Electrostimulation

Electrostimulation
Electrostimulation is the use of electrical charge to treat muscle pain and spasms, but also in the treatment of psychiatric diseases and in lifesaving situations.

Reports of the therapeutic use of electrostimulation originate as early as 400 BC from contact with torpedo fish, which can produce electric shocks between 100 and 150 volts, where it was noted that electric shocks from them were able to reduce and control pain in painful parts of the body. As the understading in electrical shock and pain increased, notably in mid-1700, with the development of the Leyden jar, and in 1965, with the introduction of the gate control theory of pain, in 1967 scientists Wall and Sweets found clinical evidence who comproved the sucess of electrical nerve stimulation in relief of chronic pain.

Nowadays, with the therapeutic sucess of electrostimulation, it started to be used in rehabilitive therapies, notably in rehabilitating injured or diseased muscle and other soft-tissue conditions.

Theory
The major therapeutic uses derive from muscle contraction or sensory stimulation or a combination of both.

The nerve and muscles are both excitable, which is dependent on permeability of the cell membrane.The major therapeutic uses of electricity derive from muscle contractions or sensory stimulation or a combination of both, so it is important to review the general physiological effects of electricity on nerve and muscle tissues.

Nerves and muscles are both excitable tissues, and this excitability is dependent on permeability of the cell membrane, since it regulates the interchange of substances from inside and outside the cells.

This cell permeability is voltage-sensitive, producing an unequal distribution of charged ions on either side of the cell membrane, which in turn creates a difference in electrical charge between the interior and exterior of the cell. When this charge occurs, the membrane is considered to be polarized. The potential difference between the inside and outside charge is known as the resting potential because the cell tries to maintain this difference in electrical charge as its normal homeostatic environment.

There is a greater concentration of diffusible positive ions outside the membrane than within it. The cell continuously moves positively charged sodium from inside to outside, and balances this by moving negatively charged potassium to the inside through a mechanism called active transport. A higher concentration of potassium occurs inside the cell, but the overall charge difference produces an electrical gradient with positive charge outside and negative charges inside (Gersh,1992).