Transcript physiologic effects of diadynamic currents

PT 158: Physical Agents II
DIADYNAMIC CURRENTS
Gilbert O. Madriaga, PTRP
Department of Physical Therapy
UP- College of Allied Medical Professions
Revised by:
Mark David S. Basco, PTRP
Department of Physical Therapy
UP - College of Allied Medical Professions
Objectives
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Describe diadynamic currents and its physical
properties.
Discuss the physiologic effects of diadynamic
currents on the body.
Identify the various indications, contra-indications
and precautions with regards the use of diadynamic
currents.
Enumerate the different methods of application of
diadynamic currents for common clinical problems.
Prescribe correct dosage, intensity, duration and
frequency of diadynamic currents on given
problems.
Appreciate the value of evidence-based clinical
practice in providing quality care to patients.
Diadynamic Currents
• Monophasic pulsatile current
• Usually a sine wave
• F=100Hz
Full wave rectification
• reversal of the the direction of AC
during alternate half-cycles. The
current is unidirectional and pulsed.
Half wave rectification
– use of a rectifier to allow current to pass in
one direction only, as the flow is blocked
during alternate half-cycles of the AC. The
current is pulsed direct current.
Diadynamic Currents
• Pulse rate
–50 pps for half wave rectified.
–100pps for full wave rectified
• Pulse duration= 10 ms
Diadynamic Currents
• Provide excitatory responses
but its long pulse duration is
very uncomfortable
• Effects are similar with DC
because its flow is also
unidirectional and it has short
or no interpulse interval
PHYSICAL PROPERTIES
OF
DIADYNAMIC CURRENTS
Fixed Diphase(DF)
• Full wave rectified AC
• f = 50Hz
• most effective in
producing a masking
effect
Fixed Monophase (MF)
• Half wave rectified AC
• f = 50Hz
Short Periods (CP)
• DF+MF
• equal phases are attenuated without
intervening pauses
Long Periods (LP)
• 10 sec MF + 5 sec DF
• peak intensity is varied and has a
tendency to rise and fall
Syncopal Rhythm (RS)
 1 sec MF + 1 sec rest period
PHYSIOLOGIC EFFECTS
OF
DIADYNAMIC
CURRENTS
Masking
• sensory nerve excitability is
altered
Vasomotor effects
• ↑ vasodilation & hyperaemia
as result of release of
histamine in tissues
• Diadynamics affect only superficial
tissues, but if by reflex activity it is
possible to have effects on deeper
structures
Muscle stimulation
– For CP & LP currents muscle
contraction is stimulated which
increases blood flow to the muscles
Stimulation of vibration sense
Indications
• Soft tissue injury
–Sprains
–Contusions
–Epicodylitis
Indications
• Joint Disorders
–Post-immobilization
–Arthritis
Indications
• Circulatory disorders
–Raynaud’s disease
–Migrane
Indications
• Peripheral Nerve Disorders
–Neuralgia
–Neuritis
–Herpes zoster
–Radiculopathies
Contraindications
• Skin Lesions
–To prevent burns, large cuts,
abrasions or open areas
–Eczema, psoriasis, acne,
dermatitis can be exacerbated by
electric currents
Contraindications
• Infection
–Can be aggravated by electric
currents and it is possible to
spread the infection
Contraindications
• Impaired sensation
–Must be checked first before any
treatment
–Density of current must be
governed by the patient’s
subjective feeling of current
tolerance
Methods of Application
Pain Spot Application
• 2 electrodes using bipolar
technique
• Anode over painful site, cathode
adjacent to it
• Cathode may be applied proximally
on the limb or over the nerve
supplying the painful area
(monopolar technique)
Nerve Trunk Application
• Apply electrodes where the
nerve is superficial
• A tingling sensation will be felt
in the area stimulated
Paravertebral Application
• Applied on both sides of the
spine at the level of the nerve
root supplying the painful area
• If there are several nerve roots,
apply alongside the spine at the
highest and lowest nerve root
levels
Vasotropic Application
• Electrodes are placed over the
vascular paths affected in the
circulatory system
Myo-energetic Application
• at each end of the muscle belly
to produce stimulation
• or monopolar technique with
one electrode on the motor
point of the muscle belly and
the other proximal to it
Transregional Application
• To treat a joint, electrodes on
opposite sides of joint
Dosage
DF-fixed diphase
• For initial treatment and before the
application of any other current
• For the treatment of circulatory
disorders
• Prickling sensation which subsides/
fine tremors
• Muscle contraction occurs at high
intensities
MF-fixed monophase
• Pain without muscle spasm
after DF
• Strong penetrating vibration
which persist for longer than
the sensation in DF
• Muscle contraction occurs at
lower intensities than with DF
CP-short periods
• For traumatic pain
• DF phase - Fine tremor rapidly
diminishes
• MF phase – strong constant
vibration
• Rhythmic contraction of muscle
LP-long periods
• Long lasting analgesic effect
particularly in the treatment of
mylagias
• Used in combination with CP for
the treatment of neuralgia
• Strong vibration
RS-syncopal rhythm
• For faradic-type stimulation
• Test the excitability of nerves
Intensity
• Gradually increased until a
definite vibration or prickling is
felt but without pain of burning
sensation
• Tetanic ms contraction should
not occur
Duration
• Not more than 10-12 mins
• 3 minutes for single applications
Frequency
• 6-7 treatments given daily or
every 2nd day
Diadynamic Currents
• The effects of diadynamic
currents can be achieved by
modern TENS with greater
comfort and ease because of its
microsecond pulses
What research tells us . . .
TITLE: Changes in pain by different types of
diadynamic current in gonarthrosis and
lumbar syndrome
• No differences concerning the changes in
pain can be demonstrated concerning the
different types of current. Nor could any
differences concerning changes in pain be
found comparing the different weeks of
therapy.
(Volklein & Callies, 1990)
We have just . . . .
. . . described diadynamic currents and its physical
properties.
. . . discussed the physiologic effects of diadynamic
currents on the body.
. . . identified the various indications, contra-indications
and precautions with regards the use of diadynamic
currents.
. . . Enumerated the different methods of application of
diadynamic currents for common clinical problems.
. . . prescribed correct dosage, intensity, duration and
frequency of diadynamic currents on given problems.
References
• Clinical Electrotherapy by Roger M.
Nelson & Dean P. Currier
• Clayton’s Electrotherapy by Sheila
Kitchen & Sarah Bazin
• Principles and Practice of Electrotherapy
by Joseph Kahn
• Electrophysical Agents in Physiotherapy
Therapeutic and Diagnostic Use by
Hilary Wadsworth & A.P.P. Chanmugam
• www.pedro.fhs.usyd.edu.au/ Physiotherapy Evidence
Database (PEDro)h