Ptha 1431 - Physical Agents In Rehabilitation - Cameron Book And Stetz Lecture - Exam 4

Front 1

What is the specific heat of water? ***

Back 1

high (meaning it retains thermal energy well)

4.19 J/g/C

Front 2

What is the thermal conductivity of water? ***

Back 2

good (meaning it conducts heat well)

(0.0014)

Front 3

What is specific gravity? ***

Back 3

the weight of a particular substance compared with the weight of an equal volume of water

Front 4

What is the specific gravity of water? ***

Back 4

1.0

Front 5

How does specific gravity affect an object in water? ***

Back 5

an object with a specific gravity
>1 will sink
<1 will float

Front 6

What is the specific gravity of a human? ***

Back 6

0.97

Front 7

Does the human body tend to sink or float? ***

Back 7

float (especially with higher fat content)

specific gravity is < 1 (0.97)

Front 8

What is buoyancy? ***

Back 8

a force experienced as an upward thrust on an object immersed in fluid

Front 9

What is Archimedes' principle? ***

Back 9

an immersed object will experience an upward thrust equal to the weight of the liquid displaced

Front 10

How does water provide resistance? ***

Back 10

its viscosity provides resistance to motion in water

Front 11

What is the relationship between resistance and speed in water? ****

Back 11

as speed increases, so does resistance

(they are directly proportional)

Front 12

What is hydrostatic pressure? ***

Back 12

the pressure exerted by a fluid on a body immersed therein

Front 13

What does Pascal's law state? ***

Back 13

- fluid exerts equal pressure on all surfaces of an immersed body at any given depth

- pressure increases as depth increases

Front 14

What are some of the physiological effects of hydrotherapy (immersion)? ***

Back 14

- cleansing (wound therapy)
- decreased weight bearing (aids exercise)
- strengthening (due to resistance)
- slowing of bone density loss
(when compared to doing no exercise at all; is not as effective as land-based, weight-bearing exercise in preventing bone density loss)

Front 15

How does hydrotherapy affect fat loss? ***

Back 15

less fat is lost in hydrotherapy (when compared to land-based exercise)

Front 16

What are the physiological effects of hydrotherapy? ***

Back 16

when compared to land-based exercise at the same rate of perceived exertion (RPE), there is a lesser increase in:
- heart rate
- systolic blood pressure, and
- VO2

Front 17

Which is more efficient, land-based exercise, or hydrotherapy? ***

Back 17

exercise on land is generally more efficient, IF the person is able to do so

Front 18

What are some uses of hydrotherapy in PT? ***

Back 18

- superficial heating or cooling
- pain control (RA, fibromyalgia)
- edema control (with cooler temperatures)
- wound care
- water exercise for:
----- neurological pts. (esp those at risk of falls)
----- cardiorespiratory fitness
----- pregnancy
----- asthma patients
----- older patients

Front 19

In what ways is hydrotherapy used for edema control? ****

Back 19

- cooler temp
- for venous or lymphatic insufficiency
- inflammation (cold)

Front 20

For which patients might hydrotherapy in the form of water exercise be beneficial? ***

Back 20

- neurological pts. (esp those at risk of falls)
- cardiorespiratory fitness
- pregnancy
- asthma patients
- older patients

Front 21

How does water exercise help neurological patients? ***

Back 21

- increases proprioceptive input
- gives weight relief
- reduces risk of falls
- allows greater movement exploration
- reduces spasticity

Front 22

How does water exercise help patients with cardiological or respiratory issues? ***

Back 22

allows them to exercise when they cannot tolerate land-based exercise

Front 23

What is important to remember about patients with cardiological or respiratory issues during water exercise? ***

Back 23

they must be monitored more closely

Front 24

How does water exercise help pregnant patients? ***

Back 24

- removes increased load from weight-bearing joints
- controls peripheral edema
- induces less of an increase in heart rate, blood pressure, and body temperature in comparison to land-based exercise, thus is safer for fetus

would also think more beneficial with respect to balance issues--less likely to fall due to the obvious shift of body's center of gravity

Front 25

How does water exercise help asthma patients? ***

Back 25

- eliminates airborne allergens
- increased humidity less likely to trigger symptoms

Front 26

How does water exercise help older patients? ***

Back 26

allows those who cannot tolerate land-based exercise to continue being active

Front 27

What types of hydrotherapy are used in wound care? ***

Back 27

- full immersion
- local immersion
- non-immersion

Front 28

How is hydrotherapy used in wound care? ***

Back 28

- cleansing
- hydration
- softening
- debridement
- increased circulation (especially with immersion)

Front 29

What are the temperature ranges used in hydrotherapy? ***

Memorize those indicated by *

Back 29

- cold (32-79F) *
- tepid (79-92F)
- neutral warm (92-96F)*
- mild warm (96-98F) *
- very hot (104-110)

Front 30

What temperature range is used with hydrotherapy for inflammation? ***

Back 30

cold (32-79 F)

Front 31

What temperature range is used for hydrotherapeutic exercise? ***

(I guess this is general patient exercise, not those with other medical issues??)

Back 31

tepid (79-92 F)

Front 32

What temperature range is used for hydrotherapeutic exercise with medical patients? ***

(Those with other medical issues, such as cardio, pulmonary, etc.??)

Back 32

neutral warm (92-96 F)

Front 33

What temperature range is used for hydrotherapy for chronic conditions? ***

Back 33

very hot (104-110F)

Front 34

Convert F to C:

Back 34

C = (F-32) * 5/9

Front 35

Convert C to F:

Back 35

F = 9/5 C + 32

Front 36

What are some general contraindications/precautions for hydrotherapy? ***

Back 36

- bleeding
- maceration (softening of skin around wound)
- recent skin graft
- infection in area (local immersion OK)
- impaired sensation/mentation

Front 37

What are some contraindications/precautions for full immersion hydrotherapy? ***

Back 37

CI
- cardiac instability
- neurological disorders
- mental disorders
- infection that may spread in water
- bowel incontinence

P
- medications
- respiratory problems (require more supervision)
- urinary incontinence
- limited strength, endurance, ROM

Front 38

What are some contraindications/precautions for hot water, full immersion hydrotherapy? ***

Back 38

- pregnancy
- multiple sclerosis
- poor thermal regulation

Front 39

What are some potential adverse effects of hydrotherapy? ***

Back 39

- hyponatremia (low sodium concentration--esp with burn patients)
- infection
- bleeding
- burns
- fainting
- aggravation of edema if temperature is warm
- chlorine (reactions to it?)

Front 40

What needs to be done to the hydrotherapy tubs regularly? ***

Back 40

they need to be cultured and checked regularly

Front 41

What are some disadvantages of hydrotherapy? ***

Back 41

- cost (money and time)
- use of large quantities of water
- limited size of tank

Front 42

What does TENS stand for? ***

Back 42

T - transcutaneous
E - electrical
N - nerve
S - stimulation

Front 43

Describe a TENS unit. ***

Back 43

- small, portable device
- battery operated (if it plugs in, it's not really TENS)

- asymmetrical, bi-phasic wave
- used for pain control

Front 44

What two pain theories are used to explain the effects of TENS? ***

Back 44

- gate control theory
- neurochemical basis of pain inhibition (a.k.a. Endorphin theory)

Front 45

What type of wave does the TENS unit use? ***

Back 45

- asymmetrical
- bi-phasic

Front 46

What is the purpose of the TENS unit? ***

Back 46

pain control only

Front 47

What is the gate control pain theory? ***

Back 47

gate (to allow pain to brain to be felt) is "opened" by:
- A-delta (lightly myelinated, small) fibers and
- C (unmyelinated, small) fibers

gate is "closed" by:
- A-beta (heavily myelinated, large) fibers

Front 48

What neurochemicals, when stimulated, act to inhibit pain? ***

Back 48

- enkephalins
- endorphins

Front 49

What is the half-life of enkephalins? Of endorphins? ***

Back 49

- 2 minutes
- 4 hours

Front 50

List four modes of TENS application. ***

Back 50

- conventional (high rate)
- acupuncture-like (low frequency)
- burst
- brief intense

Front 51

What three parameters are common to all E-stim modalities?

