Do muscle stimulators help build muscle. Muscle electrical stimulation in practical medicine

Very vulgar about muscle stimulators.

1. The key word is not an electrical stimulator, but a myostimulator (muscle stimulator)

2. For the first time, they thought about it and developed the topic, back in the USSR, military doctors. Shortly after the war.
They worked for the wounded who lay in their beds for a long time. Later - for submariners, astronauts - everyone who moves little and loses muscle tone. Even later for athletes to international sports olympiads where achievement matters.

3. With perestroika, all developments went to the west and southeast, where they received a second birth as consumer goods. By that time, cheap semiconductors had appeared that could generate short pulses without problems. There was a problem with the generation of short pulses - then it could only be radio tubes. Then there were queues for TVs.
There was no need to talk about myostimulators as consumer goods.

4. The idea of ​​electrical stimulation of muscles with short pulses proved to be fruitful.
An impulse or a burst of short impulses - 100-500 microseconds (microseconds), following rarely - 1-400 times per second, lead to a short-term displacement of ions near the nerve endings - myoneurons, and this leads to a contraction of muscle fibers.

5. The trick is that the average value of the current in the pulsed mode is insignificant. This allows you to raise the pulse amplitude up to 100 mA, i.e. create an electric field of a noticeable volume in the body and force the muscles remote from the surface of the body to contract. It should be recalled that the horse kills an AVERAGE current of 30 mA (milliamps), and here in an impulse up to 180 mA, but the average value is much less.

5a. It is useful to remind everyone who taught and forgot long ago what an electric field is. This is not a field where cows graze. This is the space in which charged particles begin to move.
All substances in nature are divided on this basis into conductors - they contain charged particles and dielectrics - substances in which there are practically no charges.
In email the field of nothing inside the dielectrics practically does not move.

Man, with his bones, meat, fat and fluids, is a conductor. It is saturated with charged particles - ions of sodium, potassium, iron, etc. Under the influence of impulses that create on a short time email field in the human body, the ions begin to move, but immediately return to their place. pulses are bipolar and short. This displacement of charged particles is enough to cause a contraction of the muscle fiber.

MYONEURON - a nerve cell attached to a muscle fiber. She, as if, receives an impulse from the brain. In fact, its impulse is a reaction to a short-term displacement of charged particles near the myoneuron itself. That's the way it is - charges interact with charges. Those charged with the same name repel each other, those with opposite charges attract. This is how the impulse penetrates the myoneuron and causes the muscle fiber to which it is attached to contract.

6. Not everything is in a decrepit body muscle fibers are shrinking. Not every myoneuron associated with a muscle fiber conducts an impulse from the central nervous system. There are many reasons for this.
And here is a powerful third-party source of a pulsed electric field - all myoneurons that find themselves in the electric field will literally pull their muscle fibers. The entire muscle will begin to contract, blood flow also changes, fat and protein deposits are crowded from the moving muscles.
The general feeling is ease in controlling the body as after a workout and there is no fatigue - lactic acid poisoning.

7. Muscle contractions occur with little or no release of lactic acid, which poisons the muscles. During normal training, lactic acid must be removed from the muscles. It is muscle poisoning that limits the duration of certain body movements. And here you can shake the muscle and quickly. Running 20 km in 20 minutes.

It is clear that this can be used to train athletes, which is done with the "training program" kept in great secrecy before important competitions.

8. Muscle mass noticeably responds to myostimulation with growth. The quality of life increases - in old age you can live in a young body. Unfortunately, the effect of such training is 1-2 days. To fix it, you either need to move more yourself or regularly connect yourself to the muscle stimulator. For obese people overweight over 10 kg - change the diet and do not wait for weight loss faster than 4 weeks. The fat comes back quickly.

9. There are contraindications, but they are few.
Side effects from prolonged (years) myostimulation are not detected.
Everything, of course, should be taken in moderation, and not up to burns at the points of contact with the electrodes.
General recommendations - three days a week for 20 minutes at the level of a comfortable muscle shudder - is enough.

10. For the elderly, it is important that the muscles of the spine and skeleton can be developed. Get rid of pain in the joints. myostimulation naturally eliminates pain from a vertebral hernia, and infringement of nerve fibers almost everywhere where applicators are placed that supply impulse currents. Also with pain in the hip joints, knee, foot, elbows and neck.

