heat mod ali ties

8/2/2019 Heat Mod Ali Ties

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Heat Modalities

Chapter 4 (still)


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Heat is commonly classified into 3 major

categories Chemical action associated with cell metabolism

Electrical or magnetic currents as those found indiathermy devices

Mechanical action as found with ultrasound

The application of heat modalities is known asthermotherapy, and methods of heating are

classified as being superficial or deep.


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Superficial heating agents must be capable of

increasing skin temp within a range of 104-113F.

The transfer of heat to underlying tissues occursvia conduction, but superficial heating agents arelimited to a depth of less than 2cm.

The use of heat is indicated in the subacute and

chronic inflammatory stages of injury.


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Because the effects of heat application areessentially opposite to those of cold, its use inthe treatment of acute injuries should be

avoided.

Applying heat to an active inflammatory cycle

will the rate of cell metabolism and

accelerate the amount of hypoxic injury


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Classification of Heating Agents

Superficial

Infrared lamps

Moist heat packs

Paraffin baths Warm whirlpools and/or

immersion

Deep heat

Microwave diathermy*

Shortwave diathermy

Ultrasound


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Local effects of heat application

Vasodilation rate of cell metabolism

capillary permeablilty

delivery of leukocytes

Edema formation Removal of metabolic waste

elasticity of ligaments, capsules, and muscle

Analgesia and sedation of nerves

nerve conduction

muscle tone

muscle spasm

Perspiration


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Some systemic effects of Heat

exposure*

body temp

pulse rate

respiratory rate blood pressure


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General

Indications/Contraindications

Indications

Subacute or chronicinflammatory conditions

Reduction of subacute orchronic pain

Subacute or chronicmuscle spasm

ROM Hematoma resolution

Reduction of Joint

contractures

Contraindications

Acute injuries

Impaired circulation

Poor thermal regulation Anesthetic areas

Neoplasms

Abnormal tissue, such as a

tumor, that grows at theexpense of healthy tissues


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Effects on the injury response

Despite heat and cold produce many of thesame outcomes, decreased pain, for example, thetiming of when to begin using heat modalities is

much more critical If heat is applied too soon in the injury response

cycle, the cell metabolism causes an increase inthe number of cells injured or destroyed becauseof hypoxia.

the inflammatory rate may possiblyextend the acute and subacute stages


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Cellular response

For each of 18F in skin temp, the cells

metabolic rate by a factor of 2-3.

As the cells metabolic rate , so does its

demand for oxygen and nutrients.

As with living organisms that consume

energy, the amount of waste excreted

from the cell as its activity

Also, metabolic rate tissue temp.


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Blood and fluid Dynamics

Response of the body to heat is dilating localblood vessels

The amount of dilation being greater insuperficial vessels than in the deeper vessels

capillary flow results in an supply of

oxygen, nutrients, and antibodies to the

effected area


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The amount of edema is , but the capability

of removing it is greater capillary pressure forces edema and

harmful metabolites from the injured area

permeability aids in the re-absorption ofedema and the dissolution of hematomas.

These wastes can drain into the venous or

lymphatic systems If venous and lymphatic return is not

encouraged, further edema occurs.


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Effects on inflammation

Local application of heat acceleratesinflammation

Soft tissue repair is facilitated through an

accelerated metabolic rate and blood supply

Blood flow must be to encourage the

removal of cellular debris and to delivery

of the nutrients necessary for the healing

of tissues


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oxygen stimulates the breakdown and

removal of tissue debris and inflammatory

metabolites

Nutrients are delivered to the area to fuel

the cells, and there is also an in the

delivery of leukocytes, encouraging

phagocytosis.


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Muscle Spasm and Tissue Elasticity

temperature reduces the primary and

secondary muscle spindles sensitivity to

stretch

the amount of muscle spasm present

Increasing blood flow and reducing local

muscle metabolites further alleviate spasm

Most muscular tissues are not directly

heated by superficial heating agents


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ROM is subsequently improved by theextensibility of collagen and the viscosity

and plastic deformation of tissues This effect alone is not sufficient to

contractures or the elasticity of healthytissues

Neither anterior laxity of the knee norhamstring flexibility has been shown to beaffected by heat modalities alone

Tension, in the form of gentle stretching, isnecessary to elongate muscle andcapsular tissues while the tissues are stillwithin the therapeutic range


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Pain Control

Mechanical deformation and/or chemical irritation ofnerve endings stimulate pain transmission

In acute injuries, the primary cause of pain is themechanical damage done to the tissue in the area.

