OVERVIEW OF SHORTWAVE DIATHERMY

1. SHORTWAVE DIATHERMY
Dr.prashanth kumar
1st yr pg in orthopaedics

2. Diathermy is a therapeutic treatment commonly
prescribed for muscular and joint associated pains.
The term ‘diathermy’ means ‘through heating’ or
producing deep heating directly in the tissues of the body.
• ‘ Dia’ through (also means two)
• ‘thermy’ heat or temperature
 It simulates the circulation, relieve pain, enhances rate of
recovery of healing the tissue.
INTRODUCTION

3. PRINCIPLE OF DIATHERMY
1.Before injury, the dipole molecules of the
body tissue are arranged on the basis of
polarity .
2.When the tissue is damaged the dipoles
distribution become irregular and deviates
from polarity based arrangement .
3.Under the influence of an electric field , they
rotate according to the polarity of their
charge in the direction of the field lines and
get rearranged and tends to acquire its
previous stage of polarity

4. CHALLENGES OF DIATHERMY
1.As the subcutaneous layer is fatty , direct
delivery of heat to the deep layers of tissue is
not possible.
2.Diathermy involves uneven and uncontrolled
delivery of heat therefore sometimes instead
of the target tissue , surrounding tissue gets
affected
Subcutaneous
layer

5. • Diathermy uses an electric current to produce
heat deep inside a targeted tissue.
• It can reach areas as deep as two inches from
the skin’s surface.
• The diathermy machine does not apply heat
directly to the body.
• Instead, the current from the machine allows
the body to generate heat from within the
targeted tissue.
• As the heat increases, it promotes blood flow.
• It can also help improve flexibility in stiff joints
and connective tissue.

6. BENEFITS OF DIATHERMY
 Intense heat delivered provides pain relief
and better flexibility
Reduces inflammation
Improves circulation
Accelerate healing

7. TYPES OF DIATHERMY
1. SHORT WAVE DIATHERMY
2. LONGWAVE DIATHERMY
3. MICROWAVE DIATHERMY
4. ULTRASOUND DIATHERMY
5. LASER DIATHERMY

8. SHORT WAVE DIATHERMY
 Def.: SWD is a modality that produces deep
heating via conversion of electromagnetic
energy to thermal energy.
• The pattern of heat produced depend on:
• ᴥFreq. used.
• ᴥ type of SWD unit.
• ᴥwater content of the tissues.

9.  Shortwave diathermy current freq. 10 – 100
MHz
• (The shortest radiofrequency wave is used in therapeutic diathermy.)
• the commonly used in medical work having
freq. of 27.12 MHz with wavelength of 11
meters

10.  Modalities:
 ether continuous or pulsed (PSWD).
o PSWD: application of series of short pulses of
SWD so that short periods of SWD interrupted
by gaps where there is no SWD.
o The pt. receives lower dose of SWD energy if
compared with continuous SWD applied of the
same time.
o The tissues will receive lower thermal load.

11. • SWD: produce both deep and sup. Tissue
heating, under certain controlled conditions
• it’s applied for 20 min at the max tolerable
dose

12. Types of Shortwave Diathermy
• Induction Field
• Capacitive Field

13. Induction Field Diathermy
• Places the patient in the
electromagnetic field
• Current flowing within the
coil produces a rotating
magnetic field
• Magnetic field produces
eddy currents in the tissues
• Eddy currents cause friction
that produce heat
• Selectively heats muscle
• Also referred to as:
• – Magnetic field diathermy

14. Capacitive Field Diathermy
• Uses the patient’s tissues as a
part of the circuit
• The tissues’ electrical
resistance produces heat
• Selectively heats skin
– Muscle is heated via
conduction from the
adipose
• Also referred to as “condenser field
diathermy”

15. TYPES OF ELECTRODES
• Flexible pads:
consist of metal
electrode encased
in rubber and
produce an
electrostatic field.

16. • Space plates:
consist of a rigid
metal electrode
encased in
• a Perspex cover
electrostatic
field.

17. • Coil or cable
electrode consists
of a wire with
plugs at either
end creates
electromagnetic
field.

18. • The monode :
flat, rigid coil
encased in
plastic cover 
electromagnetic
field.

19. • The diplode :
or drum
electrode, consists
of a flat coil
electrode encased in
a Perspex cover with
two wings 
electromagnetic field

20. FACTORS INFLUENCE FIELD
DISTRIBUTION IN S.W.D
◉ Spacing :
•allows the lines of force in the electrostatic field to
diverge before entering the tissues. This prevents
concentration of heat in the superficial tissues and
ensures more heating through the part.
• Spacing provided by:
1. wrapping flexible pads in towel.
2. flat felt spacing pads
between pad electrode
and skin
3. air when using space plates.

