PEMF- An Introduction to Pulsed Electromagnetic Field Therapy
WHAT IS PEMF ALL ABOUT?
Pulsed electromagnetic field (PEMF) therapy has shown promising therapeutic effectiveness on bone and cartilage related pathologies, being also safe for management of knee osteoarthritis. PEMF is a biophysical therapeutic modality based on the delivery of pulsed electromagnetic fields.
Pulsed electromagnetic field (PEMF) therapy has proved to be safe and has also shown promising therapeutic effectiveness on bone and cartilage related pathologies, including knee and cervical spine OA. Low frequency pulsed electromagnetic field (PEMF) can provide noninvasive, safe and easy to apply method to treat pain, inflammation and dysfunctions associated with rheumatoid arthritis (RA) and osteoarthritis (OA) and PEMF has a long term record of safety.
Osteoarthritis (OA) is a degenerative joint disease frequently affecting the knee and afflicting the constantly increasing elderly population.Knee OA symptoms include pain, stiffness, and functional limitation, leading to loss of autonomy and poor quality of life in patients affected by this disease. Nowadays, various treatment options are available for the management of this condition. They include: nonsteroidal anti-inflammatory drugs (NSAIDs) for pain management; bisphosphonates to decrease pain and improve functionality preserving the structural integrity of subchondral bone; therapeutic exercise; viscosupplementation with hyaluronic acid alone or in combination with bisphosphonates or NSAIDs to improve pain and functional activity since hyaluronic acid improves articular cartilage degeneration and decreases osteophyte formation, as showed by experimental studies using OA models. These treatment modalities are effective in reducing pain and inflammation, but their long-term administration is associated with a high incidence of side effects or may not be applicable to the elderly.
Building upon these foundations, there is an urgent need for alternative therapies for this pathological condition. Pulsed electromagnetic field (PEMF) therapy has proved to be safe and has also shown promising therapeutic effectiveness on bone- and cartilage-related pathologies, including knee and cervical spine OA.
MECHANISM OF ACTION
The primary mechanism of action of PEMF-mediated analgesia is to involve promoting the reduction and resolution of inflammation. Results from in vitro and in vivo studies indicate that PEMF therapy may regulate gene expression by influencing the activation of ion channels. Recent results in rodents have indicated that both Na+ and Ca2+ voltage-gated ion channels are activated by extremely low frequency electromagnetic fields. Activation of these channels leads to activation of second messenger pathways and downstream regulation of gene expression. Previous studies in vitro have also found that PEMF treatment of cells in culture is followed by changes in the gene expression profiles of a number of factors associated with inflammation and analgesia, including an increase in endogenously expressed opioid precursors, both at the messenger (m)RNA and peptide levels.
Additionally, results of a clinical pilot study found significantly lower levels of interleukin 1 beta peptide in postoperative wound exudates from PEMF-treated tissue relative to sham-treated tissue, which corresponded with lower pain scores in the PEMF treatment group. Together, these findings suggest that PEMF-mediated changes in gene expression underlie the anti-inflammatory and analgesic effects associated with PEMF therapy.
ROLE IN CARTILAGE REGENERATION
PEMF has a beneficial effect on chondrocyte proliferation, matrix synthesis, and chondrogenic differentiation by upregulation of TGF-β and BMPs, and it decreases anti-inflammmatory cytokines via A2A and A3 adenosine receptors in in vitro studies. In in vivo studies, PEMF has beneficial effects on OA progression and cartilage defects.
PEMF preserved morphology of articular cartilage for a long time and also found that PEMF increased the numbers of cells immunopositive to TGF-β and decreased those immunopositive to IL-1.53 TGF-β plays a significant role in the anabolism of chondrocytes.54 Therefore, PEMF is believed to have both anabolic and anti-catabolic effects.
PEMF increased TGF-β1 and decreased IL1 and TNFα, and, as a result, PEMF improved the regeneration of the defective cartilage site. These studies demonstrated that PEMF has beneficial effects on cartilage regeneration.
SAFETY OF PEMF
The usual definitions have suggested that radiation with particle or photon energies less than 10 electronvolts (eV) be considered non-ionizing. Another suggested threshold is 33 electronvolts, which is the energy needed to ionize water molecules. PEMF therapy is well below these levels & is completely safe for therapeutic use.
