Superficial Cold and Heat

Effects of Cold: Hemodynamic effects

Cold applied to the skin causes underlying vasoconstriction (lasts as long as the application

Cold induced vasodilation (hunting response/CIVD)

when cold is applied for longer periods of time or when the tissue temperature reaches less than 10 C (50*F), vasodilation may occur.

Is a protective mechanism that the body has

Increases resistance to flow

10 minutes on —> 10 minutes off —> 10 minutes on

Effects of Cold: Neuromuscular Effects

Decreases nerve conduction velocity

reduced pain and increased pain threshold

Altered muscle strength

decreased spasiticyt

facilitation of mm contraction

Decreased nerve conduction velocity

occurs with superficial cold applied for 5 minutes or longer

however it fully reverses within 15 minutes in individuals who have normal circulation

after 20 minutes of cooling, it may take 30 minutes to recover to a normal NCV

Reduced pain and increased pain threshold

gate control theory, blocks pain sensation nerve endings from reaching the brain

reducing edema via vasoconstriction can also help decrease pain by decreasing compression of free nerve endings caused edema

Altered muscle strength

associated with both increase and decreases in mm strength

increases: mm strength has been shown to increase after 5 minutes of ice massage by increasing facilitation of motor nerve excitability and increased psychological motivation to perform

decreases: after cooling for 20 minutes contraction strength decrease by reduced blood flow to the muscles, slow motor nerve conduction, increased joint and/or soft tissue stiffness

decreased spasticity

it is proposed through research that this response is a relfex reaction to stimulation of cutaneous cold receptors causing a reduction in gamma motor neuron activity

cryotherapy must be applied for 20-30 minutes in order for a reduction in spasticity to be observed

Catch 22 - CIVD

Facilitation of mm contraction

quick, brief, application of cryotherapy is through to facilitate alpha motor neuron activity to contract a muscle that is flaccid because of prolonged UMN dysfunction

Effects of cold: Metabolic effects

decreased metabolic rate

Cold decreases the rate of metabolic reactions, including reactions involved inflammation and healing

utilized to control inflammation but should not be used when healing is delayed

OA and RA

Cryotherapy should be utilized for what collagen inflammatory joint diseases?Osteoarthritis (OA) and Rheumatoid Arthritis (RA).

Clinical indications for Cryotherapy

Symptom Management in MS

Cryokinetics and Cryostretch

Symptom Management in MS

many pts with MS are heat sensitive

cooling with a vest can reduce fatigue, muscle weakness, visual dysfunction, and postural instabilityC

cryokinetics

utilized with improving stretching and/or strengthening in patients (most commonly for athletes)

reduces pain to be able to perform

apply a cooling agent shortly after an injury to the point at which the pt feels numbness, or until 20 minutes is reached. Once reported, ROM and/or strengthening exercise is performed

cryostretch

application of a cooling agent before stretching

purpose is to reduce muscle spams, thus allowing greater ROM increase with stretching

Catch 22: cryotherapy reduce tissue extensibility

Contraindications for Cryotherapy

Cold hypersensitivity (cold-induced Urticaria)

Cold intolerance

Cryoglobulinemia

Paraoxysmal cold hemoglobinuria

Raynaud disease and phenomenon

Over and area with Peripheral Circulatory Compromise/PVD

Cold Hypersensitivity (cold-induced Urticaria)

Familial or acquired hypersensitivity to cold

This causes increased redness or white patches under the area of treatment or all over the body. The patches can be smooth or elevated and are often very itchy

Cold intolerance

severe pain, numbness, and color changes in response to cold

often seen in pts with rheumatic disease

cryoglobulinemia

uncommon, characterized by serum proteins in the distal circulation when distal extremities are cooled

these proteins can block circulation and cause ischemia and/or gangrene. Associated with Lupus Erythematous and Rheumatoid Arthritis

Paroxysmal Cold Hemoglobinuria

hemoglobin from lysed RBC’s is released into the urine in response to local or generated exposure to cold

Raynauds Disease

sudden pallor or cyanosis of the skin of the digits, followed by redness — relieved by warmth

symptoms are bilateral and symmetrical even if cryotherapy is applied unilaterally

Raynauds Phenomenon

Sudden pallor or cyanosis of the skin of the digits, followed by redness — relieved by warmth

Symptoms occur unilaterally where cryotherapy is performed

may be associated with thoracic outlet syndrome, carpal tunnel syndrome or trauma

Precautions for Cryotherapy

over the superficial main branch of a nerve: may cause nerve conduction block

over an open wound

HTN

Poor sensation or mentation

very young or elderly

Examples of superficial main branch of a nerve

peroneal nerve: lateral knee

radial nerve: posterolateral elbow

may delay wound healing

Why is over an open wound a precaution for cryotherapy?

cryotherapy causes vasoconstriction

Why is HTN a precaution for cryotherapy?

pts may have limited ability to communicate properly

Why is being very young or elderly pts a precaution for cryotherapy?