11. The electric field reaches deep, even to the muscles of the stomach, which allows you to change its tone in better side. Plus improved blood flow. The body rules itself, bringing the necessary components to the diseased sore spots.

12. A few words about prices.
Actually the price prompted me to do a search for information.
For 25 years I have been suffering from the character of my wife. Her ailments, stomach, head - we share it all together.
It helped her. She dared to pay 95,000 rubles for a Korean device, which, in my opinion, as an electronics engineer, is not worth that kind of money. Simple pulse generators, and if there is a processor, i.e. a computer that controls generators according to a program that can be changed - all the same - no more expensive than a mobile phone, but here are such numbers.

It turned out that there really are inexpensive muscle stimulators from 450 rubles - toys. Make cubes on the stomach. Medium - 1500-3000 rubles - up to 50 programs for different occasions. And there are expensive ones up to 120,000 rubles. professional multi-program and multi-channel. With their help, you can heal the whole village. However, the village can be treated with cheaper models for 3-9 thousand rubles.

Expensive models are often focused on cosmetology. small electrodes. Lots of channels.
It is worth recalling that there are about 200 muscles on the face. People do not have such a simple interface for communicating with each other through facial expressions. It is important to tighten these muscles, they also grow weak, and the skin - in two faces.
Drive away fat from the face, strengthen muscles, smooth wrinkles. Apply ultrasound with skin-nourishing creams to prolong effects. It is clear that these models will exploit women's beauty needs and will be much more expensive.

Search keywords - where, what and from whom to buy on the Internet - are on the site www.allmio.ru

The EM41 model (Germans) turned out to be quite good. Runs on 3 AAA batteries. 50 programs.
The size of a pack of cigarettes. Good for hiking - weight 108g - 3 modes (pain relief, muscle training, massage)

In the "pain relief" mode, there are subroutines with short pulses that are used for electrosleep. Sleep without sleeping pills is guaranteed. Soothe your tired legs and fall asleep - you won't remember when - the device turns off automatically.

A significant drawback - Velcro electrodes - quickly age. You need to have spares.
Or make your own out of foil. Glue the foil to thin rubber, and do not remove the Velcro itself to the foil. Lubricate the foil with gel before applying the electrodes to the body.

You will be smeared in gel, but the electrodes will be long-lived. There is room for creativity here.
for example, you can create an individual "electric chair" with contact electrodes
for different parts of the body. A suitable gel is sold in a network of medical equipment stores, for example, for ultrasound.
Take a more viscous one.

Expand discussion thread

The human body is capable of self-healing, but sometimes (after suffering injuries, operations) it can take quite a long time. For a successful and faster recovery in medicine, various are used. Therefore, we will further analyze what electrical stimulation of the back muscles is, why it is useful and how it is carried out.

The technique is widely used for the rehabilitation of patients after various kinds, with impaired functioning of the nervous system, with muscle hypertonicity.

Why is the procedure useful?

The benefits of current stimulation sessions are obvious. So, The use of this technology allows to achieve the following results:

The procedure shows high results in therapy

1. Prevention of muscle atrophy.
2. Restoration of nutrition processes and excretion of metabolic products.
3. Reduction of pain of any localization.
4. Increased adaptation and muscle fatigue limit.
5. Promoting the process of tissue regeneration.

Also, regular stimulation provides recovery " feedback» with the cerebral cortex.

Due to this, the nervous regulation of muscle tissue contractions is gradually restored. This is a great achievement in the treatment of severe pathologies (paralysis, paresis).

Devices for the procedure

All devices for electrical muscle stimulation have a main unit in which a current of the required frequency and strength is generated, as well as electrodes attached to the body.

Reference. Each device has different modes of operation required for a particular muscle group.

Devices are divided into several types in accordance with their purpose:

• professional— are used in medicine and cosmetology;
• low power- Designed for home use.

Also, devices are distinguished based on the nature of the outgoing currents:

1. Amplipulse-4.5, Stimulus-1- for muscle recovery and stimulation with the help of sinusoidal currents of increased frequencies, modulated by low frequencies.
2. "Neuropulse", "UEI-1"- used for reduced electrical excitability of muscles. The currents are supplied in a rectified mode.

Various devices for muscle stimulation with current have been developed.

In medicine, there are many other devices, each of which has its own application features: "NET", "Tonus-1", "Miovolna", etc.

