CRYOTHERAPY

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CRYOTHERAPY
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• Cryotherapy or ice therapy is the application of
  cold to the body tissues after injury. This
  practice is as old as medicine itself.
• Nowadays, local cold application may be applied
  by the use of various forms of ice or frozen gel
  packs, or by evaporation of volatile fluids from
  the skin.Often skin temperature is reduced to 10
  C.

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A. Physiological Effects of Cold Application

• Circulatory Response
• The initial skin reaction to cooling is an
  attempt to preserve heat. It is accomplished by
  an initial vasoconstriction. This haemostatic
  response has the effect of cooling of the body
  part.
• After a short period of time, the duration
  depends on the area involved, a vasodilatation
  follows with alternating periods of constriction
  and dilatation. This reaction of hunting for a
  mean point of circulation is called Lewiss
  Hunting Reaction.
• During the vasodilatation, the arteriovenous
  anastomosis is closed, thus causing an increase
  blood flow through the capillaries. This is
  beneficial in the treatment of swelling and
  tissue damage.

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Physiotherapeutic Uses of the Circulatory Effect

• The initial vasoconstriction is often used to
  limit the extravasations of blood into the
  tissues following injuries (e.g. sports
  injuries). Ice therapy is then usually followed
  by some forms of compression bandage.
• The alternate periods of vasoconstriction and
  vasodilatation affect the capillary blood flow
  and it is across the capillary membrane that
  tissue fluid can be removed from the area and
  returned in the systemic circulation. Increased
  circulation allows more nutrients and repair
  substances into the damaged areas.

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• Thus ice therapy is very useful in removing
  swelling and accelerating tissue repair. i.e. ice
  cubes massage may be used to accelerate the rate
  of repair of pressure sores.
• The reduced metabolic rate of cooled tissues
  allows cooled muscle to contract many more times
  before fatigue sets in.

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Neural response

• The skin contains primary thermal receptors. Cold
  receptors are several times more numerous than
  warm receptors. The cold receptors respond to
  cooling by a sustained discharge of impulses, the
  rate of which increases with further cooling.
• The rate of conduction of nerve fibers in a mixed
  (motor and sensory) peripheral nerve is reduced
  by cooling. The first fibers affected by gradual
  cooling are the A fibers (myelinated) and
  eventually at very low temperatures the B and C
  fibers (non-myelinated) are affected.
• In practice, motor nerve paralysis is never
  produced by ice.

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Excitatory Cold Mechanism

• When cold is applied in an appropriate way on the
  skin, ice can be used to increase the excitatory
  bias around the anterior horn cell.
• Combined with other forms of excitation
  (brushing, tapping,) and with the patients
  volitation, this can often produce contraction of
  an inhibited muscle (only with intact peripheral
  nerve supply).
• This effect can be used when muscle are inhibited
  postoperatively or in the later stages of
  regeneration of a mixed peripheral nerve

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B. Uses of Ice Therapy

• Reduces pain.
• Reduces spasticity.
• Reduces muscle spasm.
• Reduces swelling.
• Promote repair of the damaged tissues.
• Provide excitatory stimulus to inhibited
  muscles.

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Reduction of Pain

• Pain reduction is one of the major effects of ice
  application which has been used for many years.
• The probable mechanism is that by the stimulation
  of cold receptors, impulses will be send back
  which will pass into the posterior root of the
  spinal cord. These impulses, arriving through
  large diameter nerves, effectively block out any
  other (pain) impulses attempting to access the
  spinal cord (pain gate theory).
• This reduces the pain temporarily. For permanent
  pain relief, positive physiotherapy
  (strengthening, mobilization) has to be given
  during this period of transient pain relief.

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Reduction of Spasticity

• Spasticity is the pathological state of increased
  muscle tone resulting from damage to the upper
  motor neurons. The small anterior horn cell from
  the higher control of extrapyramidal system and
  fires spontaneously at an increased rate. The net
  result of this is ultimately to increase tone in
  the extrafusal muscle fibers, when the hypertonic
  spastic state appears.

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• Spasm is a normal response to injury or pain and
  is manifested as an increase in muscle tone in a
  specific area with the apparent aim of limiting
  movement and further damage. However the amount
  of spasm is often exceeding and the sustained
  contraction of muscles will in turn start to
  produce pain, often resulting then in more spasm.

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• The mechanisms by which cold reduces spasticity
  and spasm are probably
• the reduced velocity of nerve conduction.
• the depressed sensitivity of receptors such as
  the muscle spindle.

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• These structures are fairly deep and it would
  take several minutes to produce a sufficiently
  low temperature to affect them.
• As it was clinically demonstrated that the
  reduction of spasm and spasticity occurs within
  30 seconds of ice application, the reaction to
  cooling can only be at the superficial tissues at
  the skin.
• The skin stimulus produced by cold must have an
  effect on the general level of excitation and
  inhibition in the region of the anterior horn
  cells.
• Once spasm and spasticity have been reduced, more
  long-time treatment is given in order to sustain
  the condition. In the case of spasm, active
  movements are used to break down the vicious
  circle of pain-spasm-more pain- more spasm.
• With spasticity, the technique will depend upon
  the preference of the physical therapist.

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Techniques of Application of Cryotherapy

• The way which ice is applied will vary according
  to the required effects.
• It may be applied in the following ways
• Ice towels
• Ice packs
• Immersion
• Ice cube massage
• Excitatory cold ( quick ice)
• Ice spray
• Cold gel

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D. Contraindications to Ice Treatment

• Cardiac Conditions
• Psychological
• Peripheral Nerve Injuries
• Vasospastic Disease
• Peripheral Vascular Disease
• Cold Sensitivity