It is not unusual at horse shows and in show barns to see pulsed electromagnetic field (PEMF) therapy systems treating stiff, sore, hard-working horses. Many devices on the market can be used for the back, shoulders and stifles, with attachments for the neck, the legs, feet and hocks. Just about any problem area can be treated. Can PEMF therapy be used to treat your horse’s problem?
PEMF therapy is another method of utilizing a magnetic field, somewhat like static magnets, which have been used for centuries. The Yellow Emporer’s Canon of Internal Medicine describes treating acupuncture points with lodestone, which emits a naturally occurring magnetic field, to relieve painful conditions. In the middle ages, magnets were very popular as they were thought to be a cure for almost any malady. Fast forward to the 20th century, when magnetic bracelets, beds, rings, belts, blankets, etc., have been sold to treat all manner of problems, from athlete’s foot to insomnia. Almost everyone has heard of using magnets therapeutically.
PEMF devices are a bit more complicated to use than just placing a magnet on the tissue. PEMF systems are composed of coils of copper wire, through which a current of electrical energy is delivered. The current is turned on and off a number of times per second, surging through the coil. The magnetic field expands around the coil, and then collapses, expands and collapses again with the pulse of current. One of the benefits of PEMF versus static magnets is that the fields are typically much larger, so you do not have to place the PEMF coil right on the area needing therapy. Given the correct amount of current and the optimum number of coil windings, some coils can emit a measurable magnetic field up to 18” from the surface of the coil. This makes it easy to use on equine patients, by strategically placing the coils in known problem areas like joints and major muscle groups.
In addition, PEMF beds are now widely used in small animal rehabilitation centers to assist in therapy for degenerative conditions like arthritis and hip dysplasia. For horses, after short treatments over several days, owners and trainers can generally see and feel an improvement in the way the horse moves.
The improvements we see from PEMF therapy are increasingly supported in the scientific literature. A quick review of PubMed (U.S. National Library of Medicine, National Institutes of Health), shows the wide range of growing literature on the biological and clinical effects of PEMF. Studies show the therapeutic effects of PEMF on:
- joint diseases
- patient recovery after arthroscopic surgery
- MS fatigue and quality of life
- nerve regeneration in the cat
- neural regeneration in the rat
- knee osteoarthritic lesion progression in guinea pigs
- articular hyaline cartilage
A significant number of studies look at how PEMF can positively affect neural regeneration. A limited number of studies exist on horses, but the few, clinical studies that have been done report that PEMF shows promise in decreasing the healing time of tendon lesions, and improved healing and remodeling of an articular and subchondral osteolytic defect in the third metacarpal bone of a four-year-old filly.
Dr. Andrew Bassett, from the Department of Orthopedic Surgery, Columbia University and Presbyterian Hospital, one of the most important researchers in the field, conducted groundbreaking work in the 1960s that eventually demonstrated the successful treatment of non-union fractures with PEMF. In 1989, he wrote a chapter in Critical Reviews in Biomedical Engineering, titled “Fundamental and Practical Aspects of Therapeutic Uses of Pulsed Electromagnetic Fields (PEMFs).” He developed a table detailing research into PEMF Mechanisms of Action, which shows first-order actions (cell and tissues,) second-order (subcellular) and third-order (biophysical) actions. In this chart he outlines and cites studies showing increased collagen synthesis, increased DNA synthesis, cell migration, and angiogenesis, leading to a host of subcellular reactions. If you would like to dig deeper into the physiological basis of this therapy, this chapter, supported by 330 citations will provide hours of interesting study.
These beneficial effects are harnessed to treat equine tendon and ligament injury, sore backs, sore stifles, chronic hock soreness, sore shoulders, non-union fractures, laminitis, founder, stone bruises, and non-healing wounds. Treatments typically last 30 minutes, and are not stressful; rather they are calming and relaxing.
Is PEMF safe? Over the last several years, we have seen the introduction of extremely high-powered PEMF systems into race tracks and other barns. Rather than having a basis in science, they were developed under the theory that if a weak PEMF field has benefit, then a very large PEMF field must be much better. These systems make a characteristic noise when the field peaks, sounding like a loud crack or snap. When placed on a horse, the horse visibly and sensitively reacts to the large magnetic field charge. The operator of the system holds the coil over the body of the horse, and is subjected to this large field, too. The beneficial effects of PEMF over the last 40 years were found in systems generating weak electromagnetic fields, not large electromagnetic fields. Until these systems undergo study demonstrating they have similar beneficial effects at the first and second orders, it may be wise to avoid their use. Accordingly, their use has been banned by the FEI in their activities.
In the meantime, many PEMF devices on the market harness weak electromagnetic fields which you can use to stimulate health, wellness and comfort in your horse.
-Respond Systems, Inc., in Branford, Connecticut, has designed, manufactured and serviced the popular Respond Laser 2400 and Bio-Pulse magnetic field therapy systems since 1986. Respond Systems was named official supplier to the United States Equestrian Team in 1995. Contact Doreen Hudson at 1-800-722-1228, or visit respondsystems.com