Electrical stimulation at home

The technique is quite simple to perform, so you can perform electrical muscle stimulation at home.

The scheme of the session includes several stages and is as follows:

Can be used at home

• electrodes are wetted with water and placed on the affected muscle tissues and fixed with bandages;
• wires are connected;
• a suitable program is started on the device;
• the current strength increases in stages, after 3-4 minutes after the start of exposure to current, until such time as they will not be felt muscle contractions;
• after the end of the session, the device is turned off and the electrodes are removed;
• the skin in the area of ​​application of the electrodes is treated with a tonic for moisturizing.

It is mandatory to study the instructions for the electrical muscle stimulator, which will ensure the correct procedure and the effectiveness of treatment. If the session technique is not followed, side effects may develop.

How often can procedures be done

How often can electrical muscle stimulation be done? Treatment with a similar physiotherapy method is carried out 2-3 times a week, however, a session is allowed every other day (depending on the indications).

Reference. The therapeutic course includes 10-20 sessions.

In this case, the duration of the procedure should be approximately 20-40 minutes. Repeated course can be completed not earlier than 1 month after the previous one.

Side effects

There are practically no side effects

There are practically no side effects of electrical muscle stimulation.

The only thing to note is feeling of muscle discomfort during the session and after it.

Also, an inflammatory reaction may appear at the points of contact between the skin and the electrodes.

In order to avoid such undesirable reactions from the body, during the sessions, the patient must monitor his well-being. If discomfort occurs, even minor, the patient should inform the doctor about it.

The list of contraindications to the electrical muscle stimulator is extensive. When prescribing therapy, it must be taken into account by the doctor.

Important! The procedure can accelerate the progression of certain diseases, which will lead to undesirable consequences.

It is forbidden to carry out the procedure in the presence of such circumstances and diseases:

Has a large list of contraindications

• oncology;
• infectious diseases;
• arterial hypertension;
• epilepsy;
• hyperthyroidism;
• blood pathology;
• heart failure above 2 degrees;
• active form of rheumatism
• the presence of pacemakers;
• education of a benign nature;
• atrial fibrillation;
• phlebitis, thrombophlebitis;
• violations of the integrity of the skin (abrasions, wounds, cuts);
• condition after stitching muscles, tendons, nerves (for 1 month).

Do not use this method of treatment in pregnant women, since the procedures can cause an increase in the tone of the uterus, which can result in a miscarriage or premature birth (depending on the gestational age).

Conclusion

Therapy of pathologies of the nervous and muscular system does not appear without physiotherapy techniques. Among the variety of procedures, electrical stimulation is the most active and shows high results in treatment.

Description of the method
Electrical muscle stimulation is an internationally recognized clinical method of physiotherapy in such specialties as orthopedic and neurological rehabilitation. Applied to a central or peripheral partially damaged nerve, electrical stimulation can induce a muscle response in patients with limited or lost muscle activity. This method is an adjunct to physiotherapy and should be combined with active training, strength and coordination exercises. The method is simple and suitable for treatment, both in the hospital and outpatient at home.

Operating principle
NMES stimulates motor nerves to generate muscle contractions, unlike low frequency TENS, which creates small muscle twitches. NMES also stimulates A-beta nerve fibers (as does TENS), which has an analgesic effect.

Reading examples

• restoration of quadriceps function after surgery
• maintaining or increasing the range of active movements
• capillarization
• reduction of atrophy / hypotrophy of muscles
• maintaining muscle strength during the period of immobilization
• prevention of loss of muscle strength after surgery, for example on the vastus medialis
• reduction of spasticity, such as reciprocal inhibition of the flexor muscles of the arms in patients with hemiplegia
• training after partial peripheral nerve injury with reinnervation symptoms such as plexus injury
• peroneal muscle stimulation
• incontinence treatment
• anesthesia
• warm-up
• increase in muscle strength
• recovery

NMES treatment

Installation of electrodes
For achievement good results Proper placement of the electrodes is essential. The muscle contracts by stimulating the motor nerve. The motor point is the area on the skin that is closest to the point where the motor nerve enters the muscle. This is the most advantageous place to induce contraction using electrical impulses. Cefar's NMES programs generate a symmetrical biphasic waveform, meaning the polarity is constantly changing. This means that both electrodes are equally active.

