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The electrotherapy is the use of electricity for therapeutic purposes, or what is the same, applying an electric current to the body to achieve our goal: relieve pain, strengthen a muscle, etc.

Effects of electric current on the body

  • When a current passes through the body it causes heat. This heat causes more blood to reach the area and that is why that reddish coloration appears on the skin (we all know the sensation of cramp that a plug can give us).
  • Analgesia.
  • Excitomotor effect or movement of the muscle to which we apply the current. We take advantage of this effect to get a muscle, which lacks or has very little movement, to move (this can be, for example, the case of an arm that has just had the cast removed).

The effects will depend on the dose (intensity and duration of the treatment), the extension of the area to be treated (since a small muscle is not the same as a large muscle mass) and the type of tissue (those that are rich in water , like muscle, they are better electrical conductors).

Types of currents in electrotherapy

There are many types of electrical currents (applied with different intensities, frequencies and durations in electrotherapy), which are classified as:

  • Low and medium frequency currents (less than 10,000Hz).
  • High frequency currents (more than 10,000Hz):
  • Short wave.
  • Microwave.
  • Ultrasounds: they are not really electrotherapy, but rather high frequency mechanical waves.
  • Magnetotherapy: it does not directly apply electric current to the body but rather a consequence of it, the magnetic field.
  • LASER: it is not part of electrotherapy either, but consists of using the emission of radiation to achieve an amplification of light, which will have great and beneficial effects.

Low and medium frequency currents

Galvanic current: its current application is practically limited to being the basis of iontophoresis. Thus, we can avoid the administration of drugs orally, but this application is limited to certain drugs. The depth of the drug is 5 centimeters maximum. The treatment is local, it accumulates under the skin and is gradually absorbed.

For example, for the treatment of excessive sweating of the hands “Glycopyrronium hydrobromohydrate” is used. This drug is placed on an electrode and placed on the skin. In general the treatment lasts 20-30 minutes. The number of sessions is 2-3 per week if the case is chronic. It is used in dentistry and dermatology. Other applications are: sciatica, facial paralysis, osteoarthritis , tendonitis and capsulitis.

  • Classic faradic current (frequency 100 Hz): used as a diagnostic test.
  • Träbert current or ultra-exciting (frequency 143 Hz): it is analgesic. It is used in blood vessel problems in the extremities.
  • Bernard’s diadynamic currents (frequency 50 Hz): depending on the type of current, its effect can be: analgesic, muscle contracture relaxant, produces muscle contraction, mobilization of connective tissue or reduces edema. It is also used in traumatic sequelae and degenerative processes such as osteoarthritis.
  • Exponential currents: they are applied in denervated muscles, also on the viscera and on the wall of the arteries to achieve the contraction of these structures. This translates into giving the muscle back its lost movement (stimulates urination if applied to the bladder, and promotes bowel movement in case of constipation ).
  • TENS (Transcutaneous Electrical Nerve Stimulation): analgesia persists from minutes to days. It is especially indicated in acute pain or localized chronic pain. These are small devices the size of a “walkman” that the person can carry with him, although he must first know the parameters of the intensity and duration that he needs.
    There are several types of TENS, some analgesics and others excitomotor.
  • Medium-frequency or interferential currents (their frequency ranges between 1000 and 10,000 Hz): some devices only operate at a fixed frequency of 4,000 Hz. With these, a greater penetration into the body is achieved, more effect with a lower dose and a better tolerance and skin sensation than with low frequency currents (the above). To be effective, two currents must be used simultaneously.

Depending on the frequency used in electrotherapy, it has several effects, among which are: the contraction of atrophied muscles, recovering inflammation, analgesic effect and muscle strengthening.

High frequency currents

High frequency currents are those whose frequency exceeds 10,000Hz, they are characterized by producing heat in the depth (in superficial thermotherapy the effect did not reach that far. High frequency currents do not have an excitomotor effect. frequency we distinguish three: short wave, microwave and ultrasound. What we cause with the heat in the depth is the following:

  • Minimal heating of the skin, where it actually produces heat is most deeply.
  • Produces vasodilation and therefore increases blood flow. This is what is required in healing processes such as sprains, dislocations, fractures, muscle tears and tears, tendonitis, osteoarthritis, contusions, etc., as long as it is not in the acute phase.
  • On the muscle: relaxation and sedation.
  • Anti-inflammatory and analgesic effect can be applied in case of nervous irritation and in pain of an amputated limb.
  • They can happen: tiredness, anxiety, headaches or dizziness.
  • They improve joint mobility.

