Electromyostimulation: mechanism of action, technique, indications and contraindications

Electromyostimulation (syn: myostimulation, neurostimulation, physiostimulation, myolifting) is the application of impulse currents to affect the neuromuscular apparatus.

The mechanism of action of electromyostimulation

Usually, the variant with the use of stationary electrodes (fixed) and currents with intensity that allows to obtain visible muscle contractions is usually called myostimulation, and myolifting is performed by moving electrodes, without visible muscle contractions, but with pronounced sensations of current flow. When electrical stimulation of muscles or nerves stimulates, their biological activity changes and spike responses are formed. Electrostimulation with a frequency exceeding 10 imp- ¹, causes the summation effect of depolarization and a strong prolonged contraction of the muscles - a jagged tetanus. With an increase in the frequency of electrostimulation, the muscle does not relax due to frequent repetition of pulses and a full tetanus occurs, which, with a further increase in the pulse frequency, is replaced by complete non-excitability (due to inactivation of the chemosensitive valves of the subsynaptic membrane).

The most intense excitation occurs in the case of coincidence of the frequency ranges of electrical stimulation and impulses in nerve conductors. Thus, under the influence of electrical stimulation of the nerve endings, impulses of more than 50 imp- ¹ excite predominantly motor nerve conductors (A- ⁰, and A-y fibers) and passively contract their muscles. One of the functions of nerve cells in the body is the regulation of the activity of other cells. Signals coming from the nerves cause muscle cell contractions. When these two types of cells (nerve and muscle) are "active", there is a rapid movement of ions through the cell membrane. The resulting electric current is called the "action potential". The action potentials in nerve and muscle cells can be detected by intracellular electrodes.

Impulses, as close as possible in their form to the potentials of the action of the nerve and muscle cells, are called neuroimpuls (in cosmetology, neuroimpulse devices are popular, because the procedure passes more comfortably, and the results are more noticeable than when applying currents of the other form).

At the cellular level, the content of macroergic compounds (ATP, creatine phosphate) increases in the cytoplasm, their enzymatic activity is increased, the rate of utilization of oxygen is increased, and energy costs are reduced by a stimulated reduction in comparison with the arbitrary one. Activation of blood supply and lymph drainage leads to an intensification of trophic energies. The expansion of peripheral vessels occurring simultaneously with passive contraction of muscles leads to the activation of blood flow in them. As a result, their weakened contractile function gradually increases. The action of the impulse current is directed primarily to the tone and the rate of response of the muscles.

The shortening and relaxation of muscle fibers occurring during electrostimulation prevent muscle atrophy, restore the nervous regulation of muscle contractions, increase the strength and volume of muscles, as a result, the adaptation and threshold of muscle fatigue increase.

Indications for electromyostimulation:

1. Weakened muscle tone.
2. Weakening of the skin turgor.
3. Modeling the face oval.

Myostimulation is widely used to treat various types of face and neck formations, restore muscle tone.

Methods of myostimulation

When the oval of the face changes, the muscles located in the buccal region are stimulated. When flabbiness of the neck use self-adhesive dermal electrodes. For the course of procedures can significantly improve the tone of the subcutaneous muscle - platisms. When the upper eyelid is lowered too, you can achieve noticeable results without resorting to plastic surgery. Here, stimulation is often carried out by mobile electrodes on a gel basis (gel lifting). The impulse current is also used to reduce the "second chin". Modern computerized devices allow you to specify many parameters in the procedure, such as:

1. pulse shape;
2. frequency of pulse repetition, most often use a low pulse frequency - from a dozen to 1,000 Hz.

The low frequency range used in physiotherapeutic cosmetology is determined by the electrophysiological lability of the skeletal muscle fibers. They are able to react by shortening to electrical stimulation with a frequency of up to 1000 Hz. When higher frequencies are used, the current pulses are not perceived by the nerves and muscles as separate stimuli, which leads to a sharp decrease in the effectiveness of the action.

To stimulate skeletal, smooth muscles and nerve wires, different pulse rates are needed. Therefore, the ability to change the frequency of pulses significantly expands the scope of the device. And the function "frequency drift" offers in one "bundle" of pulses the frequencies for all excitable cells. Thus, there is more effective stimulation and the muscles do not get used to the current so quickly. In different classes of apparatus, a different pulse frequency can be incorporated:

• VIP equipment - high-frequency filling of pulses, the recommended frequency of myostimulation is 400-600 Hz.
• Equipment of the middle class - low-frequency filling of pulses, the recommended frequency of myostimulation is 10-230 Hz.

The pulse duration is from 0.1 to 1000 ms. Short pulses (0.1-0.5 ms) are very close to natural neuroimpuls and are the most convenient for myostimulation. Rate of rise and fall of the pulse; 3↔0.8. The shape of the wave (bursts of momentum) is trapezoidal, rectangular, H-shaped, etc. Ratio parcel / pause: reduction time / relaxation time: 5 → 3.9 / 2.5 → 1.9.

Current strength in the devices is provided for working on the face (max up to 10 mA) and for working on the body (50 mA). In procedures, the intensity of the current is set depending on the patient's sensations - the contractions must be strong, but painless.

Pulses are mono- and bipolar. Monopolar pulses cause the dissociation of substances into ions, and also are capable of moving electrically charged particles deep into tissues. Thus, a monopolar pulsed current can also be used for electrophoresis. Substances are used the same as electrophoresis with galvanic current. Bipolar pulses cause vibrational motion of charged particles on biological membranes. Symmetrical bipolar impulses compensate for electrolysis, and there is no skin irritation under the electrodes. Bipolar impulses better overcome the resistance of the skin and are felt as more comfortable.

Purpose of the procedure - 2-3 times a week or every other day, duration - 20-40 minutes. Course - 15-20 procedures, break between courses - 1 month.

Scheme of the procedure:

1. Well-wetted electrodes in the water set on the active motor points of the muscles to be worked, secure with bandages (according to the schemes).
2. Connect the wires observing the polarity
3. Run the program on the device.
4. Gradually increase the strength of the current, until the appearance of active muscle contractions. There should be no painful reduction. It is recommended to increase the intensity simultaneously in symmetrical areas.
5. After 3-4 minutes after the start of the program, increase the current (the adaptation process is over, the muscles are prepared to work with a greater load).
6. After finishing the procedure, remove the electrodes, turn off the device.
7. Treat the location of electrodes with tonic or body milk with moisturizing and (or) soothing ingredients.

Recommendations for conducting body procedures

Indications: flabbiness of muscles and skin, cellulite, excessive body weight, violations of peripheral venous and arterial blood flow, venous-lymphatic insufficiency.

It is necessary to remember during the procedure about the individual sensitivity of each patient to the electric current, to start the procedure from the selection of parameters at low rates, gradually increasing them. With prolonged exposure to electric shock, the effect of "addictive" can occur, which is partially leveled by correctly formulated programs, but does not exclude the alternation of myostimulating procedures with lymphatic drainage and electrolysis to obtain the maximum effect.

In trained people or athletes, the muscles are initially stronger and require a significant load to maintain the shape and further training.

For patients of this category, special "sports" injuries are created, but here one should not forget about the alternation of the "training" and "relaxation" of muscles, since muscles can be overtrained. Also included in the program lymphatic drainage, endermological programs for athletes.

Combination with other methods:

• lymphatic drainage;
• electrophoresis;
• deep heat;
• ultrasound therapy;
• endermology;
• Pressotherapy.

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