Back 51

- amplitude (or intensity)
- frequency (or pulse rate)
- pulse duration (or pulse width)

Front 52

Parameters for conventional mode on TENS unit ***

Back 52

amplitude/intensity - sub-motor, tingling (just above threshold; what patient finds comfortable)
frequency/pulse rate - 100-150 cps (high)
pulse duration/pulse width - 50-80 microsec (low)
time - as needed (up to 24 hours, usually in 30-min intervals)

rapid, narrow pulses = tingling

Front 53

Uses for conventional mode on TENS unit ***

Back 53

- both acute and chronic pain, but
- primarily acute

(the low pulse duration/pulse width and high frequency/pulse rate are more comfortable, especially in the acute phase, as they produce a tingle, not a prolonged contraction)

Front 54

Parameters for low-frequency mode on TENS unit ***

Back 54

amplitude/intensity - local motor contraction (twitch)
frequency/pulse rate - 2-10 cps (low)
pulse duration/pulse width - 200-300 microsec (high)
time - approximately 30 minutes

longer-lasting, less frequent pulses = contraction (twitch)

Front 55

Uses for low-frequency mode on TENS unit ***

Back 55

- both acute and chronic pain, but
- primarily chronic

(the high pulse duration/pulse width and low frequency/pulse rate produce a more prolonged contraction, which is better tolerated in the subacute/chronic state)

Front 56

Parameters for burst mode on TENS unit ***

Back 56

amplitude/intensity - local motor contraction (twitch)
frequency/pulse rate - 1-10 bps (low)
pulse duration/pulse width - 200-300 microsec (high)
time - approximately 30 minutes

similar to low-frequency, but numerous bursts within each wide pulse = contraction (twitch)

Front 57

Uses for burst mode on TENS unit ***

Back 57

- both acute and chronic pain, but
- primarily chronic

(the high pulse duration/pulse width and low frequency/pulse rate with bursts within each pulse, produce a more prolonged contraction, which is better tolerated in the subacute/chronic state)

Front 58

Parameters for brief intense mode on TENS unit ***

Back 58

amplitude/intensity - motor response (vermicular)
frequency/pulse rate - 110 pps (high)
pulse duration/pulse width - 250 microsec (high)
time - approximately 15 minutes

(longer, more frequent pulses = vermicular muscle movement (wormlike, more than twitching)

Front 59

Uses for brief intense mode on TENS unit ***

Back 59

- intense acute pain

(the high pulse duration/pulse width and high frequency/pulse rate produce a vermicular muscle movement, tolerated in the acute state; can fatigue muscle and break up spasm)

Front 60

How is modulation used with TENS? ***

Back 60

changes in
- amplitude
- pulse width/pulse duration, or
- frequency/pulse rate

either individually or in combination serve to decrease patient accommodation to treatment

Front 61

How are TENS electrodes placed? ***

Back 61

- on point of pain
- on referring nerve root
- on acupuncture point proximal or distal to pain
- transarthral (across/through the joint)
- bilateral
- in a crossed-pattern technique (need 4 electrodes in this case)

Front 62

What is the isoelectric line?

Back 62

the baseline above and below which the waveform travels (in a biphasic wave)

Front 63

What is an asymmetrical, biphasic wave? ***

Back 63

A wave that is not symmetrical above and below the isoelectric line

Front 64

Why is frequency/pulse rate important in TENS setup?

Back 64

because different frequency settings target different nerve groups and the setting will determine if the "Gate Theory" or "Endorphin Theory" of TENS will be in effect

Front 65

Why is pulse duration/pulse width important in TENS setup?

Back 65

in general, the higher the pulse width, the more "aggressive" the stimulation feels (and less comfortable)

eventually, if the pulse width is high enough, it will usually elicit a muscle contraction, which may not be the desired result

if the pulse width is too low, however, the patient may not perceive the stimulation

Front 66

Simply put, amplitude in a TENS unit is

Back 66

what you feel when you "turn the unit up"

it's what causes the "buzzing" sensation of the TENS to go higher or lower

Front 67

Which TENS mode(s) work on the Gate Control theory?

Back 67

conventional
(and to a degree, brief intense)

high frequency/pulse rate electrical activity is believed to block the pain by stimulating A-beta (large, heavily myelinated) fibers

Front 68

Which TENS mode(s) work on the Endorphin theory?

Back 68

low frequency
burst
(and to a degree, brief intense)

low frequency or short bursts of mild electrical activity is believed to cause the body to release its own pain erasers (beta endorphins)

Front 69

TENS is used only for ***

Back 69

pain control

Front 70

Which fibers are believed to open pain gates?

Back 70

A-delta (small, myelinated, acute) and
C (small, unmyelinated, chronic) fibers

Front 71

Which fibers are believed to close pain gates?

Back 71

A-beta (large, heavily myelinated)

Front 72

How do the Gate Control and Endorphin theories affect pain with the application of TENS?

Back 72

- Gate Control tends to only work for the duration of the application; that is, there is little carry-over effect (thus treatment time for conventional is up to 24 hours)

- Endorphin theory modes (low frequency and burst) tend to have a carry-over effect due to the half-lives of the endorphins released

Front 73

Another name for low-frequency TENS?

Back 73

acupuncture TENS

Front 74

Brief intense mode of TENS may achieve rapid relief of intense acute pain, however:

Back 74

some patients may find the stimulation to be too much and may not be able to tolerate it for the treatment time required to achieve the desired results

Front 75

Through which pain control theory is brief intense TENS thought to work?

Back 75

through both
- Gate Control and
- Endorphin theories

because the
pulse duration/pulse width is high - Endorphin, and
frequency/pulse rate is high - Gate Control

Front 76

What tends to happen to patients that are mobile during TENS application?

Back 76

they tend to lose the electrodes

Front 77

What is the minimum number of electrodes needed for TENS application?

Back 77

2

if you can treat with 2, do so
(she said this in lab, dunno why)

Front 78

Contraindications for ES

Back 78

- cancer
- phlebitis, thrombus, thrombophlebitis
- pacemaker, other internal electrical device
- arrhythmia
- over carotid sinus
- transcerebral
- transthoracic
- over fresh fracture
- hemorrhage

Front 79

How far apart should TENS electrodes be placed?

Back 79

- at least one inch
- ideally, the width of the electrode

Front 80

When a twitch is produced by a TENS treatment, where does it appear?

Back 80

may be
- under the electrodes
- between the electrodes

Front 81

How does pulse duration/pulse width of TENS relate to comfort?

Back 81

imagine it like a needle

narrower needle goes into arm more comfortably
wider needle hurts more

Front 82

Electricity is a form of _______. ***

Back 82

energy

Front 83

Electric current is ***

Back 83

the flow of charged particles

Front 84

What charged particles flow in metal? ***

Back 84

electrons

Front 85

What charged particles flow in human tissue? ***

Back 85

ions

Front 86

What is a charge? ***

Back 86

an excess or deficiency of electrons

Front 87

What is the charge of an atom? ***

Back 87

neutral

Front 88

What is the charge of an ion? ***

Back 88

either
positive - cation (electrons lost)
or
negative - anion (electrons gained)

Front 89

What is an ion? ***

Back 89

a particle with a charge (either positive or negative)

Front 90

What is voltage? ***

Back 90

the potential difference between two points in an electrical field

the force that causes charged particles to move

Front 91

Electromotive force is measured in ______. ***

Back 91

volts

Front 92

What is current? ***

Back 92

flow of charged particles

represented as I

Front 93

How is current measured? ***

Back 93

amperes (amps)

Front 94

One ampere = ***

Back 94

6 trillion electrons/sec

Front 95

One coulomb =

Back 95

1 ampere/sec

6 trillion electrons/sec

Front 96

What is power (P)? ***

Back 96

voltage * current

P=VI

measured in watts (W)

Front 97

What is resistance? ***

Back 97

opposition to movement by charged particles

Front 98

How is resistance measured? ***

Back 98

ohms

Front 99

Resistance is directly proportional to: ***

Back 99

length of conductor

Front 100

Resistance is inversely proportional to: ***

Back 100

cross-sectional area of conductor

Front 101

What is Ohm's Law? ***

Back 101

flow of current is directly proportional to EMF (current) and inversely proportional to resistance of circuit

V = IR

Front 102

What is conductance? ***

Back 102

ease of movement of charged particles (mhos) or (siemens)

Front 103

What is a conductor? ***

Back 103

a material through which electricity flows easily

(e.g., copper, water, nerve, muscle, blood)

Front 104

What is an insulator? ***

Back 104

a material through which electricity does not flow easily

(e.g., rubber, glass, wood, fat, bone, skin)

Front 105

What is the best conductor in the body? Followed by....? ***

Back 105

best conductor in body is nerves

then muscle, then anything with water (e.g., blood)

Front 106

What is A.C.? ***

Back 106

alternating current

bidirectional flow of charged particles

Front 107

What is D.C.? ***

Back 107

direct current

unidirectional flow of charged particles

Front 108

Describe a DC and an AC waveform. ***

Back 108

DC - unidirectional flow
AC - bidirectional flow

Front 109

What is the conventional theory of current flow? ***

Back 109

current flows from positive to negative pole

(surplus to shortage)

Front 110

What is the electron theory of current flow? ***

Back 110

current flows from negative to positive pole

(negative to positive)

Front 111

What types of modes are available for E-stim? ***

Back 111

- continuous
- pulsed (mono/bi/polyphasic)
- burst
- interrupted

Front 112

What is burst mode? ***

Back 112

a finite series of pulses delivered in a package or "envelope" as a single pulse at a defined frequency

Front 113

What is interrupted mode? ***

Back 113

current flows for at least one second and ceases to flow for at least one second

(usually with a hand-held electrode where one manually opens and closes the circuit)

Front 114

For what is interrupted mode used? ***

Back 114

- trigger points
- acupuncture points

Front 115

What shapes may a waveform take? ***

Back 115

may take any of the following shapes and with each may also be symmetrical or asymmetrical

- rectangular
- square
- spiked/twin spiked
- sine

Front 116

What pulse types may the waveform take? ***

Back 116

- monophasic (pulse deviates in one direction--DC)
- biphasic (pulse is bidirectional--AC)
- polyphasic (pulse has more than 2 phases--Russian, Interferential)

Front 117

How does the TENS unit convert the DC charge from the 9V battery to AC (biphasic)?

