Electrotherapy uses electrical energy for therapeutic purposes and can be classified in several ways. It includes low-frequency currents used to stimulate nerves and muscles, medium-frequency currents used for muscle re-education and pain relief, and high-frequency currents used to produce deep heat in tissues. Other areas of study are phototherapy for pain relief and healing using light, electrodiagnosis for studying electrical muscle and nerve reactions diagnostically, and biofeedback to provide voluntary control over bodily functions. Electrotherapy is an important treatment approach in physiotherapy using various electrical modalities.

1. ELECTROTHERAPY
Dr Priyanka (PT)
MPT (Neurological Disorders)

2. Learning Outcomes
By the end of this section, you will understand:-
• Detailed Knowledge of Electrotherapy. What it is?
• What is the classification of various modalities in Electrotherapy?
• Why Electrotherapy is important in the Physiotherapy Profession?

3. Definition
The meaning of the word “therapy” is a non-surgical treatment approach.
“Electro” means electrical current or electricity or electrical means.
“Electrotherapy is a non-surgical treatment approach characterized by the
treatment of various diseases and disorders with the help of electricity or electrical
means”.
OR
“Electrotherapy is a branch of physiotherapy characterized by the treatment of
various diseases and disorders with the help of electricity or electrical means”.

4. Electrotherapy generally includes various forms of therapeutic
applications using electricity as the primary source of energy.
 Electrotherapy is a medical treatment that uses electrical energy to
stimulate or elicit a physiological response in the body.
It has been employed for various therapeutic purposes, particularly in
the fields of physical therapy, rehabilitation, and pain management The
application of electrical currents can influence nerve and muscle
activity, promote tissue healing, and alleviate pain.
Modern electrotherapy practice needs to be evidence-based and used
appropriately. Used at the right place, at the right time for the right
reason, it has a phenomenal capacity to be effective.

5. Electrotherapy
Low Frequency Current
(0-100 cycles per second)
High-Frequency Current
(more than 10000 cycles
per second).
Phototherapy
Medium Frequency Current
(1000-10000 cycles per second)
Electrodiagnosis
Biofeedback
Areas of Study in Electrotherapy

6. Current:- The flow of electrons.
Frequency:- Number of occurrence of any event per unit time.
Example:- If you take five cups of coffee per day then I may say that your frequency
of coffee intake is five cups per day.
Frequency in Electrotherapy
In electrotherapy, we use the currents whose impulses commence and cease at
regular intervals. The number of times these impulses come in a particular unit
time (second) is regarded as frequency.
Frequency is expressed in cycles per second or Hertz, Kilohertz, Megahertz.

7. Classification of Current based on Frequency
1.) Low-Frequency Current
Low-frequency currents are therapeutically used currents whose frequency is in the range of 0 to 100
cycles per second.
The primary use of low-frequency current is the stimulation of nerves and muscles.
Various currents in this category that are used for physiotherapeutic treatments are:-
i. Direct current,
ii. interrupted direct current,
iii. sinusoidal current,
iv. Diadynamic current,
v. high voltage pulsed galvanic current,
vi. micro amperage electrical nerve stimulation,
vii. transcutaneous electrical nerve stimulation, etc.

8. 2.) Medium Frequency Current
Medium frequency currents are therapeutically used currents whose frequency
is in the range of 1000 to 10,000 cycles per second.
They are basically used to stimulate deeply situated muscles and nerves since it’s
difficult to stimulate these muscles and nerves by low-frequency currents without
the spread of current.
Clinically they are used for muscle re-education, to retard the rate of muscle
atrophy, drainage of edema, and for pain relief.
Various currents in this category, which are used for physiotherapeutic purposes,
are Russian current, Interferential current, etc.

9. 3.) High-frequency currents
High-frequency currents are therapeutically used currents whose frequency is
more than 10,000 cycles per second.
High-frequency currents are used for their ability to produce the deep heat inside
the tissues.
Various electrotherapeutic modalities, which work on this type of current are:-
short wave diathermy,
long wave diathermy,
therapeutic ultrasound,
microwave diathermy.

10. Photography
Phototherapy refers to the treatment of various diseases and disorders with the help of light.
The primary effect of these phototherapeutic modalities is pain relief by heat and acceleration of healing through
elevation of temperature, counterirritation, and photochemical effects.
Various modalities such as infrared rays, ultraviolet rays, and laser comes under this category.
Electrodiagnosis
Electrical currents can also be used for the diagnostic purpose.
Electrodiagnosis means the detection of the diseases and disorders by the use of electrotherapeutic currents or
electromyography. We can use currents like interrupted direct current and perform various electrodiagnostic tests
such as rheobase, chronaxie, strength-duration curve, pulse ratio, myasthenic reaction, galvanic tetanic
ratio, nerve conduction test, nerve distribution test, faradic galvanic test, etc.
 Electromyography is the study of the electrical activity of the muscle by means of surface electrodes placed over
the skin or needle electrodes inserted in the muscle itself. By electromyography, we can study motor unit
potential, motor nerve conduction velocity, sensory nerve conduction velocity, etc.

11. Biofeedback
 Biofeedback is the process of furnishing information to an individual about the body’s function to get some
voluntary control over it.
 Some biofeedback devices are related to electrotherapy and hence, they can be included under
electrotherapy for example EMG biofeedback.

12. Classification of Currents
1. On the Basis of Direction:-
1.1) Alternating currents:- Alternating currents flow in both directions. Examples of these types of
currents are sinusoidal currents and interferential currents.
1.2) Unidirectional currents:- Currents that flow in one direction only for example direct current and
interrupted direct current. Alternating currents flow in both directions. Examples of these types of
currents are sinusoidal currents and interferential currents.
2. On the Basis of Frequency:-
2.1)Low-Frequency Current.
2.2)Medium Frequency Current.
2.3)High-Frequency Current.

13. 3. On the basis of voltage:-
3.1) Low Voltage:- Low voltage currents are with a voltage of less than 100 volts for example low-
frequency currents.
3.2) High Voltage:- High voltage currents are of several hundred volts for example high-frequency
currents.
4. On the basis of amperage:-
4.1) Low Amperage:-Low amperage currents are those currents whose amperage ranges from 1 to 30
milliampears and are the same as that of low voltage currents.
4.2) High Amperage:- High amperage currents have amperage from 500 to 2000 milliamperes and are
usually of high tension.
5. On the basis of biophysical effects:-
On this basis currents can be divided into two types such as
5.1) currents causing ionic changes and
5.2) currents causing thermal changes.

14. SUMMARY
 Various areas of study in electrotherapy are low-frequency currents, medium-frequency currents,
high-frequency currents, phototherapy, electrodiagnosis, and biofeedback.
 Low-frequency currents are used for stimulation of muscles and nerves.
 Medium frequency currents are used for the re-education of deeply situated muscles, pain relief,
and for drainage of edema.
 High-frequency currents are used for the production of deep heat inside the tissues.
 Phototherapy is used for pain relief and acceleration of healing.
 Electrodiagnosis helps in the study of electrical reactions of muscles and nerves for diagnostic
purposes.

15. Thank You