Can a magnet take away pain? Magnet therapy interests me in part because it seems far out. Like it belongs with Bruce Willis’ character in the 1997 English language French film, the Fifth Element. In it, four stones plus a humanoid fifth element played by Milla Jovovich comprise a weapon, the only defense against a evil cosmic fireball that threatens humanity every five thousand years. But perhaps it is more akin with something here on earth like the practice of grounding or crystal healing. Search for ‘the power of crystals’ on Amazon, and you get over 10,000 results, starting with the matter-of-factly titled: The Power of Crystals: An Essential Guide to Witchcraft Therapy. I won’t cast aspersions on crystal therapy or grounding though, because they are topics I know nothing about.
Magnet therapy, on the other hand, is FDA-approved.
Pulsed electromagnetic field (PEMF) therapy utilizes an intermittent magnetic field and secondary electrical current to activate enzymes in the body that upregulate growth factors, decreasing markers of inflammation and promoting bone cell proliferation. The FDA granted its approval for PEMF in 1979, for the treatment of fracture non-union (unhealed broken bones). (It is also FDA-approved for use after spinal fusion.)
For example, one small, randomized controlled trial of humans with fifth metatarsal fractures that had failed or delayed healing showed time to healing was 8.9 weeks in the PEMF-treated group compared to 14.7 weeks in the placebo group.
Given the basic science evidence that has grown since the initial FDA approval, PEMF may be suitable for wider application in the treatment of injury and disease or even for recovery in healthy individuals.
One study comparing PEMF to extra-corporeal shock wave therapy (ECSWT) found that both increased maximum load and toughness of a rabbit's Achilles repair. Another, involving sheep undergoing cartilage surgery, found that PEMF increased graft integration and prevented graft absorption.
I’ve had trouble with a different ankle tendon recently (tibialis anterior), so I decided to try the PEMF treatment. After taking care to remove all credit cards, phone and keys, I settled into a PEMF-rigged chair at a local wellness center. Once the field was up, the muscles around my chest and shoulders were contracting without any input from me. It’s a strange feeling to have your muscles contract when you’re not telling them to move. It made me wonder about my heart muscle. But, checking my pulse, that muscle seemed to be beating away at its usual rhythm. I remembered that MRIs use much stronger magnetic fields without known harmful effects. You can even get an MRI if you’re pregnant, though you would skip it if you could.
Nevertheless, the muscle contraction borders on the uncomfortable, depending on how strong you set the PEMF. This leads me to conclude that the trials that blindly compare PEMF to sham must be using a pretty low strength, or the control patients would know they’re not getting muscle stimulation. I found it strangely relaxing however. More than once during the week that I spent using PEMF every day, I found myself nodding off to sleep near the end of the session, despite the muscle contractions. After a week, I felt better, but I was also taking a break from training, so I can’t say what effect was due to PEMF and what was due to rest.
PEMF has not been a large part of my sports medicine practice but maybe it should be. The basic science of PEMF in the realm of cartilage is exciting. PEMF appears to have a pro-anabolic effect on cartilage and to act against the inflammation associated with cartilage degradation.
It has been used post-operatively for patients undergoing knee surgery. After arthroscopic treatment of knee cartilage lesions, patients treated with PEMF used fewer non-steroidal anti-inflammatory drugs (NSAIDs). Another Italian study demonstrated faster recovery after anterior cruciate ligament reconstruction (ACLR) with PEMF, with no adverse effects of the PEMF treatment. Those patients had to use the PEMF 4 hours per day for two months!
When researchers take the damaged, discarded cartilage from people getting knee replacements and subject that tissue to PEMF, it increases proteoglycan content. Proteoglycans are part of the extra-cellular matrix. Their biochemical properties enable them to help the tissue withstand compressive forces.
This may contribute to the success PEMF has had in non-operative treatment of musculoskeletal disease. Patients with knee osteoarthritis had less pain one year after PEMF treatment. Results deteriorated at 2 years but they were still better than baseline. A systematic review of six randomized controlled trials of PEMF used to treat low back pain concluded that PEMF reduced pain and increased functionality.
What about PEMF in healthy people? One small, randomized controlled trial (30 male human subjects) found that PEMF reduced the effects of delayed onset muscle soreness (DOMS) in the biceps at 24, 48 and 72 hours after exercise. PEMF can increase oxygen concentration in muscles and one pilot study of 20 semi-professional cyclists found that PEMF applied to the thigh increased muscle activity during low-load cycling.
Overall, the non-invasive nature and minimal side-effects make PEMF an appealing therapy. As evidence grows, it will likely take on an established role in treatment and recovery, especially if cost comes down over time. For now, I don’t want to pay $60-80 per hour for something I would use on a regular basis. There is also a considerable opportunity cost of all the time spent sitting on the PEMF mat, especially with some of the protocols in these research studies!