In the subacute and chronic stage of injury, ischemiaand irritation cause chemical pain from certain chemicalmediators

Mechanical pain is caused by increased swelling and thetension placed on the nerves by muscle spasm


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Mechanical pain is decreased by reducing thepressure on the nerves , thus lessening the pain-

spasm-pain cycle. By encouraging venous and lymphatic return

through the use of elevation and muscle contraction,the swelling is removed, decreasing interstitial

pressureAn increase in temperature leads to a state of

analgesia and sedation in the injured area byacting of free nerve endings.

Nerve fiber are stimulated, blocking thetransmission of pain with a conterirritant effect.

This effect appears to last only as long as the

stimulus of heat is applied


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Dissipation of heat

When therapeutic heat is applied to the body,there is a rapid rise in skin temperature

This rise occurs because energy is beingabsorbed faster than the cool blood delivered tothe area can remove it.

After approximately 10-15 minutes of exposure,the temperature gradient begins to even out.

At that point, the body is able to counteract theenergy being applied by supplying an adequate

amount of blood to cool the area


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At this time, the patient may claim that the modality hascooled down when, in fact, its intensity is unchanged.

When a maximal vasodilation has occurred and theintensity of the treatment stays constant (or increases),the vessels begin to constrict.

The phenomenon, known as rebound vasoconstriction,

will occur approx 20 min into the treatment. This is the bodys attempt to save underlying tissues by

sacrificing the superficial layer.

If the intensity of the tx is too great or if the duration is tolong, burns will result

Mottling of the skin is a warning sign that tissue tempare rising to a dangerously high level. In this case, ghost white areas and beet-red splotches mark

the patients skin

When this occurs, the tx should be discontinued immediately


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Heat vs Cold

How do you know when to use heat and whento use cold??

There are no clear cut answers to this question.

Many articles have given definitive time frames, suchas:

Use cold for the first 24 hrs

And use heat for the next 48 hrs Unfortunately, statements like these are incorrect

and unjustified.


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One of this first statements made in this classwas that the body heals an injury at its own rate.

Not only does this rate vary from person to

person but also it may vary from injury to injuryin the same person

The patients physical and psychological state, as

well as the type and amount of tissue damaged,factor into the time frame for required forhealing.


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The decision-making process is similar to thesteps involved when a pipe ruptures in thebasement of a house

Before bailing out the water and cleaning up themess, you have to stop the leak.

Likewise, before encouraging as increase in the rate

of cell metabolism in an injured area, the activeprocess of inflammation must be calmed down first.


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Remember cold is indicated under 3 conditions In the acute stages of the inflammation reaction

Before ROM exercisesAfter physical activity

Heat application is indicated under 5 conditions

To control inflammation reaction in its subacute orchronic stages

To encourage tissue healing

To reduce edema and ecchymosis

To improve ROM before physical activity orrehabilitation

To promote drainage from an infected site


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Deciding whether to use heat or cold

Does the body area feel warm to the touch?

Is the injured area still sensitive to light or moderatetouch?

Does the amount of swelling continue to increase overtime?

Does swelling increase during activity? Does pain limit the joints ROM? Would you consider the acute inflammation process to

still be active?

Does the patient continue to display improvement withthe use of cold modalities? If the answers to these questions are No heat can safely be

used. As the number of yes answers increases, so does theindication for use of cold


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Paraffin Bath

A paraffin bath contains a mixture of was andmineral oil in the ratio of 7 parts wax to 1 partoil

Melted paraffin is kept at a constant temperatureof 118-126F

Temps for tx given to the lower extremity are

decreased (113-121F) because circulation is lessefficient

Because of its low specific heat paraffin canprovide approx 6 times the amount of heat as

water


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Paraffin is a superficial heating agent used for deliveringheat to small, irregular shaped areas

Fingers Wrist

Hand

Foot

Although its use in sports medicine is limited, it is aneffective method for delivering heat, and this form ofapplication of paraffin is beneficial in chronic

conditions in which ROM is not an essential part of thetx protocol

Arthritis

Chronic inflammatory conditions


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Effects on the IRC

In addition to the standard effects of heat,paraffin increases perspiration in the treated areawhich soften and moisturizes the skin


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Setup and Application

Several methods of application, each with itsown advantages and disadvantages

Paraffin can act as an insulator is allowed to dryon the skin

With this in mind, the amount of heat deliveredcan be adjusted by increasing or decreasing the

wax layers


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Prep for treatment

To avoid contamination of the mixture, thebody part to be treated should be thoroughlycleaned and dried before treatment.

