interventions final Flashcards
what are the contraindications for the use of electrical currents?
over a pacemaker or unstable arrhythmia
over the carotid sinus
venous or arterial thrombosis or thrombophlebitis
around pregnancy
malignant tumors
precautions for electrical currents
cardiac disease
impaired mentation or sensation
skin irritation or open wounds
intensity/duration for strong muscle contractions
what are the adverse effects of electrical current
burns
skin irritation/inflammation
perception of discomfort
DOMS/soreness
how often should units be checked?
annually
never use a unit missing the third prong
what is the resting membrane potential in nerves?
-65 mV
stimulation of action potentials
all or nothing
depolarize - make outside less positive
large diameter depol first
what is the order of nerve depol?
A-beta
A-alpha
A-delta
what does a-beta depol target?
reducing pain
what does a delta depol target?
chronic pain
what does a alpha depol targer?
increasing muscle strength
name 3 factors that speed up AP conduction
myelination
axon diameter
higher temp
describe the AP pattern of motor and sensory stim
motor - one way, to body
sensory - one way, to CNS
describe the AP pattern of external stim
bidirectional
what is direct current?
continuous unidirectional flow of current
for denervated muscle
used for iontophoresis
what is alternating current?
electrodes alternate polarity in smooth fashion
bidirectional flow of charged particles
need to modulate AC to make it useful
used for russian and IFC
what is pulsed current?
interrupted flow of current in form of pulses
space between pulses not seen with AC
pain control: TENS
muscle contraction: NMES
describe modulated AC
pain control:
2 AC’s interfering with one another
amplitude modulated or beat modulated
for muscle strengthening:
time modulated or burst modulated
what are the three biphasic currents?
symmetrical
balanced
unbalanced
what are different pulse durations used for?
shorter: pain control or tissue healing
longer: muscle contraction
what are different phase durations used for?
less than pulse duration if biphasic
equal to pulse duration if monophasic
what is amplitude?
intensity or strength
what is frequency?
use Hz
A-beta nerve curve
stim these to beat C nerves to spinal cord
gate theory
a-delta nerve curve
almost impossible to directly stim
want really strong hard muscle twitch
3-4 hours relief
opioid like release
what pulse duration for sensory axon?
60-80 microsec
what pulse duration for motor axon?
150-350 microsec
what to doc?
area of body
pt positioning
specific stim parameters
electrode placement
treatment duration
pt’s response to treatment
plan
sig and date
application technique for electrical
pt positioning
electrode type - pre-gelled, self adhesive
electrode placement
current density - smaller = more current
describe best electrode placement
not over bone - sensitive to conduction
closer - shallow, more burn risk
farther apart - safer, deeper, may need higher amp
atleast 1 inch apart
what does TENS mean?
transcutaneous
electrical
nerve
stimulation
clinically describes portable stimulators
what is conventional TENS
high rate
gate control - rub it where it hurts
acute pain
races C fibers to SC
only blocks pain when gate is closed
explanation of gate theory to pt
in the spinal cord we have a gate that either allows pain signals to be delivered to the brain or shut off to stop the signal.
because the nerve that carry that signal are slow, if we stimulate faster sensation nerves, they can race to the spinal cord and close that gate. this will reduce the amount of pain we sense.
have you ever bumped your arm and then rubbed it? you closed the gate with the rubbing. it stimulated a faster sensory nerve which beat the slower one to the spinal cord.
describe the parameters of conventional TENS
pulse type: biphasic symmetrical
pulse duration: 50-80 us
pulse rate: 100-150 Hz
pulse amplitude: strong, comfortable
pain relief will not outlast stimulation
can wear up to 24 hr/day
when do you modulate?
to counter adaptation
what is strong, low rate TENS?
acupuncture-like
stimulates opioid release
relief for 3-4 hours after
a-delta fibers
want a strong muscle contraction
what are the parameter for strong, low rate?
pulse type: biphasic symmetrical
pulse duration: 150-350 us
pulse rate: 2-10 Hz
pulse amplitude: strong, sharp muscle twitch
pain relief outlasts stim by 3-4 hrs
duration of stim: 20-30 min
what is electro-acupuncture?
