The therapeutic method of applying controlled low voltage electrical stimulation frequency 1-150hz. Causes analgesic effect. There is a standard TENS, high-frequency, low-frequency and TENS with the low-current strength.
TENS is used in pain of various causes of acute and chronic type, with peripheral neuropathy, vertebral pain syndromes, pain due to degenerative joint diseases, malignant diseases and sports medicine.
CONTRAINDICATIONS- the presence of a pacemaker, pregnancy, epilepsy, allergic reaction to electrodes.
The galvanic current represents name for a constant DC current. It was first described by Luigi Galvani from Bologna in 1889, and is used in the therapeutic purposes since the end of the 19th century, after the construction of large batteries to produce such power.
Today, the galvanic current is produced from alternating current frequency of 50 vibrations per second and voltage of 220 V. Devices for such conversion consist of multiple tubes leaking AC power only in one direction (from the cathode to the anode). By that we get full wave directional pulsating DC which after the filtering becomes constant. That form is used for therapeutic purposes.
Galvanic current is applied through two electrodes of which one is a positive one (+ usually red), and the other negative (- black).
How do we apply the galvanic current?
In practice, the galvanic current as a therapeutic procedure we use in several ways:
Dry galvanizing process over wetted coating electrodes
Special forms on different regions of the body
Wet galvanizing process
Dry galvanizing process
Dry galvanizing process can be applied in several ways:
Transverse or trans-regional galvanization- is set on the body crosswise. In this way we achieve both flow-through of all the tissues between the electrodes.
The longitudinal galvanization- electrodes are placed in different heights of the limbs, that is at their ends, for example, one electrode on the shoulder and the other on the palm. With this mode we achieve surface flow-through. The longitudinal galvanization may be downward (cathode is placed distally) or upward (cathode is placed proximally).
Dotted galvanization- is applied via two electrodes, one is active and it is movable, and we usually apply it on the places of pain, while the other electrode is inactive and substantially better.
If the patient has a neuralgia nervusa trigeminusa, we apply galvanization through a special electrode in the form of semi-mask (Bergoni’s semi-mask). The electrode in the form of mask is the cathode and is placed where neuralgia is and then fixed, and inactive electrode is placed on the breastbone or in the back between the shoulder blades.
Procedure for electrode placement
The electrodes must not be placed directly on the skin, they must always be wrapped by hydrophilic fabric. Most often those are sponges that before applying are wetted with plain water. Electrodes prepared in that way we usually fix with elastic bandages or bags with sand.
The dosage and duration of treatment
When dosing galvanic current we need to respect the two parameters. The first is a subjective feeling of the patient. With the introduction of galvanic currents in the body the patient must feel tingling, not pain and annealing. Galvanic current should be introduced gradually in the body, and then evaluate the patient’s subjective feeling.
The second parameter is the current density per unit area of electrode (mA/cm2).
The current density should be within the physiological sensitivity that is from 0.1 to 0.5 mA/cm2.
One application lasts between 10-20 minutes.
Physiological effect of galvanic current
Galvanic current acts on the nerve endings responsible for pain transmission so that the pain diminishes or disappears.
Increases excitability and nerve conduction under the cathode and reduces the anode.
Under the influence of galvanic current arises vasodilation (widening of blood vessels), which causes more intense blood flow that is called hyperemia. The skin beneath the applied electrodes becomes warmer, reddish for up to 30 minutes, and wetter.
When do we apply the galvanic current?
– Rheumatic diseases, except inflammatory in the active and acute phase.
– Paresis and paralysis. In this indication the galvanic current is used as initial procedure in electrostimulation. Galvanic current decreases skin resistance with hyperemia and therefore with little stimulus we get strong muscle contractions!
– Vascular diseases and circulatory disorders.
When we must not apply the galvanic current?
– Acute inflammations, including active tuberculosis of the joints and other organs
– Diseases that affect the development of cachexia
– Decompensated heart condition
– Bleeding or bleeding tendency
– Metal in the tissue (after being wounded, endoprosthesis, osteosynthetic material)