Immersion bathThoroughly clean skin

The patient begins by dipping the body part into theparaffin and removing it. Allow this coat to dry

Dip the extremity into the wax 6-12 times to developthe amount of insulation necessary. Allow wax todry between dips


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Instruct the patient to avoid touching the

sides and bottom of the heating unit becauseburns may result

Instruct the patient who is receiving an

immersion not to move the joints that are inthe liquid. The cracking of the wax will allowfresh paraffin to touch the skin, increasing the

risk of burnsAfter the treatment, scrape off the hardened

paraffin and return it to the unit for reheating,

or discard it


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Pack (glove) Method

The glove method is the safest but least effectiveway for delivering heat to the body with paraffinwax

This method is recommended for those patientswho are in the subacute stages of healing orhave a vascular or nerve condition that wouldpredispose them to burning

The body part may also be elevated during thisform of paraffin application


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Thoroughly clean the body part

Begin treatment by immersing the extremity in the

wax so that it becomes completely covered. Removethe body part and allow wax to dry

Continue dipping for 7-12 times allowing wax to drybetween dips

After the final dip, cover the extremity with a plasticbag, aluminum foil, or wax paper. Then wrap andsecure a terry cloth towel around the area

If indicated, the body part may be elevated.

Following the treatment, remove the towel and theinner layering. Scrape off the hardened paraffin andreturn it to the bath for reheating, or discard it


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Duration of treatment

Paraffin treatments are given for 15-20 minutesand may be repeated several times daily


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Precautions

The sensation of the paraffin is misleading as tothe actual temp of the treatment. The temp ofthe paraffin is sufficient to cause burns, but its

specific heat and thermal capacity requires alonger period of time to transfer the energy

Avoid using paraffin with athletes who arerequired to catch or throw a ball or workers whoare required to maintain a good grip after thetreatment.


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Indications/contraindications

Indications

Subacute or chronicinflammatory conditions

Skin infections Peripheral nerve injuries

before electricalstimulation

Another modality shouldbe considered if the patientlacks temp perception

Contraindications

Acute conditions

Peripheral vascular

disease Areas with sensory loss or

scaring

sunburns


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Next time

Shortwave diathermy

Lab


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Infrared Lamp

Provide radiant energy for superficial heating ofthe skin

They are considered radiant modalities because

no medium is required to transmit energy 2 types

Near infrared (luminous)

Far infrared (nonluminous)Treatment energy is produced by passing an

electrical current through a carbon or tungstenfilament


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The intensity of the treatment is controlled byadjusting the current flow through the filament or

by changing the distance between the lamp and thetissues

Luminous generators produce some degree ofvisible light Which places them on the near end of the infrared

spectrum

Because visible light is present, some of the treatmentenergy is reflected by the surface of the skin

Nonluminous generators do not produce visiblelight Placing them on the far end of the infrared spectrum


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Nonluminous infrared radiation is lesspenetrating than luminous

It has effects at 2mm and at 5-10mm beneath thesurface of the skin

Because nonluminous infrared is lesspenetrating, the skin being treated will feelwarmer than with luminous

Not commonly used in a clinical setting, becauseof the wide range of heating modalities available

However, it was once thought to assist in thehealing of open wounds, such as turf burns but it actually deters the healing process because it

dehydrates the tissues


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Effect on the IRC

Heats the skin almost exclusively

Deeper tissues are heated by conduction todepths up to 1 cm.

Primary physiological effects occur almostentirely in the superficial skin

Hyperemia occurs as a result of increasedcapillary flow and increased capillary pressure


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Setup and application

Warm up the lamp if necessary

To prevent the concentration of heat, clean thearea of any sweat, dirt, or oils, and remove any

jewelry Position the patient in a comfortable manner.