placing needle electrodes into known acupuncture points
stimulate flow of chi?
acupuncture points correspond to locations of peripheral nerves?
what is burst mode TENS?
mimics strong, low rate
a burst may be better tolerated than a long duration pulse
what is inferential current?
it crosses two unmodulated currents in the body
requires two channels - 4 pads
what is a carrier frequency?
the unmod continuously alternating current
only name the lower frequency in doc
what is the beat frequency?
difference between the two interfering carrier frequencies
if one carrier freq is 4000 and the beat freq is 100, what is the other carrier?
4100
4000+100
what is the carrier and beat freq for acute IFC?
carrier - 4K or 5K Hz
beat - 80-150 Hz
what is the carrier and beat freq for chronic IFC?
carrier - 2500 Hz
beat - 2-10 Hz
another name for chronic IFC
low rate IFC
what is the shape of treatment area for IFC?
clover shape
why would you use modulations?
to avoid sensory habituation (nervous system adaptation)
can allow lower intensity
what is the sweep modulation?
frequency
sweep the freq
changes beat freq
what is the scan modulation?
amplitude
scan the amp
shifts clover side to side
is there any true difference between 4K and 5K?
nope
amp and relief time of acute IFC
amp - strong sensory sensation
relief only while active
gate theory
what is pre modulated inferential?
the currents are mixed in the machine not the pt
one channel
2 pads
drawback of pre-mod
has a lower freq so has more resistance and could be more agitating to skin
should I use true or pre mod ICF?
depends
probably similarly effective
parameters for ICF for chronic pain
strong, low-rate
opiate-like release
carrier - 2500 Hz
beat - 2-10 Hz
strong to sharp sensory sensation
want muscle contraction
relief time is 3-4 hrs after
IFC research takeaways
better than placebo
prob most effective when combined with exercise
prob not best use of time
is NEMS for innervated or denervated muscle?
innervated
which type of muscle fiber is stimulated early with contraction?
early: FT
late: ST
which type of muscle fiber is early with voluntary contraction?
early: ST
late: FT
contrast voluntary and stimulated contractions
voluntary:
smooth
asynch, fine mvmts
stimed:
jerky
sych recruitment, all or none
how do you stimulate more motor units?
more amplitude
external resistance
how to target endurance?
more reps at lower intensity
how to target strength?
fewer reps at higher intensity
at least 50% MVIC for healthy muscle
at least 10% MVIC for weakened muscle
clinical applications of NEMS
post surgery
presurgery
alternative to surgery
conditions leading to relative disuse
sports performance
contraindications of NEMS
pacemaker or unstable arrhythmia
over carotid sinus
thrombosis
pelvis, abdo, trunk, low back in preg
when contraction is contraindicated
precautions to NEMS
cardiac disease
impaired mentation or sensation
malignant tumors
skin irri or open wounds
DOMS
evidence for NEMS
more amps = more motor units
what is the pulse duration for NEMS?
150-350 usec
electrode placement for NEMS
in alignment with muscle fibers
pt position for NEMS
make sure they can freely move the joint
pulse freq for NEMS
< 20 pps for twitch
35-50 pps for tetany
> 50 pps for fatigue
on:off time for NEMS (strength building)
6-10 sec on time
1:5 ratio is typical
on:off time for NEMS (fatigue)
2-5 sec on time
1:1 ratio
ramp time for NEMS
larger muscle 3-6 sec
smaller muscle 1-3 sec
amplitude for NEMS
need enough to fully recruit motor units
more amp = more units = bigger contraction
more can be less comfy
treatment time for NEMS
10-20 contractions
if 10 sec on time, 1:5 ratio, 1 min/rep so 10 min
if for muscle spasm reduction, 10-30 min
what is FES?
elicit contraction during functional activity
evidence for FES
works with other PT interventions
rationales for denervated muscle
waiting for reinnervation
promote reinnervation
but wouldnt really do this
