Modalities Flashcards
resting membrane potential
negative inside cell, positive outside the cell
refractrory period
absolute: cannot fire.
relative: can fire, but requires stronger stimulus
Contraindications for ESTIM
trunk of pregnant woman
areas of PVD/thrombophlebitis
pacemaker/other implanted electrode
close proximity to diathermy
Precautions for ESTIM
Carotid sinus High intensity estim around heart excess adipose insensate skin seizures open wound (unless treating wound)
Galvanic current
continuous, direct current. Used only for ionto
Has polarity
Cathode
negative electrode
attracts cations
Anode
positive electrode
attracts anions
Effects of Cathode
Base reaction
increase in nerve irritability
softening of tissue
Effects of anode
acid reaction
decrease in nerve irritability
hardening of tissue
Current
Flow of charged particle
Measured in Amperes
Current=voltage/resistance
Which is more important, average or peak current?
Average
Average total current limits
Do not go over 4 (most patients uncomfortable at over 2)
Fused/tetanic contractions occur around ____ Hz
15-20
What common applications are there for polyphasic current?
IFC and Russian
What current is “jack of all trades”
Hi volt pulsed DC
Rise and decay
Rise: time from baseline to peak
Decay: time from peak to baseline
Both apply to a single phase
Ramp
Ramp up: time from zero to maximum amplitude (seconds)
Ramp Down: time from max to zero
Increases comfort
Rheobase
magnitude of current just strong enough to cause tissue excitation with long pulse duration
Chronaxie
minimal pulse duration for activation at twice rheobase intensity
Pulse Duration
100-400 us.
300-400 most used
over 800 will stimulate pain receptors
Increased pulse duration will increase recruitment of:
smaller fibers at same depth
Increased amplitude will increase recruitment of:
smaller fibers at same depth, AND
larger fibers further away
What is the desired pulses per second for strengthening
30-50pps
Monopolar electrodes
1 active pad, 1 dispersive:
dispersive is larger and away from treatment area
cycle time
on/off time
modulation
varying 1 or more parameters
increases comfort and prevents accomodation
Burst
finite series of pulses
Time interval=burst duration
often seen in TENS and Russian
Train
a continuous, repetitive series of pulses at a fixed frequency
Normal vs Evoked firing pattern
Normal: asynchronous, fine gradiations in tension, small units first
Evoked: synchronous, max tension at tetany, large units recruited first
Classification of Estim by frequency
Low (1-1000Hz): most pulsed units
Medium (1k-100k) Russian (2500Hz), IFC (4-5k)
High frequency: 100k+ diathermy: 27MHz
Use of continuous DC
ionto
Use of Interrupted DC
Denervated muscle (pulse width of over 10ms)
Use of monophasic pulsed DC with twin spikes
Hi volt pulsed DC:
Pain control
edema reduction
tissue healing
muscle stimulation (small muscles)
Use of polyphasic sine wave
Russian (motor)
IFC: analgesia, edema/spasm reduction
Low volt pulsed current
Common
less than 150v
symmetrical/asymmetrical
Portable NMES/TENS
High-Volt Pulsed
0-500V
Monophasic twin spike
Management of pain, edema, wounds.
muscle contraction in small muscle groups
fixed pulse duration at 100-150 usec
IFC
two channels with different frequencies- beats per second is difference in frequencies.
Less than 150V, but high average current
Used for pain, edema, muscle spasm
Russian current
Interrupted sine wave-medium frequency
carrier frequency typically 2500 Hz, 50 bursts per second
50% duty cycle
NMES pulse duration
May be fixed
100-600 (300)
keep as low as possible to minimize chance of stimulating A deltas.
