E Stim Flashcards
What is an electric current?
Flow of charged particles; may be electrons or ions
Alternating current
Continuous bidirectional flow of charged particles. Alternates between + & -.
- Has equal ion flow in each direction & no pulse charge remains in the tissues.
- When frequency increases, the cycle duration decreases…it happens faster.
- comfort/ pain reduction
- wavelength is similar to pulse duration of a pulsed current
- Russian, IFC, and premod all derive from AC
Interferential current (IFC)
- best for pain control & muscle relaxation
- electrodes configured so 2 ACs intersect
- when they intersect, they interfere, producing a higher amp when both currents are in same phase & a lower amp when they are in opposite phases.
Premodulated current
- similar to IFC but with 2 electrodes instead of 4; u can use it in a smaller area.
Direct current
Continuous unidirectional flow of charged particles used or iontophoresis & stimulating contraction of denervated muscle & occasionally wound healing.
- use neg electrode for neg drug & positive electrode for positive drug
- uncomfortable but better response
- leave a net charge in the tissue
Pulsed current
- often DC
- interrupted flow of charged particles ( pulses w no current)
- can use w all others
- use when giving muscle contractions
What is amplitude?
Intensity or magnitude of current or voltage
Current density
The amount of current delivered per unit area
Electrical current
Movement or flow of charged particles through a conductor in response to an applied electrical field. Current is noted as I and is measured in amperes (A)
Electrical muscle stimulation (EMS)
Application of an electrical current directly to muscle to produce a muscle contraction
Functional electrical stimulation (FES)
Application of an electrical current to produce muscle contractions that are applied during a functional activity. For example, DF during swing phase of gait with e stim
Galvanotaxis
Attraction of cells to an electrical charge
Gate control theory
Theory of pain control and modulation that states pain is modulated at the spinal cord level by inhibitory effects of nonnoxious afferent output
Impedance
Total frequency- dependent opposition to current flow.
Noted by Z.
Iontophoresis
Transcutaneous delivery of ions into body for therapeutic purpose using an electrical current
Low rate TENS
TENS w long duration, high amplitude pulses used to control pain; aka acupuncture like TENS
Motor point
Place in muscle where electrical stim will produce greatest contraction w the least amount of electricity, generally located over middle of muscle belly.
NMES
Application of an electrical current to motor nerves to produce contractions of the muscles they innervate
Ohm’s law
Math expression of how voltage, current, and resistance relate where voltage equals current multiplied by resistance.
Overload principle
Strengthening muscle that states the greater load placed on a muscle and the higher force contraction it produces the more strength that muscle will gain.
Phase
In a pulsed current, the period from when current starts to flow in one direction to when it stops flowing or starts to flow in e other direction.
- phases make up a pulse
Polarity
Charge of an electrode that will be positive (anode) or negative ( cathode) with direct or Monophasic pulsed current and constantly changing with an alternating or biphasic pulsed current
Resistance
A materials opposition to flow of electrical current. R. measured in ohms.
Pulse
In a pulsed current, the period when current is flowing in any direction
- pulses are made of phases
TENS
Application of electrical current through skin to modulate pain
Voltage
Force or pressure of electricity; difference in electrical energy between 2 points that produces electrical force capable of moving charged particles through conductor between those 2 points.
Russian
- form of DC
waveform with specific protocols to elicit a muscle contraction
What happens if pulse duration is shortened?
Greater amp is needed to achieve same strength of contraction with longer pulse duration
How do u contract a denervated muscle?
You need a pulse longer than 10ms. This is why we need e stim.
EMS
Electrical muscle stimulation
FES
Functional e stim
Phase duration
Duration of one phase of a pulse
Pulse duration
Duration from the first phase to the last phase of a pulse
Ramp time
Time it takes for current amplitude to go from zero to its max amplitude
Inter pulse interval
Time between pulses
Impedance
Opposition to current flow
Alternating current facts
Wavelength of AC is similar to pulse duration of pulsed current
Russian, IFC, and premod currents all derive from AC
