1. Interferential therapy (IFT)

4. Interferential currents
Medium frequency alternating currents with frequency of 3000 – 6000Hz.
They stimulate sensory and motor nerves and meet with little skin resistance (4000 Hz = 40 Ω per 100cm2).
Low frequency currents have high skin resistance
(50 Hz = 3200 Ω per 100cm2) and allow only small proportion of current to pass through the skin.
Negligible skin resistance is offered to high frequency currents and heat is produced in the tissues.

5. Interferential therapy
Pass two medium frequency alternating currents which are slightly out of phase in to the tissues and make a low frequency current.
At the point where the two currents intersect, intensity of the combined current will increase and decrease rhythmically and it is called amplitude modulation.

8. Interferential therapy
Physiological effects
Relief of pain
Motor stimulation
Absorption of exudate

10. Interferential therapy
Indications
Pain
Muscle spasm
Oedema
Haematoma
Chronic ligament lesions
Trigger spots in myofascial syndromes
Stress incontinence

11. Interferential therapy
Contraindications
Arterial disease
DVT
Infective conditions
Pregnant uterus
Danger of haemorrhage
Malignant tumours
Pace makers
During menstruation over abdomen
Open wounds
Unreliable patients
Dermatological conditions

12. Interferential therapy
Dosage
Intensity
Beat frequency
Carrying frequency
Treatment time
Treatment schedule

13. Types of electrodes Metal plate electrodes and pads
Quadripolar electrodes and pads

14. Types of electrodes Suction cup electrodes Quadripolar suction cup

16. Interferential therapy

17. Types of application
Pain point or trigger point application: as a bipolar technique, anode over the pain point & cathode adjacent to it.
Nerve trunk application: two electrodes are placed along the course of the appropriate peripheral nerve where the nerve is superficial.

18. Types of application
Paravertebral application: place the electrodes on both sides of the spine at the level of the nerve root supplying the painful area. If several nerve roots are involved , the electrodes may be applied alongside the spine at the highest and lowest nerve root levels.
Muscular application: two electrodes are placed on the either end of the muscle belly.
Transregional application: to treat a joint, electrodes are placed either side of the joint.

19. Interferential therapy
Dangers
Burns
Shocks
Haematoma

20. Advantages
Large doses of current can be passed to the body without chemical burns.
Decreased skin sensation is not a contraindication.
Current can be localized more effectively in a specific region.
Metal is not a contraindication.
It can not be given directly to cancer areas but the radiating pains can be treated.
It can combine with treatment like ultra sound.