1

ELECTRICAL STIMULATION

PRESENTER:DR N. BROJENDRO SINGH

MODERATOR: PROF N.ROMI SINGH

28/11/2015 at 2.00pm

2

ELECTRICAL STIMULATION

Application of suitably modified electric current to stimulate excitable tissues like nerves and muscles to produce therapeutic benefits

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

5

FARADIC CURRENT

• Interrupted direct current • Pulse duration- (0.1 – 1

ms ) • Frequency (50 – 100 Hz)• Surged form of current is

used

28/11/2015 at 2.00pm

6

FORMS OF FARADIC TYPE CURRENT

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

8

CHEMICAL EFFECTS

• Produces chemical changes in electrodes

• Current flow in one direction for short periods

• No serious danger of burns

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

11

INTERRUPTED DIRECT CURRENT

• Frequency of 30 Hz• Duration 100 ms• Applied through a

potentiometer

28/11/2015 at 2.00pm

12

TYPES OF INTERRUPTED DIRECT CURRENT

28/11/2015 at 2.00pm

13

PHYSIOLOGICAL EFFECTS OF INTERRUPTED DIRECT CURRENT

• Stimulation of denervated muscles

• Stimulation of sensory nerves

• Stimulation of motor nerves

28/11/2015 at 2.00pm

14

INDICATIONS

• To produce contractions of denervated muscles

• Re –education of muscles in early phase of re-innervation

28/11/2015 at 2.00pm

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

CellularTissueSegmentalSystematic28/11/2015 at 2.00pm

16

EFFECTS AT CELLULAR LEVEL

• Excitation of nerve cells• Changes in cell membrane

permeability • Stimulation of fibroblast,

osteoblast• Modification of

microcirculation

28/11/2015 at 2.00pm

17

EFFECTS AT TISSUE LEVEL

• Skeletal muscle contraction

• Smooth muscle contraction

• Tissue regeneration28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

20

ELECTRICAL STIMULATOR

28/11/2015 at 2.00pm

21

ELECTRODES• Purpose–Completes the

circuit – Interface

between electron and ion flow

– resistance to current

• Materials–Metallic–Carbon rubber– Self-adhesive

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

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 resistance28/11/2015 at 2.00pm

24

TYPES

• Neuromuscular electrical stimulation(NMES)

• Functional electrical stimulation(FES)

• Transcutaneous electrical nerve stimulation(TENS)

• Interferential therapy unit28/11/2015 at 2.00pm

25

NMESNMES 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

28/11/2015 at 2.00pm

26

FUNCTIONAL ELECTTRICAL STIMULATION

• Technique that used electric currents to activate nerves innervating extremities affected by paralysis and neurological disabilities to restore normal functions

28/11/2015 at 2.00pm

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 executevariety of specific movement

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

29

PARAMETER OF FES CURRENT

• Frequency-(12-100Hz)• Intensity of current-(90-200)mA• Pulse duration(20-300)msec

28/11/2015 at 2.00pm

30

STRENGHT- DURATION CURVE

28/11/2015 at 2.00pm

31

TENS• Electrical stimulation which primarily

aims to provide a degree of symptomatic pain relief by exciting sensory nerves

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

34

ENDOGENOUS OPIATE PAIN CONTROL

• Noxious stimulus causes release of β–endorphins and dynorphin resulting in analgesia

28/11/2015 at 2.00pm

35

TYPES OF TENS

High TENS (Sensory Level)o Duration (100-500 µsec)o Frequency (100-150Hz)o Sensory-level outputo Activates spinal gate

28/11/2015 at 2.00pm

36

LOW TENS

• Duration (100 to 150 µsec)• Low pulse frequency (1 to 5 Hz)• Motor-level output• Modulation through release of β-

endorphin

28/11/2015 at 2.00pm

37

CLINICAL APPLICATIONS• Acute and chronic pain,• Back and cervical muscular

and disc syndromes,• Arthritis• Shoulder syndromes• Neuropathies• Many other painful conditions

28/11/2015 at 2.00pm

38

ELECTRODE PLACEMENT Negative electrode

• Spinal nerve roots• Painful sites •Dermatomes• Myotomes• Trigger points• Acupuncture points

Positive electrodes• Placed close to spinal

segment

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

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

28/11/2015 at 2.00pm

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 membranes28/11/2015 at 2.00pm

44

THANK YOU

28/11/2015 at 2.00pm