As in previous publications on electrical stimulation, we’ll explain how this technique can be effectively used.
There is a belief that all electrical stimulators are the same and they all have the same functions, whether cheap or expensive. This is wrong.
There is also a belief that using electrical stimulation means attaching electrodes without any concern for the position. This is also wrong. This is the reason why there’s so much scepticism among experts in this sector. It all depends on the methodology.
Because the fact is, medical electrical stimulation is somewhat more complicated. The parameters of this technique must be taken into consideration so that it is safe and effective.
The history of medical and therapeutic electrical stimulation studies
The goal of all humans since antiquity has been to remain healthy.
Even the Egyptians knew of the benefits of natural current. This is known by a painting of an electric fish found in a tomb, dating back to 2750 BC. Electric current was already being used back then to help stay healthy, as mentioned.
Only very vague indications of the use of natural current in the most ancient of civilizations have reached us. However, the information that is available on Roman civilizations is much more precise and detailed.
The first electrical therapy protocol available dates back to 46 BC. That year, Siribonius Largus refers to a remedy in the pharmacopeia he wrote for patients with gout. It consisted of placing a live black electric ray under a patient’s feet while remaining seaside with the waves breaking until the patient’s leg became numb.
However, it wasn’t until the 18th century that scientific studies and possible applications of modern electrical stimulation appeared. These scientific studies were conducted by Luigi Galvani and Volta.
In 1791, Luigi Galvani noted his observations in Viribus electricitatis in motu muscolare referring to muscular contraction due to an effect he simply called “electricity” and reached the conclusion that it was possible to electrically stimulate the muscles, outlining some of the possibilities involved.
From the 19th century onward, research and technical-scientific solutions have multiplied and revolved around different fields given that generating, storing and using electric pulses can offer a significant evolutional boost in the field of medicine and physical therapy.
A look back at how medical electrical stimulation has evolved
In 1831, Faraday discovered the phenomenon of electrical induction and produced a certain type of alternating current which has been named after him - Faradic current.
Faradic current is comprised of a series of one-way pulses lasting between 0.1 and 1 msec with a frequency of 50 to 100 Hz. There is a 2 second distribution and 6 second pause between each pulse. Plus, there is constant amplitude modulation meaning no two successive stimulants are ever identical.
In 1833, Duchenne de Boulogne found the way to electrically stimulate a muscle without necessary affecting the skin by using electrodes for transcutaneous stimulation.
In 1849, Du Bois Reymond understood the importance of quickly emitting each plus to depolarize the membrane.
In 1900, Leduc took another look at prior studies inherent to ionic migration to prove that a pulse can be used to migrate some ions through the skin barrier without damaging it.
In 1902, Weiss understood the basics of induced muscular contraction and the relationship between stimulant intensity and duration.
In 1909, Lapicque used Weiss’s Law to calculate the mathematical ratio between intensity and the duration of a stimulant in order to excite tissue. He also introduced the concepts of chronaxie and rheobase, which are correlated by means of a mathematical formula.
In 1916, Adrian proved the curves of intensity and duration for innervated and denervated muscles through experimentation.
In 1919, Bourguignon began experimentally measuring the chronaxie of different muscle areas in man.
In 1925, Bernard began studying interferential currents.
In 1939, Le Go started studying how to apply interferential stimulants.
In 1950, Nemec perfected Le Go’s studies by creating an apparatus to emit these pulses.
In 1965, Melzac and Walls publishes an article in Science entitled “Pain mechanism, a new theory” on physiological control and modulation. These studies supported electrical stimulation with the development of TENS (transcutaneous electrical nerve stimulation).
In 1972, Sibilla proposed an electrical stimulation technique for idiopathic scoliosis.
In 1988, G. Cometti studied the effects of training with electrical stimulation using kotz currents and two-phase rectangular currents for sports and health.
In 1989, G. Cometti achieved optimal increases in explosive strength after doing trainings with electrical stimulation.
Thus, this timeline reflects how its medical use has been known in some capacity or another for a long time and how ever since, medical electrical stimulation has been part of the world of sports and physical therapy.
What is most important about medical electrical stimulation?
The two-phase pulse
A two-phase electrical pulse can be defined as an organized flow of electrical charges. This means it has electromotor potential and, therefore, is able to transport ions sensitive to its action during movement.
It is essential to determining specific medical electrical stimulation programmes. This is the pulse time for muscle stimulation; it is used to differentiate muscle chains.