Transcript Infrared Modalities (Therapeutic Heat and Cold)

Chapter 4: Thermotherapy and
Cryotherapy
Infrared Modalities
• Most of the heat and cold modalities have
wavelengths and frequencies that fall in the
infrared portion of the electromagnetic spectrum
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Ice Massage
Commercial cold packs
Ice packs
Cold whirlpool
Cold spray
Contrast Baths
Ice immersion
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Cryo-cuff
Cryokinetics
Warm whirlpool
Hydrocollator packs
Paraffin baths
Infrared lamps
Fluidotherapy
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• While these modalities are considered
infrared modalities they may be better
described as conductive thermal energy
modalities
• Typically used to produce a local and/or
generalized heating/cooling effect
– Cryotherapy
– Thermotherapy
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Mechanisms of Heat Transfer
• Transmission of heat occurs by three
mechanisms:
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Conduction
Convection
Radiation
*Conversion (involves change in one energy form to another)
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Appropriate Use of
Infrared Modalities
• Thermotherapy
– Heating techniques used for therapeutic
purposes
– Used when a rise in tissue temperature is the
goal of treatment
• Cryotherapy
– Used in the acute stages of the healing process
immediately following injury when a loss of
tissue temperature is the goal of therapy
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Appropriate Use of
Infrared Modalities
• Cold application is often continued
throughout the rehabilitation and reconditioning process of an injury
• Hydrotherapy is also included (hot or cold)
as water can be used as the medium through
which heat is transferred
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Appropriate Use of
Infrared Modalities
• Knowledge of the injury mechanism,
pathology and healing process are critical
when determining appropriate hot and cold
application
• Simple, efficient, and inexpensive means of
patient care
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Clinical Use of Conductive
Energy Modalities
• Physiologic effects are rarely the result of
direct absorption of infrared energy
• No form of infrared energy can have a depth
of penetration greater than 1 cm
• Effects of infrared modalities are primarily
superficial and directly affect cutaneous
blood vessels and nerve receptors
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• If significant amounts of energy are
absorbed over time, temperature of
circulating blood will increase
– Hypothalamus reflexively increase blood flow
to the area
– The reverse is true with cold application
– Deep heating modalities (US, diathermy) may
be more beneficial when increased blood flow
to deeper tissues is desired
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• Most effective use of infrared modalities
should be to provide analgesia or reduce
sensation of pain associated with injury
– Gate control theory of pain modulation
• Pain reduction to facilitate therapeutic
exercise is common practice
• Continued research and investigation is
necessary to provide athletic trainers with
effective and efficient means of injury
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Effects of Tissue Temperature
Change on Circulation
• Main physiologic effect is on superficial
circulation
– Changes due to response of temperature
receptors in skin and sympathetic nervous
system
• When cold is applied the skin vessels
progressively constrict to a temperature of
about 15° C (59° F) at which point they
reach maximum constriction
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Effects of Tissue Temperature
Change on Circulation
• At temperatures below 15° C vessels
begin to dilate
– Caused by paralysis of contractile mechanism
in vessel wall or blockage of nerve impulses
• General exposure to cold causes
sympathetic nerves to elicit cutaneous
vasoconstriction, shivering, piloerection,
and an increase in epinephrine secretion so
vascular contraction occurs
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• Simultaneously, metabolism and heat
production increase
– Aids in increasing core temperature
• Increased blood flow will also result in
increasing oxygen to the area
– Results in analgesic and relaxation effects on
muscle spasm
– Increased proprioceptive reflex may explain
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• Three types of sensory receptors in subepithelial tissue
– Cold, warm, pain
– Each responds differently at different
temperatures
– Adapt to changes in temperature, with rapid
temperature change = more rapid adaptation
• Stimulation of larger surface areas results in
summation of thermal signals  trigger
vasomotor centers in hypothalamus
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Effects of Tissue Temperature
Change on Muscle Spasm
• Physiologic mechanisms underlying the
effectiveness of heat and cold treatments in
reducing muscle spasm lie at level of
muscle spindle and Golgi tendon organs
• Heat relaxes muscles simultaneously
lessening stimulus threshold of muscle
spindles and by decreasing gamma efferent
firing rate
– Thus muscle spindles are more easily excited
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Effects of Tissue Temperature
Change on Muscle Spasm
• Muscles may be electromyographically
silent while at rest during application of
heat, but the slightest amount of voluntary
or passive movement may cause the