Back 117

via a transducer in the unit

Front 118

What are the characteristics of a balanced biphasic wave? ***

Back 118

- it has the same amount of charge both above and below the isoelectric line

- the positive and negative phases do not have to have the same shape/waveform, just the same amplitude
(e.g., may be +5 mA rectangular pulse above the isoelectric line and a -5 mA spiked pulse below the isoelectric line)

Front 119

Can a biphasic wave be balanced without being symmetrical? ***

Back 119

Yes

the waveforms above and below the line may differ from each other (asymmetrical) but as long as the amplitude is equal they are balanced

Front 120

How is DC frequency measured? ***

Back 120

in pulses per second (pps)

Front 121

How is AC frequency measured? ***

Back 121

in cycles per second (cps)

a.k.a. Hz

Front 122

Pulse width is also known as: ***

Back 122

pulse duration

(which is more correct, as we are discussing time)

Front 123

Waveform of a TENS unit? ***

Back 123

biphasic, asymmetrical

Front 124

What are the three main parameters to remember with E-stim? ***

Back 124

- Phase/pulse duration (width) - beginning to end of phase or pulse, usually measured in microseconds or milliseconds

- Amplitude - magnitude of current or voltage, measured in amps or volts

- Frequency (rate) - pps or cps

(Also phase or pulse charge - the charge within each phase or pulse)

Front 125

What is the intrapulse (a.k.a. interphase) interval? ***

Back 125

the time between two successive components of a pulse when no electrical activity occurs

Front 126

What is the interpulse interval? ***

Back 126

the time between pulses when no electrical activity occurs

Front 127

What is rise time? ***

Back 127

the time from baseline (0) to peak amplitude

Front 128

What is decay time? ***

Back 128

the time from peak amplitude back to baseline (0)

Front 129

What is ramp time? ***

Back 129

the time it takes to reach peak amplitude of a pulse train

Front 130

What is total current? ***

Back 130

current delivered to tissue/sec

= phase charge * number of phases/sec

Front 131

How can one increase the total current delivered? ***

Back 131

increase the
- intensity (amplitude),
- frequency (rate) and/or
- pulse duration (pulse width)

Front 132

What is considered
- low volt?
- high volt? ***

Back 132

- less than 100 volts

- 300 - 500 volts

Front 133

What is considered
- low frequency?
- medium frequency?
- high frequency? ***

Back 133

- up to 1,000 pps/cps/Hz
- 1,000 - 10,000 pps/cps/Hz
- > 10,000 pps/cps/Hz

Front 134

How high does the frequency go in a TENS unit? ***

Back 134

up to roughly 120 pps, which is considered "high" even though that rate places it in the "low frequency" category

Front 135

What types of electrodes are used with E-stim? ***

Back 135

- surface electrodes
----metal plate (need wet sponges)
----carbon impregnated
----self-adhering, reusable

- hand-held (wand; use gauze)

- invasive (implanted)

Front 136

What are the considerations for electrode use? ***

Back 136

- size should fit treatment area

- current density is inversely proportionate to electrode size (smaller electrode concentrates the energy)

- distance between electrodes affects penetration depth of energy (the further apart the electrodes are, the deeper the energy penetrates)

Front 137

What are the lead types used with E-stim electrodes? ***

Back 137

- banana (thicker than telephone/pin)
- telephone (pin)
- McIntosh (screw down)
- alligator (can wrap in foil and gauze and use in open wounds)

Front 138

How can electrodes be placed to get deeper tissue penetration?

Back 138

place them farther apart

Front 139

Why does a smaller electrode deliver a higher current density?

How can the therapist use this to their advantage?

Back 139

a smaller electrode is still conducting the same amount of current, therefore it will be concentrated in a smaller space

the therapist can place the smaller electrode on the target area to deliver more concentrated energy to that point

Front 140

How does polarity affect treatment? ***

(DC only, as AC alternates being anode and cathode)

Back 140

anode - positive pole
- repels positive ions
- sclerotic (toughening and desensitizing)
- analgesic effects

cathode - negative pole
- repels negative ions
- sclerolytic (softening)
- stimulating effect

Front 141

What three types of electrode configurations can be used? ***

Back 141

- monopolar - 1 active electrode (smaller) on the target, and 1 dispersive electrode

- bipolar - 2 equal-sized electrodes (spaced for needed depth)

- quadpolar - four same-size electrodes

Front 142

What are the basic uses of ES? ***

Back 142

- pain modulation (gate control/endogenous opiates)
- muscle relaxation (spasm reduction)
- muscle re-education (innervated muscle)
- stimulation of denervated muscle
- edema reduction
- wound healing
- peripheral circulation
- iontophoresis

Front 143

How are endogenous opiates (Endorphin theory) produced by ES? ***

Back 143

- low rate (1-5 pps)

- muscle contraction (high pulse duration/pulse width)

Front 144

Breakdown of E-stim:
- AC variants
- DC variants ***

Back 144

NM - neuromuscular
F - functional
M - muscular

Front 145

Precautions for ES ***

Back 145

- cardiac disease
- CVA
- over pregnant uterus (ex. possibly 3rd trimester/labor)
- decreased sensation/mentation
- obesity
- extreme osteoporosis
- skin irritation, open wound
- superficial metal

Front 146

When considering in ES:
- pulse duration/pulse width
- amplitude
- frequency/rate
what is more comfortable to the patient?

Back 146

generally speaking
- shorter pulse duration/width is more comfortable
- amplitude varies by patient tolerance
- higher frequency/rate is more comfortable

Front 147

What is interference? ***

Back 147

the superposition of 2 or more waves, resulting in a new wave pattern

Front 148

What is IFC? ***

Back 148

- use of 2 sinusoidal current sources of medium frequency (1,000-10,000 Hz), created by two separate generators

- the two currents are intersected at 90 degrees

- the results create an interference wave

Front 149

What is constructive interference? ***

Back 149

- two superimposed waves of the same frequency (exactly aligned)

- the effects add together in the interference wave

- final wave has twice the amplitude

Front 150

What is destructive interference? ***

Back 150

- two superimposed waves of different frequencies (out of sync)

- the effects detract from each other in the interference wave

Front 151

Full field or amplitude summation IFC characteristics ***

Back 151

- frequencies of both currents are equal
- interference is "constructive" or "summative"
- results in vector of twice the original amplitude
- stimulates both at the surface and within tissue
- as in above picture, third wave may be static or dynamic (scan on)
- with scan on the amplitude is modulated so patient feels it in different places (sweep is frequency modulation)

Front 152

Frequency difference IFC characteristics ***

Back 152

- the frequency of the two currents differs
- results in a clover-leaf vector (or beat frequency)
- produces polyphasic pulses
- interference is destructive
- primarily stimulation within tissue (deep)

Front 153

Contrast frequency difference IFC with scan off and scan on

Back 153

With scan off and scan on

Front 154

What is the carrier frequency? Which is it in the picture? ***

Back 154

it is the base frequency of the unit before modification (the slower/lower of the two currents when they differ)

In the picture, the blue waveform is the carrier frequency

Front 155

Advantages of IFC ***

Back 155

- medium frequency decreases skin impedance more effectively
- greater intensity can be used to drive current into underlying tissue, since less used to overcome skin impedance
- more comfortable

- in general, the higher the frequency, the more comfortable the sensation

Front 156

What are the indications for IFC? ***

Back 156

- pain
- inflammation
- muscle spasm
- edema

Front 157

What are the contraindications for IFC? ***

Back 157

same as for other ES:
- cancer
- phlebitis, thrombus, thrombophlebitis
- pacemaker, other internal electrical device
- arrhythmia
- over carotid sinus
- transcerebral
- transthoracic
- over fresh fracture
- hemorrhage