ADVANTAGES OF PEMF THERAPY
- Non Surgical, Non Invasive
- No side effects
- Outpatient treatment with no requirement for hospitalization
- Patients of any age may be treated
- Other medical conditions do not prohibit treatment
- Dependency on pain medication reduces after therapy
EVOLUTION OF PEMF
The use of magnetic fields for healing is not modern. Long before the reasoning for their benefits was understood, ancient medicine was incorporating magnetic therapies into their medical therapies. Around 4000BC Hindus refer to treatment of disease with magnetized stones (lodestones). In 2000BC, Chinese physicians developed written protocols for using lodestones on acupuncture points, as described in “The Yellow Emperor’s Book of Internal Medicine.” There is some evidence that Egyptian physicians used lodestones with some regularity, and that Cleopatra herself wore a small magnet in an attempt to preserve her youth. In ancient Greece, Hippocrates was reported to use magnets for pain, and even had people in his healing centers lay their heads on lodestones to alleviate their headaches.
EARLY AND MID-MODERN HISTORYIn the early 1500s, Swiss physician and alchemist Paracelsus, credited as the founder of toxicology, appeared to have used lodestones to treat seizures and psychiatric disorders. He used the then-undiscovered or otherwise misunderstood principles of magnetism to guide his practices in chemistry and symptom management.
In the mid-18th century, German physician Franz Mesmer developed a theory called “animal magnetism” to describe what he saw as the natural energy transference between all things. (This theory was later used by the Scottish physician James Brain to develop hypnosis and is sometimes equated with the Qi of Traditional Chinese Medicine.) Mesmer treated his patients with magnets, particularly in an effort to help psychiatric disorders.
In the late-18th century, German physician Samuel Hahnemann, widely known as the father of alternative medicine’s homeopathy, was reputed to use magnets in his treatment programs.In the 19th century, the science around magnetic fields and electromagnetism began to come into focus. English scientist Michael Faraday contributed a great deal to the study of electromagnetism, including the discovery of electromagnetic induction, diamagnetism, and electrolysis. Faraday went on to create the first electromagnetic rotary device, forming the foundation of electric motors. His work in electromagnetism established for the first time that a changing magnetic field produces an electric field. This would later be named “Faraday’s Law”, one of the four Maxwell equations. Shortly before his death, he proposed the concept of electromagnetic fields – forces extending into the space around a conductor. He did not live to see the eventual acceptance of his theory.
Late in the 19th century, Russian engineer Georges Lakhovsky became the first to posit that each cell had its own frequency oscillating at a specific amplitude. He developed what is likely the first “energy medicine” device called the Multiple Wave Oscillator or Radio-Cellulo-Oscillator. The device produced a wide range of therapeutic frequencies, from ELF all the way up to gigahertz radiowaves.
In the late 19th and early 20th centuries, Serbian-American inventor Nikola Tesla contributed to the development of the alternating current (AC) electrical system we use today, and discovered the rotating magnetic field (now the basis of most AC machinery). Tesla had an intimate understanding of the relationship between electricity and magnetic fields, and developed ideas for a huge number of inventions we use to this day: dynamos, induction motors, radar, X-Rays, and remote control being just a few. While the classic electrical device is the Tesla Coil (which produces streamers of electricity in a glass bulb – common attractions in children’s museums) a lesser-known electrical coil was also invented by Tesla. This is the standard magnetic loop coil seen in all PEMF systems today.
In the 20th century, sophisticated static magnetic therapies were being developed in the Czech Republic, including checkerboard-designed magnetic foils. PEMF devices began there as well, and were introduced in Hungary in the early 1980s. Soon thereafter, PEMF therapy spread to other parts of Europe, with a wide variety of devices being made available through a growing number of manufacturers.Simultaneously, Eastern European use and research began to blossom.
The 1980s also saw the introduction of the first FDA-approved PEMF system, intended for use as a bone stimulator to treat nonunion fractures. The seminal book “Body Electric: Electromagnetism and the Foundation of Life” was published in 1986 by Dr. Robert Becker and Gary Selden. This book is important because it was one of the first descriptions of the body as an electromagnetic apparatus and therefore very susceptible to magnetic field therapies. With the wide variety of devices available in Europe, by the late 1990s, much of Europe was already familiar with PEMF therapy.
The 1990s also saw a discussion about the use of PEMF devices in space. It remains a common misconception that PEMFs were or are used in space. The international space station is in low Earth orbit, well within the Earth’s magnetic field. As such, there really is little necessity for the application of external magnetic fields to maintain a functional biomagnetic field. In a discussion with the medical director of Russia’s space program at a meeting in Germany, it was made very clear that PEMFs are not being used on astronauts, but that the study of what would happen to the body were it outside of the Earth’s magnetic field is of great interest and importance as we consider venturing further out into space.