Short wave

It is a current whose frequency is 27.12MHz and its wavelength of 11.06 meters. It consists of a device that is connected to the electrical network and from there the current undergoes a series of modifications so that when it goes outside it has been transformed into a high frequency current.

Dangers that it can cause: burns, loss of consciousness, vertigo or cataracts.


It is a current that can be 433, 915 and 2.456 megahertz, which correspond to wavelengths of 69, 32 and 12 cm. The most frequent are 12cm. The shorter the wavelength, the less penetration.


It is a mechanical energy (and not electrical) whose frequency is 70,000-300,000Hz. They are console-type devices, not self-transporting, consisting of a head (part that will come into contact with the area) and a high-frequency alternating current generator. Normally the surface to be treated is 5-12cm2. The energy absorption will be greater if the head is placed perpendicular to the skin and it also depends proportionally on the water content of the tissue. The head should not remain stationary at any time.

Its most important actions are:

  • Analgesia
  • Relaxes tension and muscle spasm
  • It is anti-inflammatory

Caution with internal prostheses because ultrasound vibration can move them out of place.

Heat Scope :

Short wave ………………………… ..1-3cm
Microwave ………………………… ..1-5cm
Ultrasounds ……………………… ..1-5cm


Magnetotherapy is a therapeutic technique that applies magnetic fields on the human being in order to obtain benefits in return.

It uses pulsed magnetic fields, which are originated by a device that is powered by alternating current. Low frequency magnetic fields are used in physiotherapy and whose intensity does not exceed 150 Gauss.

Effects of magnetotherapy :

  • At the molecular level, it works by improving and facilitating a number of processes that cause tissue regeneration.
  • Specifically, it favors the regeneration of bone and cartilage, which is why magnetotherapy is good for consolidating bone fractures.
  • Improves metabolism and reduces oxygen consumption. As the lack of oxygen causes pain, the effect of this technique is analgesic.
  • It activates the lymphatic and platelet circulation, which reduces the probability of thrombi.
  • Anti-inflammatory action.
You may also be interested in:   Laughter therapy


The laser is simply light. It is achieved when the emission of radiation is stimulated and from there an amplified light can be obtained.

The laser is a part of phototherapy.

The beam of light that is obtained has a single direction, a single color and great brilliance, it is red.

Effects :

  • It has anti-inflammatory action.
  • Analgesia.
  • Due to its analgesic, anti-inflammatory and regenerative actions, it is used in a multitude of processes.
  • The laser has less power than the short wave and the microwave.

Advantages :

  • It is smaller in size, so it is very useful in sports medicine.
  • For people who have pacemakers and cannot be exposed to other electromagnetic fields, with the laser we can treat them thanks to the coherence and focus of the light beam (they will not reach the heart).

Electrotherapy methodology

There are many types of electrical currents (applied in electrotherapy with different intensities, frequencies and durations). The placement of the electrodes is not random but will depend on the muscle we want to treat, and they will always be placed according to it. For this, it is necessary to have a perfect knowledge of the anatomy of the organism. For this reason, the placement of the electrodes, the decision of the parameters and the monitoring of the evolution of the person is the responsibility of the physiotherapeutic professional.

If the appropriate instructions are not followed, there is a risk of suffering a burn in the area. The currents are not applicable to all people, there are situations in which submitting to it is reckless due to the repercussions it has.

Short wave methodology

It can be applied in two ways:

  1. Facing two electrodes and placing the part of the body to be treated between them. As we separate the electrodes, the deeper the effect.
  2. A cable wrapped around itself that is covered by a structure is what is placed around the area.

Dosage :

Sharp process: 0-200 watts.
Chronic process: 200-500 watts.

It will not be applied for more than 20 minutes. The use of the pulsed short wave is possible, but its effectiveness is more doubtful. Its main use is in: inflammations, osteoarthritis, tendonitis, low back pain and also in digestive processes and related to the circulatory system.

Microwave methodology

The generating apparatus is very similar to that of the short wave and also allows it to be pulsating. It does not have electrodes but an antenna that is going to face the area, which has to be exposed. The distance from the antenna to the patient varies between 5-10cm. Each session will last 25 minutes and can be daily or alternate, depending on the injury. The same dosage is followed as for the short wave. It should not be applied if there are drops of sweat, because they can get too hot. It can never be applied on the gonads. The dangers of the short wave repeat themselves here. The material of the chairs where the injured person sits is wood, since if it were metal it would burn us. In the same way, the person must get rid of any metallic object that they carry and also the contact lenses.

