Thermal ModalitiesThermal Modalities

ESAT 3640ESAT 3640

Therapeutic ModalitiesTherapeutic Modalities

Infrared ModalitiesInfrared Modalities

Ice packs, hot packs, paraffin bath, H/C Ice packs, hot packs, paraffin bath, H/C whirlpools are all infrared modalitieswhirlpools are all infrared modalities

Wavelength and frequency that falls within Wavelength and frequency that falls within the infrared regionthe infrared region

Mechanisms of Heat TransferMechanisms of Heat Transfer

ConductionConduction

ConvectionConvection

RadiationRadiation

ConversionConversion

Appropriate Use of Infrared Appropriate Use of Infrared ModalitiesModalities

Sometimes abused by athletic trainersSometimes abused by athletic trainers

Don’t use just because you have it Don’t use just because you have it availableavailable

Know benefits of useKnow benefits of use

Terminology Related to Infrared Terminology Related to Infrared ModalitiesModalities

ThermotherapyThermotherapy

CryotherapyCryotherapy

HydrotherapyHydrotherapy

Clinical ApplicationsClinical Applications

Effect is primarily superficial and directly Effect is primarily superficial and directly affects cutaneous blood vessels and affects cutaneous blood vessels and cutaneous nerve receptorscutaneous nerve receptors

Depth of penetration is 1 cm or lessDepth of penetration is 1 cm or less

Used primarily to provide analgesia and Used primarily to provide analgesia and pain reductionpain reduction

Clinical Applications continuedClinical Applications continued

Cutaneous heat can cause a reflexive increase Cutaneous heat can cause a reflexive increase in blood flow to underlying tissuein blood flow to underlying tissue

Cutaneous cold can decrease blood flow in Cutaneous cold can decrease blood flow in injured areainjured area

If primary goal is to decrease temperature and If primary goal is to decrease temperature and decrease blood flow to injured area you must decrease blood flow to injured area you must use ice or cold applicationuse ice or cold application

Effects of Tissue Temperature Effects of Tissue Temperature Change on CirculationChange on Circulation

Main physiological effect is on superficial Main physiological effect is on superficial circulationcirculation

Circulation through skin serves 2 major Circulation through skin serves 2 major functionsfunctions– Nutrition of skinNutrition of skin– Conduction of heat from internal structuresConduction of heat from internal structures

Circulatory ApparatusCirculatory Apparatus

Arteries, capillaries, and veinsArteries, capillaries, and veins

Vascular structures for heating the skinVascular structures for heating the skin– Subcutaneous venous plexusSubcutaneous venous plexus– Arteriovenous anastomosisArteriovenous anastomosis

Response of Circulatory Response of Circulatory Apparatus to ColdApparatus to Cold

Cold application to the skin causes Cold application to the skin causes constriction of the skin vessels to a constriction of the skin vessels to a temperature of 57temperature of 57° F° F

At temperatures below At temperatures below 5757° F vessel begin ° F vessel begin to dilateto dilate

Thermoreceptor ResponseThermoreceptor Response

Both cold and warm receptors adapt Both cold and warm receptors adapt rapidly to temperature changerapidly to temperature change

The faster the temperature change; the The faster the temperature change; the more rapid the receptor adaptationmore rapid the receptor adaptation

Small vs. Large surface areasSmall vs. Large surface areas

Hypothalamic CentersHypothalamic Centers

Stimulation of anterior hypothalamus Stimulation of anterior hypothalamus causes cutaneous vasodilationcauses cutaneous vasodilation

Stimulation of the posterior hypothalamus Stimulation of the posterior hypothalamus causes cutaneous vasoconstrictioncauses cutaneous vasoconstriction

Effects of Tissue Temperature Effects of Tissue Temperature Change on Muscle SpasmChange on Muscle Spasm

Physiological mechanism related to heat or cold Physiological mechanism related to heat or cold treatment in the reduction of muscle spasm lie at treatment in the reduction of muscle spasm lie at the level of the muscle spindle, GTO, and the the level of the muscle spindle, GTO, and the gamma efferent systemgamma efferent system

Heat has relaxing effectHeat has relaxing effect– Lessens stimulus threshold of muscle spindleLessens stimulus threshold of muscle spindle– Decrease in gamma efferent firing rateDecrease in gamma efferent firing rate

Effects of Tissue Temperature Change Effects of Tissue Temperature Change on Muscle Spasm Continuedon Muscle Spasm Continued

Cold decreases local neural activityCold decreases local neural activity– GTO firing rate decreasesGTO firing rate decreases– Decreased rate of afferent activity with Decreased rate of afferent activity with

increased amount of tension on the muscleincreased amount of tension on the muscle

Miglietta studyMiglietta study

Physiologic Effects of Tissue Physiologic Effects of Tissue CoolingCooling

Local decrease in temperatureLocal decrease in temperature– ““primary reason for using cold in acute injury primary reason for using cold in acute injury

is to lower the temperature in the injured area, is to lower the temperature in the injured area, thus reducing the metabolic rate with a thus reducing the metabolic rate with a corresponding decrease in production of corresponding decrease in production of metabolites and metabolic heat”metabolites and metabolic heat”

Ho, et al Am J Sports Med 23(1): 74-76, 1995Ho, et al Am J Sports Med 23(1): 74-76, 1995

Cold + Compression is most effectiveCold + Compression is most effective

Progression of Sensations Progression of Sensations Related to ColdRelated to Cold

1.1. ColdCold

2.2. BurningBurning

3.3. AchingAching

4.4. AnalgesiaAnalgesia1.1. numbnessnumbness

Effects of Cold and Heat on Effects of Cold and Heat on InflammationInflammation

ColdCold– Reduction in release Reduction in release

of inflammatory of inflammatory mediatorsmediators

– Decreased Decreased prostaglandin prostaglandin synthesissynthesis

– Decreased capillary Decreased capillary permeabilitypermeability

HeatHeat– Accelerate Accelerate

inflammationinflammation

Pain ControlPain Control

ColdCold– Gate TheoryGate Theory

HeatHeat– Gate theoryGate theory– Increased blood flow = Increased blood flow =

removal of waste removal of waste productproduct

– Removal of swellingRemoval of swelling

Physiological Effects of Heat & ColdPhysiological Effects of Heat & Cold

Indications and Indications and Contraindications – ColdContraindications – Cold

Indications and Indications and Contraindications – HeatContraindications – Heat

Cryotherapy TechniquesCryotherapy Techniques

Ice packsIce packs

Ice massageIce massage

Cold whirlpoolCold whirlpool

Cold sprayCold spray

Ice immersionIce immersion

Cryo-cuffCryo-cuff

Contrast bathContrast bath

Thermotherapy TechniquesThermotherapy Techniques

Hydrocollator packsHydrocollator packs

Warm whirlpoolWarm whirlpool

Paraffin bathParaffin bath

FluidotherapyFluidotherapy