There are different methods for positioning the electrodes. The most optimal is the installation of a pair of electrodes above the towering place of this muscle. By placing one electrode over the motor point of the muscle, you will get the strongest muscle contraction without discomfort. When placing electrodes over motor points different muscles can effectively work with large muscle groups.

What size electrodes to choose?
A large muscle group requires a larger electrode area. For a small muscle group, small electrodes are better suited, as they are more specific, which provides a greater current density (mA/cm2). Large muscle groups may also require dual channel stimulation, in which four electrodes are used simultaneously.

What frequency and pulse duration should be selected?

NMES usually operates at frequencies of 20-120 Hz. To increase blood circulation, choose frequencies up to 10 Hz. The goal is to induce vibrations, not contractions. Adjust the duration of the pulse in relation to the amount of energy in each pulse. When stimulating a small muscle group, a short pulse (say 200 µs) is usually sufficient, while a long pulse (eg 400 µs) is used for a large muscle group.

NMES 20-70 Hz

1.lift
2.Period of stimulation
3.Recession
4.Pause

The illustration above shows electrical stimulation of a muscle. It begins with a lifting phase (1), during which the contraction gradually increases, reaching a maximum contraction in the stimulation phase (2). During the decay phase (3), the stimulation gradually decreases and passes into the rest phase, in which the stimulation stops or is at a moderate level (active rest). Leisure prevents muscle injury, and prepares the muscle for the next contraction. Stimulation with regular pauses is called intermittent.

What sensations should the stimulation evoke?
The goal of NMES is to induce muscle contractions. Increase the amplitude above the somatosensory barrier until you see a motor response. The patient often experiences an electrical contraction stronger than a voluntary contraction. But cuts should not cause discomfort.

Testing the placement position of the electrodes.
The motor point electrode and gel help determine the optimal location for electrode application. Sliding over the surface of the skin with a movable electrode, you find the position with the maximum and most comfortable muscle contraction. Often the patient needs to get used to the stimulation, and therapeutic intensity may not be achieved in the first sessions. During the course of treatment, the intensity of stimulation should gradually increase. In the first session, a short session can be held to determine the patient's response. Excessively strong muscle contractions caused by electrical stimulation can injure a muscle that is not prepared for the load. A gradual increase in load and regularity of classes provide a good result of treatment.

NMES can be combined with other types to achieve good results. muscle training. muscle stimulation can act in the phase of concentric and eccentric movement, or only in one of them. It depends on how you combine stimulation with voluntary movements.

What should be the duration of the course of treatment?
Depending on the condition of the muscles and the rehabilitation phase of the patient, the treatment can last from 5 to 60 minutes and be repeated from three times a week to two times a day. In order to intensify the treatment, you can gradually increase the duration of stimulation depending on the pause. You can also increase the amplitude, frequency and/or duration of the pulse.

denervated muscles.
Stimulation of denervated muscles differs from stimulation of muscles with preserved innervation.
If the muscle is innervated, you can stimulate through the motor nerve, if the muscle is denervated, you must stimulate the muscle fibers directly to induce contraction. The goal of stimulating denervated muscles is to maintain their contractile units while waiting for possible reinnervation. To generate a contraction, the pulse duration is 100-300 ms. Rectangular pulses are used for fully denervated muscles, while triangular or trapezoid pulses are used for partially denervated muscles. This helps to separate the innervated and denervated fibers.

Switch.
To adjust the duration of the pause and stimulation periods, you can use the switch during electrical stimulation. The switch is especially useful when electrical muscle contractions are combined with voluntary contractions. The result is an effective individual treatment.

Installation of electrodes.
Here are some examples of electrode placement for the most common indications. For NMES, there is no difference in the position of the red and black electrodes.

Shoulder - subluxation and impaired abduction

Indication:

1. Functional subluxation of the shoulder after stroke.

2. Decreased function of the shoulder muscles after a fracture, dislocation, etc.

Installation of electrodes: Install one electrode in the middle deltoid muscle, and the other on the supraspinatus muscle. The position of the electrodes and the type of stimulation may differ depending on the type of subluxation.

shoulder area- dysfunction of the triceps

Indication:

1. Decrease in triceps function, for example, after stroke.

2. Fracture in the elbow joint.

Installation of electrodes: Place one pair of electrodes on the triceps.
Torso, lower back - training of the muscles that extensor the spine

Indication: Pain/Weakness in the lumbar region

Placement of electrodes: Place two pairs of electrodes in the lumbar region paravertebral along the course of the muscles that straighten the spine on both sides.
Trunk - abdominal muscle training

Indication: decreased function of the rectus abdominis muscles.

