This treatment mode may have real magnetism, but does it actually work?
“Magnet therapy” – the use of magnetic fields to treat pain and disability – is becoming increasingly popular in the athletic world. Athletes are using magnets to ease discomfort in sore joints – and even to increase strength in aching, stiff, or weak muscles. Does magnetotherapy have any real attraction, or is it simply a foolish fad? In an attempt to find out, researchers in Oklahoma City recently tested the effectiveness of magnet therapy on 30 people with carpal-tunnel syndrome. Marked by numbness and tingling sensations in the wrist and hand and pain that can radiate all the way up to the shoulder, carpal-tunnel syndrome is a disorder which can be caused by repetitive motions of the arm. Such motions can produce irritations of the wrist, which can lead to wrist swelling and then compression of nerves which travel from the forearm to the hand through a connective-tissue “tunnel” in the wrist. In the Oklahoma study, the 30 subjects had their wrists wrapped for 45 minutes with padding which contained either a 1000-Gauss magnet or else an identical-looking, placebo metal disk which was not magnetised. Pain was measured on a visual analogue scale using 0 and 10 as “anchors” (“The Effectiveness of Magnet Therapy for Treatment of Wrist Pain Attributed to Carpal Tunnel Syndrome,” Journal of Family Practice, Vol. 51(1), pp. 38-40, 2002).
A scoreless draw?
The encouraging news was that pain was significantly reduced after the 45 minutes of magnet therapy. The discouraging news, however, was that pain was diminished by the same amount in the placebo wrists! As Dr Richard Carter, one of the Oklahoma researchers, explained it: “Most likely this is a placebo effect due to the patients’ belief in the efficacy of the device. Also, it is possible that pressure over the area of pain, due to application of the wrist wrap, somehow reduces the amount of pain experienced.” Alleviation of pain via wrist-wrap pressure could explain why both groups felt better. Carter concluded: “Although this study did not show magnets to be more effective than the placebo, the reduction in pain with this simple intervention was remarkable”. His conclusion is certainly warranted, especially since pain was still reduced two weeks later during a follow-up visit to the clinic!
Although the Oklahoma study failed to distinguish the effects of magnet therapy on wrist pain from those produced by a simple Velcro-cloth wrapping, another study provided decent evidence to support the use of magnets for knee pain. In research carried out at the Institute of Theoretical Physics and Advanced Studies for Biophysical Research in Jupiter, Florida, individuals with osteoarthritic, painful knees received magnetic-field treatments eight times during a two-week period. Each treatment consisted of eight six-minute exposures to the magnetic field (48 total minutes), thus providing a total of 384 (8 x 48) minutes of magnetotherapy during the study. During treatments of control subjects, the magnetic fields were turned off, and the research was carried out in a randomised, double-blind manner, with 176 patients involved (“Low-Amplitude, Extremely Low Frequency Magnetic Fields for the Treatment of Osteoarthritic Knees: A Double-Blind Clinical Study,” Altern Ther Health Med, Vol. 7(5), pp. 54-64, 66-69, 2001).
The magnetic fields in this study were generated by a Jacobson resonator, and the range of magnetic-field amplitudes was from 2.74 x 10-7 to 3.4 x 10-8 Gauss, with corresponding frequencies of 7.7 to .976 Hz. Each subject rates his/her pain level from 1 (minimal) to 10 (maximal) before and after each treatment and two weeks after treatment. Subjects also recorded their intensity of pain twice daily in a diary for two weeks after the last treatment session (session eight) – upon awakening and just before retiring for the night.
And the result?
Somewhat surprisingly for those who believe that magnetotherapy is a bit of a hoax, magnetic-field exposure significantly reduced knee pain. In fact, knee pain was down by 46% in the magnet-therapy group, versus just 8% among the placebo subjects. The researchers concluded that low-amplitude, extremely low frequency magnetic fields are “safe and effective for treating patients with chronic knee pain due to osteoarthritis”.
Incidentally, there is also some evidence in the scientific literature to suggest that non-invasive magnetotherapeutic approaches to bone healing can be successful. There is little evidence, however, to support the idea that magnet therapy can improve muscular strength, as some magnet fans have contended. In fact, in a recent study in which magnets were utilised in an attempt to improve hand-muscle strength, the magnets flopped totally.
In the hand-muscle study, 35 university students from Rowan University in Glassboro, New Jersey (18 men and 17 women) were tested for grip strength using a grip dynamometer and for thumb-forefinger pinch strength using a pinch gauge under three different conditions: (1) before the study began, (2) while wearing a sham magnet (placebo), and (3) while sporting a flexible magnet with 700-Gauss intensity. The order of treatments was random, and data collection was double-blind (“The Effect of Flexible Magnets on Hand Muscle Strength: A Randomised, Double-Blind Study,” Journal of Strength and Conditioning Research, Vol. 16(1), pp. 33-37, 2002).
For grip-strength measurements, the magnet was placed over the “bellies” of the flexor digitorum profundus and flexor digitorum superficialis muscles; for pinch-strength tallies, the magnet was over the flexor pollicis brevis and opponens pollicis muscles. Three trials for each strength measurement for each of the three conditions were performed, with magnets (or sham magnets) placed in the right areas of the subjects’ hands three minutes before testing. Each test was separated by one minute of rest. As mentioned, the magnets were washouts: average grip and pinch strength were the same with real and sham magnets.
So what’s the bottom line? If you have wrist pain, attaching a magnetised wrist band to the sore area may well alleviate pain, although the relief may come from the band and not the magnet. If your osteoarthritic knees are acting up, there is decent evidence to suggest that magnet treatments will provide you with pain relief, as wacky as the idea may sound. Don’t count on magnets to give you a faster tennis serve, a stronger bowling arm, or a more power-packed rugby tackle, however: the touted benefits of magnets on muscle strength are unverified.