time it takes current to go from 0 to maximum amplitude for any one on time.
ratio of on time to total cycle time
Waveform produced by the interferences of two medium frequency sinusoidal AC's
Property of having two oppositely charged conductors
Time between pulses
Similar to IFC but uses only one channel
Time it takes current to go from 0 to peak during a phase
Number of cycles or pulses per second
Time form the beginning of the first phase to the end of the last phase of the pulse
Relationship between voltage(V), electrical current (I) and resistance (R)
used for iontophoresis and stimulating denervated muscles to contract
usually refered to as scan
continuou and bidirectional flow of charged particles (+ and -)
Duration of one cycle
electrical current delivered discontinuously
magnitude of the current or voltage
total frequency-dependant opposition to the current flow
usually referred to as sweep
Symmetrical biphasic pulsed is used for?
Muscle strengthening, muscle reeducation, muscle spasm (fatigue muscles to decrease spasm), Chronic edema (muscle pumping to decrease edema)
TENS (Monophasic/biphasic) is used for?
conventional (pain control via gate theory of pain), Accupuncture (pain control via endogenous opiate release)
AC is used for?
IFC (pain control), Premod (pain control for smaller area)
HVPC is used for?
Tissue healing (speed healing process), (-) for infected or acute wounds, (+) for clean wounds and theose in the roliferation stage, Acute edema (-)
DC monophasic-continuous is used for?
Iontophoresis (decreases inflammation), Denervated muscle ( depolarize muscle cells to decrease onset of atrophy)
Russian is used for ?
Muscle force-stronger and more efficent
Paremeters for Muscle strengthening are?
waveform= symmetrical biphasic pulsatile current,
muscle strenghtenign frequency is ?
muscle strenghtening pulse duration is?
150-200= small muscle and 200-350=large muscles
muscle strengthening on; off is?
6-10 on; 50-120 off, 1;5 ration
muscle strenghtening Ramp is
> 2 sec
muscle strengthening amplitude is?
> 10% MVIC if injured, > 50% MVIC if uninjured, visible contraction
muscle strengthening time of treatment is?
muscle strengthenign is treated how often ?
every 2-3 hours patient is awake
Muscle reeducation waveform is?
symmetrical biphasic pulsatile current
muscle reeducation frequency is?
35-50 pps (>60 pps is need tetanic contraction)
muscle reeducation pulse duration is?
150-200 =small muscles, and 200-350= large muscles
muscle reeducation on:off time?
varies based on functional activity
muscle reeducation ramp is?
> 2 sec
muscle reeducation time of treatment is?
during functional activity
Muscle spasm waveform is?
symmetrical biphasic pulsatile current,
muscle spasm frequency is?
muscle spasm pulse duration is?
150-200= small muscles,200-350= large muscles
muscle spasm on:off time
muscle spasm ramp?
> 1 sec
muscle spasm amplitude?
muscle reeducation amplitude is?
functional activation of muscle, visible contraction
muscle spasm time of treatment
chronic edema waveform is?
symmetrical biphasic pulsatile current
chronic edema frequency is?
chronic edema pulse duration is?
150-200= small muscles, 200-350= large muscles
chronic edema on:off time?
2-5 on, 2-5 off. 1:1
chronic edema ramp?
chronic edema amplitude is?
chronic edema treatment time is?
conventional TENS waveform
conventional TENS frequency is?
conventional TENS pulse duration is?
conventional TENS on; off is?
conventional TENS amplitude is?
"strong but comfortable"
conventional TENS time of treatment is?
up to 24 hrs a day
conventional TENS utilizes the gate theory of pain control where?
spinal cord level
Accupuncture like TENS waveform
Accupunture like TENS frequency is?
Accupuncture like TENS pulse duration is?
Accupuncture like TENS on:off
Accupuncture like TENS amplitude is?
Accupuncture like TENS treatment time is?
Accupuncture like TENS releases what?
Interferintial current waveforn is?
Interferential current on:off is?
Interferential current amplitude is?
"strong but comfortable"
Interferential current treatment time is?
Interferential current may be quad polar or
Iontophoresis waveform is?
Iontophoresis amplitude is?
