Modalities Flashcards
E-Stim, Ultrasound, Laser, Thermo and Cyrotherapy
List the goals and indications for E-Stim
- Pain modulation
- decrease muscle spasm
- improve ROM
- muscle re-education
- improve muscle strength/reduce atrophy
- wound healing
- edema reduction
- stimulate denervated muscle
List some contraindications for E-Stim
- presence of pacemaker or electronic device (insulin pump) in patient
- never over:
- carotid artery
- thrombosis
- eyes
- phrenic nerve
- pelvis or low back of a pregnant woman
- never transcerebrally
- if there is bleeding or an infection
- over malignant tumors
- over pharyngeal or laryngeal muscles
- motor-level stimulation in conditions that prohibt motion
List some precautions for E-Stim
- cardiac disease
- impaired mental status
- impaired sensation
- in areas of skin irritation or open wounds
- in patients with uncontrolled hypo/hypertension
- bleeding disorders
Define polarity
net charge of object
cathode = net (-)
anode = net (+)
define voltage
driving force that move electrons
force of attraction or repulsion (amplitude)
define amperage/current
rate of flow of electrons
mesaured in milliamps (mA)
what is Ohm’s Law?
I = V/R
current = voltage/resistance
(more resistance means greater voltage required to push the current through)
List some biological sources of resistance to current
- skin
- hair
- fascia
- ligaments
- callus
- fat
- bone
- tendon
- scar
what are some ways to reduce resistance at the skin?
- minimize air-electrode interface
- make sure there are no folds or gaps in the electrodes
- keep electrodes clean
- use electrodes on clean skin, minimize hair, oils, abrasions if possible
List the different types of currents
- Monophasic
- Biphasic
- Direct current
- Alternating current
- Pulsed current
what types of currents are unidirectional? bidirectional?
unidirectional = monophasic and direct current
bidirectional = biphasic and alternating current
pulsed can be both
What are the unique features of a pulsed current?
this type of current will periodically cease for a short time period so it has:
a frequency
a pulse duration
an amplitude
how do pulse currents influence the generation of AP differently than direct or alternating currents?
pulse currents allow for repolarization to occur (channels closing again) thus they can result in tetanic contractions
Direct and alternating currents do not allow for repolarization (the channels always remain open) thus they result in a single large contraction
the higher the current the higher the _______
heat
also the greater risk for burns
what are the effects of electrode size on stimulation?
different sizes result in different current densities
larger electrode = smaller current density/more tolerable
smaller electrode = larger current density/less tolerable
what are 2 ways to increase current density?
- increase current
- decrease electode size
what is the effect of increased current density on skin?
skin burn
avoid this by:
- removing resistance
- listen to pt’s perception
- use larger electrodes when possible
- always maintain good contact
- use appropriate coupling agent when appropriate
List several electrode configurations
- monopolar
- bipolar
- quadripolar
describe a monopolar electrode configuration
one small electrode over target area, and one large electrode placed over remote area (to complete the current)
method of choice when polarity matters
(wound healing, edema control, iontophoresis)
describe a bipolar electrode configuration
both electrodes are of similar size and are placed over the target area
current bounces between two pads
used with any waveform except DC
List some preferred uses for bipolar electrode configurations
- disuse atrophy
- neuromuscular facilitation
- ROM
- spasms
- circulatory disorders
describe a quadripolar configuration
2 electrodes from 2 separate stimulating currents are positioned so that the individual currents intersect with each other (called IFC)
how does the distance between electrodes influence current?
it influences the depth and course of current
further apart = deeper the current travels
recommended that the distance be at least one half the diameter of each electrode
List some things to keep in mind when placing electrodes for motor stimulation
- place on region where the motor nerve is most easily excited
- typically at muscle belly or proximal 1/3 of muscle
- common mistake to place one electrode over the muscle belly and the other over a distal area w/o much muscle
- results in diminished response and increased discomfort
List several specific types of ES used for strengthenig
- NMES (Neuromuscular E-Stim)
- Russian (Burst Modulation)
- FES (Functional E-Stim)
- more used to supplement orthotic devices
what are the goals for NMES?