efferents to fire
• Local applications of cold decrease local
neural activity
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Effects of Tissue Temperature
Change on Muscle Spasm
• Cold raises the threshold stimulus of muscle
spindles, and heat tends to lower it
• Local cooling results in a significant reduction
of muscle spasm greater than with use of heat
• Unclear if reduction of spasticity is caused by
excitability of motor neurons or hyperactivity
of gamma systems
• Cold effective in modifying stretch-reflex
mechanism
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Effects of Tissue Temperature
Change on Muscle Spasm
• Nerve conduction velocity reduction also
occurs with cold application
– Decreases afferent discharge from cutaneous
receptors
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Effects of Tissue Temperature
Change on Performance
• Cryotherapy
– Some disagreement on relative concentric and
eccentric torque capabilities
– May not increase torque but may improve endurance
– Decreases vertical jump
– No impact joint range of motion
– Negatively impacts functional performance, which
can be negated via an active warm-up
– Minimal or no effect on joint position sense,
proprioception, balance and agility
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Effects of Tissue Temperature
Change on Performance
• Thermotherapy
– Minimal or no effect on joint position sense,
proprioception, and balance
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Cryotherapy:
Physiologic Effects of Tissue Cooling
• General agreement that cold should be
initial treatment for musculoskeletal injuries
– Primary reason is to lower temperature in
injured area  reduces metabolic rate with a
corresponding decrease in production of
metabolites and metabolic heat (secondary
hypoxic response)
• More effective when combined with compression
– Promotes vasoconstriction and helps to control
hemorrhaging and edema
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Cryotherapy:
Physiologic Effects of Tissue Cooling
• Used immediately after injury to decrease
pain and muscle spasm
– Result of decreased nerve conduction velocity
– Cold stimulus bombards sensory receptors
resulting in pain modulation through gate
control
• Effective in treating myofascial pain
• Effective in treating acute muscle pain as
opposed to delayed onset muscle soreness
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Cryotherapy:
Physiologic Effects of Tissue Cooling
• Reduction in muscle guarding has been
observed clinically
• Initial reaction of body to cold is local
vasoconstriction
– Results in decreased nutrient and phagocyte
delivery to area
• Hunting Response
– Periods of vasodilation and constriction following
prolonged cold application to limit possible tissue
injury due to cold use© 2009 McGraw-Hill Higher Education. All rights reserved.
Cryotherapy:
Physiologic Effects of Tissue Cooling
• Cooling for too long may be detrimental to
healing
• Ice application for 20 min. = decreased
muscle blood flow
– However, effects of ice application diminishes
with increased tissue depth
• Length of cooling required is dependent on
subcutaneous tissue thickness
– Recommended treatment times = 5-45 minutes
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Cryotherapy:
Physiologic Effects of Tissue Cooling
• Ability to lower
tissue temperature
is dependent upon:
– Type of cold
applied to the skin
– Thickness of
subcutaneous fat
– Region of the body
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Cryotherapy:
Physiologic Effects of Tissue Cooling
• Cold application results in:
– Decreased cell permeability and metabolism
– Decreased edema accumulation
• Should be continued in 5-45 minute
applications for up to 72 hours initially
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Cryotherapy Techniques
• Cryotherapy techniques include
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Ice massage
Cold packs
Ice packs
Cold whirlpool
Cold spray
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Contrast baths
Ice immersion
Cryo-cuff
Cryokinetics
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Cryotherapy Techniques
• Application of cryotherapy produces a
three- to four-stage sensation
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Uncomfortable sensation of cold
Stinging
Burning or aching feeling
Numbness
• Caution should be exercised when applying
intense cold directly to the skin
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Ice Massage
• Often indicated with conditions
requiring stretching
• Appears to cool area faster than
ice bag application
• Procedures:
– Remove top 2/3 of paper or
styrofoam cupleaving 1”on bottom
of cup as handle
– Apply using overlapping circular
or longitudinal stroke
– When skin is numb to fine touch
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treatment ends(10-20 min)
Commercial Cold Packs
• Indicated for acute
musculoskeletal injuries
• Procedures
– Cold pack should be placed
against wet toweling and
covered with a towel to limit
environmental warming
– Mold cold pack around joint
– Treatment time required is
about 20 minutes
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Ice Packs
• Indicated for acute injuries
and prevention of swelling
following exercise of
injured area
• Procedures:
– Flaked or cubed ice in a
plastic bag large enough for
the area to be treated
– Applied directly to skin and
held in place by a moist or
dry elastic wrap
– Can be molded to body part © 2009 McGraw-Hill Higher Education. All rights reserved.
