The benefits of electrical stimulation modalities for treating and managing chronic and acute pain
At its simplest level, electrotherapy can be defined as the treatment of patients by an electrical apparatus to bring about physiological changes for therapeutic purposes. What is not simple to understand is the complex electrical charges generated within our bodies as a part of normal physiological processes, which take place throughout our body everyday as a result of just living life.
For the purposes of this article, I will address the effects of different electrotherapies on conditions that we may see in our offices. Textbook of Medical Physiology by Arther C. Guyton, MD, explains all the details for those wishing to review those concepts.
Hang TENS
Transcutaneous electrical nerve stimulation (TENS). This therapy was introduced into the healing profession in the 1970s and has been rapidly accepted as a standard modality in the management of both chronic and acute pain. Electrical stimulation controls pain in a noninvasive manner without narcotics. TENS is a specialized form of electric stimulation designed to reduce pain, in contrast to other forms of electric stimulation used either to produce muscle contractions or re-educate, strengthen, and tone muscles.
The physics and physiology of how electric current applied to the skin can decrease pain is usually explained by the gate theory, which states that electric current travels toward the brain along selective nerve fibers called A fibers. These fibers must pass through a segment of the spinal cord that contains specialized cells involved in neural transmission called T cells. These T cells also serve as transmission junctions for those nerve fibers carrying sensations for pain on smaller fibers called C fibers. The C fibers offer a transmission velocity that is considerably slower than that of the A fibers. Therefore, the signal along the A fiber would reach the brain before the slower C fibers carrying the pain signal. By overloading the body with electrical stimulus on the skin, the system is overloaded with nerve stimulation. The nerve stimulation on the skin is carried by the A fibers, which have a higher transmission velocity, and the high volume of nerve stimulation blocks the stimulation coming from the slower C pain fibers.
Another concept is that endorphins are released when electrical stimulation is introduced into your body. The body produces endorphin, a morphine-like molecule, to serve as an endogenous analgesic whenever the body senses pain. TENS research indicates that endorphin production may be enhanced by electrical stimulation. Also, the electric stimulation to the skin will cause muscles to contract. This contraction-relaxation cycle will increase circulation to the area involved and may also help decrease swelling in the area.
The newest form of TENS therapy is the microcurrent. The theory is to use a smaller intensity current, which is closer to the electrical current in the body. Microcurrent causes proprioceptive responses to be modulated in part by subtle bioelectric currents in the body, and appropriate external stimulation acts as an amplifier or enhancer of the rebalancing process, especially in injured and compromised tissues. There are three main techniques to apply microcurrent: electromassage, treatment with pads, and point stimulation of acupuncture points.1
These are just a few of the positive effects of electric stimulation on the body. We can be sure there are many more effects, some of which may not be positive. But overall, with what is known today, electrical therapy is an effective choice in the treatment of some conditions we will encounter.
Let Electrotherapy Be Your Guide |
| Before any modality of electrotherapy to a patient is considered, follow these basic guidelines for the application of electrotherapy: • What effect is intended and can this treatment achieve this effect? In many instances it cannot be known if the treatment is effective until it is attempted. Sometimes, effectiveness can be seen immediately with immediate relief of pain, but in other cases, it cannot be recognized for days or weeks because of the properties of this modality. • Is it safe? Will the desired effect be achieved without undesirable effects? There is no effective treatment that does not carry some risks, but for the most part, the risks of electrotherapy are negligible provided that reasonable and proper precautions are taken. Each modality has its own potential dangers and contraindications, and no treatment should be considered without a thorough knowledge of these. • Is it the best method of treatment to achieve this effect? Is it the most economical in terms of patient and or therapist time or other costs? Before any therapy is considered, it is important that a brief explanation of the therapy be given in terms that they can understand. Also, it would be good to discuss with your patients what the desired outcome and goal of using this therapy on them would be. Do not forget to let them know about risks and instruct them as to what they should feel and what they need to do and not do while the therapy is being administered. This not only reassures the patient but also ensures informed consent. At the end of each treatment the area treated should be examined, and a note should be recorded to ensure that your patient gets the best possible care and to protect yourself legally should any questions arise out of the effect of your therapy. In a chiropractic office, physical therapy seems to be area where malpractice claims arise. —Source: Low J, Reed A. Electrotherapy Explained. Oxford, England: Heinemann Medical; 1990:365. |
Laser Beam Me Up
Lasers. Another fast-growing physical therapy modality is the laser. Until the invention of the laser in 1960, using a powerful beam of light was an idea appearing mainly in science fiction. Different forms of light therapy have been around for years, and in 1903, Neils Finsen, MD, was awarded the Nobel Prize for medicine for both his investigation and clinical application of light therapy.2 Until the late 1930s, light therapy in various forms was found in widespread use in hospitals and clinics throughout the Western world. It was really the advent of antibiotics that saw the demise of the use of light treatment on a wide scale. Now, the medical profession finds itself exhausting the valuable resources of antibiotic therapy through its overuse and the advent of antibiotic resistant disease causing many doctors to look for viable alternatives.
