GRFC - electrotherapy Flashcards
Electricity
Form of energy composed of atoms
Proton (+)
Neutron
Electron (-)
Voltage/ electromotive force
Force that moves or drives electrons
Unit of measure: Volt
Current/ current intensity
Net flow of electrons
(+), (-), or both (+) and (-)
Unit of measure: Ampere
Resistance
Opposition to electron flow
Unit of measure: Ohm
Ohm’s law
I = V/R
Conductor
Facilitates electron flow or flow or electricity
Examples include H2O, metals, among others
Resistor/ insulator
Resists electron flow
Ions
Charged particles
Cation (+)
Anion (-)
Electrotherapy
The use of electric current and its variants in rehabilitation and treatment
Differences between cathode and anode in terms of
- pH
- risk for burns
- skin color
- polarization
- NCV
- effect
- function/indication
(pH)
- anode acidic
- cathode basic
(risk for burns)
- anode less risk
- cathode more risk
(skin color)
- anode pinkish hyperemia (blush)
- cathode mottled red
(polarization)
- anode hyperpolarization
- cathode depolarization
(NCV)
- anode decrease NCV
- cathode increase NCV
(effect)
- anode sclerosis (hardening)
- cathode sclerolysis (softening)
(function/indication)
- anode wound closure, skin hardening
- cathode disinfection
Law of magnetism
Opposite charges attract
Like charges repel
Electrotonus
Anelectrotonus: decreased muscle activity caused by anode
Catelectrotonus: increased muscle activity caused by cathode
Pleuger’s law/ polar formula/ Erb’s formula
For normal or innervated muscles, or for those with UMNL:
-COC-ACC-AOC-COC
For those with denervated muscles, for those with LMNL:
-ACC-COC-COC-AOC
NOTE:
- COC: cathode opening circuit
- CCC: cathode closing circuit
- AOC: anode opening circuit
- ACC: anode closing circuit
Resting membrane potentials
Muscle: -90mV
Nerve: -70mV
Heart: -88mV
GIT: -56mV
Electrical properties of nerves
- Electrical excitability/ resting membrane potential
- Refractory period
- Accommodation
Factors affecting resting membrane potential
- Speed
- Intensity
- Duration
Types of refractory period
Absolute refractory period:
-No AP can be generated even with supramaximal stimulus
Relative refractory period
-AP can be generated with supramaximal stimulus
Accommodation
Decreasing intensity as the body adapts
Dubois Raymond law
A sudden change in current intensity is needed to stimulate a nerve
Types and characteristics of currents
LFC
- frequency (Wadsworth): 1Hz to 2000Hz
- frequency (O’Sullivan): 1Hz to 1000Hz
- affects innervated and denervated muscles
- for motor purposes
- AC, DC, ES, FES, NMES, TENS (value)
MFC
- frequency (Wadsworth): 3000Hz to 6000Hz
- frequency (O’Sullivan): 1000Hz to 10000Hz
- affects innervated muscles
- for sensory purposes
- IFC, Russian current, TENS (effect)
HFC
- frequency (Wadsworth): >500000Hz
- frequency (O’Sullivan): >10000Hz
- does not affect nerves
- for thermal purposes
- UTZ, SWD, MWD, IRR-UVR, LASER
Direct/ monophasic/ Galvanic current
One phase/ polarity
Best for wound healing (especially high volt pulsed Galvanic current (HVPGC))
Best for denervated muscles (especially rheobasic current)
Types of direct current
Direct continuous/ direct uninterrupted:
No off-time or pulsed interval
For iontophoresis
Incrased risk for medical Galvanism (burn, fatigue)
Direct pulsed/ direct interrupted:
With off-time
Decreases risk for burn or fatigue
Types of direct interrupted/ direct pulsed current
Short DIC/ Faradic type Frequency: 50Hz to 70Hz Pulse duration: 0.02ms to 1ms Application: Tetanic contraction Sensation: Marked stabbing Use: For innervated muscles
Long DIC
Types of long direct current/ long direct interrupted current
Rectangular long DIC/ quick rise
Frequency: no fixed
Pulse duration: 1ms - 600ms
Use: For innervated, denervated muscles
Sharp long DIC/ exponential progressive current/ slow rise
Frequency: 300ms - 1000ms
Use: For denervated muscles
Forms: Triangular, saw-toothed, trapezoid
Alternating current/ biphasic/ polyphasic
Has 2 polarities; switches from (+) to (-) to (+)
Decreased risk of burn and fatigue
Types of alternating current
Faradic Uneven, assymmetrical AC Frequency: 50Hz Pulse duration: 1ms Application: Tetanic contraction Sensation: Mild tingling Use: For innervated muscle
Sinusoidal Even, symmetric Frequency: 50Hz Pulse duration: 10ms Application: Tetanic contraction Sensation: Mild tingling Use: For innervated muscle
Iontophoresis
Process of introducting medications (in the form of ions) to the body via electricity
Principles in iontophoresis
Like charges repel
Hydrolysis
Electrolysis
Ionization
Factors affecting ion transfer
Duration
Ion concentration
Current intensity
Anion medications
NaCl - for muscular adhesions/ connections Salicylic acid - inflammation, pain, analgesia Acetic acid - calcium deposits Iodine - wounds and keloid scars Dexamethasone - inflammation, pain H2O - for iontophoresis C (-caine) - pain C (-cortisone) - inflammation
Cation medications
Remotin - adhesions
Mecholyl sulfate - scleroderma, varicose ulcers, chronic arthritis, sympathetic RSD
Hyaluronidase - edema
Glycopyronium bromide glycoprolate - hyperhidrosis
Vinca alkaloid - neuralgia (lirica), nerve pain (tic douloureux)
MgSO4; CaCl - muscle spasm
CuSO4 - fungal infections
ZnSO4 - hay fever, allergic rhinitis, indolent ulcers
Bipolar medications
NaCl Dexamethasone (-) wyadase, not pure dexamethasone, with hyalunoridase, (+) decadone C (-caine) C (-cortisone)
LFC application methods
Monopolar
1 pair - 1 active, 1 dispersive
1 active on muscle belly, motor point, nerve trunk
1 dispersive anywhere near
For innervated muscle
EXCEPTION: Bell’s palsy (denervated) - use pen-type electrode
Bipolar
1 pair - 2 active
2 active on muscle belly, muscle bulk, motor point
For innervated or denervated muscle
