A.THANGAMANI RAMALINGAM

Electricity is an element of PT modalities most frightening and least understood.

Understanding the basis principles will later aid you in establishing treatment protocols.

•  Amplitude window

• Frequency window

• Acute window

• chronic window

• Energy based window

• Time based window

• Interval based window

420B.C-hippocrates-in torpaedo fish 46A.D-scribonius largus-gout/headache 1700-luigi galvani & alessantro volta 1745-leyden jar for ES 1831-michael faraday 1850s-duchene-motor points(father of ES) 1909-rheo/chron-louis 1916-SD curve-Adrian FES-1961-liberson 1962-HVPC-robert becker

Introduction Definition Physical characteristics Therapeutic uses Treatment regimes Practical application Contra-indications Dangers

Widely used electrotherapy modality Used since the 1950s to utilise the therapeutic

aspects of low frequency currents without the discomfort

Two medium frequency currents of slightly differing frequency are applied to the body in such a manner to produce;

an amplitude modulated medium frequency current within the body.

Amplitude modulation provides a beat frequency that is within the biological frequency range

PRODUCTION OF IFT

medium frequency A + medium frequency B = low (therapeutic) frequency C

1.

Z=1/2 fC Π

,Z = skin impedance

f = frequency in Hertz (Hz)

C = capacitance of skin in microfarads

Skin impedance is of two types ohmic resistance and capacitive resistance.

Capacitive resistance is developed deep in the tissues due to electrolytic potential difference generated in the cell membrane

2.Accomodation is delayed.

3.Current can travel at the depth of the tissue.

4.Alternating current can be used

5. Stimulus asynchronous stimulation is applied for production of interferential current so Wedensky inhibition doesn’t takes place and thereby there is no accommodation phenomenon.

Stimulus asynchronous produces Gilde-Meister effect.

(In low-frequency currents, stimulus synchronous is used which causes Wedensky inhibition and thus nerve or muscle gets accommodated to that current.

Inability of tissue to respond during the refractory period due to stimulus synchronus current is known as Wedensky inhibition)

Plate Electrodes Vacuum Electrodes Combined Electrodes(probe electrode) Quadripolar/bipolar method Scannig/static Constant/variable frequency

Suction machine

Suction electrodes with moistened sponges

Electrodes placed so that the two circuits produce an interferencecurrent and the patient experiencesthe tingling sensation on and around the site of their problem

Left knee

Electrodes placed above Thigh , Knee , Upper back & Lower back Region

4KHZ-pain relief 2KHZ-muscle stimulation Pre modulated/4EL Able to penetrate tissues with little resistance No accomadation/gildemeister effect

100Hz - pain relief 50-60 Hz = muscle contraction 1-50 Hz = increased circulation The higher the frequency (Hz) the more quickly

the muscle will fatigue 1-4 Hz-beta endorphin 40-100Hz-enkepalin,serotonin

Interferential current is commonly used for pain relief

Relief of muscle spasm Promote tissue healing Relief from edema Re-education of deeply situated Muscles.

Facial nerve neuritis Orthopedic conditions Pain-LBP.jaw pain,OA pain,fibromyalgia ( same like tens) Gynecological problems-incontinence DOMS Edema Post surgical pain Bone healing

Vasoconstrictive disease Venous insufficiency Delayed union Pseudo arthrosis Sudeck’s atrophy Muscle reeducation(PFM)

Relief of pain – pain gate theory 80-140Hz (higher IFT frequencies) Stimulates Aβ fibres To inhibit impulse transmission in A∂ and C

fibres Used for both acute and chronic pain Temporary pain relief

Relief of pain – Ascending pain suppression, 2-30Hz (lower frequencies)

Stimulates A∂ fibres: To inhibit C fibre transmission Via the release of encephalins and endorphins More longer lasting pain relief Only effective on chronic pain

Reduction of oedema 0-100 Hz Stimulates autonomic nerves to produce

vasodilatation Increases circulation

Motor stimulation 0-25 Hz - twitch 25-100 Hz - muscle contraction Can be used to treat incontinence or

muscle weakness secondary to trauma/surgery (in conjunction with active exercise).

Acute sepsis - risk of spread of infection Tumours - risk of increased growth of activity Pregnancy – no treatment over uterus or its’

nerve supply Cardiac disease – no treatment over the heart,

cervical ganglia or vagus nerve

Cardiac pacemakers Febrile conditions Large open wounds Menstruation - risk of bleeding or pain if treating

abdominal of lumbar region Dermatological conditions-open wound,cuts or

eczema Thrombophlebitis – risk of embolus being

dislodged

Severe or BP – avoid lower cervical region – BP control via cervical ganglia

Acute inflammation, oedema, haemorrhage or haematoma when using suction cups

Hypersensitivity or fear of electrical treatment

Patients who are unable to understand the treatment or what is required of them

Aesthenic individuals/children for rib cage placements

Acute trauma Near by SWD Senile and confused patients

Burns – high intensity currents can cause sufficient heating to cause a burn.

