Foundations of Clinical E-Stim

motor nerve

muscle

sensory nerve

spinal cord

big three for action potentials

amplitude

phase duration

rate of rise

amplitude requirement

must be high enough to reach thresholdp

phase duration requirement

must be long enough to deliver charge

rate of rise requirement

must be fast enough to prevent accommodation

support crew for ap (3)

frequency

duty cycle

waveform type

order of strength duration curve firing (5)

alpha beta sensory

motor

alpha o sharp pain

c dull pain

denervated

intensity measured as (4)

subsensory

sensory

motor

noxious

short vs long phase duration

short: <125 microsec

long: >125 microsec

intensity is used for

course adjustment

phase duration is used for

fine adjustment

treatment frequencies (3)

monophasic

biphasic

polyphasic

combo of amplitude and phase duration determins

if ap is generate

treatment ferquency

how often aps occur in 1 sec

clinical waveforms (3)

DC

AC

Pulsed

DC waveform used for (3)

denervated muscle

iontophoresis

wound healing

AC waveform used for (2)

true ac not really used

pulsed: paid relief

burst: muscle strengthening (russian)

pulsed waveform used for (4)

tens

nmes

fes

hvpc

duty cycle equation

pulse duration/(duration+interval)

DC vs monophasic

AC vs biphasic

polyphasic vs AC

polyphasic pulsed currrent created by

carrier frequency c

carrier frequency

phase duration control

1000-5000 hz

carrier frequency / phase duration relationship

inverse

cannot adjust duration directly, can choose carrier frequency

channel factors

2 lead wires

each lead minimum 1 electrode

minimum 2 leads for 1 channel

electrode techniques

monopolar

bipolar

current density

how electrode size / placement impacts comfort, safety, and treatment precision

skin impedance

why resistance matters and how we can reduce it

total current

what determines the total electrical dose delivered over time

current density equation

current density = current / electrode size

high current density

small pads

high current

less comfort, more painful

increase risk of burns

increased focus

low current density

large pads

lower current

more comfort, less painful

lower risk of burns

less focused

skin impedances

tissue type

hydration levels

electrode condition

varies between sites and days

ways to minimize impedance

clean moist skin

minimal hair

warm skin

ensure good contact

total current equations

total current = amplitude x pulse duration x frequency

burn risk reduction strategies

good contact

lower skin impedance

correct size

good condition

total current considerations

unit in good working order