Electrotherapy Flashcards
What are the therapeutic effects of Electrotherapy?
- decreased edema, pain, and eliminate disuse atrophy
- facilitate bone repair and wound healing as well as improve ROM
- muscle re-education and strengthening
- relaxation of muscle spasms
What are the indications for E-stim?
- bell’s Palsy
- Decreased ROM
- facial neuropathy
- fracture
- idiopathic scoliosis
- joint effusion
- labor and delivery
- muscle atrophy/weakness or spasms
- open wound/ulcer or pain
- stress incontinence or shoulder subluxation
What are the contraindications for Electrotherapy?
- cardiac arrythmias
- pacemakers
- malignancy
- osteomyelitis
- over a pregnant uterus
- over carotid sinus
- patient with a bladder stimulator
- phlebitis
- seizure disorders
What must an action potential do in order to trigger a muscular or cellular response?
Must have a high enough stimulus to break the established action potential threshold for that cell
What is Electrical Current?
How is current measured?
the directed flow of charge from one place to another
measured in Amperes (Amps)
What is Electrical Voltage?
How is it measured?
a measure of electromotive force or the electrical potential difference
measured in volts
What is electrical Resistance?
How is it measured?
the ability of a material to oppose the flow of ions through it
measured in Ohms
What is Ohm’s law?
how to calculate electrical resistance
Resistance= (voltage) / (current)
What is a Direct Therapeutic Current?
What is it mostly used for?
Constant flow of ions from the anode (positive electrode) to the cathode (negative electrode) for longer than 1 second
mostly used for Iontophoresis
What is an Alternating Therapeutic Current?
What is it mostly used for?
polarity that continuously changes from positive to negative with the change in direction of current flow that is biphasic
Measured in Hertz (cycles per second)
used frequently in a modulated form as burst or time-modulated
What is a Pulsatile Therapeutic Current?
What is it mostly used for?
non-continuous flow of direct or alternating current
What are the characteristics that increase or decrease when using a small electrode size?
Increased current density
Increased impedance
Decreased current flow
What are the characteristics that increase or decrease when using a big electrode size?
decreased current density
decreased impedance
increased current flow
How do you place the electrodes for a monopolar technique for electrotherapy?
What is a monopolar technique used for?
active electrode is placed over the target area and a second dispersive electrode is placed at another site away from the target area
Active electrode is typically smaller than the non-active electrode
mostly used with wounds, iontophoresis and edema treatment
How do you place the electrodes for a bipolar technique for electrotherapy?
What is a bipolar technique used for?
two active electrodes placed over the targeted area
used for weakness, neuromuscular facilitation, spasms, and ROM
What 3 things control the effectiveness of a current on target tissues?
Amplitude-enough to reach threshold
Rise Time- fast enough to reduce accommodation
Phase duration-long enough to exceed the capacitance of the tissue
How is amplitude measured?
volts, microvolts, or millivolts
What is rise time?
How should it differ for different tissues?
What is decay time?
time it takes for the intensity or amplitude to go from 0 to its peak
faster rise time for larger motor nerves
Time it takes for the amplitude to fall from the peak to 0
What is frequency?
the amount of pulses delivered through each channel per second or Hertz
What is Neuromuscular E-stim?
NMES is a technique used to facilitate skeletal muscle activity
What should the current amplitude be for NMES?
What should the Pulse Duration be?
What should the Frequency be?
What should the duty cycle be?
What should the Ramp time be?
What should the treatment time be?
Amplitude: depends on the desired strength of the muscle contraction
Pulse Duration: high enough to overcome the low capacitance of motor nerve fibers
Frequency: 35-50 pulses per second is usually normal, higher frequency will not produce a stronger contraction but will promote more rapid fatigue
Duty Cycle: must have a long enough rest time to not over fatigue the muscle so on time should be between 5-10 seconds and off time should be 5x longer than on time the first time but off time can be modulated to be less as more treatment sessions go on
Ramp time: Usually 1-4 seconds if the on time is 5-10 seconds
Treatment time: minimum of 10 contractions and a maximum of 20 contractions (usually 10-20 minutes)
What happens to pulse amplitude as you shorten the pulse duration?
a higher amplitude will be needed in order to produce the same strength of contraction
When would you use a lower pulse duration?
When would you want to increase pulse duration?
For smaller muscles to increase patient’s comfort level
longer pulse duration is usually more comfortable for larger muscles
What is TENS usually used for?
What are the 4 most common types of TENS?
mostly used for pain management via the gate control theory or endogenous opiate pain control theory
Conventional
Acupuncture-Like
Brief Intense
Noxious
What is Conventional TENS?
What are the normal parameters? (Amplitude, Pulse Frequency, Pulse Duration, and Treatment Time)
short duration high frequency and low amplitude stimulation that does not trigger a motor response in order to treat pain, usually only relieves pain during the stimulation with very little long lasting effect
Amplitude: enough for a sensory response
Pulse Frequency: High (30-150 pps)
Pulse Duration: short (50-100 nanoseconds)
Treatment Time: variable based on activity
What is Acupuncture-Like TENS?
What are the normal parameters? (Amplitude, Pulse Frequency, Pulse Duration, and Treatment Time)
long duration and low frequency with moderate amplitude to generate a muscle twitch that can provide longer lasting pain relief
Amplitude: enough for muscle twitching
Pulse Frequency: low (2-4 pps)
Pulse Duration: Long (100-300 nanoseconds)
Treatment Time: 20-45 minutes
What is Brief Intense TENS?
What are the normal parameters? (Amplitude, Pulse Frequency, Pulse Duration, and Treatment Time)
delivery of electrical pulses having long duration and high frequency with moderate current amplitude to minimize pain during otherwise painful activities
Amplitude: sufficient for motor response or strong paresthesia
Pulse Frequency: high (60-200 pps)
Pulse Duration: Long (150-500 nanoseconds)
Treatment Time: 15 minutes
What is Noxious TENS?
What are the normal parameters? (Amplitude, Pulse Frequency, Pulse Duration, and Treatment Time)
Painful high density current used to treat trigger points, stimulate nerve roots, or act as acupuncture
Amplitude: highest tolerated
Pulse Frequency: high or low
Pulse Duration: long (250 nanoseconds up to 1 sec)
Treatment Time: 30-60 seconds for each point
What is interferential current?
combines two medium frequency alternating waveforms that are biphasic through two sets of electrodes from separate channels of the same stimulator to create a higher amplitude when they are in the same phase and a lower current when in opposite phases
most often used for pain relief, muscle stimulation, and to increase circulation
What is the bipolar delivery method for interferential current?
two sets of electrodes on different channels of the same stimulator which creates a beat frequency (difference between the two currents of the different channels) which allows for the amplitude to be modulated before treatment delivery
What is the quadripolar delivery for interferential current?
four electrodes with each pair connected to a single channel
creates a four leaf clover shaped treatment field within the area of all four electrodes
