Double-blind placebo-controlled trial of static magnets for the treatment of osteoarthritis of the knee: results of a pilot study.
ABSTRACT Outpatient clinical studies of magnet therapy, a complementary therapy commonly used to treat osteoarthritis (OA), have been limited by the absence of a credible placebo control.
Our objective was to assess the feasibility and promise of studying static magnetic therapy for knee OA and determine the ability of a new placebo-magnet device to provide concealment of group assignment.
Randomized, double-blind, placebo-controlled clinical trial.
Academic teaching hospital in Boston.
We enrolled 29 subjects with idiopathic or post-traumatic OA of the knee.
Subjects received either high-strength magnetic (active) or placebo-magnetic (placebo) knee sleeve treatment for 4 hours in a monitored setting and self-treatment 6 hours daily for 6 weeks.
Primary outcomes were change in knee pain as measured by the WOMAC Osteoarthritis Index Pain Subscale at 6 weeks and extent of group concealment at study end.
At 4 hours, VAS pain scores (+/- SE) on a 5-item scale (0-500, 500 worst) decreased 79 +/- 18 mm in the active group and 10 +/- 21 mm in the placebo group (P < 0.05). There were no significant differences in any primary or secondary measure of efficacy between the treatment groups at 6 weeks. Despite widespread testing for magnetic properties, at study end, 69% of the active group and 77% of the placebo group (P > 0.2) believed that they had been assigned to the active treatment group.
Despite our small sample size, magnets showed statistically significant efficacy compared to placebo after 4 hours under rigorously controlled conditions. The sustained efficacy of magnetic therapy for knee osteoarthritis could be assessed in an adequately powered trial utilizing an appropriate control such our new placebo-magnet device.
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ABSTRACT: Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields. This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz) on the reproductive systems of male Wistar rats (70 days old). The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz), pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz) exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays. The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer) are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents. Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.Clinics (São Paulo, Brazil) 07/2011; 66(7):1237-45. DOI:10.1590/S1807-59322011000700020 · 1.42 Impact Factor
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ABSTRACT: To test the effectiveness of a typical magnetic wrist strap for reducing pain and stiffness, and for improving physical functioning amongst patients with osteoarthritis. A randomised double-blind placebo-controlled crossover trial. Each participant wore four devices over a 16-week period. Forty five patients with osteoarthritis were recruited from general practices in rural and urban areas of Yorkshire. Experimental device: a commercially available magnetic wrist strap. Control devices: a weak magnetic wrist strap, a demagnetised wrist strap, and a copper bracelet. The WOMAC Osteoarthritis Index, the McGill Pain Questionnaire-Pain Rating Index (PRI), a pain visual analogue scale (VAS), and medication use. No difference was observed between devices in terms of their effects on pain as measured by the primary outcome measure (WOMAC A), the PRI and the VAS. Similar results were obtained for stiffness (WOMAC B), physical function (WOMAC C), and medication use. Further analyses of the PRI subscales revealed a statistically significant difference between devices (P=0.025), which favoured the experimental device. Participants reported lower sensory pain after wearing the standard magnetic wrist strap, than when wearing control devices. However, no adjustment was made for multiple testing. Our results indicate that magnetic and copper bracelets are generally ineffective for managing pain, stiffness and physical function in osteoarthritis. Reported therapeutic benefits are most likely attributable to non-specific placebo effects. However such devices have no major adverse effects and may provide hope.Complementary therapies in medicine 10/2009; 17(5-6):249-56. DOI:10.1016/j.ctim.2009.07.002 · 2.22 Impact Factor
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