Therapeutic Electrical Modalities. Learning Objectives Be familiar with the characteristics of...

Therapeutic Electrical Therapeutic Electrical ModalitiesModalities

Learning ObjectivesLearning Objectives

Be familiar with the characteristics of Be familiar with the characteristics of electric modalities that are applied for electric modalities that are applied for therapeutic purposestherapeutic purposes

Identify physiological and therapeutic Identify physiological and therapeutic effects of electric modalitieseffects of electric modalities

Be familiar with contraindications and Be familiar with contraindications and precautions in using electric modalitiesprecautions in using electric modalities

Identify adverse effects for each Identify adverse effects for each modalitymodality

Learning Objectives Cont’d . . .Learning Objectives Cont’d . . .Be familiar with the multiple uses of Be familiar with the multiple uses of electrical stimulation (ES)electrical stimulation (ES)

When given a clinical scenario, be When given a clinical scenario, be able to:able to:– Define goals of treatment with ESDefine goals of treatment with ES– Choose the appropriate device Choose the appropriate device – Select the appropriate parametersSelect the appropriate parameters– Apply the treatment safely and Apply the treatment safely and

competentlycompetently– Modify treatment if neededModify treatment if needed

Therapeutic Electrical Therapeutic Electrical CurrentsCurrents

The application of electrical current to The application of electrical current to the body for therapeutic purposes, the body for therapeutic purposes, such as:such as:– Pain reliefPain relief– Neuromuscular Electrical stimulationNeuromuscular Electrical stimulation– Tissue/wound healingTissue/wound healing– Direct stimulation of denervated Direct stimulation of denervated

musclemuscle

TerminologyTerminology

ChargeCharge

CurrentCurrent

ResistanceResistance

ConductanceConductance

ImpedanceImpedance

Current: Current: – ACAC– DCDC– Pulsatile/pulsedPulsatile/pulsed

AmplitudeAmplitude or or

intensityintensity

Pulsed currentsPulsed currents

Monophasic or biphasicMonophasic or biphasicPulse duration Pulse duration Pulse frequency Pulse frequency

- - interval between pulsesinterval between pulses– can be manipulated independently can be manipulated independently

ModulationsModulations– FrequencyFrequency– AmplitudeAmplitude– BurstBurst

Therapeutic ElectricalTherapeutic Electrical Stimulation Applications Stimulation Applications

Pain ReliefPain Relief

Neuromuscular Electrical Stimulation Neuromuscular Electrical Stimulation (NMES)(NMES)

Tissue/wound healingTissue/wound healing

IontophoresisIontophoresis

Deinervated muscleDeinervated muscle

Transcutaneous Nerve Transcutaneous Nerve Stimulation Stimulation

(TENS)(TENS)

TENSTENS

Stimulates nerve fibers for the Stimulates nerve fibers for the symptomatic relief of painsymptomatic relief of pain

Device applies an electrical signal Device applies an electrical signal through lead wires and electrodes through lead wires and electrodes attached to the patient's skinattached to the patient's skin

Electrode placement varies:Electrode placement varies:– Typically placed in a peripheral nerve Typically placed in a peripheral nerve

distributiondistribution– Locations can be distal or proximal to pain Locations can be distal or proximal to pain

sitesite

How It WorksHow It Works

Gate Control Theory:Gate Control Theory:– Pain signals can be blocked at the Pain signals can be blocked at the

level of the spinal cord before they are level of the spinal cord before they are transmitted to the thalamustransmitted to the thalamus

– TENS stimulates large Ia myelinated TENS stimulates large Ia myelinated afferent nerve fibers that stimulate afferent nerve fibers that stimulate the substantia gelatinosa in the spinal the substantia gelatinosa in the spinal cord, closing the gate on pain cord, closing the gate on pain transmission to the thalamustransmission to the thalamus

Gate Control TheoryGate Control Theory

Physiological Effects of Physiological Effects of TENSTENS

Selective stimulation of large diameter, Selective stimulation of large diameter, myelinated fibresmyelinated fibres– Gate Control TheoryGate Control Theory

Stimulates release of endorphinsStimulates release of endorphins– Endorphin/opiate theory Endorphin/opiate theory

Stimulates release of other transmittersStimulates release of other transmitters– NA, 5-HTNA, 5-HT

