To the Editor: Dr Winemiller and colleagues1 found that magnetic insoles did not improve symptoms among patients with chronic heel pain. I question the methods used to arrive at this conclusion.
Plantar heel pain is common and has many causes. The ability to distinguish various foot conditions by clinical examination alone can be fraught with error because of symptom overlap and spectrum bias.2 - 3 There is no evidence that patients in the study by Winemuller et al had magnetic resonance imaging, radiographs, or nerve conduction studies. There is also no mention of patients' weights, activity levels, or whether or not they had diabetes mellitus.
Plantar fasciitis originates in the calcaneal region. However, in this study the magnetic foil was placed under the proximal arch of the foot and therefore the calcaneal region may not have received magnetic exposure. Because morning pain is an important symptom of plantar fasciitis, it is surprising that the authors did not have the patients wear the magnetic devices continually during sleep, or better, for 24 hours per day. Other studies have reported that wearing night splints that maintain the arch can decrease morning pain by up to 88%.4
Winemiller et al treated symptoms refractory for up to 14 years with magnetic application of only 4 hours per day, 4 days per week, for 8 weeks. Therefore, during the 2-month study period, patients received only 16 hours of magnetic exposure of a possible total of 168 hours per week. The authors also did not cite my randomized placebo-controlled trial of magnetotherapy in diabetic peripheral neuropathy, another cause of foot pain, which found statistically significant benefits from cumulative exposure.5
At this stage, it would be premature to either advocate or reject the use of magnetic insoles in plantar fasciitis because this study clearly failed to effectively test the hypothesis.
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
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