Drape the body part so that only the area to be

treated is exposed If a moist heat treatment is desired, place a

damp terry cloth towel over the area


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Place the lamp so that the source of heat isapprox 24 inches away from the patient. Adjust

the lamp so the energy will strike the tissues at aright angle (inverse square law)

To prevent burns, instruct the patient not to

move Check the patients comfort periodically. The

intensity may be adjusted by moving the lamptoward the skin (increasing temp) or away from

the skin (decreasing temp) Instruct the patient to summon assistance if the

intensity of the treatment becomes too great


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20-30 minutes

Given as needed


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Indications/contraindications

Indications Subacute or chronic inflammatory conditions

Skin infections

Peripheral nerve injuries before electrical stimulation Another modality should be considered if the patient lacks temp

perception

Contraindications Acute conditions

Peripheral vascular disease Areas with sensory loss or scarring

sunburns


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Shortwave Diathermy

A deep-heating modiality

Uses energy that is similar to broadcast radiowaves but has a shorter wave length

The energy is delivered to the body is acutally ahigh-frequency alternating current, but lacks theproperties needed to depolarize motor or

sensory nerves.The Federal communication Commission has

reserved the frequencies of 13.56, 27.12, and40.61 for medical use


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Structures with high water content, like adiposetissue, blood, and muscle, are selectively heated

at depths of 2-5cm. Local tissue temp may reach 107, but the

subcutaneous fat layer dissipates a significantportion of the energy

This leads to a secondary heating of thesuperficial muscle layer by heat conducted fromthe adipose tissue

The amount of intramuscular temp increasecompares favorably with that seen duringultrasound application

Producing an increase of more than 7 degrees F


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Because of the relatively large area affected bydiathermy, the deep heating effects are longerlasting than those experienced with ultrasound

However, it is less effective on those personswho have a large amount of subcutaneous fat.

2 units that are commonly used

The condenser unit

The conduction unit


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Condenser unit

Application by way of a condenser unit places thepatient within the actual circuit of the machines unit

2 insulated plates are place on either side of the sitebeing treated

The flow of electromagnetic energy passes through thetissues, which act as electrical resistors and producefrictional heating

Heating occurs at depths of 2.5-5 cm but is uneven

because of differences in the resistance to energytransportation of various tissues When condenser plates or pads are used, heating tends

to occur in the subcutaneous tissues and the superficialmuscle layer


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Induction Unit

Does not place the patient directly in the unitscircuit.

Tissues are affected by radiation emitted form

the electromagnetic field created by theelectrode

The effects of the induction method may heattissues up to 5cm beneath the skin But the primary temp increase occurs in the

superficial and middle muscle layers


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The tissues are place in the electromagnetic fieldby the use of an insulated cable electrode

The cable may be wrapped around the extremity

or coiled flat like a pancake and placed on theskin

Another method ahs the cable in a self-

contained drum


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Effects on the IRC

Heating properties are similar to those of otherforms of heat application

But tend to occur deeper within the tissues and are

based on the treatment intensity

During vigorous heating skin temp in the treatedarea increases 4.3 degrees, and the intra-articular

temp of the knee increases 2.5 degrees. Blood flow in the deeper tissues increases, and

fibroblastic activity, collagen deposition, and

new capillary growth are stimulated.


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Muscle spasm is reduced by the sedation ofsensory and motor nerves

As with all heat applications, there is a local

increase in cellular metabolic rate and inperspiration, which must be removed during thetreatment

General prep


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General prep

There must be no metal within the immediate treatment

area. The presence of metal will collect and concentratethe energy from the treatment in the same manner thatan antenna collects radio waves

For personal safety, the clinician should remove any

rings, watches, bracelets, and so on Cover the area to be treated with a dry terry cloth towel

to absorb perspiration. A portion of the treatment areamust remain visible to check for burns during

treatment. Avoid any moisture buildup during thetreatment because water tends to collect heat. Theintensity must be turned to zero before drying thearea


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Condenser method

Plate setup

Adjust the plates so that they are parallel to the skin,1 inch above the patient. On most units, it is

essential that both plates be placed at an equaldistance above the tissue. This adjustment can beaccomplished by using a spacer, such as a piece of

wood. Place the spacer on the patient and lower the

plate until the plate and the spacer touch. Removethe spacer and repeat for the other plate. The spacermust be removed before the treatment is started.