Placement of the electrodes: Place two pairs of electrodes on the rectus abdominis muscles on both sides.
Forearm - violation of the strength / hypotrophy of the extensors of the hand

Indication:

1. Violation of wrist extension and/or spasticity of the flexors after a stroke, etc.

2. Decreased function of the wrist extensors after a fracture, etc.

Installation of electrodes: Place a pair of electrodes over the extensor muscles of the hand.
Knee joint - instability

Indications:
1. Postoperative period after plastic surgery of the anterior cruciate ligament of the knee joint.
2. Extension contracture of the knee joint.

Electrode Placement: Place one pair of electrodes over the quadriceps.
Knee joint - muscle imbalance

Indication: Muscular imbalance of the medial head relative to the lateral head of the quadriceps.

Installation of electrodes: Place one pair of electrodes over the medial head.
Thigh area - Positive Trendelenburg's sign

Indication: 1. Positive Trendelenburg sign. 2. Decreased function of the hip abductors after central disorders such as stroke.

Installation of electrodes: Place one pair of electrodes over the hip abductor muscle and over the flexor muscle.
Calf area - dysfunction of the Achilles tendon

Indication: Dysfunction of the Achilles tendon.

Electrode Placement: Place one pair of electrodes over the gastrocnemius muscle.
Calf area - reduced foot flexor strength

Indication: Decreased dorsal flexion, spasticity.

Placement of electrodes: 1. One electrode above the exit of the peroneal nerve immediately below the head fibula and the other on the anterior surface of the tibia. 2. Both electrodes on the anterior surface of the tibia.
Contraindications

1. Patients with a pacemaker, intracardiac defibrillator, or other active implants should not be treated with NMES.
2.Carefully exercise in the first trimester of pregnancy.
3. In a pregnant woman, never connect a pair of electrodes across the abdomen.
4. Do not stimulate near the carotid glomus, in the projection of the throat next to carotid artery, as it is dangerous by pressure drop.
5. Do not stimulate during acute inflammation and acute blood loss.
6. Be extremely careful when stimulating patients with a disease of the lymphatic system.
7. If there are contraindications to the load on the tendon or muscle.

Go to CATALOG

EMS training (Electrical Muscle Stimulation) is the effect on the muscles of a device or simulator that sends weak electrical signals through electrodes attached to the surface of the skin. In fact, the apparatus for electrical muscle stimulation generates impulses similar to real muscle contractions during strength exercises.

Advertisements for equipment and reviews of training studios EMS promises to create strong muscles and fit athletic body in just 20 minutes of training three times a week, and homemade EMS ab belts “guarante” sculpted cubes without exhausting twists. It is enough just to put on this electric belt while watching TV, while there is no need for exercises.

Unfortunately, the evidence base for EMS training is highly controversial. Even if the myostimulation method can increase muscle tone, in most cases training advertising significantly overestimates the pros (especially for losing weight and fighting cellulite) - and never talks about the cons, possible harm and contraindications. In turn, home EMS ab simulators are more like just a toy.

Who invented EMS?

The history of muscle stimulators dates back to the 18th century, when researchers discovered that a weak electrical current could provoke contractions of a certain muscle in the human body. In the 1960s, Soviet scientists announced that they had developed an innovative training mechanic for professional athletes that increased their muscle strength by a significant 40% (1) .

Later it turned out that it was more about a special restorative and rehabilitation therapy, and not at all about a technique for increasing strength and muscle mass at healthy athletes. Then, in the 1970s, in Germany they began to use the technique of electrical muscle stimulation in physiotherapy and accelerated recovery of athletes. The first EMS training studios also appeared in Germany - Bodytec and Miha.

EMS trainer - customer reviews

In terms of feedback on the actual operation of such equipment and the sensations during EMS training, most people note noticeable indications. Impulse currents as if compressing the body from all sides, forcing the muscles to contract. It is quite difficult to resist them, so even simple physical exercise become a test. During exercise, the pulse quickens, breathing may go astray.