Front 158

How many electrodes are required for true IFC? ***

Back 158

four

Front 159

Which tissue is more excitable, nerve or muscle? ***

Back 159

nerve

Front 160

Which tissue has higher capacitance, nerve or muscle? ***

Back 160

muscle

Front 161

What is an action potential? ***

Back 161

- sequence of depolarization and repolarization of nerve (or muscle) in response to stimuli

- "the basic unit of nerve communciation" (Cameron)

- also occurs along muscle (Michlovitz)

Front 162

What happens when nerve or muscle cell depolarizes? ***

Back 162

- the cell at rest has a negative charge and there is a high concentration of sodium outside its membrane

- depolarization opens sodium channel, sodium rushes in and changes polarization of (depolarizes) the cell

Front 163

What is the resting potential of the cell membrane? ***

Back 163

inside cell is -60 to -90 mV

(average used -70 mV)

Front 164

How does depolarization work? ***

Back 164

- Na+ channels open rapidly
- K+ channels open slowly

- sodium rushes in and causes depolarization (Na+/K+ pump)

Front 165

How does the depolarization affect polarity of the cell? ***

Back 165

- reverse polarization

- influx of Na+ reverses membrane polarity

- inside becomes more positive (goes from -70 to +30 mV)

Front 166

What brings about repolarization of the cell? ***

Back 166

- once cell membrane potential reaches +30 mV, it becomes impermeable to Na+
- K+ channels rapidly open
- becomes more permeable to K+, allowing it to leave the cell and remove the positive charge inside
- membrane polarization returns to its resting state of approximately -70 mV

Front 167

What does hyperpolarization initiate? ***

Back 167

the refractory period (where the cell will temporarily not respond to additional stimulation)

Front 168

Will a muscle cell membrane allow depolarization in response to ES if the nerve is not intact? ***

Back 168

it may, if a pulse of long duration and adequate amplitude is applied

Front 169

Contrast natural physiologcial contraction (NPC) of muscle with an ES contraction (ESC) of muscle. ***

Back 169

NPC
- AP occurs only in one direction
- small-diameter, slow-twitch fibers activated first; then large-diameter, fast twitch fibers recruited
- small-diameter, slow-twitch fibers are more fatigue resistant
- less fatiguing to patient
- contractions are smoother

ESC
- AP may propagate in both directions
- large-diameter, fast-twitch fibers activated first; then small-diameter, slow-twitch fibers are recruited later
- large-diameter fibers fatigue more quickly
- more fatiguing to patient
- contractions are jerkier

Front 170

ES can be used to facilitate action potential in:

Back 170

- sensory nerves
- motor nerves
- denervated muscles

but require different amplitudes and durations

Front 171

What is the relationship between strength and duration of ES application? ***

Back 171

- they are inversely proportional

- the stronger the current, the shorter duration needed

Front 172

What is rheobase? ***

Back 172

- the intensity of amplitude, with long duration stimulus, required to produce an action potential

- essentially, "amplitude"

Front 173

What is chronaxie? ***

Back 173

- the duration of ES application required to stimulate tissue at 2X rheobase (amplitude)

- essentially, "duration"

Front 174

Indications for NMES? ***

Back 174

- decreased strength and endurance
- decreased ROM
- post injury or surgery
- muscle spasms
- edema reduction
- orthotic substitution and FES
- rehab post nerve injury (dennervated muscle) (EMS)

Front 175

How is NMES used to treat decreased strength and endurance? ***

Back 175

in conjunction with active exercise

Front 176

How is NMES used to treat decreased ROM? ***

Back 176

- to stimulate muscle groups that can increase ROM

(e.g., with elbow flexion contracture, stimulate the triceps; or, alternately, stimulate the agonist, then the antagonist)

Front 177

How is NMES used post injury or surgery? ***

Back 177

- assist in initiating movement in a muscle or muscle group

Front 178

How is NMES used to treat muscle spasms? ***

Back 178

- the involuntary contractions may fatigue the muscle and allow it to rest
- break the pain-spasm-pain cycle

Front 179

How is NMES used for edema reduction? ***

Back 179

- contractions can help pump fluid from the area
- if DC is used, place the negative electrode at the area to repel negatively charged proteins

Front 180

How is NMES used for orthotic substitution and FES? ***

Back 180

- ambulation assistance--(e.g., attachment with heel switch to counter foot drop)
- shoulder rehab post shoulder subluxation

Front 181

Rehab post nerve injury (dennervated muscle) is more specifically referred to as: ***

Back 181

EMS

Front 182

What factors need to be considered when using NMES for rehabilitation? ***

Back 182

- how to apply
- placement of electrodes
- parameters to use
- diagnosis and goals
- patient age, tolerance, muscle size
- equipment available

Front 183

What three variations of electrode setup can be used with NMES? ***

Back 183

- monopolar
- bipolar
- quadrapolar

Front 184

What should be considered in electrode placement with NMES? ***

Back 184

- try to put one electrode on a motor point
- place electrodes parallel to direction of muscle fibers

Front 185

What is a motor point? ***

Back 185

- where the nerve enters the muscle
- where electrical stimulus produces greatest contraction with least amount of stimulus
(see pp. 25-35)

Front 186

What should be considered in electrode placement with NMES? ***

Back 186

- try to put one electrode on a motor point
- place electrodes parallel to direction of muscle fibers

Front 187

What is a motor point? ***

Back 187

- where the nerve enters the muscle
- where electrical stimulus produces greatest contraction with least amount of stimulus
(see pp. 25-35)

Front 188

NMES monopolar electrode setup ***

Back 188

Front 189

NMES bipolar electrode setup ***

Back 189

Front 190

NMES quadrapolar electrode setup ***

Back 190

Front 191

Parameters for Russian ***

Back 191

- middle frequency
- AC

Front 192

Frequency for NMES
- twitch
- vermicular
- tetanic contraction ***

Back 192

- 5 pps
- between 5 and 35 pps
- over 35 pps

Front 193

Pulse duration/width for NMES ***

Back 193

- generally high (200-400 microsec)

- need to consider comfort

Front 194

Duty cycle for NMES ***

Back 194

on:off with "on" phase of about 6-10 sec
- early rehab 1:5
- progress to 1:3
- for spasm or edema 1:1 (2-5 sec)

- ramp up/down

Front 195

Amplitude for NMES ***

Back 195

enough to get contraction, but not cause pain

Front 196

Things to consider for contraction of denervated muscle ***

Back 196

- muscle cannot contract physiologically
- does not respond to AC
- may respond to DC with a long-duration pulse (usually with a manual switch)
- presently, is not the recommended treatment, although it was in the past

Front 197

What happens to an injured nerve during the first 14 days or so? ***

Back 197

reaction of degeneration
- anterograde/Wallerian degeneration - distal to injury site
- retrograde degeneration - proximal to injury site

Front 198

How fast can nerve tissue regenerate? ***

Back 198

IF the nerve regenerates, it heals
- approx. 1 mm/day, or
- 1 inch/month

Front 199

What should the therapist remember to do before changing ES treatment parameters? ***

Back 199

TURN THE INTENSITY DOWN!

Front 200

In what forms may AC be delivered? DC? ***

Back 200

both AC and DC may be delivered either continuously or pulsed

Front 201

At what pulse duration/pulse width is DC considered to be continuous? ***

Back 201

if the pulse is >= 1 second

< 1 second is pulsed

Front 202

Which is more comfortable to the patient, AC or DC? ***

Back 202

DC is less comfortable than AC

it stings a bit

Front 203

By what mechanisms has in vivo/vitro research suggested ES (specifically DC) can assist wound healing? ***

Back 203

- alters cell membrane function
- increases protein synthesis
- has antibacterial effects
- promotes blood flow
- improves tissue oxygenation
- induces galvanotaxis

Front 204

What is galvanotaxis? ***

Back 204

occurs when charged cells are attracted to an electric field

(e.g., negatively charged ions are attracted to a positive electrode)

Front 205

Describe the electrical potential difference within the skin. ***

Back 205

the epidermis is negatively charged relative to the dermis

------ Epidermis
+++ Dermis

Front 206

What happens to the electrical potential difference across the skin when there is a soft tissue injury? ***

Back 206

the wound and adjacent epidermis become positive relative to the uninjured tissue

this electrical potential difference steadily declines over time, returning to normal only after the wound closes

ES may accelerate tissue healing by replicating or enhancing this process

Front 207

Current of injury

Back 207

- the transcutaneous potential of intact skin can be measured at 40-80 mV, but as soon as a full-thickness incision is made, this disappears so that a voltage gradient forms between the wound and surrounding intact skin (Jaffe & Vanabe, 1984)

- a microcurrent will then flow from the area of higher potential (the intact skin) into the wound so that a current of injury is generated

- the voltage peaks immediately after injury and gradually decreases as the wound heals (McGinnis & Vanable, 1986), leading to the concept that current flows may be defective in chronic wounds, and that applying electrical currents to wounds may stimulate healing (Kloth, 1995)

Front 208

How can ES (specifically DC) help with wound healing? ***

Back 208

- if barrier is broken, a flow of positive polarity occurs within the wound

- placing a negative charge (cathode) in the wound also attracts positive ions and is thought to trigger wound healing.