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Consult the users manual for the minimum andmaximum distance allowed between the condenser

plates. Condenser pad setup

Cover the area to be treated with six layers oftoweling

Place the condenser pads on the toweling. If thepads are used on the same side of the body, placethem as far apart as possible. If they are used on theopposite side of the body part (anterior or posterior,

medial or lateral), avoid having the patient lie on thepad

Secure the pads in place with sandbags or somethinglike that.


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Induction Method

Cable setup

Place six layers of toweling around the body part

Using spacers, wrap the cable around the body part,

leaving a minimum of 1 between the coils. Theleads to and from the coil should be of equal length

Secure the cable ends so that they do not touch each

other, the patient, or the shortwave unit itself


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Coil setup

Using spacers, form a coil of at least three circles

approximately equal to the area being treated. Thereshould be a minimum of 1 between the circles, and

the leads should be of equal length. Use an insulatoror 1 of padding to separate the end of the inner coil

from the coil itself

Insulate the skin with at least 6 layers of toweling

Place the coil on the patient and lightly secure in

place with sandbags Position the leads so they do not come in contact

with each other, the patient, or the unit.


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Drum setup

Position the drum approx .5-1 above the toweling.There is a direct relationship between the distance of

the drum from the patient and the intensity ofenergy required for the treatment.


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Application

Turn the unit on: allow it to warm up ifnecessary

Some units must be turned to allow for maximal

energy transfer. If tuning is necessary, consultthe users manual and follow the manufacturers

instructions.

Instruct the patient not to move until themachine is turned off.

Increase the intensity until the athlete feels mild

warmth


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If the electrodes must be moved or if it becomesnecessary to dry the area, return the intensity tozero before making any adjustments

Check patient regularly. Observe the skin forsigns of burns, and inquire as to any unusualsensations. Adjust as necessary

After the treatment, return the intensity dial tozero and shut off the unit.


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At moderate intensities, treatments may be givenfor 20-30 minutes and may be repeated asneeded for 2 weeks. When higher treatment

temps are used, decrease the duration oftreatment and apply on alternate days.


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Precautions

Many states require a physicians prescriptions

for the application of SWD.

Never allow the cables to touch each other. This

may create a short circuit

The skin exposed to the treatment must alwaysbe covered by at least .5 of toweling

Do not allow perspiration to collect in thetreatment field


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Never allow the skin to come into direct contactwith the heating unit or cables. Severe burns

may result. Excessive amounts of adipose tissue overlying

the treatment area can result in overheating theskin

Overheating of the patients tissues may causetissue damage without any immediate signs.Deep-tissue burning can cause destruction of

muscular tissue of subcutaneous fat necrosis.A deep, aching sensation may be a symptom of

overheating the tissues


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It is difficult to heat only localized areas. Waterpathways within the tissues dissipate heat formed in thetreated area

The electromagnetic energy is not localized to thetreatment area, radiating 2 to 3 feet from the source of

continuous SWD and 2 feet from the source of pulseddiathermy. Clinicians may be placed in the field of thisscattering radiation, possibly overexposing them todiathermy. A distance of 3 feet from the source of the

energy should be maintained to ensure the operatorssafety.


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Indications

Joint inflammation (bursitis, tendinitis, synovitis) Usewith caution as the deep heating may cause collagendestruction within the joint.

Large areas, such as the paraspinal muscles, that cannotbe effectively heated through other methods because ofthe size of the target tissues

Fibrositis

Myositis

Subacute and chronic inflammatory conditions in deep-tissue layers

osteoarthritis


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Contraindications

Ischemic areas: the increased metabolic rateincreases the need for oxygen, causing furtherhypoxia

Peripheral vascular disease Metal implants or metals such as jewelry. The

metal collects and concentrates the energy,potentially causing burns

Perspiration and moist dressings. The watercollects and concentrates the heat

T d h h i l di


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Tendency to hemorrhage, includingmenstruation.

Cancer Fever

Sensory loss

Cardiac pacemakers

Areas of particular sensitivity

Epiphyseal plates in children, the genitals, sites of

infection, the abdomen with an implantedintrauterine device (IUD), the eyes and face

heat mod ali ties

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