Cold Whirlpool
• Indicated in acute and subacute situations where exercise
in cold environment is desired
• Must be mindful of gravity
dependent position
• Procedures
– Fill appropriate size whirlpool
with cold water and flaked ice
with temp. at 50° to 60° F
– Use for massaging action
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– Most intense application of cryotherapy
• Inability to develop thermopane (insulating layer of
water) due to water turbulence
• Convection provides for continuous circulation of cold
water
• Results in significantly longer periods of temp. reduction
following treatment
• Additional care must be used with total body immersion
• With increased treatment area systemic effects are
possible
– Equipment maintenance and cleaning are critical
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Cold Spray and Stretch
• Flourimethane is used
• Acts as a counterirritant to
block pain
• Cooling is superficial without
significant penetration
• Useful in treating trigger points
• Not effective in treating edema
or hemorrhaging
• Indicated in situations where
cooling and stretching are
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desired
• Procedure
– Spraying technique
• Same direction, even sweeps
• Work proximal to distal
• For trigger points, work from point to referred pain
area
• Affected muscles should be sprayed from the
affected area to the insertion
• Static stretching can be incorporated as you spray
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Contrast Baths
• Used to treat subacute swelling
• Does not reduce edema through
“pumping” action as suggested
o
• Uses alternating hot (104-106 )
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and cold (50-60 ) immersions
• 3:1 or 4:1 heat:cold ratios have
been recommended
• Best used as a transition from
cold to heat
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Cold Compression Units:
Cryo-cuff
• Used both acutely following
injury and post-surgically
• Applies both cold and
compression simultaneously
• Ice chills water which flows
into sleeve from cooler
• As cooler is raised pressure in
cuff is increased
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Cryokinetics
• Combines cryotherapy with exercise
• Goal is to numb injured part (12-20 min) then work
toward achieving normal ROM through progressive
active exercise
• Numbness usually last for 3-5 min. at which point
ice is reapplied for 3-5 minutes until numbness
returns
– Can be repeated five times
• Exercises should be pain free and progressive in
intensity concentrating on both flexibility and
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strength
Ice Immersion
• Ice buckets allow ease of
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application (50-60 )
• Container should be large enough
to allow for movement of body
segment if being used for
cryokinetics
• Body segment is subject to
gravity-dependent positions
• Cold pain may be more
significant than that experienced
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Thermotherapy:
Physiologic Effects of Tissue Heating
• Local superficial heating (infrared heat) is
recommended in subacute conditions for
reducing pain and inflammation through
analgesic effects
• During later stages of healing a deeper
heating effect is desirable and should be
achieved using the diathermies or
ultrasound
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Thermotherapy
Physiologic Effects of Tissue Heating
• Increase in temperature increases metabolism
– 13% increase in metabolism for each 1° C
• Superficial heat vasodilates vessels, which
increases capillary blood flow thus increasing
tendency toward formation of edema
– In mild or moderate inflammation increased
capillary blood flow causes an increase in supply of
oxygen, antibodies, leukocytes, and other nutrients
and enzymes, along with clearing of metabolites
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Thermotherapy
Physiologic Effects of Tissue Heating
• Used to produce an analgesic effect through
gate control
– Most frequent indication for the use
• Heat is applied in musculoskeletal and
neuromuscular disorders
• Increases the elasticity and decreases the
viscosity of connective tissue
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Thermotherapy
Physiologic Effects of Tissue Heating
• Produces a relaxation effect and a reduction in
muscle guarding by:
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Relieving pain
Lessening hypertonicity of muscles
Producing sedation
Decreasing spasticity, tenderness, and spasm
Decreasing tightness in muscles and related
structures
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Thermotherapy
Physiologic Effects of Tissue Heating
• Primary goals of thermotherapy include
– Increased blood flow
– Increased muscle temperature to stimulate
analgesia
– Increased nutrition to the damaged cells
– Reduction of edema
– Removal of metabolites and other products of
inflammatory process
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Thermotherapy Techniques
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Warm Whirlpool
Hydrocollator Packs
Paraffin Bath
Infrared Lamps
Fluidotherapy
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Warm Whirlpool
• Temperature Range
– Upper Extremity 98° -110° F
– Lower Extremity 98- 104° F
– Full body 98° - 102° F
• Time of application should be
15 to 20 minutes
• Caution is indicated in
gravity-dependent position in
subacute injuries
• Whirlpool maintenance
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Warm Whirlpool
• Provides massaging effect and will
stimulate circulation
– Monitor for changes in edema
• Excellent post-surgical modality
– Increases systemic blood flow and mobilization
of body part
• Also noted to be one of the most abused
clinical modalities
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Hydrocollator Packs
• Canvas pouches of petroleum
distillate
o
• Water temperature 170
• 6 layers (1”) of toweling
recommended
• Don’t lie on top of hot pack!!
