electical 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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