- exogenous ES may mimic body’s own bioelectric currents, facilitating or reinitiating (in a chronic wound) the wound healing process

Front 209

At what stage of healing should negative polarity be used? ***

Back 209

negative polarity (cathode) should be used in the acute stage of healing (3-7 days)

(Kloth)

Front 210

When should the therapist switch to treatment with positive polarity in wound healing? ***

Back 210

change to positive polarity (anode) in proliferative phase to facilitate epithelial cell migration

Front 211

When would the therapist continue with treatment with negative polarity after the acute stage? ***

Back 211

continue with negative polarity (cathode) if infection and/or inflammation present

Front 212

What treatment should be used if tissue necrosis without inflammation is noted? ***

Back 212

use positive polarity (anode)

Front 213

What do some other wound treatment protocols suggest? ***

Back 213

alternating polarities every few days

Front 214

Protocol for DC wound ES ***

Back 214

- place one electrode in wound
(saline-soaked gauze, aluminum foil, attached to alligator clip)

- another option is to place the electrodes around (outside) the wound with the target electrode proximal

- place the larger, dispersive electrode at convenient site
(Prentice suggests anode should be placed proximally, while Michlovitz, Behrens suggest placement away from the wound where skin is intact)

- some argument as to whether better to place proximal or distal
(go with proximal)

Front 215

Cathode

Anode
***

Back 215

- negative, usually black

- positive, usually red

Front 216

What physiological effects tend to occur under the cathode? ***

Back 216

- sodium combines with water to form sodium hydroxide
- alkaline reaction
- can cause softening (sclerolysis) of tissues

- stimulating effect on nerves, muscles
- bacteriostatic or bacteriocidal effects
- attracts fibroblasts (evolve into collagen), mast cells, platelets

Front 217

What physiological effects tend to occur under the anode? ***

Back 217

- chloride combines with water to form hydrochloric acid
- acidic reaction
- can cause hardening (sclerosis) of tissues, especially skin.

- analgesic effect
- attract macrophages

Front 218

What is the other use of DC ES? ***

Back 218

- can be used to treat edema

- place cathode at site of swelling to repel negatively charged proteins

Front 219

What is iontophoresis? ***

Back 219

introduction of ionic substances into the body for therapeutic purposes by use of DC

Front 220

Why is iontophoresis used? ***

Back 220

most common uses:
- reduction of inflammation (most often)
- pain relief

- alternative to injection
- less chance of systemic side effect

Front 221

What forms of medication are used in iontophoresis? ***

Back 221

- aqueous solutions
- ointments
- creams

Front 222

What are the two most common medications used in iontophoresis, and what are their polarities? ***

Back 222

- Decadron (dexamethasone) - negative (-)

- Lidocaine - positive (+)

Front 223

How deeply do medications delivered by iontophoresis typically penetrate? ***

Back 223

3-20 mm

Front 224

What are some other uses for iontophoresis? ***

Back 224

- calcium deposits- acetic acid (-)
- scar tissue- sodium chloride (-)
- athlete’s foot- copper sulphate (+)
- plantar warts- salicylate (-)


(Need to know other indications; but do not need to know the polarity needed in treatment for these.)

Front 225

Parameters for iontophoresis delivery ***

Back 225

- current type is most commonly continuous DC

- dosage is written as mA.min (mA minutes, NOT mA per minute!!)

- current (mAmp)
- time (minutes)

Front 226

What are the typical dosages for
- phoresor unit?
- patches? ***

Back 226

Recommended dosage with a
- phoresor unit is 40 mA.min
- patches may be higher: 80 mA.min

Front 227

How is the 40 mA-min dosage administered with the phoresor unit? ****

Back 227

time X mA

- if amplitude is set at 4 mA, it would take 10 min. to complete tx.

- if amplitude is set at 2 mA, it would take 20 min. to complete tx.

(It all depends upon what level of mA the patient can tolerate.)

Front 228

Electrode configuration for iontophoresis ***

Back 228

- active electrode over pathology
- indifferent is proximal or distal, but nearby

- medication goes under active electrode

- meds with a negative charge go under cathode.
- meds with a positive charge go under anode

(Thus opposites repel and medication is driven into skin.)

Front 229

Which electrode in DC/iontophoresis tends to be a bit more irritating? ***

Back 229

the negative electrode (cathode)

Front 230

What can be done to reduce skin irritation with DC/iontophoresis? ***

Back 230

if skin irritation occurs, increase size of negative electrode, regardless of which is active

(because of alkaline reaction)

Front 231

What are the contraindications and precautions for iontophoresis? ***

Back 231

besides
- allergy to medication
- use with other modalities

the same as other ES
CONTRAINDICATIONS
- cancer
- phlebitis, thrombus, thrombophlebitis
- pacemaker, other internal electrical device
- arrhythmia
- over carotid sinus
- transcerebral
- transthoracic
- over fresh fracture
- hemorrhage

PRECAUTIONS
- cardiac disease
- CVA
- over pregnant uterus (ex. possibly 3rd trimester/labor)
- decreased sensation/mentation
- obesity
- extreme osteoporosis
- skin irritation, open wound
- superficial metal

Front 232

An electrical current is:

Back 232

a flow of charged particles (electrons or ions)

Front 233

The effects of electrical currents include:

Back 233

- nerve depolarization
- muscle depolarization
- ionic effects

Front 234

Most uses of electrical stimulation are based on its ability to depolarize nerves to produce:

Back 234

action potentials

Front 235

Once an action potential is created by an electrical current, the body responds to it the same way:

Back 235

as it does to an action potential generated physiologically

Front 236

An electrically stimulated action potential can affect both:

Back 236

- sensory nerves, producing a pleasant or painful sensation, or

- motor nerves, producing a muscle contraction

Front 237

Sensations produced by electrically stimulated action potentials in sensory nerves can:

Back 237

control pain

Front 238

The muscle contractions produced by electrically stimulated action potentials in motor nerves can:

Back 238

- strengthen muscles,
- increase muscle endurance,
- improve function,
- assist with joint positioning,
- decrease spasticity,
- increase circulation,
- control pain
- reduce edema due to poor circulation or lack of use

Front 239

The ionic effects of electrical currents can be used to:

Back 239

- facilitate tissue healing
- control the formation of inflammation-related edema
- promote transdermal drug penetration

Front 240

What parameters must be considered for application of electrical stimulation?

Back 240

- electrode placement
- waveform
- polarity
- current amplitude
- pulse duration
- pulse frequency
- on:off times
- ramp time
- treatment time

Front 241

Another term for low-rate TENS

Back 241

acupuncture-like TENS

Front 242

Acupuncture-like or low-rate TENS is used for what type of pain?

Back 242

acute or chronic, but mainly chronic


PD/PW = 200 – 300 microsec. (HIGH)
A = local motor contraction
F/R = 2-10 cps (LOW)
Time = approx. 30 min.

wide PD/PW is less comfortable

so this is continuous, unlike burst mode, which uses the same PD/PW and A, but F/R of 1-10 bps

Front 243

The anode is the:

Back 243

positive electrode

Front 244

Burst mode TENS is used for what type of pain?

Back 244

acute or chronic, but mainly chronic

PD/PW = 200 – 300 microsec. (HIGH)
A = local motor contraction
F/R = 1-10 bps (LOW)
Time = approx. 30 min.

wide PD/PW is less comfortable

so this is burst, unlike low-rate or acupuncture-like mode, which uses the same PD/PW and A, but F/R of 2-10 cps (thus continuous)

Front 245

What is another name for conventional TENS?

Back 245

high-rate TENS

Front 246

Conventional or high-rate TENS is used for what type of pain?

Back 246

acute and chronic, but primarily acute

PD/PW = 50 - 80 microsec (LOW)
A = sub-motor, tingling
F/R = 100 - 150 cps (HIGH)
Time = as needed up to 24 hrs.

narrower PD/PW is more comfortable for acute pain

Front 247

The cathode is:

Back 247

the negative electrode

Front 248

Charge is:

Back 248

one of the basic properties of matter (which is either neutral, negative, or positive)

it is noted as Q and measured in Coulombs (C)

Front 249

Charge is equal to:

Back 249

current X time

Q = It

Front 250

What is current density? How can it be altered?

Back 250

the amount of current delivered per unit area

a larger electrode reduces current density, a smaller electrode increases it

Front 251

What is electrical current?

Back 251

the movement or flow of charged particles though a conductor in response to an applied electrical field

noted as I and measured in amperes (A)

Front 252

What is electrical muscle stimulation (EMS)?

