E- stim Flashcards
3 wave forms of electrical current:
DC
AC
Pulsed
E-stim is used in PT for these 5 reasons:
Pain Weakness Wound care Functional deficits Re-educate muscles
IFC used mainly for____ and uses___ electrodes
Pain
4
IFC machine does crossing in machine so instead of 4 electrodes we use
two
Premodulated Current (Premod) does the same as IFC but only needs ___ electrodes and doesn’t deliver___amplitude to skin like IFC and doesn’t have as large_____ area as IFC
2
lower
stimulation
Russian is medium frequency AC that gives bursts of AC __millisecond bursts___millisecond interburst interval ___burst per second
10
10
50
Pulsed Current is
Interrupted flow of charged particles
Three types of pulsed current
Monophasic
Biphasic
High voltage pulsed
Three types of biphasic pulsed current are:
Biphasic Symmetrical
Biphasic Asymmetrical balanced
Biphasic Asymmetrical unbalanced
This tends to be more comfortable when stimulating large muscles
Biphasic Symmetrical
This tends to be more comfortable when stimulating smaller muscles
Biphasic asymmetrical
Most of the asymmetrical we use is balanced/unbalanced
Balanced
Three dependent parameters
Pulse duration (width) Phase duration (cannot change) Interpulse interval (cannot change)
shorter pulse duration =
pain control
longer pulse duration =
muscle contraction (this pulse duration also feels stronger to pt)
name 4 other electrical current parameters
1 Amplitude
2 Frequency
3 On time and Off time
4 Ramp up and Ramp down time
Pulse duration measured in
microseconds
Units of Amplitude
mA milliamps or volts (V)
Frequency measured in
Hz or pps (pulse per sec)
On and Off time measured in:
10 seconds on 50 seconds off 1:5 or 10:50
These are used to improve patient comfort
Ramp on & ramp off
Effects of electrical currents (3):
Stimulation of action potentials
Direct muscle depolarization
Ionic effects of electrical currents
Basic unit of nerve communication
Action Potentials
Lower amplitudes and shorter pulse durations are required to depolarize ____nerves (_ beta nerve fibers))
sensory
A
Higher amplitudes and longer pulse durations are required to depolarize ____- nerves
motor
Even higher amplitudes and even longer pulse durations are required to depolarize ___ nerves
pain
as you gradually increase amplitude and pulse duration
Sensation to Muscle contraction to Pain
Shorter pulse durations are used for sensory stimulation - these are usually ____ microseconds
80
Longer pulse durations are used for motor stimulation these are usually ____ microseconds
150-350 microseconds
Longer pulse durations feel ___ and are less comfortable
stronger
Pulse durations longer than 1 millisecond are required to stimulate __ nerve fibers
C
Pulse durations longer than __ milliseconds are required to stimulate denervated muscle
10
We normally stimulate the motor nerve that goes to the muscle but have to stimulate this type of muscle directly
denervated
The longer pulse duration makes the stim feel stronger because
it grabs more muscle fibers bc it has more time to cause ap in more muscle
What happens when the nerve ACCOMODATES to the stimulus
prevents depolarization
If this is too long the nerve may accomodate
ramp time
May need to change one of these three things if accomodation is met
amplitude
frequency
duration
Negative electrode and attracts positive ions and repels negative ions
Cathode
Positive electrode and attracts negative ions and repels positive ions
Anode
When electrodes are farther apart current goes
deeper
When electrodes are closer together current is more
superficial
Contraindications
Cardiac pacemaker unstable arrhythmia over carotid sinus implanted electronic device over venoous/arterio thrombosis pregnancy
Precautions
cardiac disease impaired sensation or mentation Malignancy skin irritation/open wound in area where muscle contraction could disrupt surgical repair
Adverse effects (3):
Burns
Skin irritation
Pain
Decrease pain by
using larger electrodes
increasing intensity very slowly
using shorter pulse durations
Application:
turn machine on ensure intensity is off inspect wires place electrodes set parameters inform pt
Ending tx
turn intensity to 0 remove electrodes turn machine of inspect area document
Do not do this during ttx
plug or unplug machine
turn machine on or off while electrodes are on pt
Document
area of the body
pt position
parameters
duration
pt response - skin inspection, decreased pain, etc
Activities performed with stim if applicale
Neuromuscular Electrical Stimulation is the application of electrical current to motor nerves to cause contractions of the muscles they innervate. Must have intact and functioning
peripheral nervous system
NMES stimulated contractions can (5) things
strengthen muscle improve cardiovascular health retard or prevent muscle atrophy reduce spasticity restore function
NMES recruit
type II muscle fibers before type I
Parameters for NMES
Russian protocol or pulsed biphasic waveform normally used
Electrode placement: one over motor pt of muscle and one on muscle aligned parallel to muscle fiber direction. Apply electrodes at least 2 inches apart
Patient positioning
Parameters for NMES pulse durations:
150-350 microseconds
150-200 ms for smaller muscles
200-350 ms for larger muscles
Parameters for NMES Freq. & on:off time
35-50 pps
50-80 pps may increase strength but also increases fatigue
on:off 1:5 initial with on time 6-10 seconds
To reduce muscle spasm or to pump out edema 1:1 woth both on and off times of
2-5 seconds