- atrophy treatment/prevention
- stregthening
- achieve synchronous firing/recruitment of motor units
What is Burst Modulation (Russian)?
variation of alternating current that is interrupted and delivered in short bursts
(AKA medium frequency burst alternating current)
most common form of NMES
List the typical parameters for Russian
- Bipolar electrode placement
- pulse width/duration = 150-200 µsec
- pulse frequency = 50-70 pps
- amplitude = max contraction/tolerance
- On:Off time = varies dependent on use
- 10 sec on, 50 sec off is common for >10 reps
- Ramp = 1-5 secs up/down
- Trx determination similar to that of TherEx prescription
List the parameters that are different in NMES from Russian
- pulse width/duration = 200-800µsec
- pulse frequency = 30-100 pps
List some generalizations with NMES parameters
- if you want to continue to increase force output, need to increase amplitude during/between trxs
- to decrease adapation and optimize strenghting with ES, increase current amplitude as often and as much as tolerated
- the shorter the off time and longer the on time the greater the chance of fatigue
- longer on time = greater decrease in force output over time
- align electrodes parallel to muscle fiber, not transverse
- use larger electrodes with bigger muscles
T/F: NMES has been shown to improve strength and function in patient’s status post surgically
TRUE
T/F: Russian Current is more often used and more tolerable than NMES pulsed current
FALSE
it is more often used BUT
NMES produces less discomfort
what is the goal of FES?
this is a type of NMES in which e-stim is utilized as an alternative or supplement to orthotic devices or braces
T/F: the peripheral nerve does not have to be intact for FES to work
FALSE
must have an intact peripheral nerve
list 2 common uses for FES
- shoulder subluxation
- foot drop
List the types of E-Stim used in pain modulation
- Interferential Current (IFC)
- TENS
- Conventional (High Rate) transcutaneous E-Stim
- Acupuncture-like (Low Rate) E-STIM
- Brief Intense TENS
- Burst mode TENS
- Hyperstimulation (point simulation) TENS
how is IFC characterized?
by crossing sinusoidal waves that interfere with one another to generate an amplitude-modulated beat frequency
define beat-frequency
(amplitude-modulate)
resultant frequency produced by the two frequencies going into and out of phase
describe the parameters for IFC
goal = pain reduction
- quadripolar electrode setup
- Wave form = alternating current amplitude modulated beats
- pulse width/duration = 200-400 µsec
- frequency = 10-150 pps
- amplitude = strong but tolerable sensation
- trx duration = 10-30 min
what are the unique effects of IFC treatment
sensory nerve fibers receive a lower amplitude stimulation than the area of tissue affected by vector
thus IFC is said to be more comfortable than equal amplitudes delivered by conventional means
List the parameters for High-rate (conventional) TENS
- wave form = typically asymmetrical biphasic
- current = continuous, pulsatile, or burst
- pulse width/duration = 50-100 µsec
- pulse rate/frequency = 50-80 pps
- amplitude = comfortable tingling sensation, NO MUSCLE response
- duration of trx = 10 min to several hours
- onset of pain relief = relatively fast
- duration of pain relief = temporary
how is the modulation of pain via High-rate TENS different from Low-rate TENS?
high-rate = gate control theory
low-rate = descending pathways release of endogenous opiates
List the parameters for Low-rate (acupuncture-like) TENS
- wave form = typically asymmetrical biphasic
- current = continous, pulsatile, or burst
- pulse width/duration = 150-300 µsec
- pulse rate/frequency = 1-5 pps
- amplitude = strong, but comfortable rhythmic muscle twitch
- duration of trx = 20-40 min
- onset of pain relief = 20-40 min
- duration of pain relief = long last >1 hour
what is brief intense TENS used for?
used to provide rapid-onset, short term pain relief during painful procedures
(wound debridement, passive stretching, joint mobilizations)
List the parameters for brief intense TENS
- wave form = typically asymmetrical biphasic
- current = continuous, pulsatile, or burst
- amplitude = patient’s tolerance
- pulse rate = 80-150 pps
- pulse duration = 50-250 µsec
- duration of trx = 15 min
- onset of pain relief = relatively fast
- duration of pain relief = temporary (30-60 min)
what is burst-mode TENS?
combines characteristics of both high and low rate TENS
stimulation of endogenous opiates, but current is more tolerable to patient than low-rate TENS
list the parameters of burst-mode TENS
- wave form = typically asymmetrical biphasic
- current = continous, pulsatile, or burst
- amplitude = comfortable, intermittent paresthesia
- pulse rate = 50-100 pps, delivered in packets or bursts 1-4 pps
- pulse duration = 50-200 µsec
- duration of trx = 20-30 min
- onset of pain relief = 20-40 min
- duration of pain relief = long lasting (hours)