Appendix III: Reports on Randomized Clinical Trials of Magnetic Therapy for Pain from January 1997 to March 2004
Questions & Answers About Using Magnets to Treat Pain - Part 9
Static Magnetic Therapy
Authors: Wolsko et al., 2004,27
Description: Participants (26) with osteoarthritis of the knee received either a sleeve containing magnets, to be worn over the knee area, or a placebo sleeve that appeared identical. They wore their sleeves for the first 4 hours and then at least 6 hours a day for 6 weeks. Knee pain was measured at 4 hours, 1 week, and 6 weeks.
Findings: There was a statistically significant improvement in pain in the treatment group at 4 hours, but not at 1 week or 6 weeks.
Authors: Winemiller et al., 2003,7
Description: Participants (95) who had had plantar heel pain for at least 30 days received either shoe insoles containing a magnet or insoles that were identical except for having no magnet. They wore the insoles at least 4 hours a day 4 days/week for 8 weeks. Outcomes were measured by a daily pain diary.
Findings: There were no significant differences in pain outcomes between the two groups. Both experienced significant improvement in morning foot pain and in enjoyment of their jobs (because of reduced foot pain).
Authors: Weintraub et al., 2003,24
Description: Patients (259) with diabetic peripheral neuropathy wore static magnetic shoe insoles or an unmagnetized sham device continuously for 4 months. Primary outcome measures were burning, numbness and tingling, exercise-induced foot pain, and sleep interruption due to pain.
Findings: Authors found that statistically significant reductions in burning, numbness and tingling, and exercise-induced foot pain occurred in the treatment group, but only during months 3 and 4. Some patients in the treatment group with more severe baseline pain had significant reductions in numbness and tingling and in foot pain throughout the study period.
Authors: Hinman et al., 2002,25
Description: Participants (43) with chronic knee pain wore pads containing static magnets or placebos over their painful joints for 2 weeks. Outcomes were measured using self-administered ratings of pain and physical function, and a timed 50-foot walk.
Findings: At the end of 2 weeks, those wearing magnets reported significantly less pain, and better daily physical function and walking speed, than those wearing placebos. Most of those wearing magnets experienced pain relief within 30 minutes of the initial application of the magnets.
Authors: Carter et al., 2002,22
Description: Participants (30) with carpal tunnel syndrome wore a magnetic or placebo device on the wrist over the carpal tunnel area for 45 minutes. Participants rated their pain at 15-minute intervals while wearing the device, after removing the device, and after 2 weeks.
Findings: The magnet was no more effective than the placebo in relieving pain. Significant pain reduction was reported for both treatment and placebo groups during a 45-minute application. The reduction in pain was still detectable 2 weeks later; authors suggested that this could be from a placebo effect.
Authors: Segal et al., 2001,28
Description: Patients (64) with rheumatoid arthritis of the knee received one of two magnetic devices: one containing four strong magnets or one containing only one weaker magnet. There was no nonmagnetic or sham treatment. Devices were worn continuously for 1 week. Outcome measures were the participants' pain diaries in which they assessed their level of pain twice a day.
Findings: Both devices produced significant pain reduction after 1 week of use. A significant difference was not seen between the two groups. The authors indicated that a nonmagnetic placebo treatment should be used in future studies.
Authors: Alfano et al., 2001,26
Description: Patients with fibromyalgia (94 subjects) received either (1) usual care, (2) a pad containing static magnets placed between the mattress and box springs, (3) an eggcrate-like foam mattress pad containing static magnets of varying strength, or (4) a mattress pad containing magnets that had been demagnetized. Outcome measures were functional status, pain, and the number and intensity of tender points after 6 months.
Findings: Compared with the usual-care group and the sham group, people who used the pads containing active magnets reported improvements in function, pain intensity level, number of tender points, and intensity of tender points after 6 months. However, except for pain intensity, measurements were not significantly different from scores reported for the sham treatment group or the usual-care group.
Authors: Collacott et al., 2000,8
Description: Participants (20) who had had chronic low-back pain for at least 6 months wore a magnetic device for 1 week (6 hours/day, 3 days/week). After 1 week of no treatment, the participants wore a sham device for 1 week (6 hours/day, 3 days/week). The primary outcome was pain intensity, which was measured by a visual analog scale.
Findings: No significant differences in outcomes were found between the magnetic and sham therapies.