?mild heating ?mild heating enhanced healing? enhanced healing?PlaceboPlacebo

Therapeutic uses of TENSTherapeutic uses of TENS

PAIN RELIEF:PAIN RELIEF:– Acute, Subacute, Chronic & Referred Acute, Subacute, Chronic & Referred – MusculoskeletalMusculoskeletal– NeurologicNeurologic– ObstetricObstetric– Oncologic*Oncologic*– Cardiac- anginaCardiac- angina

Modes of TENSModes of TENS

ConventionalConventional

AcupunctureAcupuncture

Burst modeBurst mode

Brief-intense/noxious levelBrief-intense/noxious level

Conventional TENSConventional TENS

High-frequency, low-intensity stimulationHigh-frequency, low-intensity stimulation– most effective type of stimulationmost effective type of stimulation

Amplitude is adjusted to produce Amplitude is adjusted to produce minimal sensory discomfortminimal sensory discomfort

Pain relief begins after 10–15 minutes Pain relief begins after 10–15 minutes and stops shortly after removing and stops shortly after removing stimulationstimulation

Useful for neuropathic painUseful for neuropathic pain

Duration of treatment is 30 minutes to Duration of treatment is 30 minutes to hourshours

AcupunctureAcupuncture

Low frequency, high intensity stimulationLow frequency, high intensity stimulation

Amplitude high enough to produce Amplitude high enough to produce muscle contractionmuscle contraction

Onset of pain relief can be delayed Onset of pain relief can be delayed several hoursseveral hours

Pain relief persists hours after removing Pain relief persists hours after removing stimulationstimulation

Useful for acute musculoskeletal Useful for acute musculoskeletal conditionsconditions

Treatment sessions last 30–60 minutesTreatment sessions last 30–60 minutes

Burst ModeBurst Mode

High frequency stimulation bursts at High frequency stimulation bursts at low frequency intervalslow frequency intervals

Delayed onset of pain reliefDelayed onset of pain relief

Treatment can range 30–60 minutesTreatment can range 30–60 minutes

Brief-intense/Noxious LevelBrief-intense/Noxious Level

Hyper-stimulationHyper-stimulation

High frequency, high intensity High frequency, high intensity stimulationstimulation

It is considered that this mode It is considered that this mode stimulates C-fibers causing counter-stimulates C-fibers causing counter-irritationirritation

Rarely tolerated more than 15–30 Rarely tolerated more than 15–30 minutesminutes

TENS UnitTENS Unit

intensity

Pulse width

timer

mode

frequency

TENS Dosage TENS Dosage

ConventionalConventional Burst modeBurst mode Brief IntenseBrief Intense

80-125 pps80-125 pps 2 bursts per 2 bursts per secsec

125 pps125 pps

60-100 60-100 microsecmicrosec

220-250220-250 250250

Comfortable Comfortable tinglingtingling

Muscle twitchMuscle twitch Strong Strong sensationsensation

Acute pain, Acute pain, fast relieffast relief

Deep, chronic Deep, chronic achy painachy pain

Rapid relief Rapid relief for intense for intense pain pain

Modulation ModesModulation ModesSD: strength-durationSD: strength-duration– Amplitude and width modulate alternately – Amplitude and width modulate alternately –

subtle change in sensationsubtle change in sensation– Allows higher total amount of charge to be usedAllows higher total amount of charge to be used

MW: modulated widthMW: modulated width– StrongerStronger Weaker Weaker

MR: modulated rateMR: modulated rate– Faster Faster Slower Slower

CM: combination modulationCM: combination modulation– Rate and width Rate and width

– ‘‘Diffuse’ sensationDiffuse’ sensation

Electrode placementElectrode placement

Single channel:Single channel:– 2 electrodes2 electrodes

Dual channel:Dual channel:– 4 electrodes4 electrodes

Single channelSingle channel

Surround the painSurround the pain

Over the painOver the pain

Within dermatome/myotomeWithin dermatome/myotome

On trigger points or acupuncture On trigger points or acupuncture points within dermatomepoints within dermatome

Spinal segment: one near spine, Spinal segment: one near spine, other over pain or trigger point other over pain or trigger point within the dermatome/myotomewithin the dermatome/myotome

Dual channelDual channelBracket Bracket

Cross – fireCross – fire

Bilateral placement- both limbsBilateral placement- both limbs

Contralateral: Contralateral: – Phantom pain, skin irritation or woundPhantom pain, skin irritation or wound

General placement: flood the limbGeneral placement: flood the limb– Overlap channelsOverlap channels

PrecautionsPrecautions

Decreased sensationDecreased sensation

PregnancyPregnancy

MalignancyMalignancy

Decreased mentationDecreased mentation

Be careful with repeated applications and prolonged use, adhesives/tape and gel can all cause dermatitis

Make sure the entire electrode has good coverage for gel and don’t use too high a current - can cause electrical burns on the skin!