21. • Normal spacing 
even field distribution.
• Increased spacing  deep
field concentration.
• Decreased spacing
superficial
concentration

22. • ◉ Electrode size:
•if the electrodes are too
small than the diameter of
treated part line of force
will be concentrated
superficially.
• ◉ If the electrodes are
markedly larger the line of
force will be lost in the air.
• ◉ Ideally, the electrodes
should be slightly larger than
the area treated.

23. • To concentrate heat on one aspect of the part
the electrode should be unequal in size
(smaller one placed over the area where
concentration of heat is required).
• You can produce concentration of heat by
using equal size electrodes but with unequal
spacing (25 mm over concentrated area and
more than 30 mm on other electrode).

24. THERAPEUTIC VARIATION IN THE
FIELD DISTRIBUTION
 Coplanar application to
structures on one aspect of
the body. If the spacing is less
than 25 mm more concentration
in the treat superficial tissue.
 If spacing Increases more
depth achieved
 .The distance between
adjacent ends must be
greater than the sum of skin
electrode distance (A+B)
otherwise the line of force
willpass directly between
Electrodes rather than tissues

25. • Contra
planar
applications
• Two flexible pads,
two space plates or
flexible pad with
a space plate
are used.
• It is essential to put a
cotton towel between
the two limbs to any
absorb perspiration.

26. • Cross-fire application:
 For the treatment of
sinuses,space plates positioned after
half diagonally,of treatment time
the positions are alternate.
 this ensures that the all the sinses
membranesare heated.
 Care must be taken to avoid direct
placement over the eye
,uterinedisorders such as
dysmenrrohea.

27. • Application using a
coil electrode:
• 1. The coil
wound evenly
firmly
• 2 Pancake
application

28. • Application using
diplode:
• Adjust wings of
diplode parallel
to the skin of the
treated area,
electromagnetic
field will
produce.

29. PHYSIOLOGICAL EFFECTS
The principal effect of SWD on the body is the
production of heat in the tissues due to the rise
of temperature.
1. Increased metabolism:
• Heating tissues accelerates chemical changes
such as metabolism, so oxygen and food stuffs
are used up.
• With increased metabolism, there will be
increased output of waste products.

30. Increased blood supply:
• As a result of increased output of waste products
such as metabolites, which act on the walls of the
capillaries and arterioles, these tissues dilate.
• In addition, heat has direct effect on blood
vessels, causing vasodilatation.
• Heat also produces stimulation of superficial
nerve endings, causing reflex dilatation of the
arterioles.

31. . General rise of temperature:
• As blood passes through the heated tissues, it
also becomes heated and carries the heat to
other body parts.
• Rise of temperature induces muscle relaxation
and increases the efficiency of muscle action.

32. . Fall in blood pressure:
• The generalized vasodilatation reduces the
peripheral resistance to blood flow.
• Heat also reduces blood viscosity, which helps
in the reduction of blood pressure.

33. . Increased activity of sweat glands:
• If a general rise of temperature occurs, there
will be increased activation of the sweat
glands.

34. Therapeutic Uses
• Effect on Inflammation
Vasodilation
O2 and Nutritive
material
Antibodies &
White blood cells
Assist in removal of Waste Products
All these effects bring about resolution of
inflammation

35. . Effect on Bacterial Infection
• Inflammation is normal response of Body to bacteria
• Heating the tissue auguments these changes so
reinforces body's normal mechanism to of dealing
with infecting organisms
Ex. Boils, Carbuncles, Abscesses

37. . Reducing Healing time
• Increased Blood supply
• More Nutritive Material
• More O2 supply

38. . Relief of Pain
• Sedative Effect
• Removal of Waste Products
• Resolution of Inflammation
• Counter irritation

39. Effect on Muscle Tissue
• Muscle relaxation
• Relief of Muscle Spasm

40. • Musculoskeletal Disorders
 Degenerative Joint Disorders
Ex. OA and RA
 Sprain
 Strain
 Hematoma
 Muscle & tendon Tears
 Capsule Lesions
USES

41. • Inflammatory Conditions
 Boils
 Carbuncles
 Sinusitis
 Pelvic Conditions
 Infected Surgical Incisions

42. DANGERS
1. Burns
• Concentration of electric field
• Excess current
• Impaired blood flow
• Hypersensitive skin
• Leads touching skin
1. Scalds
2. Electric shock
3. Overdose
4. Precipitation of gangrene
5. Faintness
6. Giddiness

43. Contraindications
• Metal implants or metal
jewelry (be aware of body
piercings)
• Cardiac pacemakers
• Ischemic areas
• Peripheral vascular disease
• Perspiration and moist
dressings: The water collects
and concentrates the heat.
• Tendency to
hemorrhage, including
menstruation.
• Pregnancy
• Fever
• Sensory loss
• Cancer
• Deep X ray
• Tumours
• Unreliable patients
• Areas of particular sensitivity:
– Epiphyseal plates in children
– The genitals
– Sites of infection
– The abdomen with an
implanted intrauterine device
(IUD)
– The eyes and face
– Application through the skull