Hot vs Cold

• Pain transmission:

  • pain receptors are called nocioceptors
  • they are sensitive to: mechanical, temperature, chemical
  • type of nerve: afferent nerve
• Two types of pain signals:

  • A-delta = fast pain; myelinated; protective mechanism; large diameter; touch, pressure, temperature; located in the skin; do not block
  • C-fibres = slow pain; unmyelinated; informative mechanism; small diameter; pain and temperature; located in the skin and deep tissue; block
• Gate control theory:

  • without stimulation = A-beta and C-fibres are quiet; SG and inhibitory interneuron block signal to t-cell and no signal goes to the brain
  • pain = c-fibres are active; they block SG, which blocks the inhibitory interneuron; pain goes to brain
  • non-painful stimulation = A-beta fibres are activated; activated SG; activated inhibitory interneuron; blocks signal to brain
• Types of A-beta input:

  • pressure
  • vibration
  • position sense
• What is accomodation?

  A-beta fibres experience a constant current and the nerve shows decrease excitability

  • A-beta fibres will accommodate
  • c-fibre does not accommodate
• Body‘s response to ice depends on:

  • the cold media being applied
  • conductivity of the area being cooled
  • length of time of application
• What is happening with acute injuries?

  tissue injury at primary and secondary locations

  cell death due to hypoxia

  increased bleeding into the area

  pain

  swelling
• Against ice…

  • one early application of ice can slow down healing for the first 3-7 days
• For ice…

  • good for pain
  • for every 1° drop in temperature you cool a nerve, you decrease conduction velocity
  • with a 4° cooling you knock out c-fibres

  when combined with exercise:

  • decreases swelling better
  • improvement in function
  • maintain cell viability

  4 sensations:

  • cold
  • burning
  • aching
  • numbness
• Body’s response to heat depends on:

  • type of heat applied
  • intensity of heat
  • duration of application
• Inflammation phase:

  • red, hot, swollen, pain
  • tissue inflammation/destruction (primary and secondary)

  goals:

  • optimize healing environment
  • decrease pain
  • decrease swelling
• Repair:

  • fibroplasia
  • proliferation and regeneration
  • connective tissue formation
  • endothelial capillary buds
  • weak scar formation
  • type 3 collagen

  goals:

  • protect tissue
  • idealize healing environment
  • increase blood flow via heat
  • idealize ROM
  • strengthening

  what is the heat used for?

  • increase blood flow
  • decrease spasm
  • increase collagen elasticity
  • decrease stiffness
• Remodelling:

  • increase force
  • Wolf’s law
  • change from type 3 to type 1
  • realign fibres

  goals:

  • idealize strength
  • functional movements (speed, power, agility)
  • prepare for return to play