ContraindicationsContraindications

UNDIAGNOSED PAINANY electronic implant– Some Pacemakers (fixed rate ok Some Pacemakers (fixed rate ok

but rate responsive are affected)but rate responsive are affected)– Cardioverter-defribrillatorsCardioverter-defribrillators

– Some Bladder stimulatorsSome Bladder stimulators Metal implants???

Interferential CurrentInterferential Current(IFC)(IFC)

Interferential CurrentInterferential Current

Another form of TENS:Another form of TENS:– Differs from TENS as it allows deeper Differs from TENS as it allows deeper

penetration with more comfort penetration with more comfort (compliance) and increased circulation(compliance) and increased circulation

AMC AMC (amplitude modified current)(amplitude modified current)

Frequencies interfere with the Frequencies interfere with the transmission of pain messages at the transmission of pain messages at the spinal cord levelspinal cord level

How does it work?How does it work?

2 “medium frequency” currents2 “medium frequency” currents– Low frequency (e.g. TENS) = <1000HzLow frequency (e.g. TENS) = <1000Hz– Medium frequency 1000-10,000 HzMedium frequency 1000-10,000 Hz

2 currents with different frequencies2 currents with different frequencies

Currents ‘interfere’ with one another Currents ‘interfere’ with one another

““Beat frequency” is the difference Beat frequency” is the difference between the 2 currentsbetween the 2 currents

ExampleExample

– C1 = 5000 C1 = 5000 HzHz– C2= 5100 HzC2= 5100 Hz– fixed Beat fixed Beat

frequency = 100 frequency = 100 bpsbps

Indications for IFCIndications for IFC

Urinary incontinenceUrinary incontinencePain reliefPain reliefBlood flow/edema managementBlood flow/edema management– May be effective due to the combination May be effective due to the combination

of pain relief (allowing more of pain relief (allowing more movement), muscle stimulation and movement), muscle stimulation and enhanced blood flowenhanced blood flow

TENS vs. IFCTENS vs. IFC

Physiological effects:Physiological effects:– Depolarize sensory and motor nervesDepolarize sensory and motor nerves

Why not TENS?Why not TENS?– ““Medium frequency” Medium frequency” less skin less skin

impedanceimpedance– Less impedance Less impedance more patient comfort more patient comfort– More patient comfort More patient comfort tolerate higher tolerate higher

amplitude current amplitude current deeper penetration deeper penetration

ContraindicationsContraindications

Same as TENSSame as TENS

Plus: Plus: – With suction cup electrodes:With suction cup electrodes:

BruisingBruising

Cross-infection from spongesCross-infection from sponges

IFC Application IFC Application

Stimulator typeStimulator typeElectrode placementElectrode placement– As precisely as possible so that patient As precisely as possible so that patient

feels the stimulation over the targeted feels the stimulation over the targeted areaarea

Electrode fixationElectrode fixation– Self-adhesive padsSelf-adhesive pads– Non-adhesive taped in placeNon-adhesive taped in place

Coupling mediumCoupling medium– Gel for electrode padsGel for electrode pads

SweepSweep

Beat frequencyBeat frequency is modulated is modulated

Thought to prevent adaptationThought to prevent adaptation

E.g. E.g. – C1 fixed at 5000C1 fixed at 5000– C2 C2 varies varies – Gives a VARIABLE BEAT FREQUENCYGives a VARIABLE BEAT FREQUENCY

Uses of sweepUses of sweep

Sweep ranges: Sweep ranges: – Pain relief 80-150 bpsPain relief 80-150 bps– Muscle rehab 10-100 bpsMuscle rehab 10-100 bps– Edema 1-10 bps (intermittent Edema 1-10 bps (intermittent

muscle contractions)muscle contractions)– Selection of a wide frequency i.e 1-Selection of a wide frequency i.e 1-

100Hz is less efficent + ? Counter-100Hz is less efficent + ? Counter-productiveproductive

