-
inensity
- important for determining which nerves generate an action potential
- once threshold amplitude is met for a particular nerve it will not respond any differently
- inc in amp means inc number of nerves recruited
- higher amp greater the depth of penetration if all else is held constant
-
four levels to define intensity
- subsensory
- sensory
- motor
- noxious
-
subsensory
used in pain control and wound healing
-
sensory
used in segmental pain control and wound healing
-
motor
- 3 levels:
- minimal- muscle re-education
- moderate- muscle re-education and possibly use for suprasegmental pain control
- maximally tolerated contractions (MTC)- muscle strengthening
-
noxious
used for suprasegmental pain control
-
phase duration
- allows one to fine tune response
- achieve desired response at a lower intensity with less risk of unwanted responses
- part of the determination of what nerves are activated
- unit of measure usec
-
short phase duration
- <125usec
- segmental pain control
- to minimize chance of uncomfortable tetanic muscle contraction
-
long phase duration
- suprasegmental pain control, muscle contraction
- to reach the stimulus faster
-
frequency
- unit of measure is pps, Hz, cps
- determines how often any nerve activated by the intensity/phase duration combination responds
- range from 1-250
- suprasegmental <10
- segmental 20-250
- muscle strengthening 35-80
- wound healing 100-105
- muscle re-education 30-40
- muscle pump 1-10
-
higher frequency the
stronger contraction and quicker the muscle will fatigue
-
output channel modes
- two leads per channel
- + and -
- NO GROUND LEAD
- continuous- no interrruption
- synchronous- on/off simultaneously
- alternate or reciprocate- on/off alternately
- possibly delayed- stimulate one then wait a sec or several sec
-
on/off time
- only use with muscle strengthening or re-education
- on time should be sufficient length to perform decent contraction
- off time is longer than on time
- smaller ration between on/off faster muscle will fatigue
- NEVER INC AMP DURING OFF CYCLE
-
ramp up/ ramp down
- used for comfort during motor level stimualtion
- be sure not to let it eat into your contraction time
-
polarity
- only find on DC or monophasic pulsed current generators
- DC units- polarity influences physiologic response (skin pH which can lead to burns)
- pain control polarity doesn't matter
- muscle strengthening bipolar don't matter monopolar active electrode is negative
-
waveform
- comfort factor (poly used more often)
- wound healing must use HVPS
- iontophoresis and denervated muscles must use DC
-
modulations
- reduce patient adaptation during stimulation
- primarily for segmental pain control
- most clincs only have frequency on units
-
treatment time
- segmental- 15min- 24hrs
- suprasegmental- 15-30 min
- muscle strengthening- long enough to get 15 contractions
- muscle re-education- long enough to do exercise
- wound healing- 45-60 min
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