Note that the cost of a professional EMS simulator can be hundreds of thousands of rubles - this pushes sellers to the methods of "black" Internet marketing, which consists in publishing fake reviews. In no other material by Fitseven do we see such a high activity of “joyful buyers”, telling in detail how satisfied they are with pumped up muscles and a thinner body.

How EMS training works

As a rule, one full workout at the EMS studio lasts about 20-30 minutes. A person puts on a special suit with electrodes, and the trainer adjusts the power of the electrical impulses for each part of the body, based on the sensations and endurance of the trainee. Then the simplest physical exercises are performed for various parts of the body - squats, flexion and extension of the arms, swings to the sides, and so on.

The final stage of the training is lymphatic drainage massage, during which you only need to lie down and enjoy the pleasant tingling sensations.

Trainings are held 2-3 times a week.

Real reviews about EMS

As a physiotherapist, he repeatedly encountered complications from impulse currents in ladies of all ages and young girls - there was a life-threatening bleeding from the uterus (rupture of the corpus luteum). It has now been convincingly proved that, even in the absence of contraindications, ladies and girls should not carry out such procedures.

After 4 workouts, fluid formed over the patella, by the evening the knee was all swollen. I went to the emergency room and the doctor said that because of the heavy load on the body, in general, he forbade such training, everyone's body is different and it is not known how he will react to such training.

First, electrical stimulation on a permanent basis adversely affects the heart; secondly, external stimulation is not a neural impulse, the muscle works without communication with the brain, where is the development of movement stereotypes?; thirdly, these studios hire anyone for the positions of coaches (look at the ads at least on the headhunter); fourthly, this trend is for the lazy and those who allegedly do not have time for full workouts and the desire to break with their own body.

EMS training- pros and cons

The first commercial EMS personal training machines appeared in the United States in the late 1990s. Manufacturers tried to give their products and the method of myostimulation for the press as much credibility as possible, organizing all kinds of scientific congresses and developing intricate methods for certifying their own equipment - but without real scientific support.

In one such certification attempt, the wording "weight loss and weight loss device" was used - but it was vehemently rejected by regulators as misleading. As a result, EMS was certified as a treatment for muscle wasting and spasms in bedridden patients, but not as a technique for muscle growth or body contouring (2) .

EMS abs belt - does it work?

A separate area of ​​EMS technology is home exercise equipment and belts for creating relief press. Intrusive advertising and numerous reviews of "joyful buyers" promise fat burning, instant drawing of cubes, getting rid of cellulite and others positive effects. It is enough just to buy this belt and watch TV in it - and the stomach will go away on its own.

Unfortunately, most households EMS belts for the press are just a low-quality toy from an unnamed manufacturer. Even with careful use, they fail literally in the second week. We also note that such a belt must be “glued” to the skin using replaceable gel pads or even paper tape - which means that the stomach will have to be shaved.

EMS: contraindications and harm

We also note that the EMS training method has a serious list of contraindications - from pregnancy to the presence of a number of chronic diseases - including any circulatory disorders, diseases gastrointestinal tract, kidney failure, cancer and so on. Among other things, there are risks in the presence of a common cold.

IN separate group contraindications for electrical stimulation include people with pacemakers and other correction devices heart rate as well as persons who have suffered bone fractures, sprains or any damage to the skin in the recent past. However, when selling a subscription in EMS studio training about this is often “forgotten” to warn.

final opinion

Although EMS training may be effective for bedridden and paralyzed patients, they are not able to affect either muscle growth, or weight loss and noticeable fat burning, or getting rid of stretch marks, cellulite, or any other improvement in body contours. In addition, the EMS method has a significant list of contraindications and is not recommended even for a serious cold.

Manufacturers of EMS trainers have been repeatedly fined for false advertising and misleading claims that the muscle stimulation technique can replace power training and create "an iron press completely effortless and without a drop of shed sweat" (3) . At the same time, most of the rave reviews on the Internet are most likely fake, written by order of manufacturers.

***

EMS training increases muscle tone exclusively in untrained people and in paralyzed patients, while not affecting either fat burning or getting rid of cellulite. It is also important that manufacturers of such equipment have repeatedly been fined for misleading advertising that EMS simulators able to "create muscle without effort".

Scientific sources:

1. Russian electrical stimulation: the early experiments,
2. FDA: Import Alert 89-01,
3. FTC Charges Three Top-selling Electronic Abdominal Exercise Belts with Making False Claims,