The document provides information on different types of low frequency therapeutic currents, including: 1) Faradic current, which is a short-duration interrupted current ranging from 0.1-1 msec at 50-100 Hz, used to produce near normal muscle contraction and relaxation. 2) Galvanic current, which is a direct current that flows continuously in one direction, and an interrupted form used for denervated muscle stimulation. 3) Sinusoidal currents, which are evenly alternating 50 Hz waves similar to mains current, providing 100 pulses per second. 4) Diadynamic currents, which are variations of sinusoidal currents involving single or double-phase rectification of alternating current produced

1. AVANIANBAN CHAKKARAPANI
Lecture 5
Date:19.01.15
Time: 14.00 to 15.00
Venue: K342, UTAR, Bandar Sungai Long
TYPES OF LOW FREQUENCY
THERAPEUTIC CURRENTS

2. Learning Objective
 To provide students with knowledge and
understanding of;
a. Faradic current;
b. Galvanic current;
c. Sinusoidal currents; and
d. Diadynamic currents

3. Learning Outcome
 After successful completion of this topic
students should be able to;
1. Explain the different types of therapeutic
currents namely, faradic, galvanic, sinusoidal
and diadynamic currents;
2. Describe the pulse characteristics, frequency
and dosage of the currents discussed;
3. Explain the uses of the currents discussed; and
4. Apply the different currents in real life situation
for treatment purposes.

4. Technical notes:
1. It is an alternating current named after
inventor Michel Faraday.
2. This unevenly alternating current consists
of 2 unequal phases in each cycle, with
the 1st phase having a EMF of 1ms
followed by train of damped oscillations
with a frequency of 1000Hz.
Faradic Type Currents

5. 3. This short duration interrupted surged direct
and alternating currents are capable of
producing tetanic contraction.
Summary:
Faradic current is a short-duration interrupted
current, with a pulse duration ranging from 0.1
and 1 msec and a frequency of 50 to 100 Hz.
Faradic currents are always surged for treatment
purposes to produce a near normal tetanic-like
contraction and relaxation of muscle. Current
surging means the gradual increase and
decrease of the peak intensity.

6.  Pulse Shape: Saw tooth, triangular or
trapezoidal.
 Pulse length: 0.02 to1.0 ms.
 Current frequency: 50 to 100Hz.
 Pulse type: Unsurged or plain
faradic, surged faradic,
interrupted surged faradic.
 Dosage: 15 to 20 contraction per
nerve trunk and or per
motor point of each
individual muscle per day.
Cease when voluntary
contraction is achieved to
a maximum of 90
contraction in summation.

7. Forms of faradic current
 Each represents one impulse:
1. In surged currents, the intensity of the successive impulses
increases gradually, each impulse reaching a peak value greater than
the preceding one then falls either suddenly or gradually.
2. Surges can be adjusted from 2 to 5-second surge, continuously
or by regularly selecting frequencies from 6 to 30 surges / minute.
Rest period (pause duration) should be at least 2 to 3 times as long as
that of the pulse to give the muscle the sufficient time to recover (regain
its normal state).
3.The most comfortable pulse is either 0.1-msec pulse, with a frequency of
70 Hz or 1-msec pulse with a frequency of 50 Hz.

8. 1. For Stimulating Innervated Muscle.
2. Re-education Of Muscle Action.
3. Train New Muscle Function.
4. Strengthen Healthy Muscle.
5. Prevent Disuse Atrophy.
6. Maintain Or Improve Joint Mobility.
7. Prevent Or Stretch Adhesions.
8. Promotes Peripheral Circulation.
9. Prevent Fibrotic Changes.
10. Provide Proprioceptive Feedback.
Uses

9. Technical notes:
1. It is a direct current named after inventor
Dr.L. Galvani.
2. Its direction of polarity is constant and passing
continuously in one direction only, so termed as
constant direct current.
3. Because of its unidirectional property, when
applied to a muscle tend to contract and
remain in that position till it is brought to zero,
which seems to be very painful.
GALVANIC CURRENT

10. 4. To relieve this a relaxation period is advisable and so the
current thus applied in a form of short duration with
regular pulse between two consecutive pulses where the
polarity is altered.
5.This altered polarity, paused, constant current is termed as
interrupted depolarized direct current or Interrupted
galvanic current.
6. The Constant Direct Current(CDC) is generally used for
iontophoresis and Interrupted Galvanic Current(IGC) is
generally used for denervated muscle stimulation in
regular clinical practice.

11.  Pulse Shape: Saw toothed, triangular,
trapezoidal, rectangular
and depolarized.
 Pulse lengths: 0.1 to 600 ms.
 Current frequency: 30 impulses per
minute(also
variable) repetitions.
 Pulse type: constant direct current, interrupted
direct current, surged interrupted
direct current, depolarized direct
current, surged interrupted
depolarized direct current.
 Dosage: A regular 20-30 contractions with an
average of 90- 200 contractions per
muscle per day. Cease when motor
point responds to faradic current.

12. Uses:
1. Constant direct currents are used for iontophoresis
2. Modifide direct current are used to stimulate denervated
muscles.
3. Maintain the properties of muscle.
4. Retards the denervation atrophy.
5. Helps the muscle to utilize all the substances and maintain
nutrition.
6. Improves absorption and activates pumping function of
muscle.
7. Prevents venous and lymphatic stasis.
8. Maintain the working hypertrophy of denervated muscles.
9. Maintain the extensibility of the muscles.
10.Improves local circulation.
11.Prevents contracture.

13. Sinusoidal currents :
 Sinusoidal currents are evenly alternating wave
currents of 50Hz, the form of the mains current
(shown in fig below). This gives 100 pulses or
phases in each second of 10 ms each, 50 in
one direction and 50 in the other. It can be
produced from the mains by reducing the
voltage to 60 or 80 V with a step-down
transformer.

15. Diadynamic currents
 Diadynarnic currents were introduced by Pierre
Bernard nearly 60 years ago.
 These currents are basically variation of
sinusoidal currents and the waveform involves
single or double- phase rectification of an
alternating current.
 For therapeutic purpose these currents are
made available in five different forms.

16. Fixed Monophase(MF): This is a half wave rectified alternating
current with a frequency of 50 Hz.
Fixed Diphase (DF): This is a full wave rectified alternating
current with a frequency of 50 Hz.

17. Short Pulse (SP): Equal phase of DF & MF are alternated
without intervening phases.
Long Periods(LP): This consists of 10s phases of MF
followed by a 5s phases of DF in which
the peak intensity is varied, with a
general tendency to rise and fall

18. Rhythmic Syncop:This consists of 1s phase of MF followed by a1s
rest phase.

19. THANK YOU………!