Question

Difference between galvanic and faradic current

Answer 1

Faradic current

A faradic type current is a short duration interrupted direct current. They have a pulse duration of 0.1 to 1 ms and a frequency of 50 to 100 Hz. The point here to note is faradic current is direct current but with a short duration interruption of 0.1 to 1 microsecond.

The following figures differentiates between a alternating current (AC), direct current (DC), interrupted direct current.


galvanic vs faradic current in physiotherapy
Indications of faradic type current.

Muscle re-education.
Training new muscle action.
Muscle strengthening.
Galvanic current

A Galvanic type current is a long duration interrupted direct current. Please try to note that if faradic is a short duration interrupted D.C, then galvanic is a long duration interrupted D.C (see image above).

But in galvanic type current the duration of interruption can be adjusted, a duration of 100 ms is commonly used. And a frequency of 30 per minute is used. But as we increase the duration we must reduce the frequency.

Indication of galvanic type current.

Contraction of denervated muscle. For example, use of galvanic current in foot drop
Stimulation of small muscles which easily gets tired. Like muscles of .
This is mainly used to influence the pain threshold.
Produce hyperemia
Iontophoresis and analgesia with the stimulation simultaneous application of certain medicines will facilitate better penetration of medicine.
Galvanic vs Faradic current

Here is brief difference between a galvanic type current and faradic type current.

Galvanic Faradic
Type of current Direct Current Direct Current
Duration of interruption Long duration interrupted D.C of 100 ms Short duration Interrupted D.C of 0.1 to 1 ms
Frequency of current 30 per minute 50 to 100 Hz
Denervated muscle contraction Can produce contraction of denervated muscle
Can NOT produce contraction of denervated muscle
Commonly used to stimulate small muscles (like facial muscles) Commonly used to stimulate large muscles (ex: quadriceps)
Categories: Electrotherapy
Tags: electro-therapy, faradic stimulation, galvanic stimulation, physio

Answer 2

Galvanic current:

• Galvanic currents are used chiefly for facial muscles.  
• A galvanic current uses mild electric currents that consist of positive and negative ions to fuel the local muscles.  
• The outcome of a galvanic current is upholding the muscle physiology.

Faradic current:

• The faradic current is the current produced by the reduction or oxidation of some chemical substance at an electrode.  
• The total faradic current is the algebraic sum of all the fardaic currents flowing through an indicator electrode or occupied electrode.

Hope it helped.....