Back 252

application of an electrical current directly to muscle to produce a muscle contraction

Front 253

What is functional electrical stimulation (FES)?

Back 253

application of an electrical current to produce muscle contractions that are applied during a functional activity

(e.g., electrical stimulation of dorsiflexion in a patient with foot drop during the swing phase of gait)

Front 254

What is galvanotaxis?

Back 254

the attraction of cells to an electrical charge

specific cells, including neutrophils, macrophages, lymphocytes, and fibroblasts can be attracted to an injured healing area by an electrical charge because the cells themselves carry a charge

Front 255

What is the gate control theory?

Back 255

a theory of pain control and modulation that states pain is modulated at the spinal cord level by inhibitory effects of nonnoxious afferent input

Front 256

What is impedance?

Back 256

the total frequency-dependent opposition to current flow

noted by Z and measured in Ohms

for biological systems, impedance describes the ratio of voltage to current more accurately than resistance because it includes the effects of capacitance and resistance

Front 257

What is iontophoresis?

Back 257

the transcutaneous delivery of ions into the body for therapeutic purpose using an electrical current

Front 258

What is a motor point?

Back 258

the place in a muscle where electrical stimulation will produce the greatest contraction with the least amount of electricity

generally located over the middle of the muscle belly

Front 259

What is neuromuscular electrical stimulation (NMES)?

Back 259

application of an electrical current to motor nerves to produce contractions of the muscles they innervate

Front 260

What is Ohm's law?

Back 260

a mathematical expression of how voltage, current, and resistance relate where voltage equals current multiplied by resistance

V = IR

Front 261

What is the overload principle?

Back 261

a principle of strengthening muscle that states the greater the load placed on a muscle and the higher force contraction it produces, the more strength that muscle will gain

Front 262

What is phase?

Back 262

in pulsed current, the period from when current starts to flow in one direction to when it stops flowing or starts to flow in the other direction

a biphasic pulsed current is made up of two phases;
- the first phase begins when current starts to flow in one direction and ends when the current starts to flow in the other direction, which is also the beginning of the second phase
- the second phase ends when current stops flowing.

Front 263

What is polarity?

Back 263

the charge of an electrode that will be
- positive (the anode) or
- negative (the cathode)

with a direct or monophasic pulsed current and constantly changing with an alternating or biphasic pulsed current

Front 264

What is pulse?

Back 264

in pulsed current, the period when current is flowing in any direction

Front 265

What is resistance?

Back 265

a material's opposition to the flow of electrical current

noted as R and measured in Ohms

Front 266

What is TENS?

Back 266

transcutaneous electrical nerve stimulation

application of electrical current through the skin to modulate pain

Front 267

What is voltage?

Back 267

the force or pressure of electricity

the difference in electrical energy between two points that produces the electrical force capable of moving charged particles through a conductor between those two points

voltage is noted as V and is measured in volts (V); also called potential difference

Front 268

Voltage is also known as:

Back 268

potential difference

Front 269

What is alternating current?

Back 269

a continuous bidirectional flow of charged particles

AC has equal ion flow in each direction, and thus no pulse charge remains in the tissues

most commonly, AC is delivered as a sine wave

with AC, when the frequency increases, the cycle duration decreases and when the frequency decreases, the cycle duration increases

Front 270

What is medium frequency AC?

Back 270

an AC with a frequency between 1,000 and 10,000 Hz (1-10 kHz)

most medium frequency currents available on clinical units have a frequency of 2500 to 5000 Hz

medium frequency AC is rarely used alone therapeutically but two medium frequency ACs of different frequency may be applied together to produce an interferential current

Front 271

What is continuous current?

Back 271

a continuous flow of charged particles without interruptions or breaks

a continuous current that goes in one direction only is known as a direct current (DC)

a continuous current that goes back and forth in two directions is known as an alternating current (AC)

Front 272

What is a direct current (DC)?

Back 272

a continuous unidirectional flow of charged particles

it is used for
- iontophoresis
- stimulating contraction of denervated muscle
- occasionally to facilitate wound healing

Front 273

What is interferential current?

Back 273

interferential current is the waveform produced by the interference of two medium frequency (1,000 to 10,000 Hz) sinusoidal ACs of slightly different frequencies

these two waveforms are delivered through two sets of electrodes through separate channels in the same stimulator

the electrodes are configured on the skin so that the two ACs intersect

when the currents intersect, they interfere, producing a higher amplitude when both currents are in the same phase and a lower amplitude when the two currents are in opposite phases

this produces envelopes of pulses known as beats

the beat frequency is equal to the difference between the frequencies of the two original ACs

the frequency of the original AC is called the carrier frequency

(for example, when a carrier frequency of 5000 Hz interferes with a current with a frequency of 5100 Hz, a beat frequency of 100 Hz will be produced in the tissue)

typically, electrical stimulation units that produce interferential stimulation allow the clinician to set the beat frequency and some also allow the clinician to select the carrier frequency

Front 274

Why is interferential current thought to be more comfortable?

Back 274

it is proposed that interferential current is more comfortable than other waveforms because it allows a low-amplitude current to be delivered through the skin, where most discomfort is produced, while delivering a higher current amplitude to deeper tissues

interferential current also delivers more total current than pulsed waveforms and may stimulate a larger area than other waveforms

however, although a number of studies have found that interferential current can decrease pain associated with inflammation or ischemia in animals and humans, the few studies where biphasic pulsed currents (as typically used for TENS) have been compared with interferential current have not found one to be more effective than the other, although one study found that the effects of interferential current lasted longer

Front 275

What is premodulated current?

Back 275

an alternating current with a medium frequency and sequentially increasing and decreasing current amplitude, produced with a single circuit and only two electrodes

this current has the same form as an interferential current that is produced by the interference of two medium-frequency sinusoidal ACs that requires four electrodes

the advantages of interferential current, including a lower current amplitude being delivered to the skin and a larger area of stimulation, are not reproduced by premodulated current

("Fake" IFC)

Front 276

What is pulsed current?

Back 276

an interrupted flow of charged particles where the current flows in a series of pulses separated by periods when no current flows

the current may flow in one direction only or flow back and forth during each pulse

a series of pulses where the charged particles move only in one direction is known as a monophasic pulsed current

a series of pulses where the charged particles move in one direction and then in the opposite direction is known as a biphasic pulsed current

Front 277

What is monophasic pulsed current?

Back 277

monophasic pulsed currents may be used for any clinical application of electrical stimulation but are most commonly used in tissue healing and acute edema management applications

the most commonly encountered monophasic pulsed current is HVPC, (also known as pulsed galvanic current)

this waveform is made up of pulses composed of-a pair of short, exponentially decaying phases, both in the same direction

Front 278

What is biphasic pulsed current?

Back 278

a biphasic pulsed current may be symmetrical or asymmetrical, and if asymmetrical, may be balanced or unbalanced

with a symmetrical or a balanced asymmetrical biphasic pulsed current the charge of the phases are equal in amount and opposite in polarity, resulting in a net charge of zero

with an unbalanced asymmetrical biphasic current the charge of the phases are not equal, and there is a net charge

in general, the biphasic pulsed current waveforms available are balanced

although there is often little clinical difference in the effects of symmetrical and asymmetrical pulsed currents, one study found that subjects found asymmetrical biphasic waveforms to be more comfortable when used to produce contractions of smaller muscle groups, such as the wrist flexors or extensors, and symmetrical biphasic waveforms to be comfortable when used to produce contractions of larger muscle groups, such as the quadriceps

Front 279

What is Russian protocol?

Back 279

Russian protocol is a waveform with specific parameters intended for quadriceps muscle strengthening

this protocol was developed by Kots who was involved in the training of Russian Olympic athletes

it uses a medium frequency AC with a frequency of 2500 Hz delivered in 50 bursts/second

each burst is 10 ms long and is separated from the next burst by a 10 ms interburst interval

this type of current is also known as medium-frequency burst AC (MFburstAC), and when this term is used, the frequency of the medium-frequency current or the bursts may be different from the original protocol

Front 280

What is frequency?

Back 280

the number of cycles or pulses per second

frequency is measured in Hertz (Hz) for cycles or pulses per second (pps) for pulses

Front 281

What is the interphase interval (intrapulse interval)?

Back 281

the time between phases of a pulse

Front 282

What is the interpulse interval?

Back 282

the time between pulses

Front 283

What is on:off time?

Back 283

on time is the time during which a train of pulses occurs

off time is the time between trains of pulses when no current flows

on and off times are usually only used when electrical stimulation is used to produce muscle contractions

during the on time, the muscle contracts, and during the off time it relaxes

the off times are needed to reduce muscle fatigue during the stimulation session

the sequential on and off times also attempt to mimic the voluntary contract and relax phases of normal physiological exercise

the relationship of the on and off time is often expressed as a ratio, for example, if a muscle is stimulated for 10 seconds and then allowed to relax for 50 seconds, this may be written as a 10:50 second on:off time or a 1:5 on:off ratio

Front 284

What is phase duration?

