Electrical stimulation involves applying modified electric currents to excitable tissues like nerves and muscles to produce therapeutic benefits. Direct and alternating currents can be used to stimulate tissues. Faradic and interrupted galvanic currents of varying durations and frequencies are used for stimulation of normal and denervated muscles. Electrical stimulation modalities like TENS, NMES, FES and interferential therapy are used for pain management and rehabilitation by stimulating nerves and muscles. Precise electrode placement is important for effective stimulation.

1. ELECTRICAL STIMULATION
PRESENTER:DR N. BROJENDRO SINGH
MODERATOR: PROF N.ROMI SINGH
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2. ELECTRICAL STIMULATION
Application of suitably modified electric current to
stimulate excitable tissues like nerves and muscles to
produce therapeutic benefits
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3. ELECTRIC CURRENT
• Flow of electric charge
• Two types: direct current and alternating current
• Direct current (DC) : the unidirectional flow of electric
charge.
• Alternating current(AC) : flow of electric charge
periodically in reverses direction
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4. • Electric current can stimulate excitable tissue in body.
• Intermittent current are used
• Current duration range used:(0.01ms-3sec)
• Short duration less than 10 ms is faradic type-used for
stimulation of normal muscle
• Long duration more than10ms is called interrupted
galvanic type –used for stimulation of denervated muscles
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5. FARADIC CURRENT
• Interrupted direct current
• Pulse duration- (0.1 – 1 ms )
• Frequency (50 – 100 Hz)
• Surged form of current is used
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6. FORMS OF FARADIC TYPE CURRENT
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7. PHYSIOLOGICAL EFFECT OF FADADIC
CURRENT
• Sensory nerve stimulation
• Motor nerve stimulation
stimulation with 50 Hz frequency and 0.1 – 1ms with
surged current
• Effect on muscle contraction:
• Effect on denervated muscles
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8. CHEMICAL EFFECTS
• Produces chemical changes in electrodes
• Current flow in one direction for short periods
• No serious danger of burns
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9. STIMULATION OF MOTOR POINTS
• Superficial location of motor nerve
• Usually located at upper and middle one-third of belly of
muscles
• Suitable frequency and duration is used
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10. INDICATIONS OF FARADIC CURRENT
• Facilitation of muscle contraction
• Re – education of muscle action
• Training of new muscle action
• Neuropraxia of a motor nerve
• Severed motor nerve
• Improved venous and lymphatic drainage
• Prevention and loosening of adhesions
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11. INTERRUPTED DIRECT CURRENT
• Frequency of 30 Hz
• Duration 100 ms
• Applied through a potentiometer
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12. TYPES OF INTERRUPTED DIRECT
CURRENT
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13. PHYSIOLOGICAL EFFECTS OF
INTERRUPTED DIRECT CURRENT
• Stimulation of denervated muscles
• Stimulation of sensory nerves
• Stimulation of motor nerves
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14. INDICATIONS
• To produce contractions of denervated muscles
• Re –education of muscles in early phase of
re-innervation
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15. PHYSIOLOGICAL RESPONSE TO
ELECTRICAL CURRENT
• As electricity moves through the body's conductive
medium, changes in the physiologic functioning can
occur at various levels
Cellular
Tissue
Segmental
Systematic
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16. EFFECTS AT CELLULAR LEVEL
• Excitation of nerve cells
• Changes in cell membrane permeability
• Stimulation of fibroblast, osteoblast
• Modification of microcirculation
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17. EFFECTS AT TISSUE LEVEL
• Skeletal muscle contraction
• Smooth muscle contraction
• Tissue regeneration
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18. EFFECTS AT SEGMENTAL LEVEL
• Modification of joint mobility
• Muscle pumping action to change circulation and
lymphatic activity
• Alteration of the microvascular system not associated
with muscle pumping
• Increased movement of charged proteins into the
lymphatic channels
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19. SYSTEMIC EFFECTS
• Analgesic effects as endogenous pain suppressors are
released and act at different levels to control pain
• Analgesic effects from the stimulation of certain
neurotransmitters to control neural activity in the presence
of pain stimuli
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20. ELECTRICAL STIMULATOR
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21. ELECTRODES
• Purpose
– Completes the circuit
– Interface between
electron and ion flow
– resistance to current
• Materials
– Metallic
– Carbon rubber
– Self-adhesive
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22. ELECTRODE PLACEMENT
• Electrodes spaced far apart penetrate more deeply with less
current density
• Larger the electrode the less density
• A multitude of placement techniques may be used to create
desire able clinical and physiological effects
