Electro - Parameters & Types of Currents

Amplitude defintion

strength;

affects depth and recruitment

increased amplitude →

stronger contraction;

recruits deeper / larger motor units

Amplitude synonyms / alt terms

Intensity, Magnitude, Output, mA, Volts

Pulse duration defiintion

time current flows in one pulse

increased duration recruits

more motor units;

smaller or deeper fibers

Pulse duration synonyms

Pulse width

Frequency definition

Number of pulses per second

increased frequency →

smoother (tetanic) contraction;

but also increased fatigue.

Frequency synonyms

Pulse Rate, pps, Hz

Phase Duration definition

Time from start to end of a single phase

Interpulse Interval definiton

Time between successive pulses

Interphase Interval definition

time between phases in a biphasic pulse

Ramp Time definition

grad increase or decrease in current to improve comfort

longer ramp improves

comfort

and mimics natural motor recruitment

Ramp time synonyms

Ramp Up / Down

Duty Cycle definition

Ratio of ON to OFF time;

affects muscle fatigue

longer off time of a duty cycle →

reduces fatigue

Duty Cycle synonyms

On / Off Time

Train definition

Series of continuous pulses at a fixed frequency

Burst definiton

series of pulses w/ breaks b/t groups;

in Russian & TENS

Burst synonyms

Burst Mode

Average Current definition

Mean current delivered over 1 second

higher average current =

stronger effect

but more fatigue / heat

Peak Amplitude definition

Maximal current in one pulse

Waveform defintion

Shape of the pulse current

_______ is generally most comfortable.

symmetrical biphasic

Polarity defintion

Direction of current flow

Cathode (-) _________; Anode (+) _______

increases excitability; decreases it

Polarity synonyms

Positive/Negative Electrode

Electrode Size/Placement affects

current density and tissue recruitment

Current Density =

Current per unit area;

higher in smaller electrodes

Continuous Direct Current (DC) definition

UNI

continuous

used for iontophoresis

Continuous Direct Current (DC) synonyms

Galvanic, uninterrupted DC

Alternating Current (AC) definition

BI

continuous

not commonly used clinically

Alternating Current (AC) synonyms

uninterrupted AC

Pulsed Current definiton

Intermittent flow with interpulse and/or interphase intervals; common in NMES, TENS

Pulsed Current synonyms

Monophasic, Biphasic, Polyphasic

Russian Current definition

Polyphasic AC at 2500 Hz;

strong motor contraction

Russian Current synonyms

Medium Frequency AC

High-Volt Pulsed DC (HVPC) definition

Twin-peaked monophasic;

used for edema, pain, wound healing

High-Volt Pulsed DC (HVPC) synonyms

Twin Spike

Interferential (IFC) definiton

Two AC currents intersect to create beat frequency in tissue

Microcurrent defintion

Very low amplitude current

below sensory threshold

Microcurrent synonyms

MENS, LIS