Set-Up of IFCSet-Up of IFC

Bi-polarBi-polar

QuadripolarQuadripolar

Quadripolar with scanQuadripolar with scan

Bi-polar methodBi-polar method““Pre-mod”Pre-mod”2 electrodes2 electrodesSingle channelSingle channelCurrent is ‘modulated’ within the machineCurrent is ‘modulated’ within the machineSimilar to TENSSimilar to TENS

Quadripolar methodQuadripolar method4 electrodes4 electrodes

2 channels2 channels

Interference occurs where the fields cross one Interference occurs where the fields cross one another WITHIN the tissuesanother WITHIN the tissues

Cloverleaf patternCloverleaf pattern

Quadripolar fieldQuadripolar field

Quadripolar With ScanQuadripolar With Scan““Automatic vector scan”Automatic vector scan”

AMPLITUDE is varied by the AMPLITUDE is varied by the machinemachine

E.g. E.g. – C1 fixed amplitude/intensityC1 fixed amplitude/intensity– C2 variable amplitudeC2 variable amplitude

Pattern of interference is different Pattern of interference is different

Quad With ScanQuad With Scan

IFC Scan IFC Scan

Uses of scan:Uses of scan:– Large area of treatmentLarge area of treatment– Diffuse painDiffuse pain– Location of pain difficult to Location of pain difficult to

pinpointpinpoint

Neuromuscular Electric Neuromuscular Electric StimulationStimulation

(NMES)(NMES)

NMESNMES

Consists of transcutaneous electrical Consists of transcutaneous electrical stimulation for muscles with or without stimulation for muscles with or without intact PNS, or central controlintact PNS, or central control– More powerful than TENS unitMore powerful than TENS unit

Multiple muscles can be activated in a Multiple muscles can be activated in a coordinated fashion to attain certain coordinated fashion to attain certain functional goals (ambulation, transfers)functional goals (ambulation, transfers)

Types of Muscle ContractionTypes of Muscle Contraction

Voluntary:Voluntary:– Recruits Type I first, then Type 2 Recruits Type I first, then Type 2 – Spatial summationSpatial summation

Recruitment of additional motor unitsRecruitment of additional motor units

– Temporal summationTemporal summationIncreased firing rateIncreased firing rate

– Gradual increase in force Gradual increase in force generatedgenerated

Types of Muscle ContractionTypes of Muscle Contraction

Electrically stimulated Electrically stimulated contraction:contraction:– Reverse pattern of recruitment Reverse pattern of recruitment

Type IIType II Type I Type I

– All motor units fire at onceAll motor units fire at once– Easy to produce fatigueEasy to produce fatigue

Use “Ramp up” for comfortUse “Ramp up” for comfort

Features of NMES CurrentsFeatures of NMES Currents

Pulse durationPulse duration

Pulse rate/frequency: 30-50 ppsPulse rate/frequency: 30-50 pps

Therapeutic Uses of NMESTherapeutic Uses of NMES

Strengthens musclesStrengthens muscles

Motor Re-educationMotor Re-education

Increases ROMIncreases ROM

Enhances enduranceEnhances endurance

Reduces muscle spasm/spacityReduces muscle spasm/spacity

Strength TrainingStrength Training

Recruits maximum numbers of motor Recruits maximum numbers of motor unitsunits

Used if volitional control affected by Used if volitional control affected by – pain pain – reflex inhibitionreflex inhibition– motivationmotivation

Works by overloadWorks by overload fatigue fatigue

Strength TrainingStrength Training

Can improve strength but not as well Can improve strength but not as well as:as:– voluntary contractionvoluntary contraction– ES + voluntary contractionES + voluntary contraction

““high load/low reps”high load/low reps”

Longer rest periodsLonger rest periods

Motor Re-Education Motor Re-Education

Use NMES for:Use NMES for:– Contraction is not readily under Contraction is not readily under

voluntary control (e.g. pelvic floor)voluntary control (e.g. pelvic floor)– Teaching a new action (e.g. tendon Teaching a new action (e.g. tendon

transfer)transfer)– Injured peripheral nerve is Injured peripheral nerve is

regeneratingregenerating

Motor re-educationMotor re-education

Demonstration to convince patient Demonstration to convince patient that contraction IS possible (e.g. that contraction IS possible (e.g. hysterical paralysis)hysterical paralysis)