Ultrasound methodology

Direct contact with the skin by means of a contact gel.
Underwater treatment: the transmission medium is water. A container filled with water is used where we are going to introduce the part of the body to be treated and the head of the device. This shape is reserved for areas that are not very accessible or that are very small.

Dosage :
Continuous ——————– Up to 1.5w / cm2
Pulsed ——————— Approx. 0.3w / cm2

The duration of the session varies depending on the extension of the area to be treated and the intensity that is chosen. It varies between 3-15 minutes. Acute injuries will have less time but more sessions followed. In no case should the person feel pain.

Magnetotherapy methodology

The device connected to an alternating current source is shaped like a cylinder, it is made of plastic and inside it we find a solenoid. It can have different sizes: 15-20cm or 60cm, depending on the size of the area to be treated. The solenoids can also be in series or positioned opposite each other. Sweeping magnetotherapy consists of a cylinder that runs through the body of the person from the neck to the feet, it is a generalized treatment.

Laser methodology

The dose that we will choose will depend on the potency and the time. In physiotherapy we use low-power laser, it is usually of a power less than 1W / cm2. High power lasers are used in surgery (they are capable of cutting tissue).

Indications and contraindications

Shortwave indications

  • To produce analgesia.
  • Relax the muscles.
  • It has an anti-inflammatory effect.

Microwave indications

  • Decreases muscle tension. It can be applied in muscle contractures.
  • Repair of trauma such as sprains, dislocations or fractures.
  • Osteoarthritis, as long as it is not in the acute phase.

Ultrasound indications

  • Fibrosis and scars
  • Non-acute injuries to the musculoskeletal system: low back pain, herniated discs, sprains, tendinitis, muscle retractions, open wounds … Never in the 24-36 hours after the injury.
  • Prosthetics: be careful when they carry material that can come off

Indications for magnetotherapy

  • Delays in fracture healing.
  • Osteoporosis , osteoarthritis and arthritis .
  • Lumbargias.
  • Rheumatoid arthritis.
  • Muscle tears
  • Psoriasis .
  • Schizophrenia: periods of calm with lunar changes have been observed in them.
  • Sinusitis .
  • Ankylosing spondylitis: characterized by loss of movement of the spine, it becomes rigid.
  • Headaches
  • Neuralgia.
  • Bronchial asthma and bronchitis.

Laser indications

  • It has anti-inflammatory action.
  • It favors the healing and regeneration of tissues.
  • Analgesia.
  • It improves lymphatic circulation, there are those who use it to make cellulite disappear .
  • Hemorrhoids
  • Cosmetic surgery: it is used a lot.

Due to its analgesic, anti-inflammatory and regenerative actions, it is used in a multitude of processes. The laser has less power than the short wave and the microwave.

General contraindications of electrotherapy

Although some electrotherapy techniques, which are detailed later, have their specific contraindications, whenever we treat with electrical current, the following situations must be considered:

  • Pacemaker.
  • Internal prostheses or osteosynthesis material (nails, plates, screws): these can become too hot and injure the surrounding tissue.
  • Anesthetized area: because we cannot assess whether any damage is being caused.
  • Tumors in the injured area: we would induce an extension of the tumor to other healthy tissues.
  • In pregnancies it is not necessary to do an abdominal application.
  • Thrombophlebitis and varicose veins : the thrombus could detach, reach the lung and produce a pulmonary embolism.
  • Acute systemic infections or inflammations, eg tuberculosis .
  • When there is a wound in the place where the electrode is to be placed.
  • Never on the heart area, nor on the sides of the neck, nor on the head.
  • Eye area: can cause retinal detachment .
  • Growth cartilages.
  • Recent bleeding.

Contraindications of magnetotherapy

  • When we have an infection.
  • Hemorrhage.
  • Pacemaker.
  • Hyperthyroidism : with magnetotherapy we would activate it even more.
  • Malignant tumors: because we would help to spread them.
  • Venous obstruction: danger of embolism.
  • Metal implants.
  • Acute myocardial infarction.
  • Diabetics: danger of hypoglycemia .
  • With a very prolonged treatment, loss of bone mass may appear.

Absolute laser contraindication

The eye.

Relative contraindications

Pregnant women, tumors, infections and conditions of the thyroid gland.

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Hello Readers, I am Nikki Bella a Psychology student. I have always been concerned about human behavior and the mental processes that lead us to act and think the way we do. My collaboration as an editor in the psychology area of ​​Well Being Pole has allowed me to investigate further and expand my knowledge in the field of mental health; I have also acquired great knowledge about physical health and well-being, two fundamental bases that are directly related and are part of all mental health.

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