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23. STIMULATION POINT
• Motor Points
– Superficial location of motor
nerve
• Trigger Points
– Localized, hypersensitive
muscle spasm
– Trigger referred pain
– Arise secondary to
pathology
• Acupuncture Points
– Areas of skin having
decreased electrical resistance
– May result in pain reduction
• Traumatized Areas
– Decreased electrical resistance
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24. TYPES
• Neuromuscular electrical stimulation(NMES)
• Functional electrical stimulation(FES)
• Transcutaneous electrical nerve stimulation(TENS)
• Interferential therapy unit
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25. NMES
NMES applies electrical impulses to the nervous system to
stimulate sensory and/or motor neurons
Common Uses
• Relaxation of muscle spasms
• Prevention or retardation of disuse atrophy
• Improvement of local blood circulation
• Re-education of the muscle
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26. FUNCTIONAL ELECTTRICAL
STIMULATION
• Technique that used electric currents to activate nerves
innervating extremities affected by paralysis and
neurological disabilities to restore normal functions
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27. MECHANISM OF FES
• Stimulate muscles in a programmed synergystic sequence
that allow patient to accomplish a specific functional
movement pattern
• Multichannel microprocessors
are pre-programmed to execute
variety of specific movement
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28. USES
• Prevent or correct diffuse atrophy
• Improve ROM in stiff joints and spasticity
• Re- education of new muscle action in muscle and
tendon transfers
• Supplementation or substitution of orthosis
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29. PARAMETER OF FES CURRENT
• Frequency-(12-100Hz)
• Intensity of current-(90-200)mA
• Pulse duration(20-300)msec
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30. STRENGHT- DURATION CURVE
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31. TENS
• Electrical stimulation which primarily aims to provide a
degree of symptomatic pain relief by exciting sensory
nerves
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32. MECHANISM OF TENS
• Gate Control Theory(Malzack and Wall)
• Activation of peripheral sensory Aβ fibers stimulates the
inhibitory interneuron in substansia gelatinosa in dorsal
horns of the spinal cord
• Activated interneurons produces inhibition of pain
carrying A-delta and C fibres and closes spinal pain gate
to prevent painful impulse to reach at sensory cortex
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33. DESCENDING PAIN CONTROL
• stimulation of smaller peripheral Aδ and C fibers through
the CNS causes a release of enkephalins blocking pain at
the spinal cord
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34. ENDOGENOUS OPIATE PAIN CONTROL
• Noxious stimulus causes release of β–endorphins and
dynorphin resulting in analgesia
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35. TYPES OF TENS
High TENS (Sensory Level)
o Duration (100-500 µsec)
o Frequency (100-150Hz)
o Sensory-level output
o Activates spinal gate
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36. LOW TENS
• Duration (100 to 150 µsec)
• Low pulse frequency (1 to 5 Hz)
• Motor-level output
• Modulation through release of β-endorphin
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37. CLINICAL APPLICATIONS
• Acute and chronic pain,
• Back and cervical muscular and disc syndromes,
• Arthritis
• Shoulder syndromes
• Neuropathies
• Many other painful conditions
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38. ELECTRODE PLACEMENT
 Negative electrode
• Spinal nerve roots
• Painful sites
•Dermatomes
• Myotomes
• Trigger points
• Acupuncture points
Positive electrodes
• Placed close to spinal
segment
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39. INTERFERENTIAL THERAPY
• Two medium frequency currents pass through the tissues
simultaneously
• Their paths cross; and interfere with each other
• Gives an interference or beat frequency which has low-
frequency stimulation
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40. MECHANISM OF INTERFERENTIAL
THERAPY
• Low frequency stimulation of muscle and nerve tissues at
sufficient depth without painful and side effects
• Medium frequency currents penetrate the tissues with little
resistance, but the resulting interference current allows
effective stimulation of the biological tissues
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41. ELECTRODE PLACEMENT
• When electrodes are arranged in a square and
interferential currents are passed through a homogeneous
medium - a pattern of interference will occur
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42. ELECTRODE PLACEMENT
• Ensure adequate coverage of the stimulated area
• Placement of the electrodes should be such that a
crossover effect is achieved in the desired area
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43. CONTRAINDICATIONS
• Undiagnosed pain
• Pacemakers
• Heart disease
• Epilepsy
• Pregnancy: first trimester-over the uterus
• Over the carotid sinus
• On broken skin
• On dysaesthetic skin
• Over the eyes, larynx, pharynx, over mucosal membranes
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44. THANK YOU
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