Enhanced recruitment or timing Enhanced recruitment or timing during a functional movement: during a functional movement: – Functional Electrical StimulationFunctional Electrical Stimulation

Related to a particular task e.g. sit-to-stand, Related to a particular task e.g. sit-to-stand, hand to mouthhand to mouth

Increase ROMIncrease ROM

Stretch contractures *Stretch contractures *

Contract-relaxContract-relax

Facilitate tendon glideFacilitate tendon glide

Break adhesions *Break adhesions *

*Patient may not be able to generate *Patient may not be able to generate sufficient forcesufficient force

Enhance EnduranceEnhance Endurance

Use sub-maximal force over longer Use sub-maximal force over longer period of timeperiod of time

Similar to low load/high reps at the Similar to low load/high reps at the gymgym

Equal work and rest periodsEqual work and rest periods

Promote circulationPromote circulation

Muscle pumpMuscle pump

Prolonged immobilizationProlonged immobilization

Prevents complications from Prevents complications from immobility such as deep vein immobility such as deep vein thrombosis (DVT), and osteoporosisthrombosis (DVT), and osteoporosis

Low load, high repsLow load, high reps

Decrease spasm/spasticityDecrease spasm/spasticity

Stimulate antagonistStimulate antagonist– reciprocal inhibitionreciprocal inhibition

Stimulate agonistStimulate agonist– fatiguefatigue

Stimulate both alternatelyStimulate both alternately

Contraindications and Contraindications and PrecautionsPrecautions

The Big FiveThe Big Five

Carotid sinusCarotid sinus– Venous or arterial thrombosis/ Venous or arterial thrombosis/

thrombophlebitisthrombophlebitis

Areas of skin irritationAreas of skin irritation

Open woundsOpen wounds

Features of NMES CurrentsFeatures of NMES Currents

On timeOn time

Off timeOff time

Rise time/ramp upRise time/ramp up

Fall time/ ramp downFall time/ ramp down

IFC Set-UpIFC Set-Up

Size matters! Size matters! – Small electrodes Small electrodes concentrates the concentrates the

charge charge greater effect greater effect– Larger electrodes Larger electrodes dissipates the dissipates the

charge charge can tolerate greater amplitude can tolerate greater amplitude

Match electrode size to the size of Match electrode size to the size of the musclethe muscle

Set-Up ContinuedSet-Up ContinuedConductivity matters!Conductivity matters!– Skin prepSkin prep

Sensation testingSensation testing

Skin prepSkin prep

– Coupling medium:Coupling medium:Lots of gelLots of gel

Cover ENTIRE electrodeCover ENTIRE electrode

No gel on skin between electrodesNo gel on skin between electrodes

Set-Up ContinuedSet-Up Continued

Location matters!Location matters!– Parallel to muscle fibersParallel to muscle fibers– Over motor pointsOver motor points– Farther apart Farther apart deeper penetration of deeper penetration of

current?current?– No closer than ½ the diameter of each No closer than ½ the diameter of each

electrode electrode – Precision vs. overflowPrecision vs. overflow

Adverse AffectsAdverse Affects

Electrical burn due to fold or poor gel Electrical burn due to fold or poor gel techniquetechnique

Skin irritationSkin irritation

IontophoresisIontophoresis

What is it?What is it?

Introduction of ions into the body Introduction of ions into the body using direct electrical currentusing direct electrical current

Transports ions across a membrane Transports ions across a membrane or into a tissueor into a tissue

Painless, sterile, noninvasive Painless, sterile, noninvasive techniquetechnique

Demonstrated to have a positive Demonstrated to have a positive effect on the healing processeffect on the healing process

Continued . . .Continued . . .

Low-level electrical current carries Low-level electrical current carries drug ions through the skin and into drug ions through the skin and into underlying tissueunderlying tissue

Type of medication used will be Type of medication used will be based on the desired effect to the based on the desired effect to the treated areatreated area– Most common medication is Most common medication is

DexamethasoneDexamethasone

How it WorksHow it Works

Electrical unit uses a direct current Electrical unit uses a direct current that is either a positively or that is either a positively or negatively charged active electrode negatively charged active electrode

An oppositely charged dispersive An oppositely charged dispersive electrode is attachedelectrode is attached

The medication is placed on the The medication is placed on the active electrode so that the active active electrode so that the active electrode has the same charge as electrode has the same charge as the medicationthe medication

Continued . . . Continued . . .