NMES frequency
30-50 pps (true russian is 50)
Ramp down is usually ___ of ramp up
1/2
Gate Control
Stimulate A-Beta. “closes pain gate” so C and A delta cannot reach cerebral cortex)
Enkepahlins vs Endorphins
Enkephalins: depress receptive ability of pain receptors in SC
- short half life (2 min)
- high frequency, low pulse stim
Endorphins: released from pituitary
- long half life (4 hours)
- low frequency, high pulse duration stim
Sensory TENS settings for acute pain
*2-50 usec pulse duration
*50-100 pps
20-30 min
residual relief variable
High rate TENS, Conventional TENS
Motor level stimulation TENS for chronic
150 usec pulse duration
2-4 pps
30-45 min in research, 20 min in practice
Residual relief for hours
ESTIM noxious stimulation protocol
-For chronic pain
-Pulse duration as high as possible
1-5 pps, or greater than 100 pps
Advantages of IFC
has vector scan (amplitude modulation) built in
Preferred by many pts
Frequency modulation (sweep)
Has a high average current (can be advantage or disadvantage)
Should the anode or cathode be put over inflammation for edema management
cathode
What stages of pressure ulcers are most appropriate for estim use
stage 3/4. (2 can be used, but may not be necessary).
infected or edematous wounds most appropriate
Is Estim appropriate over osteomyelitis?
no
Effects of negative polarity on wound healing
epidermal proliferation increased blood flow fibroblast proliferation neutrophil attraction edema reduction
bacteriocidal
Effects of positive polarity on wound healing
attracts macrophages
epithelial growth
new capillarization
bacteriocidal for STAPH
Ionto
uses continuous DC.
Pole used is determined by drug
Dosed in “mA*min”
Dexamethasone for ionto
for inflammation
negative polarity
lidocaine for ionto
sodium channel blocker
positive polarity
Inverse Square law
intensity of radiation is inversely proportional to the square of the distance
Cosine law
Absorption of rays is optimal when they are perpendicular. As angle increases from perpendicular, efficiency is decreased proportional to cosine of the angle
Levels of heating effects
0-1C: mild (subacute injuries)
1-2C: moderate (chronic inflammation, pain, trigger pt
2-3*C: vigorous: stretching collagen
Heating effect on muscle firing
increased GTO firing and decreased secondary afferent firing
combine to decrease motorneuron firing
How deep can superficial heating therapeutically reach?
3 cm (most effects up to 1 cm)
What temperature should hydrocollator packs be kept at?
165-175 (76-80* C)
What temperature should parafin be kept at?
125-135 (52-53C)levels
Buoyancy
at ASIS 50% WB,
at C7 10% WB
Cold Urticaria
Release of histamine in response to cold.
causes: wheals, erythema, swelling, systemic effects (syncope, GI, respiratory)
Cryoglobinemia
pt has substances in blood that precipitate in cold
Raynauds
vasoconstriction of distal vessels in response to cold. most common in 18-30 yo females, usually bilateral
Hunting reaction
Prolonged cold leading to vasodilation in the area
Biophysical effects of cold on spasm, spasticity, and flaccidity
decreased spasm d/t decreased muscle spindle activity
decreased spasticity d/t decreased gamma motor neuron activity
Facilitation of contraction in flaccidity
Temperature for cold baths
55-65* F
Vapocoolant Sprays
hold 18-24” from pt
spray at 30* at rate of 4”/s
Contrast bath temps
100-110, 55-65
depth of US
1 MHz: 2-5 cm
3 MHz: 0-3
Biological effects of US
increased metabolism
increased blood flow
increased collagen extensability
decreased neural sensitivity
Acoustic Streaming
unidirectional movement of fluid in US field.
“micromassage”
increase diffusion, permeability
promotes tissue repair
Cavitation
alternate compression and expansion of gas
Some is desired, so is undesired
Phonophoresis
uses nonthermal effects to enhance diffusion
pulsed US
Diathermy
Microwave: 2450 MHz (gets superficial)
Shortwave: 27.12 MHz
Capacitance diathermy field
places pt in circuit: need both heads
more heat in areas of fat/skin (superficial)
Inductance diathermy field
places patient in field: only need one head
muscle, synovial fluid (deeper)
Contraindications to diathermy
metal in area, metal or plastic implants eyes CA pregnant carotid sinus, heart, stellate ganglion pacemaker
Biofeedback on weak muscles pad placement and sensitivity
Placement far apart with high sensitivity in order to increase detection.
As pt gets stronger, decrease sensitivity
Biofeedback to decrease muscle activity
Place pads close together with low sensitivity (in order to isolate muscle.
Progress to higher sensitivities
