Chapter 4 Thermotherapy and Cryotherapy Infrared Modalities Most

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 l l l l Ice Massage Commercial cold packs Ice packs Cold whirlpool Cold spray Contrast Baths Ice immersion l l l l Cryo-cuff Cryokinetics Warm whirlpool Hydrocollator packs Paraffin baths Infrared lamps Fluidotherapy © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

• 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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Mechanisms of Heat Transfer • Transmission of heat occurs by three mechanisms: Conduction n Convection n Radiation n *Conversion (involves change in one energy form to another) © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

• 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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

• 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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

• 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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

• 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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Effects of Tissue Temperature Change on Muscle Spasm • Nerve conduction velocity reduction also occurs with cold application – Decreases afferent discharge from cutaneous receptors © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Effects of Tissue Temperature Change on Performance • Thermotherapy – Minimal or no effect on joint position sense, proprioception, and balance © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 Mc. Graw-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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Cryotherapy Techniques • Cryotherapy techniques include – – – Ice massage Cold packs Ice packs Cold whirlpool Cold spray – – Contrast baths Ice immersion Cryo-cuff Cryokinetics © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Cryotherapy Techniques • Application of cryotherapy produces a three - to four-stage sensation – Uncomfortable sensation of cold – Stinging – Burning or aching feeling – Numbness • Caution should be exercised when applying intense cold directly to the skin © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. treatment ends(10 -20 min) All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 Mc. Graw-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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

– 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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved. 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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Contrast Baths • Used to treat subacute swelling • Does not reduce edema through “pumping” action as suggested • Uses alternating hot (104 -106 o) o 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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved. strength

Ice Immersion • Ice buckets allow ease of application (50 -60 o) • 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 with cold pack application © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Thermotherapy Physiologic Effects of Tissue Heating • Produces a relaxation effect and a reduction in muscle guarding by: – Relieving pain – Lessening hypertonicity of muscles – Producing sedation – Decreasing spasticity, tenderness, and spasm – Decreasing tightness in muscles and related structures © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Thermotherapy Techniques • • • Warm Whirlpool Hydrocollator Packs Paraffin Bath Infrared Lamps Fluidotherapy © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved. biochemical reactions

Therma. Care 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 2 cm © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Infrared Lamps • Superficial tissue temperature can be increased even though unit does not touch patient • Seldom used because of limited depth of skin penetration (<1 mm) • 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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Counterirritants • Not classified as infrared modalities • Topically applied ointments that chemically stimulate sensory receptors of the skin • Contains – Menthol – Methyl salicylate – Camphor – Capsaicin © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

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 © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Summary Indications for Cryotherapy • Acute or subacute inflammation • Acute pain • Chronic pain • Acute swelling • Myofascial trigger points • Muscle guarding • Muscle spasm • • Acute muscle strain Acute ligament sprain Acute contusion Bursitis Tenosynovitis Tendinitis Delayed onset muscle soreness © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Summary Contraindications for Cryotherapy • • • Impaired circulation • Peripheral vascular disease Hypersensitivity to cold Skin anesthesia Open wounds or skin conditions (cold whirlpools and contrast baths) • Infection © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Summary Indications for Thermotherapy • Subacute and chronic inflammatory conditions • Subacute or chronic pain • Subacute edema removal • Decreased ROM • Resolution of swelling • • Muscle guarding Muscle spasm Subacute Muscle strain Subacute Ligament sprain • Subacute contusion • Infection • Myofascial trigger points © 2009 Mc. Graw-Hill Higher Education. All rights reserved.

Summary Contraindications for Thermotherapy • • • Acute musculoskeletal conditions • Impaired circulation Peripheral vascular disease Skin anesthesia Open wounds or skin conditions (cold whirlpools and contrast baths) © 2009 Mc. Graw-Hill Higher Education. All rights reserved.