When the electrodes are placed on When the electrodes are placed on the skin and activated, the charge the skin and activated, the charge from the electrode will drive the from the electrode will drive the medication away from the electrode medication away from the electrode and into the area being treatedand into the area being treated

The electrical charge will push the The electrical charge will push the medication through the skin and into medication through the skin and into the tissue to be treatedthe tissue to be treated

IndicationsIndications

InflammationInflammation

EdemaEdema

Bone spurs/calcium depositsBone spurs/calcium deposits

Fungal infectionsFungal infections

ScarsScars

WoundsWounds

Muscle spasmsMuscle spasms

Physiological and Physiological and Therapeutic EffectsTherapeutic Effects

Physiological:Physiological:– Decreased edema Decreased edema

and inflammationand inflammation– Pain controlPain control– Tissue adhesionTissue adhesion– Decreases muscle Decreases muscle

spasmspasm– Wound healingWound healing

Therapeutic:Therapeutic:– Delivers medication Delivers medication

at a constant rate at a constant rate so the effective so the effective plasma plasma concentration concentration remains within the remains within the therapeutic windowtherapeutic window for an extended for an extended period of timeperiod of time

Therapeutic windowTherapeutic window

The range between the minimum The range between the minimum plasma concentration of a drug plasma concentration of a drug necessary for a therapeutic effect necessary for a therapeutic effect and the maximum effective plasma and the maximum effective plasma concentration (above which adverse concentration (above which adverse effects may occur)effects may occur)

Preparing the Patient for ESPreparing the Patient for ES

Sensory testing: Sensory testing: – Which sensation?Which sensation?– Why?Why?

Skin prepSkin prep– Remove oilRemove oil– MoistenMoisten

HairHair– Clip, don’t shaveClip, don’t shave

Iontophoresis GeneratorIontophoresis Generator

Intensity:Intensity: 3-5 mA 3-5 mA Unit adjusts to Unit adjusts to

normal variations normal variations in tissue in tissue impedance impedance Reduces the Reduces the

likelihood of likelihood of burnsburns

Automatic Automatic shutdown shutdown


Adjustable TimerAdjustable Timer Up to 25 minUp to 25 min


Lead wiresLead wires Active electrodeActive electrode Inactive electrode Inactive electrode

Current IntensityCurrent Intensity

Low amperage currents are more Low amperage currents are more effective than high currentseffective than high currents– Higher currents tend to reduce effective penetration Higher currents tend to reduce effective penetration

Recommended current: 3-5 mARecommended current: 3-5 mAMaximum current may be determined Maximum current may be determined by the size (surface area) of the by the size (surface area) of the active electrodeactive electrode– Current may be set so that the current Current may be set so that the current

density under the active electrode falls density under the active electrode falls between 0.1 - 0.5 mA/cmbetween 0.1 - 0.5 mA/cm22

Current IntensityCurrent Intensity

Increase current slowly until patient Increase current slowly until patient reports tingling or prickly sensationreports tingling or prickly sensation

If pain or a burning sensation occurs, If pain or a burning sensation occurs, current is too great and should be current is too great and should be decreased decreased

When terminating treatment, current When terminating treatment, current should be slowly decreased to zero should be slowly decreased to zero before electrodes are disconnectedbefore electrodes are disconnected

Treatment TimeTreatment Time

Ranges between 10-20 minRanges between 10-20 min

Check skin every 3-5 minutes for Check skin every 3-5 minutes for signs of irritationsigns of irritation

Decrease current during treatment to Decrease current during treatment to accommodate for decrease accommodate for decrease in skin impedance to avoid pain or in skin impedance to avoid pain or burningburning

Dosage of MedicationDosage of Medication

Dosage is expressed in milliampere-Dosage is expressed in milliampere-minutes (mA-min)minutes (mA-min)

Total drug dose delivered (mA-min) = Total drug dose delivered (mA-min) = currentcurrent X X treatment timetreatment time

Typical iontophoresis drug dose is Typical iontophoresis drug dose is 40 40 mA-minmA-min

Traditional ElectrodesTraditional Electrodes

Older electrodes made of tin, copper, Older electrodes made of tin, copper, lead, aluminum, or platinum backed by lead, aluminum, or platinum backed by rubber rubber

Completely covered by sponge, towel, Completely covered by sponge, towel, or gauze which contacts skin or gauze which contacts skin

