Context Despite anecdotal reports, rigorous scientific evidence of the effectiveness
of magnetic insoles for the pain of plantar fasciitis is lacking.
Objective To determine whether magnetic insoles provide greater subjective improvement
for treatment of plantar heel pain compared with identical nonmagnetized insoles.
Design, Setting, and Participants Randomized, double-blind, placebo-controlled trial conducted from February
12, 2001, to November 9, 2001, of a volunteer sample of 101 adults with diagnoses
of plantar heel pain for at least 30 days from a multispecialty group practice
clinic in Rochester, Minn. Daily pain diaries were kept for 8 weeks.
Interventions Cushioned insoles, with either active bipolar magnets or sham magnets,
which were worn daily by the participants for 8 weeks.
Main Outcome Measures Reported average daily foot pain (by metered visual analog scale [VAS]
and by categorical response of change from baseline) at 4 and 8 weeks, and
impact of insoles on employment performance and enjoyment.
Results No significant between-group differences were found on any outcome variables
studied when comparing active vs sham magnets. Both the nonmagnetic and magnetic
groups reported significant improvements in morning foot pain intensity, with
mean (SD) VAS scores improving from 6.9 (2.3) and 6.7 (2.0), respectively,
at baseline to 3.9 (2.6) for each group at 8 weeks (P =
.94). At 8 weeks, 33% of the nonmagnetic group and 35% of the magnetic group
reported being all or mostly better (P = .78). At
baseline, foot pain interfered moderately with participants' employment enjoyment
(mean VAS, 4.2) and improved in both groups by 8 weeks (1.3 and 1.5, respectively; P = .68).
Conclusion Static bipolar magnets embedded in cushioned shoe insoles do not provide
additional benefit for subjective plantar heel pain reduction when compared
with nonmagnetic insoles.