Authors: Caselli et al., 1997,23
Description: Participants (34) with heel pain wore a molded insole with or without a static magnetic foil insert for 4 weeks. The outcomes were measured in terms of the foot function index (pain, disability, and activity restriction).
Findings: Use of the magnetic insole was no more effective than the sham as measured by the foot function index. About 60% of patients from both groups noted improvement in heel pain after 4 weeks, which suggests that the molded insole itself was effective in treating heel pain.
Authors: Smania et al., 2003,18
Description: Participants (18) who had painful trigger points from myofascial pain syndrome received, over a period of 2 weeks, either 10 sessions of rMS or a sham treatment. During each 20-minute treatment, two different coils from the rMS device delivered pulsed ET when placed on each patient's trigger point. Patients were evaluated for 1 month after the treatments, using pain scales and clinical exams.
Findings: The participants who received the magnetic therapy had significant improvement in all pain measurements and in some range-of-motion measurements that persisted throughout the evaluation period. The placebo group did not show any significant improvement.
Authors: Nicolakis et al., 2002,30
Description: Participants (32) with osteoarthritis of the knee lay on a pulsed electromagnetic mat or a sham mat for 30 minutes twice a day for 6 weeks. The primary outcome measures were pain, stiffness, and physical function.
Findings: At the end of 6 weeks, physical function scores were significantly improved for the treatment group compared with the sham group. Pain and stiffness decreased for both groups, with what the study authors called a "marked" placebo effect for participants using the sham treatment. There was no significant difference between the groups for pain and stiffness.
Authors: Thuile and Walzl, 2002,29
Description: Two prospective studies of ET for low-back pain (100 participants) and whiplash (92 participants). Half of the participants in each study received ET twice a day for 2 weeks plus standard medications. The other half received only standard medications. ET consisted of applying a low-energy, low-frequency magnetic field cushion for 16 minutes and using a whole-body mat for 8 minutes. Evaluation of the low-back pain participants consisted of counting the interval to reported pain relief and/or painless walking, and measuring hip flexion to the point of pain. Participants in the whiplash study reported their pain on a 10-point scale and had their range of motion measured.
Findings: In the low-back pain study, the ET group reported the following compared with the control group: statistically significant pain relief and/or pain-free walking 3.5 days sooner and increased ability to bend at the hip. In the whiplash study, the ET group, compared with the control group, had significantly decreased pain in the head, neck, and shoulder/arm areas after treatment, and significantly greater range of motion.
Authors: Pipitone and Scott, 2001,11
Description: Patients (69) with osteoarthritis of the knee used a pulsed electromagnet or a sham device for 6 weeks. Devices were placed on or between the knees for 10 minutes three times a day. The primary outcome measure was a reduction in pain.
Findings: Pulsed ET significantly reduced pain, measured by several scales, over a 6-week period in the treatment group, and did not produce any adverse effects. No improvements were noted with the placebo-treated group. The authors suggested further studies of pulsed ET for osteoarthritis and other conditions.
Authors: Jacobson et al., 2001,10
Description: Participants (176) with osteoarthritis of the knee were treated with ET for a total of 48 minutes per treatment session for eight sessions during a 2-week period or sat near the electromagnet with the magnet off (placebo). Participants used a subjective 10-point scale to rate their pain level before and after each treatment and 2 weeks after the final treatment. Patients also kept a diary of pain intensity before, during, and 2 weeks after the trials, in which they recorded entries daily upon waking and before going to sleep. They did not take any medicines or use topical analgesics.
Findings: ET significantly reduced pain after a treatment session in the magnet-on (treatment) group (46% reduction) compared to the magnet-off (placebo) group (8%).
Authors: Pujol et al., 1998,17
Description: Patients (30) with localized injury to the musculoskeletal system received 40 minutes of either rMS treatment or sham treatment. Stimulation intensity was adjusted in each patient to avoid excessive discomfort. Outcome measure was a 101-point pain rating scale.
Findings: After one treatment, the pain score decreased significantly in rMS-treated patients compared with sham-treated patients (59% versus 14% reduction). The effect persisted for several days.
NCCAM has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your primary health care provider. We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy in this information is not an endorsement by NCCAM.
National Center for Complementary and Alternative Medicine (NCCAM)
National Institutes of Health
Bethesda, Maryland 20892 USA
NCCAM Publication No. D208