Absorbent material is soaked with Absorbent material is soaked with ionized solution (medication)ionized solution (medication)

Commercial ElectrodesCommercial ElectrodesElectrodes have a small chamber Electrodes have a small chamber covered by a semi-permeable covered by a semi-permeable membrane into which ionized solution membrane into which ionized solution may be injected may be injected

The electrode self adheres to the skinThe electrode self adheres to the skin

Electrode PreparationElectrode Preparation

Shave and clean skin Shave and clean skin prior to attaching the prior to attaching the electrodes to ensure electrodes to ensure maximum contact maximum contact

Do not excessively Do not excessively abrade the skin during abrade the skin during cleaningcleaning

Damaged skin has Damaged skin has lower resistance to lower resistance to current current – Increased risk of Increased risk of

burnsburns


Attach self-adhering Attach self-adhering active electrode to active electrode to skinskin


Inject ionized solution Inject ionized solution into the chamberinto the chamber


Attach self-adhering Attach self-adhering inactive electrode to inactive electrode to the skin and attach the skin and attach lead wires from the lead wires from the generatorgenerator

Electrode PlacementElectrode Placement

Size of electrodes can cause variation in Size of electrodes can cause variation in current density current density – Smaller = higher densitySmaller = higher density– Larger = lower densityLarger = lower density

Electrodes should be separated by at Electrodes should be separated by at least the diameter of active electrodeleast the diameter of active electrode Wider separation minimizes superficial Wider separation minimizes superficial

current densitycurrent density Decreased risk for burnsDecreased risk for burns

Electrode PlacementElectrode Placement

Selecting the Appropriate Selecting the Appropriate IonIon

Negative ions (medication) driven into Negative ions (medication) driven into tissues by the negative leadtissues by the negative lead– Accumulation of negative ions in the Accumulation of negative ions in the

tissues tissues

Produces an Produces an acidic reactionacidic reaction through through the formation of hydrochloric acidthe formation of hydrochloric acid Results in hardening of the tissues by Results in hardening of the tissues by

increasing protein densityincreasing protein density

Continued . . .Continued . . .

Positive ions (medication) driven into Positive ions (medication) driven into tissues by the positive leadtissues by the positive lead– Accumulation of positive ions in the tissues Accumulation of positive ions in the tissues

Produces an Produces an alkaline reactionalkaline reaction through the formation of sodium through the formation of sodium hydroxide hydroxide Results in softening of the tissues by Results in softening of the tissues by

decreasing protein densitydecreasing protein density Useful in treating scars or adhesionsUseful in treating scars or adhesions Some positive ions may also produce Some positive ions may also produce

an analgesic effect an analgesic effect

Selecting the Appropriate Selecting the Appropriate IonIon

InflammationInflammation Dexamethasone (-)Dexamethasone (-) Hydrocortisone (-)Hydrocortisone (-) Salicylate (-)Salicylate (-)

SpasmSpasm Calcium (+)Calcium (+) Magnesium (+)Magnesium (+)

AnalgesiaAnalgesia Lidocaine (+)Lidocaine (+) Magnesium (+)Magnesium (+)

EdemaEdema Hyaluronidase(+)Hyaluronidase(+) Salicylate (-)Salicylate (-) Mecholyl (+)Mecholyl (+)

Open Skin LesionsOpen Skin Lesions Zinc (+)Zinc (+)

Scar TissueScar Tissue Chlorine (-)Chlorine (-) Iodine (-)Iodine (-) Salicylate (-)Salicylate (-)

Adverse EffectsAdverse Effects

Chemical burnsChemical burns

Thermal burnsThermal burns

Skin irritationsSkin irritations

Patient PreparationPatient PreparationFor All Types of ESFor All Types of ES

Preparing the PatientPreparing the Patient

Explain Explain what, why, howwhat, why, how– What: What:

full name plus ‘translation’ of what it full name plus ‘translation’ of what it isis

– Why: Why: Pain relief, muscle strengthening, etcPain relief, muscle strengthening, etc

– How:How:Gate control?Gate control?

Opiate release?Opiate release?


Sensation testingSensation testing

Test/demonstrate on yourself firstTest/demonstrate on yourself first– Check for Check for

broken leads broken leads

dead batteriesdead batteries

Sensitive dialsSensitive dials

– Gain confidence of patientGain confidence of patient


Prepare electrodesPrepare electrodes– Plug the leads in firstPlug the leads in first– Use correct gelUse correct gel

No gel BETWEEN electrodes!No gel BETWEEN electrodes!

