HEAT THERAPY OR THERMAL TREATMENT
Heat therapy,medically used by a Physiotherapist. Heat therapy also called thermotherapy, is the use of heat
in treatment.
Mode of action Heat helps in the following ways:
• It reduces pain
• It relieves the stiffness of the joints
• It reduces the muscle tightness
• It increases the blood flow to the area by causing vasodilatation.
Benefits The heat therapy warms up the tissues and readies
it for the future exercise therapy. Its action is similar to that of the
warm-up exercises before the main exercises by sports persons.
Goal It aims to increase the temperature and increase the
blood flow to the area of treatment.
Time Optimal benefits are achieved within 20 minutes of application.
Beyond this time, there is no further increase or raise of temperature noted.
Types Two types are described:
1. Superficial heating agents these heat only the skin and
subcutaneous tissue (i.e. structures upto 10 mm beneath
the skin).
2. Deep heating agents these heat the deeper structures like
muscles and bones.
SUPERFICIAL HEATING AGENTS
In this category are included the hydrocollator packs,
infra-red lamps and paraffin baths. These are the most popular and common form
of heat therapy advised after fractures.
Hydrocollator packs these packs contain silica gel
which is encased in a canvas bag. This can be contoured to the various body
regions.
Note Silica gel is able to maintain a heat of 40°C (104° of Fahrenheit)
for a period of about 30-40 minutes.
Hydro collator pack is a form of conductive heat.
Contraindications
• Open wounds
• Anesthetic skin
• Significant edema
• Skin diseases and infections.
Infrared Infrared heating is delivered through an
artificial source called the infrared lamp. This heats structures only 10mm
beneath the skin.
Advantages
• It induces relaxation in the patient.
• It mobilizes the skin and subcutaneous tissues.
• It provides no pressure on the body.
• The area under treatment can easily be inspected without
interrupting it.
• It is easy and simple to use even by the patient.
Optimum time Twenty minutes. It may cause burns, if allowed
to heat for long.
Contraindications These are the same as for hydro collator
packs.
Paraffin wax bath this consists of a mixture of one part of
liquid petroleum to seven parts of paraffin. It is most often indicated to
treat small areas like hands and feet (as in Rheumatoid arthritis, etc.).
Contraindications are the same as for hydro collator packs.
Note Paraffin bath
• Immersion for short time heats only the skin and Subcutaneous
tissue.
• Immersion for a longer time heats the deeper Structures
like bones and joints.
Other superficial heating methods These include Hot
packs,Hot water bottle and a small electric heating pad. They are Found to be
equally effective as the other sophisticated methods Described so far. They
have the advantage of being simple,Clean and easy to use even by the patients.
Caution Patient should be educated that too hot may
be too
Bad and may cause burns.
Mode of action, indications, timing and contraindications are
the same as for the other methods mentioned earlier.
DEEP HEATING AGENTS
These agents include microwave,shortwave,ultrasound etc and
they act through the electromagnetic or mechanical waves.
They heat the structures 30-50 mm beneath the skin surface.
Note
• Electromagnetic waves generate heat by tissue’s Resistance
to electric current.
• Mechanical waves generate heat by causing tissue vibration.
Deep heating agents
•Diathermy This term denotes deep heating by electromagnetic
or mechanical waves.
• Heating by electromagnetic waves, e.g. Microwave or short
wave.
• Heating by mechanical waves, e.g. ultrasound
Microwave
• This is more frequently used method than the short wave.
• It is known to selectively heat muscles.
• It is indicated in muscle shortening following fractures.
• It is contraindicated if there is an implanted metal or if
the patient has a cardiac pacemaker.
Shortwave
• These waves though called short, have a greater wave length
than the microwaves.
• It heats the subcutaneous tissue more effectively than the
superficial heat modalities.
• It is indicated in post fracture contractures and
subcutaneous adhesions.
• Its usage now has declined in favor of microwave.
• The contraindications are the same as for microwave.
Ultrasound
• Ultrasound waves are mechanical unlike shortwave and microwave.
• Ultrasonic waves are not faster than sound but have a greater
frequency.
• It heats the bone muscle junction effectively.
• It is indicated in post-fracture muscle shortening and
joint capsule contraction.
• Fractures fixed with implants are not suitable for
ultrasound therapy.
Deep heat facts
• Microwave—selectively heats the muscle
• Shortwave—selectively heats the subcutaneous tissue
• Ultrasound—effectively heats the bone-muscle junction
and the bones.
Other Deep Heat Therapy
The general purpose of a deep heat therapy is to increase the extensibility of soft tissues, remove toxins from cells, enhance blood flow, increase the functioning of tissue cells, encourage muscle relaxation and help relieve pain.
