Electrotherapy

Electrotherapy (syn: electrotherapy) includes physiotherapy methods based on the use of dosed effects on the body of electrical currents, as well as electrical, magnetic or electromagnetic fields. This method of physiotherapy is the most extensive and includes methods using both constant and alternating current of different frequency and shape of impulses.  

The passage of current through the tissues causes the transfer of various charged substances and the change in their concentration. It should be borne in mind that intact human skin has a high ohmic resistance and low electrical conductivity, so the body penetrates into the body mainly through the excretory ducts of the sweat and sebaceous glands and intercellular spaces. Since the total pore area does not exceed 1/200 parts of the skin surface, most of the current energy is expended to overcome the epidermis, which has the greatest resistance.

It is in the epidermis that the most pronounced primary (physico-chemical) reactions to the action of direct current develop, and the irritation of the nerve receptors is more pronounced.

• Electromagnetic field - a special form of matter, through which the interaction between electrically charged particles (electrons, ions).
• The electric field is created by electric charges and charged particles in space.
• A magnetic field is created when electric charges move along a conductor.
• The field of a motionless or uniformly moving particle is inextricably connected with the carrier (a charged particle).
• Electromagnetic radiation - electromagnetic waves, excited by various radiating objects

Overcoming the resistance of the epidermis and subcutaneous adipose tissue, the current extends predominantly through the intercellular spaces, muscles, blood and lymphatic vessels, significantly deviating from the straight line, which can conditionally connect the two electrodes. To a much lesser extent, the direct current passes through the nerves, tendons, adipose tissue and bones. Electric current practically does not pass through the nails, hair, horny layer of dry skin.

The electrical conductivity of the skin depends on many factors, and above all on the water-electrolyte balance. Thus, tissues in a state of hyperemia or edema have a higher electrical conductivity than healthy ones.

The passage of current through the tissue is accompanied by a series of physico-chemical shifts, which determine the primary action of the electric current on the body. The most significant change is the quantitative and qualitative relationship of ions. In connection with the differences in ions (charge, size, degree of hydration, etc.), the speed of their movement in the tissues will be different.

One of the physico-chemical effects in galvanizing is the change in the acid-base balance in tissues due to the displacement of positive hydrogen ions to the cathode, and negative hydroxyl ions to the anode. The change in pH of tissues is reflected in the activity of enzymes and tissue respiration, the state of biocolloids, and serves as a source of stimulation of skin receptors. Since the ions are hydrated, that is, they are covered with a water "coat," along with the motion of ions during galvanization, fluid (water) moves in the direction of the cathode (this phenomenon is called electroosmosis).

Electric current, acting on the skin, can lead to a redistribution of ions and water in the site of exposure, causing local changes in acidity and edema. Redistribution of ions, in turn, can affect the membrane potentials of cells, changing their functional activity, in particular, stimulating a mild stress reaction leading to the synthesis of protective heat shock proteins. In addition, alternating currents cause the formation of heat in the tissues, which leads to vascular reactions and changes in blood supply.

[1], [2], [3], [4], [5], [6], [7]