Infrared radiation lies between visible light and microwaves in the electromagnetic spectrum. It can be subdivided based on wavelength. There are two main types of infrared generators used in physiotherapy - luminous generators which emit infrared, visible light, and ultraviolet rays, and non-luminous generators which only emit infrared rays. Luminous generators penetrate less deeply but are used for more chronic conditions while non-luminous generators penetrate more deeply and are used for acute conditions. Infrared radiation has physiological effects like increasing metabolic rate and cutaneous blood flow, and therapeutic effects like reducing pain and increasing joint mobility. New infrared therapies have emerged but proper technique and safety precautions must still be followed to avoid potential dangers like burns.

1. INFRARED RADIATION
BY RAMESH G.A
I YEAR M.P.T

2. INTRODUCTION
•Infrared rays are electromagnetic waves
•It lies between visible light and microwaves
•Wavelength 750nm to 400000nm
•Frequency 4 x 10^14Hz and7.5 X10^11 Hz

3. RADIATION
INFRARED RADIATIONS ARE SUBDIVIDED INTO
IRR A 760-1400nm
IRR B 1400-3000nm
IRR C 3000nm-1mm
WAVELENGTH
TYPE
FORMER CLASSIFICATION
NEAR OR SHORT IRR 760-1500nm
FAR OR LONG IRR 1500-15000nm

4. TYPES OF LAMPS
Two types of generators are used in physiotherapy practice:
A)Non luminous generators
B)Luminous generators

5. NON LUMINOUS GENERATORS
Produces only inra red rays of wavelength 750nm-15000nm
These generators are heated by passage of electric current
Through a bare wire or carbon held in a non conducting material
Like porcelain,mounted in the centre of parabolic reflector.
For recent injury,sedative effect of non luminous generators may
Prove useful.

6. Non luminous generators

7. LUMINOUS GENERATORS
Emits visible rays ultraviolet rays and infra red rays of wavelength
350nm to 4000nm
Are in the form of incandescent bulb-consists of a wire filament
Enclosed in a glass bulb which may contain an inert gas at low
Pressure.wire is usually tungsten.
For lesion of more chronic type ,the shorter rays may prove more
Beneficial.

8. Luminous generator

9. NO
Luminous
generators
Non luminous
generators
1 Sources Electrically heated filament Electrically heated resistance wire coiled
2 Gives IR + visible rays Only IR rays
3 Produce Short IR Long IR
4 Wavelength 350 – 4000 nm [ max .= 1000 nm ] 1500 – 12000 nm [ max. 4000 nm ]
5 Emission
70 % near IRR
24 % far
5 % visible light
1 % UV
90 % far IRR
10 % near IRR
6 Penetration
Epidermis , dermis &
Subcutaneous tissue [ 5-10 mm ]
Epidermis & superficial dermis [ 2 mm ]
7 Heating Deeply Superficial
8 Uses Chronic inflammation Acute inflammation
9
Physiological
effect
Pain reduction via
counter – irritant effect
Pain reduction via
sedative effect
10
Therapeutic
effect
Heating Sensory heating
11 Treatment time 15 -20 minute 20 -30 minutes
12 Distance 40 – 60 cm form treated area 75 -90 form treated area
Difference between luminous and non luminous generators :
Difference between luminous and non luminous generators

10. LAWS REGULATING ABSORPTION OF
RADIATION
GROTHUS LAW
LAWOF INVERSE SQUARE LAW
COSINE LAW
BEER-LAMBERT LAW
KIRCHOFFS LAW
WIENS LAW
ARNDT- SCHULTZ LAW
STEFAN-BOLTZMAN LAW

11. PENETRATION
IR rays produced by luminou generators can penetrate into
Dermis and epidermis.
IR rays produceed by Nonluminous generators can penetrate
The superficial dermis only.
Penetration of energy into medium depeds upon:
a)Intensity of the source of infra red
b)Wavelength and frequency.
c)Angle at which the radiationhits the surface.
d)Coefficient of absorption of the material.

12. PHYSIOLOGICAL EFFECTS
•Increases metabolic rate
•Cutaneous vasodilation
•Sweating
•Stimulation of thermalheat receptors

13. THERAPEUTIC USES
•Relief of pain
•Muscle relaxation
•Increased blood supply
•Increase in joint mobility
•Acceleration of healing and repair

14. RECENT ADVANCES
IN IRR THERAPY
WAON THERAPY IN JAPAN
Body is warmedin an IR Chamber for15 minutes at 60 degrees centigrade
Then the patient is wrapped in thermal blankets and laid down to maintain heat
For 40 minutes.
Patient is made to drink lot of water to replenish moisture lost by perspiration.
It seems to increase cardiac function.
This can be applied as an alternate to moderate exercise in sedentary patients.
(OA,CARDIO PULMONARY PATIENTS)

15. IRR EMITTING MATERIAL FOR CLOTHING
Sports professionals use FIR emitting garments to enhance performance and
Recovery.
Garments absorb body emitted heat energy and they reemit it throughradiation
(FIR)Wavelength back to body.
FIR emitting polymers or ceramic nanoparticles are incorporated into sports apparel
Which help in reducing pain and inducing tissue repair.

16. DANGERS
•Burns
•Electric shock
•Faintness or giddiness
•Headache
•Gangrene
•Injury to the eyes
•Dehydration

17. TECHNIQUE OF APPLICATION
Explanation:Explain the nature and effects of the treatment to the
Patient.
Examination:Examine the skin to be treated and test the thermal
Sensation and also check for contraindications.

18. CONTRAINDICATIONS
•Defective arterial blood supply
•Haemorrhage
•Defective skin sensation
•Over pelvic region during pregnancy
•Varicose veins
•Malignancy
•Directly over the eyes
•Patient whose conciousness is lowered
•After deepxray and cobalt therapy
•Skin diseases like dermatitisand eczema
•Advanced cardiac disorders

19. APPARATUS
•Nonluminous generators take some time to get heated,so they
•Should be switched on 5-7minutes before treatment.
•Luminous generators need no such warmup time.

20. ARRANGEMENT OF LAMP AND
PATIENT
Expose the skin to be irradiated and shield the eyes.
The lamp is positioned in such a way that the rays strike theskin at
Right angles.
Set the lamp at approprate distance of 50-75 cm

21. INSTRUCTIONS AND WARNINGS
The patient is instructed to report immediately if heating becomes
Excessive.
Patient should be warned not touch any part of the instrument
Or to move nearer to it.

22. APPLICATION
Initially the intensity of the radiation should be low but after 5-10 minutes
(after vasodilation)strength of the radiation can be increased.
Physiotherapist should be near the patient throughout the treatment duration.
Sweating is encouraged.

23. TERMINATION
On completion of treatment the skin should be checked carefully.
Moderate erythema and warmth should be evident.
Afterexcessive irradiation the patient should not rise suddenly from
Recumbent position.

24. DOSAGE
For acute cases irradiation can be given for 10 to 15 minutes
Daily for 1to 3 timesas per the requirement.
For chronic cases upto 30 minutes daily or on alternate days can be
Given.

25. REFERENCE
Electrotherapy explained (low and Reed)
Textbook of Electrotherapy(Jagmohansingh)
Electrotherapy evidence based practice 12th edition
(shiela kitchen)
Online journals