Physical Agents Flashcards
Thermal types
Deep heating: diathermy
Superficial heating: hot pack
Cooling: ice pack
change rate circulation
change rate chemical reactions
Mechanical types
Traction
Compression
Water
Sound
Control motion
Alter fluid flow
_Electromagnatic _
Electromagnetic fields: Ultraviolet
Electrical current: TENS
Alter cell membrane permeability and transport
Other effects of physical agents
Pain control: modify pain transmission (SC or peripheral)
or change underlying process causing sensation
Collagen extensibility: temp dependent
Muscle tone: directly alter nerve conduction
alter biomech properties of muscle
decrease muscle spasm
Contraindications
Pregnancy
Malignancy
Pacemaker/implanted device
Impaired sensation
Impaired mentation
Specific heat
“amount energy required increase temperature of given mass of material a certain # of degrees”
”# of calories required to increase temp of 1 gram of substance 1 degree Celsius”
high specific heat–>more energy heat up–> hold more energy/temp
J/c/degrees Celsius
H20 4.19
Air 1.01
Body 3.56
Skin 3.77
Muscle 3.75
Fat 2.30
Bone 1.59
Conduction
Thermal conductivity
heat transfer by direct contact (high temp->low temp)
efficiency of material or tissue to conduct heat
“rate at which transfer heat by conduction”
(Cal/sec)/(cm2 x degrees Celsium/cm)
Silver 1.01
Aluminum 0.5
Ice .005
H20 20degrees .0014
Bone: .0011
Muscle: .0011
Fat: .0005
Air 0 degrees Celsius: .000057
Convection
direct contact between circulating medium + material different temp
(fluidotherapy, whirlpool, blood circulation)
Conversion
Nonthermal form energy–>heat
rate depends on power of energy source
(ultrasound, diathermy)
_Radiation _
no intervening medium of contact needed for transfer energy high temp–>low temp
(infrared lamps)
Evaporation
absorption energy as result conversion liquid–>
gas/vapor
(perspiration, vapocoolant, alcohol)
