Interference therapy is a medicinal application of low-frequency (1-100 Hz) “pulses”, which could be either homogeneous in frequency during the procedure or alternate periodically within a selected frequency range. “Pulses” represent series of medium-frequency current fluctuations and are generated inside the tissues due to interference (combination) of two medium frequency currents, being initially applied to the body surface through two separate chains of different frequency.
Being of medium frequency (3850-4000 Hz), such initial currents easily penetrate the epidermis with no significant excitation of the surface tissues and no unpleasant sensation under the electrodes. At the same time, the “pulses” render excitation on motor nerves and muscular fibers, thus stimulating intensive blood circulation, activating metabolic reactions and reducing pain in the area of application. Interference currents with less excitation performance, as compared to direct currents, are used for treating peripheral nervous system, basically in the subacute stage of pathology.
The leading role in the interference therapy curative performance is served by peripheral blood circulation intensification. This benefits to normalization of the pathologically changed tone of main arteries and capillary network, increase of collateral number, microcirculation improvement. When dealing with peripheral vessels enlargement, inhibition of sympathetic vegetative nervous system and intensive generation of vasoactive substances, caused by interference currents, provide the major effect. Besides, the currents cause muscular contractions, exert specific massage effect, which may result in intensified peripheral blood circulation and lymphokinesia.
Stimulated blood circulation leads to local temperature increase, improved oxygen supply to tissues and their anoxemia eradication, faster excretion of toxic products of metabolism, reticuloendothelial system activation. During interference therapy pH value in tissues is reduced to alkaline area, thus benefiting to inflammation healing. Reference to many researchers, interference current is characterized with bactericidal or bacteriostatic features. It also possesses trophicoregenerative action.
Indications for use: diseases of the nervous system (neuritis, neuralgia, neurological manifestations of spine osteochondrosis, causalgia, phantom pain, bedwetting, etc.), diseases of the cardiovascular system (hypertension Degree I and II, vegetative dystonia, atherosclerotic occlusion of the extremity vessels, varicose veins, thrombophlebitis effects, etc.), injury of musculoskeletal system, arthritis, arthrosis, joint contractures, osteochondropathy, diseases of the gastrointestinal tract with predominant motility disorders, inflammatory diseases of the uterus, some skin diseases, etc.
Interference therapy methods and techniques.
During the procedure the patient is sitting or lying down, depending on the nature of the disease and place of application. For interference therapy, metal electrodes (two pairs) with thin hydrophilic spacers are used. For the most widely used stable method of exposure, electrodes are set in such a way that the electric currents overlap in the pathological focus or target structures (tissues). Zakharyin-Ged zone, corresponding segmental areas, specific sympathetic nodes can also be effected, or transcerebral technique can be used. Also, moving (kinetic) method of interference can be used, which specifies for two of the four electrodes to be moved along the patient body during the procedure, thus influencing expansively the skin surface.
The current strength during interference therapy is adjusted depending on its density at the electrodes and patient’s sensations. The patient should feel deep, strong enough, but pleasant vibration when rhythmically varying frequencies or feeling "crawling" at a constant frequency. Please remember: the more intense painful sensations, the weaker should be the current value. In the acute stage, typically weaker currents are used, but in chronic cases – stronger currents shall be applied. Because of tissue habituation phenomenon, in the process of application the current strength should be gradually increased to compensate reduction of sensations.