Cryotherapy sensation order

intense cold

burning

aching

analgesia and numbness

Application Techniques of Cryotherapy

ice massage

vapocoolant sprays

Contolled Cold Compression Unit (50-70*F)

Rehabilitation use of Thermotherapy

control pain, increase soft tissue extensibility and circulation, and accelerate healing

non-rehabilitation use of Thermotherapy

destroy malignant issue or treat cold-related heat injuries

Effects of heat: Hemodynamic Effects

Heat causes vasodilation

a reduction in sympathetic output from the CNS in response to cutaneous sensors causes relaxation of the smooth muscles in blood vessels —> increasing the rate of BF

Superficial heating agents do not heat to the depth of most muscles. To heat deep muscles, use exercise or deep-heating modalities (u/s or diathermy)

Effects of Heat: Neuromuscular Effects

increased temperature causes increased nerve conduction velocity but decreases the latency of sensory and motor nerves (healthy myelinated nerves)

Demyelinated nerves undergo a conduction block when heat is applied. This occurs because heat shortens the opening time of the sodium channel and can prevent the node from depolarizing

• pts with carpal tunnel syndrome or MS exhibit peripheral nerve demyelination

Decrease pain

Heat Causing a Decrease in pain

superficial heat can increase the pain threshold and decrease sensation of pain by increased activity of the cutaneous thermo-receptors, which can have a gating effect on transmitting the pain signal to the spinal cord

Effects of heat: metabolic Effects

can increase local metabolic rate and therefore can exacerbate inflammation

Effects of Heat: Altered tissue Extensibility

heat increases collagen extensibility allowing for more soft tissue stretch with less tension

• ultimately reaching the plastic phase of the stress-strain curve with less tension

Can improve ROM and decrease joint stiffness

104-113 F (40-45C), for 5-10 minutes

When is maximum soft tissue extensibility is gained with heat?

Precautions for the use of Thermotherapy

acute injury or inflammation

pregnancy

impaired circulation

poor thermal regulation

edema

cardiac insufficiency

metal in the area

over an open wound

demyelinated nerves

over areas where topical counterirritants have recently been applied, or adhesive material

Contraindications for the use of thermotherapy

recent or potential hemorrhage

thrombophlebitis

impaired sensation/mentation

impaired sensation/mentation

malignant tumor

IR irradiation of the eyes

Vasodilation and increased circulatory response may cause a thrombus to become dislodged

Why is thrombophlebitis a contraindication for thermotherpay?

Adverse effects of Thermotherapy

burns

fainting, peripheral dilation and decreased HR

bleeding

skin and eye damage from Infrared Radiation

Application Techniques of Thermotherapy: Hot packs

stored in hot water kept at 158-167* F (70-75*C)

6-8 towel layers, hot pack covers account for 3-4 layers

Application techniques of Thermotherapy: Paraffin

Paraffin is kept in a controlled heated container at 126-134*F (52-57*C)

Clean the hand/foot thoroughly prior to dipping. Dip hand, with fingers apart 6-10 times

Leave the paraffin on for 10-15 minutes

to avoid heat loss sufficient mitts should be placed on the hands or feet post paraffin dipping

discard used paraffin wax post treatment

Application Techniques of Thermotherapy: Fluidotherapy

dry heating agent that transfers heat

consists of a unit containing finely ground cellulose particles made from corn cobs

heated air is circulated through the particles allowing them to act like liquid

the temperatures is set at 100-118*F (38-48*C)

the pt may move or exercise while the treatment is taking place

tx lasts for 20 minutes

Remove all jewelry prior to use

Application Techniques of Thermotherapy: Contrast Bath

Contrast baths are frequently used clinically when the treatment goal is to achieve the benefits of heat, including decreased pain and increased flexibility, while avoiding increased edema

One container is filled warm or hot water, 100-111*F (38-44*C). Fill another container with cool or cold water 50-64*F (10-18*C)

Immerse the area to be treated in warm water for 3-10 minutes followed by in the cold water for 1-3 minutes (3:1 ratio, heat:cold)

repeat this sequence 5-6x to provide a total treatment time to ~30 minutes

Dry area thoroughly