There continue to be exciting new developments in the study of magnetic field stimulation of the body. There is a rapidly growing body of evidence to support the use of high intensity PEMFs, especially for the brain. This technology was developed primarily to avoid the need for electrical stimulation, which was effective, but incredibly uncomfortable and widely considered barbaric. Even so, electroconvulsive therapy (ECT) had been used for decades to treat psychiatric disorders. High intensity PEMF stimulation has been shown to have similar beneficial effects without the invasive or otherwise unbearable components of ECT, such as convulsions. This specific type of PEMF therapy is known as transcranial magnetic stimulation (TMS). A high intensity coil is placed at the side of the head. The intensity of the magnetic field produced by the coil is increased until it is sufficient enough to cause a muscle contraction of the hand. Then the intensity is either maintained or lowered slightly, and the coil is moved to the part of the brain requiring the treatment, depending on the psychiatric indication of interest. Studies are also being done with these high intensity magnetic fields to treat other parts of the body for a huge variety of medical conditions.
In the meantime, other lower intensity PEMF systems continue to be developed, including for transcranial applications. Development of new systems is being made easier in the US by the recently updated FDA position, allowing PEMF systems to be marketed without FDA approval if their primary purpose is for the management of wellness.
MAGNETIC SCIENCE REVISITED
To understand magnetic science is to understand magnetism. Magnetism is one element of the combined electro-magnetic force. This term refers to any physical phenomena that arise from force caused by magnets. For clarity, magnets are objects that produce attraction to or repulsion from other objects. Motion of electrically charged particles gives rise to magnetism. Although all materials experience magnetism, only ferromagnetism can be felt by people, with rare exception. Ferromagnetism is the strongest type of magnetism and is responsible for the common magnetism encountered in everyday life. An example of a ferromagnet is a refrigerator magnet. This type of attraction was the quality of magnetism first apparent to the ancient world, as well as to us today.
HOW MAGNETIC THERAPY WORKS
The term “magnetic therapy” refers to various practices ranging from wearing a magnetized bracelet, to sleeping on magnetized mattresses, to therapy involving magnetic field machinery, small and large. When it comes to the effects that magneticfieldshave on the body, there are multiple theories, all correct to some degree, none of which completely explain the magnetic phenomena. However, the general consensus is that magnetic fields act upon the body at the molecular level, by enhancing or affecting the natural electrical charges in the tissues that correct disruptions. According to laboratory studies, magnetic fields can modulate the transport of ions and related neuronal and cell activity. Through these actions magnetic field therapies have been found in hundreds of research studies to have benefits in numerous health conditions.
ILLUSTRATING MAGNETIC FIELDS
There are two ways to illustrate a magnetic field, with vectors or field lines. When we describe a magnetic field mathematically, it is known as a vector field, which we can plot directly as a set of vectors on a grid. Each vector points as a compass would, with a length that is dependent on the strength of the magnetic force. Alternatively, we can represent forces within a vector field using field lines. These disperse within a grid pattern and connect vectors with smooth lines.Useful properties of a field-line description include that field lines:
- Never cross.
- Don’t begin or end anywhere, making only closed loops.
- Naturally, bunch together where magnetic fields are the strongest.
MEASURING MAGNETIC FIELDS
There are two aspects of a magnetic field (a vector quantity) that we need to measure: its strength and its direction. While measuring the direction is quite simple, measuring the strength is significantly more challenging. We can use a magnetic compass to measure direction (the same kind of magnetic compass used for navigation using the Earth’s magnetic field). On the other hand, it takes a magnetometer to measure the strength of a magnetic field. Magnetometers have only been around since the 19th century and most function by exploiting the force electrons feel as they move through magnetic fields.
MORE ABOUT MAGNETIC FORCE
A magnetic force is a result of the electromagnetic force (one of the four basic forces of nature) and is due to the motion of charges. Two objects with charge of the same direction of motion will have a magnetic attraction to each other. In a similar fashion, two objects with charge moving in opposite directions will have a repulsion to each other. Essentially, a magnetic force arises as a result of interacting magnetic fields.
USES OF MAGNETIC THERAPYScientific evidence is constantly accumulating to support positive results of magnetic therapy. A significant amount of this is summarized in the book Power Tools for Health by Dr. William Pawluk, MD, MSc. Practitioners of magnetic therapy report that individuals find pain relief and other clinical benefits for the following conditions:
- Post-polio syndrome
- Muscle strains
- Multiple sclerosis
- Circulatory issues
- Nerve pain, such as diabetic neuropathy
- Nausea and vomiting
- Wound healing
THE HISTORY OF PEMF
No history of PEMF would be complete without examining the therapeutic use of natural energy fields over thousands of years. Electro Magnetic Therapy has a long history back to at least Ancient China, and shows the separate use of two related phenomena that would later be combined into one method (Pulsed Electromagnetic Field Therapy):
There are many ancient references to the healing use of magnetite (the most common mineral with magnetic properties, also known as lodestone and also used for navigation at sea).
