“By Dr. William Pawluk”
The use of magnets and magnetic fields as they relate to healing has long been studied. Magnetic bracelets and necklaces, mattresses and shoe inserts are both widely available and widely used. Cleopatra herself was reported to have slept on a lodestone, or magnetized rock. Understanding the difference between static magnets and pulsed electromagnetic fields—and there is a place for both—is paramount to using the therapies effectively.
Static vs. Pulsed Magnetic Fields
If you have ever held two magnets in your hands, tried to force them together, and felt a resistance between them, then you have experienced a magnetic field. These are called static magnets, and their magnetic fields—which interact with one another, causing the resistance you feel—would be there whether or not you were forcing the magnets together.
The devices we refer throughout this website are Pulsed Electromagnetic Field Therapy devices. It is a common misunderstanding to assume that these systems are related to the static magnets to which we are accustomed – refrigerator magnets or magnetic bracelets or necklaces, for example.
A static magnet has a set magnetic field – it is unchanging. A PEMF requires no physical static magnets. Instead, a magnetic field is produced by way of passing electricity through a set of winding copper coils inside the applicator. This creates a much larger and entirely dynamic magnetic field.
A magnetic field can generate a current in any conductive material, such as nerves or other body tissues within its field. The electromagnetically-induced field accomplishes the result of transferring charge to cells of the body. This induced current can lead to nerve firing, muscle contraction, stimulation of cell signal pathways causing cell growth, and a number of other effects. The current generated by the PEMF mimics normal internally-generated electrical currents.
The body can become accustomed to non-moving (or static) magnetic fields, which are generally unable to deeply penetrate the body. Because of this, they generally must be stronger in intensity, and must be applied for longer intervals of time than PEMF devices.
Small static magnets are commonly used on acupuncture points, for the reflex system, and for superficial tissue actions. Acupuncture point magnets can vary from 500 Gauss to more than 3,000 Gauss in intensity. For shorter treatments, 10-20 minutes, higher dose magnets would be better. If the magnet is to be worn for an extended period of time (for smoking cessation, for example), small bead-like magnets of 500 Gauss would suffice. It would not make sense to use static magnets over very deep acupuncture points, however. They should only be used over acupuncture points that are within 10mm of the skin surface.
With static magnets, a lot of information focuses on the differential effects of north or south polarity. There is virtually no good published scientific evidence supporting these claims—even less that has been peer-reviewed. North vs. South polarity is probably of minimal importance in guiding clinical practice, and is based on limited science. In any case, multi-polar magnets make this argument irrelevant.
A pulsed electromagnetic field is able to penetrate all the way through the body and creates a cascade of effects within the body. Because it is a dynamic field, the body is unlikely to become accustomed to the magnetic field, making even long-term treatments genuinely effective.
PEMF treatments can be shorter than treatments with static magnets, and the intensity of the magnetic field can be significantly less while causing similar actions within the body. Pulsed magnetic field devices are available for treatment at the picoTesla to kiloGauss level, depending on the system used.
A multitude of different signals and types of magnets (both static and travelling or pulsed) have been studied, used, and found to be effective. Some argue that only this or that specific signal will create a desired clinical or biological goal. While we all seek this level of certainty, it is clear that the same biological outcome is often achieved with very different signals. Laboratory systems have shown measurable identical responses to both pulsed and static magnetic fields.
The Ca2+/Calmodulin-dependent myosin phosphorylation system—which makes muscles work better and relax better—has been extensively studied with both static and pulsed magnetic fields. A comparison of typical results shows that a 450 Gauss static field and a 0.2 Gauss pulsed field both accelerate phosphorylation (a process which helps turn “on” and “off” many enzymes and other cellular processes) by nearly twofold. Similar behavior has been obtained for nerve cell growth, which increased about twofold with both static and pulsed signals.
The differences between static and pulsed magnetic field systems and approaches must be better demonstrated. For the moment, Dr. Pawluk continues to use static magnets for acupuncture/reflex systems and local superficial tissue actions. Otherwise, they remain to him as a second cousin to PEMFs in the overall value expected and his goals for better overall health.