– Moisten self-adhesive electrodes or IFC Moisten self-adhesive electrodes or IFC pads WELLpads WELL

Tape or strap electrodes securelyTape or strap electrodes securely

Questions??Questions??

Comprehension CheckComprehension Check

1.1. What are the 4 main purposes of What are the 4 main purposes of applying therapeutic electric currents?applying therapeutic electric currents?

2.2. What pain mechanism is affected by What pain mechanism is affected by the use of TENS?the use of TENS?

3.3. What are the 4 modes of TENS? Which What are the 4 modes of TENS? Which would be used for chronic pain?would be used for chronic pain?

4.4. What are the contraindications for What are the contraindications for TENS?TENS?

5.5. When and why is IFC used over TENS?When and why is IFC used over TENS?

Comprehension CheckComprehension Check

6.6. How should the electrodes be set up to How should the electrodes be set up to achieve a quadipoloar field for IFC?achieve a quadipoloar field for IFC?

7.7. What are the therapeutic uses for What are the therapeutic uses for NMES?NMES?

8.8. What are the indications for What are the indications for iontophoresis?iontophoresis?

9.9. How is the maximum current of How is the maximum current of iontophoresis determined?iontophoresis determined?

10.10.What is the typical dosage of a drug What is the typical dosage of a drug for iontophoresis?for iontophoresis?

AnswersAnswers1.1. The 4 main purposes of applying The 4 main purposes of applying

therapeutic electric currents are:therapeutic electric currents are:– Pain reliefPain relief– Neuromuscular Electrical stimulationNeuromuscular Electrical stimulation– Tissue/wound healingTissue/wound healing– Direct stimulation of denervated muscleDirect stimulation of denervated muscle

2.2. The pain mechanism affected by the The pain mechanism affected by the use of TENS is the gate control theoryuse of TENS is the gate control theory

AnswersAnswers

3.3. The 4 modes of TENS are:The 4 modes of TENS are:– ConventionalConventional– AcupunctureAcupuncture– Burst mode (used for chronic pain)Burst mode (used for chronic pain)– Brief-intense/noxious levelBrief-intense/noxious level

AnswersAnswers

4.4. The contraindications for TENS are:The contraindications for TENS are:– UNDIAGNOSED PAIN– ANY electronic implant

Some Pacemakers (fixed rate ok but rate responsive are Some Pacemakers (fixed rate ok but rate responsive are affected)affected)

Cardioverter-defribrillatorsCardioverter-defribrillators

– Some Bladder stimulatorsSome Bladder stimulators – Metal implants???

5.5. When and why is IFC used over TENS?When and why is IFC used over TENS?

AnswersAnswers5.5. IFC is used over TENS because:IFC is used over TENS because:

– ““Medium frequency” Medium frequency” less skin less skin impedanceimpedance

– Less impedance Less impedance more patient comfort more patient comfort– More patient comfort More patient comfort tolerate higher tolerate higher

amplitude current amplitude current deeper penetration deeper penetration

6.6. To achieve a quadipolar field for IFC To achieve a quadipolar field for IFC the electrodes from the same circuit the electrodes from the same circuit diagonal to each other forming a box diagonal to each other forming a box around the target sitearound the target site

AnswersAnswers

7.7. The therapeutic uses for NMES are:The therapeutic uses for NMES are:– Strengthens musclesStrengthens muscles– Motor Re-educationMotor Re-education– Increases ROMIncreases ROM– Enhances enduranceEnhances endurance– Reduces muscle spasm/spacityReduces muscle spasm/spacity

AnswersAnswers

8.8. The indications for iontophoresis The indications for iontophoresis are:are:– InflammationInflammation– EdemaEdema– Bone spurs/calcium depositsBone spurs/calcium deposits– Fungal infectionsFungal infections– ScarsScars– WoundsWounds– Muscle spasmsMuscle spasms

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9.9. The maximum current of The maximum current of iontophoresis is determined by the iontophoresis is determined by the size (surface area) of the active size (surface area) of the active electrodeelectrode

10.10.The typical dosage of a drug for The typical dosage of a drug for iontophoresis is iontophoresis is 40 40 mA-min

Therapeutic Electrical Modalities. Learning Objectives Be familiar with the characteristics of...

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