The earliest mention is in the Yellow Emperor’s Book of Internal Medicine, written in China and dated to around 2600 BC, the earliest known medical text. It describes the placement of lodestones on specific points on the body to correct various imbalances. Similar practices are described in the Vedas, the ancient Hindu scriptures of India.
Further references appear from ancient Greece, with Plato describing the physician Pliny’s use of magnetite to treat wounds and bladder problems. The main theory behind these techniques was that they helped to circulate energies and fluids around the body, an approach that can be seen with the Swiss physician Paracelsus in the 1500’s, and in 1600 with the Englishman William Gibert, physician to Queen Elizabeth I.
Pointing the way to modern electro therapy and electro stimulation, there are various ancient references to the use of electric discharges from ray fish, or torpedo fish, and electric eels. Both Aristotle in Greece around 250 BC and the Roman imperial physician Scribonius Largus in 46 AD describe the use of their electrical discharges through seawater to treat arthritis, gout and other pain.
It was not until the 1800’s that the invention of various electrical technologies made modern electro-therapy possible. In 1800, Alessandro Volta, an Italian physicist, invented a type of chemical battery to generate a steady electric current. And in 1820, Andre-Marie Ampere showed that passing an electric current through a wire coil would produce a magnetic field.
Then, in 1831, English physicist and chemist Michael Faraday demonstrated the reverse. He created an electric dynamo from a magnet moving inside a coil of copper wire — the first practical means of producing electricity in volume. In many ways, Faraday was the father of modern electro-magnetism.By the end of the century, a bewildering range of electrical inventions came from the great Serbian-American inventor, Nicola Tesla. He was also one of the first electrical engineers to believe that some electrical fields had therapeutic properties.
In 1932, an early form of PEMF, the Diapulse, was developed by American physician Abraham Ginsberg and physicist Arthur Milinowski. It consisted of a large cylindrical applicator device mounted on an articulated arm for localised treatments. Its primary aim was in boosting circulation and healing wounds and burns.
In the late-1940’s, post-war Japanese medical clinics began using some early PEMF prototypes.
The 1960’s were an active decade for PEMF development. Manufacturing began in several countries in Eastern Europe and the Soviet Union. And in Germany Dr. Rutger Wever showed that shielding test subjects from sunlight, Earth’s magnetic field, and atmospheric frequencies led to various mental and physical problems.
They were only relieved by exposure to a PEMF field using the frequencies discovered in 1952 by Dr. Winfried Otto Schumann (later known as the Schumann Resonances).Still in the 1960’s, Antoine Priore and a team of French scientists were funded by the French government to test PEMF technology on laboratory animals, with promising results.
By the 1970’s, Dr. Kyoichi Nakagawa in Japan was showing that fatigue, insomnia and idiopathic pain common among industrial workers could be relieved by magnetic fields. PEMF was also drawing attention in the USA for its use on top racehorses, and Dr. Andrew Bassett showed that low-frequency PEMF could heal some of the most difficult types of bone fracture (non-union and delayed union). This use was approved by the FDA in 1979.
NASA and the home user
By the 1990’s, we see the challenge of long stays in Space with the Soviet Union launching the Mir space station into near-Earth orbit. It reportedly used PEMF equipment to deliver Schumann Resonances to those on board.
In the 2000’s, NASA became one of the most active researchers in PEMF. A four-year study that it published in 2003 concluded that it has the potential for “repairing traumatized tissues and moderating some neuro-degenerative diseases.”
In 2005, NASA published “Pulsed Electromagnetic Fields – A Countermeasure for Bone Loss and Muscle Atrophy” and said this would become important for longer space flights in the future. And in 2009, Dr. Thomas Goodwin and other NASA scientists were awarded a patent for using it to accelerate tissue repairs.
Since 2000, we’ve seen the history of PEMF really take off as it became increasingly popular with the general public as a pain relief and wellness technology. The fastest initial growth was in Austria, Germany and Switzerland, but usage has recently boomed in the USA and Asia.
PEMF is backed by a mountain of research: over two thousand controlled clinical studies, and tens of thousands of research papers. Most have shown positive results, and there have been no signs of widespread harmful side effects (although field strength needs to be matched with the intended usage and the state of the individual user). PEMF has long been used as a delivery route for natural frequencies but this is likely to expand significantly in the future.
We already see it being combined with regulation of circadian rhythms (our body clock), brain entrainment (using Sound and Light), music therapy and bio-feedback (using Heart Rate Variability). The growing popularity of PEMF, and our exploding levels of EMF pollution, suggest that magnetic therapy is now entering a totally new age.