989.

        • Tenforde TS
        Thermoregulation in rodents exposed to high-intensity stationary magnetic fields.
        Bioelectromagnetics. 1986; 7: 341-346
        • Weintraub MI
        • Wolfe GI
        • Barohn RA
        • Magnetic Research Group
        • et al.
        Static magnetic field therapy for symptomatic diabetic neuropathy: a randomized, double-blind, placebo-controlled trial.
        Arch Phys Med Rehabil. 2003; 84: 736-746
        • Vallbona C
        • Hazlewood CF
        • Jurida G
        Response of pain to static magnetic fields in postpolio patients: a double-blind pilot study.
        Arch Phys Med Rehabil. 1997; 78: 1200-1203
        • Colbert AP
        • Markov MS
        • Banerji M
        • Pilla AA
        Magnetic mattress pad use in patients with fibromyalgia: a randomized double-blind pilot study.
        J Back Musculoskeletal Rehabil. 1999; 13: 19-31
        • Harlow T
        • Greaves C
        • White A
        • Brown L
        • Hart A
        • Ernst E
        Randomised controlled trial of magnetic bracelets for relieving pain in osteoarthritis of the hip and knee.
        BMJ. 2004; 329: 1450-1454
        • Toysa T
        Headache treated with magnets on the peroneal zone of the legs.
        Acupunct Med. 1997; 15: 112-113
        • Winemiller MH
        • Billow RG
        • Laskowski ER
        • Harmsen WS
        Effect of magnetic vs sham-magnetic insoles on plantar heel pain: a randomized controlled trial [published correction appears in JAMA. 2004;291:46].
        JAMA. 2003; 290: 1474-1478
        • Caselli MA
        • Clark N
        • Lazarus S
        • Velez Z
        • Venegas L
        Evaluation of magnetic foil and PPT Insoles in the treatment of heel pain.
        J Am Podiatr Med Assoc. 1997; 87: 11-16
        • Segal NA
        • Toda Y
        • Huston J
        • et al.
        Two configurations of static magnetic fields for treating rheumatoid arthritis of the knee: a double-blind clinical trial.
        Arch Phys Med Rehabil. 2001; 82: 1453-1460
        • Hong CZ
        • Lin JC
        • Bender LF
        • Schaeffer JN
        • Meltzer RJ
        • Causin P
        Magnetic necklace: its therapeutic effectiveness on neck and shoulder pain.
        Arch Phys Med Rehabil. 1982; 63: 462-466
        • Lin JC
        • Singleton GW
        • Schaeffer JN
        • Hong CZ
        • Meltzer RJ
        Geophysical variables and behavior, XXVII: magnetic necklace: its therapeutic effectiveness on neck and shoulder pain, 2: psychological assessment.
        Psychol Rep. 1985; 56: 639-649
        • Collacott EA
        • Zimmerman JT
        • White DW
        • Rindone JP
        Bipolar permanent magnets for the treatment of chronic low back pain: a pilot study.
        JAMA. 2000; 283: 1322-1325
        • Borsa PA
        • Liggett CL
        Flexible magnets are not effective in decreasing pain perception and recovery time after muscle microinjury.
        J Athl Train. 1998; 33: 150-155
        • Brown C
        • Parker N
        • Ling F
        • et al.
        Effect of magnets on chronic pelvic pain.
        Monday Posters. 2000; 95: 29S
        • Sanfilippo II, PB
        • Stess RM
        • Moss KM
        Dynamic plantar pressure analysis: comparing common insole materials.
        J Am Podiatr Med Assoc. 1992; 82: 507-513
        • Johnson GR
        The effectiveness of shock-absorbing insoles during normal walking.
        Prosthet Orthot Int. 1988; 12: 91-95
        • Basford JR
        • Smith MA
        Shoe insoles in the workplace.
        Orthopedics. 1988; 11: 285-288
        • Tooms RE
        • Griffin JW
        • Green S
        • Cagle K
        Effect of viscoelastic insoles on pain.
        Orthopedics. 1987; 10: 1143-1147
        • Pfeffer G
        • Bacchetti P
        • Deland J
        • et al.
        Comparison of custom and prefabricated orthoses in the initial treatment of proximal plantar fasciitis.
        Foot Ankle Int. 1999; 20: 214-221

      Linked Article

      • What Is Controlled for in Placebo-Controlled Trials?
        Mayo Clinic ProceedingsVol. 80Issue 9
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          Randomized, double-blind, placebo-controlled clinical trials are the gold standard for determining the efficacy of an intervention. Many treatments have shown tremendous promise based on case studies and uncontrolled clinical studies, only to be found ineffective in the context of a carefully conducted placebo-controlled trial. The importance of a credible placebo condition is particularly evident when evaluating the effectiveness of pain treatment, for reasons that we will discuss in detail.
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