Patient tolerance, no more than 4mA
Iontophoresis tiem of treatment is?
depends on amplitude
iontophoresis polarity is?
same as drug (drives drug into skin)
iontophoresis total dose=
Tissue healing waveform is?
DC monophasic or HVPC
Tissue healing frequency is?
tissue healing pulse duration is?
tissue healing on:off is?
tissue healing amplitude is?
comfortable tingling sensation
tissue healing treatment time is?
tisssue healing polarity is?
+ for clean wound, --for injection
Acute edema wavefrom is?
DC monophasic or HVPC
Acute edema frequency is ?
acute edema pulse duration is ?
acute edema on:off is
acute edema amplitude is?
comfortable tingling sensation
acute edema treatment time is?
acute edema polarity is?
What is charge (Q)?
matter has a positiv charge ( +), a negative (-), or is electrically neutral, measured in coulombs (C)
free electrons flow from an area of excess electrons (negative pole) to an area defiecient in electrons (positve pole)
What is electricl current (I)?
the flow or movement of charged particles through a conductor following an applied electrical field.
What is Voltage (V)?
electrical force moving charged particles through a conductor between 2 regions or points, may also be called potential difference, measured in volts (V).
What is resistance (R)?
property of the conductior that resists the flow of charged particles, measured in Ohm's
Direct current (DC) Waveforms
continuous and unidirectional flow of charged particles (either + or -), used for Iontophoresis and stimulting denervated muscles to contract, occasionally will be used with wound healing
Alternating current (AC) Waveforms
continuous and bidirectional flowof charged particles (+ and -), no pulse charge remains in tissues as there is equal ion flow in both directions
AC wavelength= duration of one cycle=
inverse relationship between cycle duration and frequency, as frequency increases, cycle duration decreases
Pulsed/Pulsatile current is?
electrical current delivered discontinuously, periods of pulsing followed by periods where no current is flowing( usually off longer than on), may be unidirectional.
what is interferential current (IFC)?
waveform produced by the interference of 2 medium frequency sinusoidal AC's of slightly different frequencies at a 90 degree angle, Waveforms are delivered through 2 sets of electrodes in separate channels through one machine (4 electrodes, 2 channels), produces beats
IFC amplitude of current
higher amplitude current when both are in the same phase and a lower amplitude current when they are in opposite phases
IFC beat frequency =
difference between the frequencies of the original AC's (usually set by machine)
IFC Carrier frequency=
slower original AC (ex: 4100 Hz frequency interferes with 4000 Hz frequency
what is Beat frequency?
Benefits of IFC
more comfortable as it has a low amplitude current when going through the skin, delivers higher current in deeper tissues--continuouis AC with increase average amplitude, stimulates a larger area
what is premodulated current?
continuous sinusoidal waveform with medium frequency coupled with a sequentially increasing and decreasing current amplitude (same concept as IFC), wave interference occurrs in machine then is delivered through 2 electrodes, 1 channel, not the same benefits as IFC
2500Hz carrier AC frequency with 50 burst per second, each burst is polyphasic waveform delivered for 10 usec, followed by a rest interval of 50 usec, usually a 10 minute treatment (10/50/10 protocol)
What is Phase duration?
duration of one phase of the pulse, described in microseconds (us) or milliseconds (ms), controls comfort of stimulation, less skin impedance, less chemical changes under the electrode, better discrimination
What is Interphase interval?
time between phases of a pulse
What is decay time?
time it takes form peak to decrease to 0 during a phase
what is ramp down?
time it takes current to go from mazimum to 0 amplitude for any one on time, allows patient to acclimate to the stimulation, providing comfort as compared with attaining maximum amplitude right from the start, Off time
what is On time?
time when a run of pulses occurs and current exists,muscle contraction, usually expressed as a ratio 1;5
what is Off time?
time between trains of pulses when no current exists, relaxation, ususally expressed as a ration 1;5
What is Duty cycle?
ration of on time to totla cycle time, On 10 sec, off 50 sec=10;60 or 1;6 duty cycle
what is modulation?
any vartiation, cyclic or random, of one or more of the stimulation paramaters, limits adapttion of the neurons to current
what is frequency modulation?
varying the number of pulses or cycles per second , usually referred to as sweep
what is amplitude modulation?
