Modalities Ch. 15 Flashcards
radiation
propagated through empty space as EM waves
includes heat, light, electricity, x-rays
forms
all are caused by minute particles moving through space
wavelength
distance of one repetition of the wave, crest to crest
frequency
rate at which the wavelengths are moving, cycles/sec
Hz and Mhz
wavelength and frequency relationship
speed = wavelength x freq.
all travel at 186,000 mi/sec
-linear velocity = 186,000 mi/sec
linear speed remains constant
diathermy
“through heat”
a therapeutic modality that uses high frequency EM waves to heat deeper tissue
involves transmissions and absorption of EM by the body
why is it not used?
expense of 5,000 to 25,000 poor information -speculation lack of research -changes in equipment
diathermy classification
medical
surgical
classification based on frequency
longwave
shortwave
microwave
longwave
2 MHz
oldest method
not used any more
shortwave
27.12 MHz
wave identical to a shortwave radio
most common type used in sports medicine
microwave
2450 MHz
similar to radar
seldom used in the US
more contraindications than SWD
drum electrode
most common type
drum electrode is made up of copper foil
SWD device
runs on 110 V electricity from a wall outlet
frequency is 27.12 MHz
radio frequency that passes through the drum to the coil
coil sends wave into the tissue
one applicator unit is called a monode
two applicator is a diplode
inside applicator is single copper electrode coil
dipole
ends carry opposite energy charges
as they rotate, friction is occurring causing heat
rotation + friction = heat
eddy currents
a magnetic field generates small circular electrical fields
fields vibrate and increase cell membrane permeability, which causes heat
heating effects
created by resistance in the tissue to things going on
resistance is highest in muscle
SWD can heat muscle without overheating skin or adipose tissue
muscle is a denser tissue, more resistance, more heat
types
SWD can either be continuous or pulse waved
most treatments are…
pulsed
why use pulse?
on time, offtime, peak power stops tissue from overheating
peak power
pulse width with pulse frequency
-both important variables
how to create more heat
increase frequency and pulse width
PG 289
average watts is power
physiological effects of diathermy
increase blood flow increase metabolism more effect at cellular level fibroblastic activity collagen deposition new capillary growth white blood cell infiltration healing decreased pain and muscle spasm
diathermy indications
strains sprains contusions tendonosis bursitis pain joint stiffness osteoarthritis decreased ROM increase extensibility of collagen fibers
diathermy contraindications
when tissue temperature rise is not indicated ischemic areas anesthetic areas effusion eyes, testes, ovaries caution over pelvis during pregnancy moist wound dressings fever epiphysis cancer pacemakers metal implants
US
can heat tissues 3-5 cm deep to > 40 degrees C
heats small areas
short stretch/thermal window
5-10 min.
SWD
can heat tissues 3-5 cm deep to > 40 C heats large areas long stretch/thermal window 10-15 min consistent treatment over a certain area