Back 284

the duration of one phase of a pulse

phase duration is generally expressed in microseconds (μs = 10 -6 seconds) or milliseconds (ms = 10 -3 seconds)

Front 285

What is pulse duration?

Back 285

the time from the beginning of the first phase of a pulse to the end of the last phase of a pulse

pulse duration is generally expressed in microseconds (μs= 10 -6' seconds)

Front 286

What is ramp up/ramp down time?

Back 286

the ramp up time is the time it takes for the current amplitude to increase from zero, at the end of the off time, to its maximum amplitude during the on time

a current ramps up by having the amplitude of first few pulses of the on time gradually be sequentially higher than the amplitude of the previous pulse

the ramp down time is the time it takes for the current amplitude to decrease from its maximum amplitude during the on time back to zero

Front 287

Why is ramp time used?

Back 287

ramping is used to produce a "soft start," allowing patients to become accustomed to the stimulation as it increases to reach motor threshold

the ramp up time is generally included in the on time while the ramp down time is generally included in the off time

ramp up and ramp down time are different from rise and decay time; the latter describe the time for the current amplitude to increase and decrease during a phase.

Front 288

What is rise time/decay time?

Back 288

rise time is the time it takes for the current to increase from zero to its peak during any one phase

decay time is the time it takes for the current to decrease from its peak level to zero during any one phase

note that this is different from ramp up/ramp down time

Front 289

What is wavelength?

Back 289

the duration of 1 cycle of AC

a cycle lasts from the time the current departs from the isoelectric line (zero current amplitude) in one direction and then crosses the isoelectric line in the opposite direction to when it returns to the isoelectric line

the wavelength of alternating current is similar to the pulse duration of pulsed current

Front 290

What is amplitude (intensity)?

Back 290

the magnitude of current or voltage

Front 291

What is amplitude modulation?

Back 291

variation in peak current amplitude over time

Front 292

What is burst mode?

Back 292

a current composed of series of pulses delivered in groups known as bursts

the burst is generally delivered with a preset frequency and duration

burst duration is the time from the beginning to the end of the burst

the time between bursts is called the interburst interval

PD/PW = 200 – 300 microsec (HIGH)
A = local motor contraction
F/R = 1 – 10 bps (LOW)
Time = approx. 30 min.

for acute and chronic pain, but primarily chronic because producing a contraction and a long pulse duration would likely be too uncomfortable for acute pain

Front 293

What is frequency modulation?

Back 293

variation in the number of pulses or cycles per second delivered

Front 294

What is modulation?

Back 294

any pattern of variation in one or more of the stimulation parameters

modulation is used to limit neural adaptation to an electrical current and may be cyclic or random

Front 295

What is phase duration or pulse duration modulation?

Back 295

variation in the phase or pulse duration

Front 296

What is scan?

Back 296

amplitude modulation of an interferential current

amplitude modulation of an interferential current moves the effective field of stimulation, causing the patient to feel the focus of the stimulation in a different location

this may allow the clinician to target a specific area in soft tissue.

Front 297

What is sweep?

Back 297

the frequency modulation of an interferential current

Front 298

What is the absolute refractory period?

Back 298

the period of time immediately after nerve depolarization when no action potential can be generated and nerve cannot be further excited, regardless of strength of stimulus

Front 299

What is accommodation?

Back 299

a transient increase in threshold to nerve excitation

Front 300

What is an action potential?

Back 300

the rapid sequential depolarization and repolarization of a nerve that occurs in response to a stimulus and transmits along the axon

Front 301

What is adaptation?

Back 301

a decrease in the frequency of action potentials and a decrease in the subjective sensation of stimulation that occurs in response to electrical stimulation with unchanging characteristics

Front 302

What is chronaxie?

Back 302

the minimum DURATION an electrical current at twice rheobase intensity needs to be applied to produce an action potential

Front 303

What is depolarization?

Back 303

the reversal of the resting potential in excitable cell membranes, where the inside of the cell becomes positive relative to the outside

Front 304

What is myelin?

Back 304

a fatty tissue that surrounds the axons of neurons, allowing electrical signals to travel more quickly

Front 305

What are Nodes of Ranvier?

Back 305

small, unmyelinated gaps in the myelin sheath covering myelinated axons

Front 306

What is propagation?

Back 306

the movement of an action potential along a nerve axon

also called conduction

Front 307

What is the relative refractory period?

Back 307

the period after nerve depolarization in which the nerve membrane is hyperpolarized, and a greater stimulus than usual is required to produce an action potential

Front 308

What is resting membrane potential?

Back 308

the electrical difference between the inside of a neuron and the outside when the neuron is at rest, usually 60-90 mV, with the inside being negative relative to the outside

Front 309

What is rheobase?

Back 309

the minimum current amplitude, with a long pulse duration, required to produce an action potential

Front 310

What is saltatory conduction?

Back 310

the rapid propagation of an electrical signal along a myelinated nerve axon, with the signal appearing to jump from one node of Ranvier to the next

Front 311

Clinical applications for electrical stimulation in rehabilitation

Back 311

- muscle strengthening
- muscle reeducation
- pain control
- facilitating healing of recalcitrant wounds
- resolving edema and inflammatory reactions after injury or surgery
- enhancing transdermal drug delivery

Front 312

What is the message unit of the nervous system?

Back 312

the action potential

Front 313

For most applications, how does electrical current exert physiological effects?

Back 313

by depolarizing nerve membranes and producing action potentials

Front 314

With sufficient amplitude (rheobase) and duration (chronaxie) will cause enough of a change in

Back 314

nerve membrane potential to generate an action potential

Front 315

How is resting membrane potential maintained?

Back 315

by most of the sodium ions (Na+) being outside the cell and most of the potassium (K+) ions being inside the cell

Front 316

Strength-duration curve (easiest to most resistant)

Back 316

minimum combination of amplitude (rheobase) and pulse duration (chronaxie) needed to depolarize a nerve

- Aβ sensory
- motor
- Aδ sharp pain
- C dull pain
- denervated muscle

Front 317

Average pulse duration for sensory stimulation? Muscle contraction?

Back 317

short (less than 80 μsec)

longer (150 to 350 μsec, unless for smaller muscles or treating a child/frail elderly, then 125 to 250 μsec likely to be more comfortable and better tolerated)

Front 318

By keeping pulse durations under 1 ms at all times, pain is minimized because

Back 318

C fibers are not depolarized

(1.0 ms seems to be pulse duration threshold for depolarization of C fibers)

Front 319

How much of a pulse duration is needed to produce contractions of denervated muscle where the stimulus directly depolarizes the muscle cell rather than the motor nerve?

Back 319

about 10 ms or more

Front 320

Why is stimulation of denervated muscle generally uncomfortable?

Back 320

since the pulse duration for depolarization of denervated muscle is 10ms or more, you've already passed the thresholds for stimulating C fibers (1 ms) and Aδ fibers (150 μsec)

Front 321

Will increasing the current amplitude or pulse duration beyond threshold to stimulate action potential have any effect?

Back 321

no, action potentials are all-or-none

increasing a parameter produces the same action potential, it cannot become larger or longer

Front 322

In addition to sufficient current amplitude and pulse duration, the current amplitude must rise quickly to produce an action potential. What can happen if it does not?

Back 322

accommodation occurs due to the prolonged subthreshold stimulation

Front 323

Contrast action potential propagation with electrical stimulation and natural physiological stimulation.

Back 323

generally, with physiological stimulation, action potentials propagate in only one direction

with electrically stimulated action potentials propagation occurs in both directions from the site of stimulation, however, only those action potentials transmitted in the "usual" physiological direction actually have an effect

Front 324

The speed of propagation of an action potential depends upon:

Back 324

- diameter of the nerve (thicker = faster)

- myelination (myelinated = faster)

Front 325

Does denervated muscle tissue accommodate to stimuli?

Back 325

no

Front 326

What types of currents produce a net charge in tissue?

Back 326

- DC
- pulsed monophasic currents
- unbalanced biphasic waveforms

Front 327

Contrast electrically stimulated muscle contractions with physiologically initiated muscle contractions.

Back 327

electrically stimulated muscle contractions recruit larger, fast-twitch muscle fibers first; these fatigue rapidly and atrophy quickly with disuse; contractions are also jerkier because all motor units of a given size fire simultaneously when stimulated

physiologically initiated muscle contractions recruit smaller, slow-twitch muscle fibers first; these are more fatigue- and atrophy-resistant; contractions are also smoother because of asynchronous recruitment of motor units

Front 328

What can patients do to optimize funcitonal integration of strength gains with electrical stimulation?