varying the peak amplitude, usually referred to as scan
what is phase duration/pulse duration modulation?
varying the phase or pulse duration
what is Burst mode?
series of pulsed delivered in an "envelope" as a single pulse, frequency and duration preset
what is burst duration?
time from beginning to end of the burst
what is interburst interval?
time between burst
basics of nerve depolarization?
nerves communicate with one otnother through the production of aton potientials(AP), created by depolarization and repolarization of nerves,
AP are all or none
increased amplitude or duration dosent increase strenght of the AP, providing current below the needed amplitude of pulse duration for nerve type is considered subthreshold and will not cause an AP. Once the AP are produced, the body will react similary to if it were experiencing the same change physiologically
Resting potiential is?
difference in electrical potential across the cell membrane when information is not being transmitted.--70 mV= maintainted by Na+/K+ pumps and large, negatively charged ions trapped inside the cell.
--55mV= threshold level that will reate an AP, relies on Na+ channels opening, sodium channels open fast and sodium rushes into make inside more positiively charged.
membrane potential returns to more negative state and resting potential is restored , when membrane potential is +30mV, Na+ channels close and K+ channels open to allow K+ out of the cell and the membrane replarizes to --70mV.
What happens to an AP during Depolarization?
The neuron is rapidly depolarized by the opening of voltage-gated Na+ channels. Na+ is pulled into the cell by the negative charge inside and because of the larger concentration of Na+ outside the cell.
What happens to an AP during Repolarization?
The Na+ channel close and voltage-gated K+ channels open to reploarize nerve. K+ is pushed out of the cell becuse of the large concentration of K+ inside of the cell and because of the positive charge inside the cell.
first fibers stimulated in physiological contrations are
slow twitch, smaller, unmylelinated
first fibers stimulated in a stimulated contraction?
principle of muscle strenghtenign overload principle
Greater load-->grater force production-->greater strength
principle of muscle strenghtening specificity principle
activating type 2 fibers-->greater force-->greater strength
Specific uses of estim with innervated muscles
increasing strength and endurance, increasing muscle strenght for stabilizing joint, decreasing spasticity with altered agonist-antagonist faciliation, treating uringry incontinence seconday to pelvic floor dysfunction, and muscle contraction to promoate blood flow-0-> decrease risk of DVT
muscle contraction for deenervated muscles
helps slow the process of muscle atrophy and tissue fibrosis formation, continuous DC with longer pulse duration can allow denervated muscles to contract, Ramp up current amplitude to reach desired amplitude, may slow nerve regeneration, so should not be used if this is the goal
Conventional or high rate TENS is used for ?
In conventional or high rate TENS, pain modulation basics are?
activateing AB nerves, alter pain pereption carried on A? an C fibers, requres certain parameters in order to be stimulated, can alter pain-spasm-pain cycle and further decrease pain, adaptation can occurs if no changes are made, this is the reason for modulation
General parameters of Conventional or High rate TENS are
short pulse duratrion, comfortable amplitude (strong but comfortable), suded while pain is presient, can be used constantly
Low rate or acupuncture like TENS basics are
stimulation and depolariation of muscles and A? leads to release of endorphins and enkaphalins (endogenous opiates), controls pain for 4-5 hours after treatment of 20-30 minutes
general parameters for low rate or acupuncture like TENS are?
longer pulse duration, higher amplitude (visible contraction), treatment must be less than 30 minutes to prevent DOMS.
What is absolute refactory period?
when the membrane is deplarized, it is not possible to create antother AP
what is relative refactory period?
after depolarization occurs, a short hyperpolarization period occurs, a stronger than normal AP would be required to produce antother AP, this is an important consideration when talking about AP conduction being unidirectional, as time is required for repolarization before sending antother signal
AP triggered in adjacent nerves and along the neuron, phjusiologically , propogation usually occurs in olnly one direction, with estim, AP propagation can occur in both directions but effects are only seen in the direction typically seen with physiological AP propagation
Sensory nerves do what?
(Afferent) will always submit sensory info to the brain,also lowe current amplitude and shorter pulse duration depolarize
motor nerves do what?
(Efferent) will always submit motor infor to the muscles, higher amplitude and longer pulses are requred to depolarize.
