OBJECTIVE
To determine whether magnetic insoles are effective for relieving nonspecific subjective
foot pain in the workplace, resulting in improved job satisfaction.
SUBJECTS AND METHODS
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.
RESULTS
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.
CONCLUSIONS
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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Article info
Footnotes
This project was funded by an unrestricted educational grant from the Spenco Medical Corp, Waco, Tex. Spenco was not involved in any way in the study design, data collection, data analyses, or data interpretation or in manuscript preparation, review, or approval. Both the active and sham-magnetic insoles were provided at no charge directly from the manufacturer.
None of the authors have any affiliations or financial involvement with any organization or entity with a financial interest in the subject matter discussed in this article.
Individual reprints of this article are not available.
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Copyright
© 2005 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.
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- What Is Controlled for in Placebo-Controlled Trials?Mayo Clinic ProceedingsVol. 80Issue 9
- PreviewRandomized, 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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