Laser is the popular term and acronym for Light Amplification by Stimulated Emission of Radiation. The power levels of light are greatly amplified by the emission of radiation from stimulation of specific substances. Every substance radiates emissions in varying wavelengths or frequencies. A laser used in physical therapy is a tube filled with a mixture of helium and neon stimulated electronically to the correct emission levels with the intensity of only 1 mW, which is less than the power of a 60-watt lightbulb held a few inches from your face.
Commercial and industrial lasers, called hot lasers, range in thousands to millions of watts and are used for cutting, drilling, and destructive applications. Part of the reason lasers are effective is that their light shines in only one direction in a concentrated narrow beam, unlike a lightbulb, which will diverge in all directions.1
In the early 1960s, several European surgeons experimented with using high-intensity, or hot, lasers in surgery. Significant benefits observed were faster healing times and reductions in bleeding, swelling, pain, and scar tissue formation. It was easy to explain that the laser surgery produced less bleeding because of the vaporization of tissue, which seals off blood vessels. But the reduction of healing times by one-third without scar tissue formation puzzled scientists for years. Later experiments showed that the hot laser was also giving off a low-energy light. Through experiments, scientists found that this low-energy light had healing properties.
The physiology of how lasers are effective is in the fact that ordinary light does not penetrate the skin, where a laser can penetrate approximately 0.8 mm and have partial absorption up to 10 mm to 12 mm deep. It is important to understand the fundamental point that light therapy, in whatever form it is applied, does not cure anything. When applied correctly, light actually stimulates the cells toward balance or to reregulate themselves, resulting in cellular regeneration. By doing this, the laser is able to stimulate the mitochondria on a cellular level to ensure that they are functioning properly as well as stimulating the production of enzymes.
Laser therapy has been shown to stimulate the synthesis and repair of DNA and RNA, reduce pain and inflammation, increase collagen production, increase ATP production, stimulate nerve growth and sprouting, alleviate lymphatic congestion, activate a host of enzymatic reactions, reduce scar tissue and adhesion formation, and enhance the immune system.
For pain control, the laser light is directed to acupuncture points, trigger points, and nerve roots. For wound healing, the recommended dosage is 90 seconds for every square centimeter; and for pain control, the dosage is 15 to 30 seconds for each point stimulated.3
Unfortunately for health care practitioners trained in North America, little or no attention is given to low-level laser therapy and its healing properties. Generally, if a technique or principle is not taught in school, it does not have merit. The fact remains that this is a therapy that is currently being used extensively in Europe and Asia with great success for more than 30 years.
When deciding what electrotherapy methods to use in your office, you have a multitude of choices. The therapy you are using may be good and may have worked for years as far as pain control is concerned, but many of the new therapies work with the body in electrical frequencies or light frequencies in ranges that do not just overload the body with stimulation to block pain. CP
William M. Austin, DC, CCSP, CCRD, Roanoke, Va, has more than 35 years of health care experience, including athletic training, emergency medicine, English bonesetting, and chiropractic. Currently, he speaks on topics such as subluxation reduction, coordinating the nervous system, adjusting, rehabilitation, and orthotic therapy; and serves on the postgraduate faculty of many chiropractic colleges. Austin can be reached at 540-345-0008.
References
1. Jaskoviak P, Shafer RC. Applied Physiotherapy. 2nd ed. Arlington, Va: American Chiropractic Association; 1993:381–399.
2. Leberman J. Light Medicine of the Future. Santa Fe, NM: Bear and Co; 1991:71.
3. Kahn J. Electrotherapy. New York: Churchill Livingstone; 1994:36–39.
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