Propagation speed is what?
depends on nerve diameter and myelination
What is Salutory conduction?
impulse jumps between spaces in myelin sheaths, known as nodes of RAnvier, this leads to greater speed of impulse conduction
Pain transmitting C fibers do what?
high amplitude and longer pulses are required to depolarize
What is Strength-duration curve?
minimum amount of electrical current (combination of amplitude and pulse duration) requred to depolarize the nerfe and lproduce an AP in a specific type of nerve.
what is Rheobase?
minimum amplitude requred with a long pulse duration to produce an AP (meauseures amplitude)
what is Chronaxie?
minimum duration to stimulate nerve at twice rheobase (measures time/duration)
What is accomodation?
decreased response to same amplitude of nerve stimulation, must rise fast enough that nerve cannot acclimate to the current produced.
what is muscle depolarization?
innervated muscles contract with electricity from depolarization of motor nerves, denervated muscles contract with electricity from depolarization of the muscle cell membrane (requres longer pulses)
Ionic Effects are what?
Result from a net charge in the tissues following estim, requireing DC monophasic waveforms, not biphasic waveforms, used in the clinic with ionto to repel ions from the anode or cathode (depending on medication) and increase transdermal deliver of drug, may be used for inflammatory phase and to facilitate tissue healing.
Brief intense TENS is used when?
to provide immediate, short term relief, often used in the clinic befor especially painful procedures(joint mob, PROM, etc)
Burst mode TENS is used to?
combines conventional and acupuncture TENS, stimulated endogenous opiates like low-rate TENS but may be tolerated better, provides pain reliler similar to high rate TENS
Tissue healing occurs through?
attraction and activation of cells needed for tissue healing in the area (neutrophils, leukocytes,), modification of endogenus electrical potential of tissues, reduction of edema, increased antimicrobial activity, promotion of circulation,increased synthesis of DNA and collagen most effective at healing pressue ulcers
Waveforms found to be the most useful is HVPC
(-) HVPC can decrease the amount of new edema formation but dosen't alter existing edema, (+) HVPC dosen't effect edema
Negative electrode attracts?
activated neurophils ( present with infection or inflammation) lymphocytes, platlets and mast cells, fibroblast, used for infected of inflamed wounds, acute stage of healing
Postive electrodes atrracts?
inactive neutrophils and macrophages, epiderma cells, used with necrosis without inflammation and wounds in the proliferation stage, clean wounds.
Transdermal drug delivery (Iontophoresis)
use a low voltage DC to move charged ions across the drmis by increasing the permeability of th statum corneum, penetratio is likely 3-20 mm, current must be the least suffiecent to overcome the resistance of th skin and electrode
common medication used in therapeutic setting is
Dexamethosone (0.4 % soultion (-), corticosteroid tht acts as an anti-inflammatory, useful with tendonitis or bursitis
Iontophoresis is described as milliamp minutes (mA. minutes)
set ampliuitde to patient comfort and adjuist time fro there 40 mA is currently recommended for treatment.
Demand cardiac pacemaker or arrhythmias, estim can interfere with the pacemakers's thythm, can alter unstable arrhytmias that are not treated
Pacement of electrodes over crotid sinus on th anterior or laterna neck, induce rapid decrease in BP
Areas of venous or arterial thrombosis or thrombophlebitis
Pregnancy-over or around the abdoment or low back
cardiac disease, MI, congential or acquired abnormalities
Impaired sensasation or mentation
malignant tumor, estim can enhance tissue growth, inculding malignant tissue
Areas with skin irritation or open wounds, open/damaged skin has lower sensation--> too much current delivery, if being used to treat the wound this is ok
Iontophoresis after other physical agents, alterled skin permeability--> too much current, with heat increased blood flwo--> drug delivery away form treatment area, ofpend skin pores allow too much drug to enter skin, with cold, decreased sensation prevents determining comfortale stimulation levels
Adverse effects to estim
electrical burns, skin reaction to the electrodes, pain
Alkaline reaction (-)
sodium hydroxide forms under the negative electrode. causes discomfort, skin irritation or chemical bursn, reduced likelihood by increasing the size of the negative electode
Acidic reaction (+)
Hydrochloric acid forms under the postive electrode, less umcomfortable than alkaline reaction