Mains current shock – faulty equipment Electric shock – abrupt application of high intensity

current – turn current up/ down slowly General malaise Nausea Vomiting Dizziness / Faintness Migraine / Headache Neurological effects

Metal implants are not the contraindications of interferential therapy

Pain80-140 Hz 15 minutes4 Hz constant 15 minutes

Circulation0-100Hz 20-30 minutes

Muscle stimulation10-50 Hz 15 minutes50Hz constant with surge

IncontinenceStress incontinence - 10-50Hz, surge 15 minutes.Urge incontinence - 5-10Hz 10 minutes

Tens Med Fit Mini 4 Pole Inferential Stimulator (IF)

performing interferential therapy with suction pads to reduce swelling and alleviate pain.

A patient receiving ICT(Interferential Current Therapy)for pain in hand

Laser + Ultrasound + IFT Machine

Electrode placement of interferential therapy in plantar fasciatis

Professional Interferential Unit With AC Adapter

Ultra IF - Interferential Unit

JPM Interferential Therapy & Vacuum

Chronic Pain Suppressor CPS-2000Interferential Current Therapy

Vectorsonic Vu720 Combination Interferential

Quattro 4-Channel Interferential Unit

Interferential Current Therapy Equipment

 Russian currents are alternating currents (AC) at a frequency of 2.5 kHz that are burst modulated at a frequency of 50 Hz with a 50% duty cycle. The stimulus is applied for a 10-second “on” period followed by a 50-second “off” or rest period, with a recommended treatment time of 10 minutes per stimulation session.1 This stimulation regimen (called the “10/50/10” regimen), applied once daily over a period of weeks, has been claimed to result in force gains, but many of the claims appear to be anecdotal

We believe some of the popularity of Russian electrical stimulation stemmed from a talk given by Russian scientist Dr Yakov Kots13 at a conference in 1977. Kots is reported to have advocated a stimulus regimen for increasing muscle force that he claimed was able to increase the maximum voluntary contraction (MVC) of elite athletes by up to 40%. Unfortunately, the only details of Kots'work were brief conference notes, translated from Russian and not readily accessible.13

A monophasic/unipolar current 50to 250 micro seconds 3000hz Czechoslovakia in1970

Frequency Analysis Method The external currents with different

frequencies are considered to cause different effects in tissues. Thus we assume that tissue reactions on different frequencies in different states of the body will also differ from each other.

Measuring the sensory, motor and pain thresholds by stimulating the tissue with the interference current may offer a diagnostic tool in physiotherapy and rehabilitation

Pain control treatment Can cause muscle contractions, but that is not why

it is used Decreases patient’s pain perception by decreasing

the conductivity & transmission of noxious impulses from small pain fibers (effects large diameter fibers)

Moderate caffeine levels (200 mg, approx 2-3 c. coffee) may decrease effectiveness of TENS

Introduce yourself to patient

Give assurance/confidence

Go through the medical reports Find out diagnosis/general contra-

indications/previous physiotherapy treatment

Hyper pyrexia Epilepsy Severe renal and cardiac problems Severe hypo/hypertension Cardiac pacemakers Infections Pregnant women Metal implants Mentally retarded/upset patients Malignancy Anterior aspect of neck/carotid sinus/eyes

Skin resistance lowering/testing tray

Pillows Cotton Soap Towel Mackintosh Petroleum jelly Test tubes ( hot &cold) U-pin (sharp &blunt) Clips Bowl of water IR lamp Hot &cold packs

Treatment tray Pillows Towel Bed sheet Cotton Adhesive tapes Straps/goggles Salt/Powder Scissor/ Inch tape Paper Graph paper Pencil/scale/eraser Machine& accessories Sand bags/crepe bandages

Open wounds Scars Local skin infections Cuts Abrasions Eczema Local hemorrhagic spots Skin sensitivity (testing)

Check the apparatus& accessories like electrodes, leads, cables, plugs, power sockets, switches, controls, dials and others

Demonstration of the treatment Check the functioning of machine in front of the

patient Explanation of treatment

Comfortable Relaxed appropriate

Do skin resistance lowering Neatly &perfectly Use items required in an orderly manner

Use proper technique of application

Appropriate placement according to the condition &patient

Use adhesives &straps Apply gel evenly on electrode Maintain good contact with the skin No leads crossing each other Confirm connections &above all

Instructions Don’t move Don’t sleep Don’t touch leads,

apparatus, therapist and any other metal near by you

Warnings Inform more

heating/uncomfortable sensations

Inform burning sensation immediately

Proper execution of treatment Appropriate intensity should be used Set duration of treatment acc. to condition

status Supervise the treatment through out the

session

Put knobs to zero Remove electrodes Switch off the machine &mains Clean the area &inspect for adverse reactions Manage if anything &give instruction regarding

next coming Windup procedure

Accurate record of all parameters of treatment including area treated , technique, dosage and the outcomes

Low J. and Reed A. (1992) Electrotherapy Explained: Principles and Practice. Oxford

Watson T. (2000) The role of electrotherapy in contemporary physiotherapy practice. Manual Therapy Aug:5(3);132-41