HIGH VOLTAGE GALVANIC
Electrotherapy
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OBJECTIVES
• Review of the Introduction to the Subject
• Specify the Characteristics of High Voltage
Galvanic Current
• Explain the Physiological Effects
• Detail and Summarize the Usage of HVGC:
– Indications and Contraindications
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Introduction
• Previous currents were either not comfortable (as in continuous
currents).
• Some were not as effective as needed and only acting
superficially ( as in surged direct current).
• The Farradic Current gave more effects but on superficially
innervated muscles ( as in alternated surged currents).
• The High Voltage Current has been designed as an new
alternative to be reaching deeper layers of the muscles.
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High Voltage Galvanic Current
• It is abbreviated HVGC
• High-voltage galvanic stimulation (HVGS) produces a
high-voltage current with a high-peak intensity of a
maximum of 300 to 400 ma
• but with a low-frequency current and a very short
duration, ranging between 50 and 100 msec.
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Characteristics:
• The high-peak intensity produced is of a twin-pulsed
shape.
• It is safer and more comfortable to the patient than
faradic current because of its short duration.
• It penetrates deeper than that of low-voltage currents.
• Direct stimulation of deep nerves and muscles can be
effective.
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Characteristics (cont.):
• It can stimulate either an isolated muscle or muscle
group according to the appropriate technique.
• It does not produce contraction in the denervated muscle
as the pulse duration is too short to depolarize the
muscle membrane.
• Partially innervated or totally innervated muscle will
respond well to high-voltage galvanic current.
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Physiological Effects of HVGC:
Pain reduction:
• It is accomplished either through:
– decreasing pain by using two small electrodes
closely-spaced in a narrow area.
– or minimizing pain fiber stimulation by using two
widely-spaced large electrodes.
Both of these methods can stimulate the release of opiate
substance; ß-endorphins in the central nervous
system in order to suppress pain.
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Effects in Pain Relief
– The endorphin substance
( morphine like
substance) is found in
high concentration in the
hypothalamus and
pituitary glands.
– Electrical stimulation
will activate the portion
of the brain to release
B-endorphin and
stimulate the analgesic
system.
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Physiological Effects of HVGC:
• Increase of joint mobility:
• It is due to reduction of pain
through the direct effect of the
current on blood vessels,
which leads to improvement of
circulation.
• So, high voltage galvanic
stimulation is effective in healing
after fractures, menisectomy,
osteoarthritis and frozen
shoulder.
• Reduction of post-traumatic
edema is evident immediately
after treatment.
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Physiological Effects of HVGC:
• Improvement of
peripheral circulation:
It is due to:
• the stimulation of
muscle pumping effect
on the venous
circulation and
• stimulation of
sympathetic neurons,
which subsequently
cause vasodilatation.
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Physiological Effects of HVGC:
• Healing of ulcers:
• It is accomplished
through electrical
stimulation with the
positive electrode, which
increases the repair
process.
• Furthermore, electrical
stimulation with the
negative pole destroys
bacteria (abiotic effect).
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Physiological Effects of HVGC:
• Relief of muscle spasm:
• It is done due to reduction of pain through strong
muscle contraction, which produces relaxation.
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Indications:
• As a low-frequency current, with the exception of treating
the denervated muscles, it may be used for:
•
•
•
•
Facilitation of muscle contraction inhibited by pain.
Re-education of weak muscles.
Reduction of post-traumatic edema.
Mobilization of joint stiffness.
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Indications:
• Reduction of pain and muscle spasm (arthritis, sprain
and strain).
• Improvement of peripheral circulation.
• Healing of ulcers.
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Contraindications:
They are similar to those of the other low
frequency currents:
• Skin lesions.
• Acute infections and inflammations.
• Thrombosis.
• Loss of sensation.
• Cardiac pacemakers.
• Superficial metal
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Dosage:
• It is adjusted according to the patient’s tolerances.
•
In cases of edema, muscle spasm and stiff joint, the
dose must be high enough to produce muscle
contraction:
• - Pulse rate: 80 pulses / sec.
• - Treatment duration: 20 - 30 minutes.
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Cutaneous Pain
• Cutaneous pain: This pain is perceived as a result of
stimulation of Pain receptors in the skin.
• Pain receptors are slowly adapting receptors, which
continuously inform the CNS about tissue damage.
• Thin myelinated Alpha fibers : have a diameter of 1 -5
microns and conduction velocity of 5-15 meters /sec.(fast
pricking pain-reflex)
• Non-myelenated C fibers: Having a diameter of less than
1 micron and a conduction velocity of 0.5 meter
/second.(slow burning
pain)
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Electrotherapy combined with
Hydrotherapy
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Revision and Conclusion
The Characteristics of High Voltage Galvanic Current?
The main effects on the patients?
Which pathologies are treated and which are not?
Explain the procedure of application.
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