Exam 1 Flashcards
Chronaxine
The time required to depolarize a nerve fiber when the peak current is twice Rheobase.
When amplitude is twice rhoebase and the phase duration is slightly greater that Chronaxine the result will be the greatest comfort for the patient
Frequency
Number of pulses or cycles generated per second
Increased frequency leads to summation.
Wedenskis inhibition
Stimulation the the increased frequency refacing period of the sensory were cases inhibition
Action potential failure
Capacitance
Ability of a material to store a charge
Physiological effects of electrical stimulation
Decreased pain, decreased muscle spasm, reduced edema
Stimulate exercise by muscle contraction, stimulate healing
Monophonic current
Current flow in one direction
Direct current
Aka Galvanic
Unequal sized electrodes, one is active; at the target site. One is dispersive, away from target site
Biphasic current
Alternating current
Flow of electrons changes direction regularly
Phase duration
Time time it takes current to leave the isoelectric lines to when it returns to this line
Amplitude
Intensity or magnitude of the current
Must be high enough to reach threshold of muscle or nerve
Increase peak currents is associated with greater depth of penetration
Average current
Amount of current supplied over a period of time
Strength duration curve
Describes the relationship between amplitude (strength) of electrical current and the duration (phase)
Phase charge
Alter phase charge by changing the phase duration and the amplitude
Muscle cx: A alpha motor neurons have been exceeded (burning, needling)
Rheobase
Minimum amplitude need to depolarize a nerve fiber when phase duration is infinite
If peak amplitude fails to exceed Rheobase the nerve will not depolarize
Bipolar
2 equal sized electrons
Most common used in TENS
Quadripolar
Mused with interferential currents
2 separate medium frequency currents are used with electrons placed as cross currents
NMES
Goal is to stim alphs motor nerves causing strong muscle cx
1* retain lost muscle function, decrease muscle atrophy
2* decrease muscle spasm
NMES physiological
Slow twice fiber safe contracted first, minimal fatigue
MNES electrical
Larger diameter, fast twitch fibers are reactive first, lower captainanc
Nerves fatigue rapidly
NMES currents
Russian- biphasic sine waves
Biphasic pulsed- symmetrical, biphasic
Interferential- 2 or more biphasic sine wave currents
TENS
Transcutaneous electrical nerve stimulation
Stim of nerve thru skin
Modification of neurological aspects of pain
Acute paint also use ice and heat
Sensory level stimulation
Large diameter target tissue (a beta fibers) High pulse rate .. 60-150 hz Sub motor stim Acute 20-30 mins
Motor level stimulation
Cause depolarization do alpha motor neurons
More vigorous then sensory
NOT for acute
Pulse rate low 0-15 he
Noxious level stimulation
Stimulation of C fiber s
Used on trigger points
Pulse rate high (60-150)
Tolerable….10-20
Interferential currents.
true, pre mod, vector scan, stereodynamic
3000-5000 hz
2 channels= 4 electrons
Must apply electrode sin CRiSSCROSS
Constructive interferential
When 2 sinusoidal waves that are exactly in phase combine, the waves supplement each other in common interferential
Destructive interferential
When 2 sinusoidal waves are exactly out of phase the result is cancellation of both waves
Heterodyme interferential
Combination of both resulting in a wave with a beat effect
True interferential
2 channel 4 electrodes, applied Quadripolar crisscross
Most intense where currents cross
Pre modulated INF
Pain relief
Good for small areas
2 electrodes on either side
Vector scan interferential
Quadripolar electrode placement
Uses true interferential
Cloverleaf pattern, larger tx area
Stereodynamic
3 channels, 6 electrodes
3 D pattern, flower
Effects / indications of INF
Pain reduction ( acute and chronic)
Muscle strengthens/ reeducation (pelvic floor)
Increase circulation
Slow bowel transit
Setting for pain INF
To beat frequency
Acute= 60-150. Chronic =0-15. Subacute=1-150
Tx time 15-20 mins
Amp. Comfort (tingling)
Settings for strength INF
Amp. Tolerance
Tx freq 40-60 hz
Russian current
Kots
Duty cycle off/on to cause muscle cx for muscle strengthing
Indications for Russian current
Muscle re education, retard atrophy, strength, decrease muscle spasm
Can be uncomfortable
1 sec/50sec for strength
10swec/10sec for muscle fatigue
Electrodes placement for Russian stem
Always along fibers of same muscle or muscle group
Monopolar= 2 unequal sized electrode
Bipolar= 2 equal sized
Quadripolar=4 electrodes
High voltage pulsed current
ESTHR
Aka galvanic
Sued for enhancing soft tissue repair
Must have form peak momphasic DC current
Benefits of ESTHR
Deeper penetration
Avg current remains low due to short phase duration resulting in a safe current
Microcurrent
Continued or pulsed current with polarity reversal
Peak amp is below Rheobase of a beta afferent fibers
No depolarization takes place
Galvanotaxis
Polarized cells are attracted to the opposite polarity, enhances healing
Inflammatory phase
Positive polarity, attracts neutrophils and macrophages
Proliferation phase
Negative polarity,
Attracts fibroblasts that promote collagen function
Remodeling / maturation phase
Negative polarity
Attracts kertanocytes and epithelial cells
Edema reduction with high volt
Negative polarity
Monophasic electrode placement, over area of swelling
Dispersal electrode proximal, for deeper penetration
Indications for high volt
Muscle spasm reduction
Pain reduction but it preferred like INF
Under stock for high volt and Mirco
Stimulate wound healing
Decrease edema
Decrease spasm
PH changes in monophasic current
Positive polarity attracts acids
Repels bases
Negative polarity attracts bases
Repels acids
