Cold Modalities Flashcards
4 mechanisms of transference of thermal energy
CONDUCTION: heat lost or gained through directs contact
CONVECTION: heat lost or gained through movement of fluid or air between regions of unequal temperature
RADIATION: emission of energy
CONVERSION: changing from one energy form to another
conduction
heat lost or gained through direct contact
- temp change depends on
- – the temp diffrerence between the 2 surfaces
- – duration of exposure (time surfaces in contact)
ex:
- ice massage
- cold packs
- hydrocollator packs
- cold spray
- ice immersion
- contrast baths
- cyro cuff
- paraffin bath
convection
heat loss or gain though movement of fluid or air between regions of unequal temp = temp change depends on --- differences in temp --- duration of exposure --- size of area to be treated
ex:
- hot whirlpool
- cold whirlpool
- fluidotherapy
radiation
emission of energy
- may be emitted from a source (heat lamp) and absorbed by body
ex:
- infrared lamps
- laser
- uv lamps
conversion
changing from one energy form into another
ex:
- ultrasound converts acoustic energy into thermal energy
- diathermy
cryotherapy
application of cold modalities with temp 32 - 65 deg F (0 deg C)
- heat removed fro body and absorbed by modality
- local and systemic effects
thermal agent
represent transfer of heat energy to or away from tissue
- heat transfer is unidirectional
- fundamental principle: one object must have higher temp than other
“tissues warm cold modalities by losing heat to them”
“cold modalities work by absorbing heat from their immediate environments”
how cryotherapy works
- lowers metabolic rate of tissue
- -> limits suffocating cell’s need for oxygen
- —> reduced seondary metabolic (hypoxic) injury
- lowering temp by 1 deg C = 13% decrease in metabolic rate
- during 20 min ice application = cell metabolism decreases by 19%
Effects of Cold on Cellular Response
decrease in cell metabolism –> less need for oxygen
effects of cold on blood and fluid dynamics
- vasoconstriction
- decrease blood flow to area
- decrease hydrostatic pressure
- decrease capillary permeability
effects of cold on inflammation
- decreased inflammation
- decrease release of inflammatory mediators
- decrease prostroglandin synthesis
- decrease capillary permeability (decreasing histamine)
effects of cold on nerve conduction
- reduced afferent NCV
- reduced threshold of afferent nerve endings
cold on pain
cold
- -> decreases capillary permeability
- —> decreases edema formation
- ——> lessens mechanical pressure on nerves
- ———-> reducing pain
- –> decreases amount of inflammatory mediators
- —-> decreased amour of cellular waste by-products (cause tissue damage and pain)
- ———> less tissue damage/pain
effects of cold on muscle spasm
decrease sensitivity of muscle spindle
- -> muscle relaxes
- —-> spasm relieved
cold affects pain perception and transmission by…
- interrupting pain transmission (stimulates large diameter A-beta n. fibers) via gate theory
- decrease nerve conduction velocity
- reducing muscle spasm
- reducing / limiting edema
