Medically Reviewed by Dr. Luis Alberto Vallejo
- 1 What are high frequency currents?
- 2 Application Methods:
- 3 Classification of high frequency currents
- 4 Dosage of electromagnetic energy
- 5 High frequency current indications
- 6 Contraindications of high frequency currents
What are high frequency currents?
It is a technique by which energy is supplied to the body, in order to accelerate metabolic responses at different levels.
It is carried out through the application and transformation of electromagnetic energy, of a band of the non-thermal electromagnetic spectrum, made up of alternating currents ranging from 0.5 Mhz to 2,450 Mhz (millions of hertz), which when introduced into the body is transformed into electromagnetic energy in another band different and higher from the spectrum, that of heat, that is infrared.
- 1-Capacitor Field
- 2-Induction field
- 3-Irradiation field
It consists of placing two electrically charged metal plates, one is (+) and the other has a charge (-) facing each other, and between them the part of the organism to be treated is positioned.
Having different charges between both electrodes results in a potential difference that will generate an electromotive force between the space that separates them.
Said electromotive force acts on the ionic charges of the organic solutions which will move closer or further away from the electrodes.
The polarity (+) of one plate and the (-) of the other are inverted or alternated millions of times per second, causing a sway in the organic ions millions of times per second.
The application of the electrodes in the condenser field can be done in three ways:
- Coplanar: The electrodes are placed in the same plane or slightly angled adapting to the body surface.
- Contralateral: The electrodes are placed opposite each other.
- Longitudinal: Greater depth and location of the thermal effect is achieved in areas of difficult access.
2-The inductive field:
It is produced by the electromagnetic induction that appears in the coils when they are circulated by an electric current.
It is called the straight conductor coil that bends in circles in a continuous way and if it is of great length it is called “solenoid”.
If one of our members is inside the coil, the magnetic force will induce movement to the ionic charges contained in the tissues
If instead of winding a coil on the body segment, two flat coils are applied against the sides so that the faces that are looked at are of opposite magnetic polarity (north – south), instead of causing rotating displacements of the ions, they will be shape perpendicular to the sense of the magnetic force.
It consists of the irradiation of electromagnetic waves from an antenna until they reach the organism invading and penetrating it to generate electromagnetic turbulence in the ions of organic solutions
Classification of high frequency currents
– Short wave:
- Frequency 27 Mhz.
- Its fundamental electrophysical effect is based on the capacitance or effect of the capacitor.
- It is applied with plates or coils separated from the skin.
- Heat is generated by displacement of electric charges.
- More heat is generated in higher conductivity tissues.
– Ultra short:
- Frequency of 432 Mhz.
- It is applied with irradiator or directed antennas.
- The applicator is kept separate from the skin a few centimeters.
- It is not based on the capacitive or inductive effect, but on the field of irradiation.
- A single electrode is used.
- Electromagnetic energy penetrates deep tissues through the skin and subcutaneous cellular tissue.
- There is no danger of the patient’s electrical shunts to the ground.
- Heat is generated by molecular vibration instead of the displacement of internal electrical charges in the body.
- Frequency of 2,450 Mhz.
- It is called radar therapy because it matches the same frequency as conventional radar.
- It is applied with very directional antenna electrode.
- It has strong reflection and refraction effects.
- The caloric energy generated is achieved by the phenomenon of molecular rotation, taking as reference the water molecule.
Dosage of electromagnetic energy
- Grade I, subliminal or imperceptible heat: The patient does not perceive any thermal sensation despite the application with some power.
- Grade II, mild heat, slightly noticeable: Supraliminal but very low intensity.
- Grade III, moderate heat, clearly noticeable: With some intensity but pleasant.
- Grade IV, intense heat, strongly noticeable: It can reach the threshold of pain, especially after a certain time.
- Grade V, burning heat, burning sensation: The heat becomes painful.
High frequency current indications
High frequency currents are used in cases of:
- Chemical pain
- Ischemic pain
- Muscle contractures
- Chronic inflammation
- Edemas of low intensity.
- Arthroscopic joint processes.
- Non-acute arthritic processes.
- Degenerative processes due to insufficient trophism.
- Sympathetic cotton reflex.
Contraindications of high frequency currents
High frequency currents should not be applied in:
- Acute inflammatory processes
- Implementation of intrauterine devices in applications over the area.
- During menstruation
- About osteosynthesis and metal stents.
- Beginning calcification processes.
- Infectious processes and purulent abscesses – except when we intend to explode –
- Active and inactive tuberculosis.
- Tumor processes
- About Central Nervous System.
- Total denervations.
- Infarcted lymph nodes
- Do not apply to the eyes, the heat generated in the vitreous humor produces long-term cataracts and excessive increase in intraocular pressure at the time of application.
- Do not apply in the ears where there are liquids contained in non-elastic cavities, with the risk of causing compressions in the nerve endings.
- Do not apply on cardiac area.
- Cardiac pacemaker
- Do not apply tissue ruptures or recent and acute effusions to bruises.
- Do not apply in thrombophlebitis as it can release and partially dilute clots and thrombi.
- Do not apply on testicles.
- Do not apply during pregnancy processes.
- In the presence of fever.
- In hemophiliac patients.
- Do not apply in treatments with anticoagulants.
- In joints with septic arthritis, arthritis and acute phase osteoarthritis, joint effusions