• Time of application should be
15 to 20 minutes
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Paraffin Baths
• Mixture ratio of paraffin to
mineral oil (2 lbs : 1 gallon)
• Mineral oil reduces temp of
the paraffin to 126° F
• Extremity dipped into paraffin
for a couple of seconds then
removed to allow paraffin to
harden
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Paraffin Bath
• Repeat until 6 layers
have accumulated
• Wrap in a plastic bag
with several layers of
toweling
• Must exercise caution
with use to reduce
chance of burning
patient
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Fluidotherapy
• Dry heat modality that uses a
suspended air stream of corn
husks
• Recommended temperatures
vary by body part & tolerance
in a range of 110° to 125°F
• Active and passive exercise is
encouraged during treatment
• Treatments are approximately
20 minutes
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Fluidotherapy
• Medium allows for much
higher treatment temperatures
– Skin irritation and thermal shock
limited as well
– Mechano- and thermoreceptor
stimulation reduces pain
sensitivity (counterirritation)
• Pressure may assist with edema
reduction
• Increases blood flow, sedates
blood pressure, accelerates
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biochemical reactions
ThermaCare Wraps
• Cloth like material that
conforms to body
• Contains iron, charcoal,
table salt and water that
heat up when exposed to
oxygen
• Shown to be effective in
increasing tissue temp.
up to 2cm
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Infrared Lamps
• Superficial tissue temperature can
be increased even though unit
does not touch patient
• Seldom used because of limited
depth of skin penetration (<1mm)
• Moist towels should cover the
area to be treated
• Distance from treatment area to
lamp should be adjusted
according to treatment time
• 20 inches = 20 minutes
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Infrared Lamps
• Luminous and non-luminous infrared lamps are
classified as electromagnetic energy modalities
– Effects on tissue temperature are not related to conduction
• Non-luminous
– Metal coil wrapped around core of non-conducting
material
• No longer used
• Luminous
– Tungsten filament and quartz red lamps
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Counterirritants
• Not classified as infrared modalities
• Topically applied ointments that chemically
stimulate sensory receptors of the skin
• Contains
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Menthol
Methyl salicylate
Camphor
Capsaicin
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Counterirritants
• Ingredients have been shown to be effective
in reducing chronic pain and provide
analgesic effects
• Mechanism of pain relief not understood
– Application alone may trigger gate control theory
– May stimulate both noxious and thermal receptors
• Capsaicin is thought to have preferential action on Cfibers, stimulating release and depletion of substance P
• Capsaicin may also affect synapses of spinothalamic
tract
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Summary
Indications for Cryotherapy
• Acute or subacute
inflammation
• Acute pain
• Chronic pain
• Acute swelling
• Myofascial trigger
points
• Muscle guarding
• Muscle spasm
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Acute muscle strain
Acute ligament sprain
Acute contusion
Bursitis
Tenosynovitis
Tendinitis
Delayed onset muscle
soreness
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Summary
Contraindications for Cryotherapy
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Impaired circulation
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Peripheral vascular disease
Hypersensitivity to cold
Skin anesthesia
Open wounds or skin conditions (cold
whirlpools and contrast baths)
• Infection
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Summary
Indications for Thermotherapy
• Subacute and chronic
inflammatory
conditions
• Subacute or chronic
pain
• Subacute edema
removal
• Decreased ROM
• Resolution of swelling
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Muscle guarding
Muscle spasm
Subacute Muscle strain
Subacute Ligament
sprain
• Subacute contusion
• Infection
• Myofascial trigger points
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Summary
Contraindications for Thermotherapy
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Acute musculoskeletal conditions
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Impaired circulation
Peripheral vascular disease
Skin anesthesia
Open wounds or skin conditions (cold
whirlpools and contrast baths)
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