Back 328

for best results, patients should conduct physiological contractions in conjunction with the electrical stimulation

Front 329

What should also be included in therapy with electrical stimulation of muscle contractions?

Back 329

long rest times, since the recruitment first of larger, fast-twitch muscle fibers is fatiguing

Front 330

By what two mechanisms is electrical stimulation thought to strengthen muscles?

Back 330

- overload principle

- specificity theory

Front 331

With electrically stimulated muscle contractions, by what means is force primarily increased? What limits this increase?

Back 331

- force is primarily increased by increasing the total amount of current

- this is limited by patient tolerance and fatigue

Front 332

How does changing the on:off cycle affect force of muscle contraction?

Back 332

stronger contractions are produced when longer off times are used

Front 333

What does the specificity theory state?

Back 333

because ES recruits larger, fast-twitch muscles that produce a greater level of force to contract, ES should have more effect on these fibers than the slow-twitch fibers

in weak patients in whom there is generally primarily fast-twitch muscle atrophy, early use of ES can result in more rapid functional recovery and greater strength gains than exercise alone

Front 334

To produce strength gains in healthy muscle, force of stimulated contraction must be at least

Back 334

50% of maximum voluntary isometric contraction (MVIC)

Front 335

What MVIC level has been effective in injured patients?

Back 335

10%

but the stronger the better; the greatest strength gains are seen with the maximally tolerated force of contraction

Front 336

To increase strength

To increase endurance

Back 336

- higher force contractions

- prolonged stimulation with more lower-force contractions

Front 337

How can ES be used to help patients with CNS damage?

Back 337

if peripheral motor nerves are intact, NMES of lower extremities can
- improve voluntary recruitment of motor units and gait
- increase ankle dorsiflexion torque
- reduce agonist:antagonist cocontraction

Front 338

How can NMES help with joint positioning?

Back 338

it can be used to reduce glenohumeral separation and shoulder subluxation in stroke patients with hemiplegia

Front 339

Though traditionally ES has been used for limbs, what other uses is it finding?

Back 339

- helping with dysphagia, particularly following stroke

- urinary incontinence associated with pelvic floor disfunction (but also stress, urge and mixed incontinence)

- improved circulation, reduction of DVT

Front 340

What type of ES is used to provoke contraction in denervated muscle?

Back 340

continuous DC (of 10 ms or more regulated manually)

although since there is controversy about whether this retards motor nerve regeneration, it is not currently recommended by most

Front 341

Denervation causes muscles to

Back 341

atrophy and fibrose

Front 342

How are electrodes placed when ES is applied to produce muscle contraction?

Back 342

- one electrode over motor point

- other placed on the muscle so the two electrodes are parallel to direction of muscle fibers

should be at least 2 inches apart to avoid them becoming too close (less than 1 inch apart) when the muscle contracts

Front 343

What is the motor point?

Back 343

the place where an electrical stimulus will produce the greatest contraction with the least amount of electricity

area of skin over which the motor nerve enters the muscle

generally, most motor points are over the middle of the muscle belly

Front 344

What waveform should be used when ES is used to produce muscle contractions?

Back 344

- pulsed biphasic waveform
or
- Russian protocol

Front 345

When using ES to produce muscle contraction in innervated muscle, what should the pulse duration be?

Back 345

between 150 and 350 μsec

Front 346

Which do patients generally find more comfortable, longer or shorter pulse durations?

Back 346

shorter for smaller muscles

longer for larger muscles

smaller people and children often find shorter durations more comfortable as well

Front 347

What adjustments must be made when using a shorter pulse duration?

Back 347

a greater amplitude is needed to achieve the same strength of contraction

Front 348

How does the clinician decide on the best pulse duration and current amplitude for producing muscle contraction?

Back 348

base on patient comfort and achievement of the desired outcome

Front 349

Pulse frequency determines

Back 349

type of response or muscle contraction produced

Front 350

Low frequency of less than 30 pps will produce

Back 350

twitch

Front 351

As frequency increases, twitches move closer together, eventually producing smooth, tetanic contraction. What frequency is required?

Back 351

35 to 50 pps

Front 352

What happens when frequency is increased beyond 50-80 pps

Back 352

greater muscle strengthening, but

also more rapid fatigue

Front 353

On:off recommendation for muscle strengthening ES

Back 353

on - 6-10 seconds
off - 50-120 seconds

start at 1:5 to minimize fatigue,
work to 1:4 or 1:3

Front 354

On:off recommendation to reduce spasm or pump out edema

Back 354

spasm - 2-5 seconds at 1:1 to fatigue the muscle and relax the spasm

edema - also 2-5 seconds at 1:1

Front 355

Pulse frequency for
- muscle strengthening
- muscle reeducation
- muscle spasm reduction
- edema reduction using muscle pump

Back 355

- 35-80 pps
- 35-50 pps
- 35-50 pps
- 35-50 pps

Front 356

Pulse duration for
- muscle strengthening
- muscle reeducation
- muscle spasm reduction
- edema reduction using muscle pump

Back 356

150-200 μsec for small muscles
200-350 μsec for large muscles

for all purposes

Front 357

Amplitude for
- muscle strengthening
- muscle reeducation
- muscle spasm reduction
- edema reduction using muscle pump

Back 357

- to >10% MVIC if injured; >50% if uninjured
- sufficient for functional activity
- to visible contraction
- to visible contraction

Front 358

On:off times/ratios for
- muscle strengthening
- muscle reeducation
- muscle spasm reduction
- edema reduction using muscle pump

Back 358

- 6-10 sec on; 50-120 sec off and ratio of 1:5, progressing to 1:4 or 1:3
- depends on functional activity
- 2-5 sec each in 1:1 ratio
- 2-5 sec each in 1:1 ratio

Front 359

Ramp times for
- muscle strengthening
- muscle reeducation
- muscle spasm reduction
- edema reduction using muscle pump

Back 359

- at least 2 seconds
- at least 2 seconds
- at least 1 second
- at least 1 second

Front 360

Treatment time for
- muscle strengthening
- muscle reeducation
- muscle spasm reduction
- edema reduction using muscle pump

Back 360

- 10-20 minutes to produce 10-20 reps
- depends on functional activity
- 10-30 minutes
- 30 minutes

Front 361

Times per day tx for
- muscle strengthening
- muscle reeducation
- muscle spasm reduction
- edema reduction using muscle pump

Back 361

- every 2-3 hours when awake
- NA
- every 2-3 hours until spasm relieved
- twice daily

Front 362

A-beta nerves can be activated by both short- and long-duration electrical current pulses, but why are short-duration pulses better?

Back 362

short-duration pulses (between 50-80 μsec) and a comfortable current amplitude selectively activate these nerves without activating motor nerves

Front 363

How can conventional TENS interrupt the pain-spasm-pain cycle?

Back 363

pain reduction continues (slightly) after treatment stops, this keeps spasms from returning, further reducing pain

Front 364

Why is the stimulus used for conventional TENS generally modulated?

Back 364

to limit adaptation

(decrease in the frequency of action potentials and decrease in subjective sensation of stimulation)

nerve membrane exhibits decreased excitability with repeated stimulation

Front 365

How do endogenous opioids (endorphins and enkephalins) modulate pain perception?

Back 365

- they work similarly to morphine

- they bind to opiate receptors in the brain and act as neurotransmitters and neuromodulators

- they activate descending inhibitory pathways that involve nonopioid (serotonin) systems

Front 366

How can TENS be used to stimulate endogenous opiod production and release?

Back 366

repetitive stimulation of motor or nociceptive A-delta nerves to produce repetitive muscle contractions or brief, sharp pain can stimulate their production and release

- use longer pulsed durations, higher amplitudes, and lower frequencies (2-10 pps) than those used for conventional TENS (Low-rate/acupuncture-like)

Front 367

How long will low-rate/acupuncture-like TENS control pain after treatment?

Back 367

4-5 hours after a 20-30 minute treatment

Front 368

Why should low-rate/acupuncture-like TENS not be applied for more than 45 minutes?

Back 368

it can result in delayed-onset muscle soreness (DOMS)

Front 369

Electrode placement for ES for pain control

Back 369

if 2 channels/4 electrodes
- surround pain
- may intersect channels to allow current to cross at area of pain
- may place channels parallel, either vertically or horizontally

if 1 channel/2 electrodes
- place around the painful area
- place over trigger or acupuncture points
- if can't place near or over painful area, place proximal to the site of pain along the pathway of the sensory nerves supplying the area

Front 370

Waveform for ES for pain control

Back 370

- pulsed biphasic (requires only 2 electrodes), or
- interferential (may be more comfortable, affect a larger area, and provide longer-lasting effects)

Front 371

When using IFC for pain control, what pulse duration is used?

Back 371

trick question!

IFC uses AC, so wavelength/frequency altered, not pulse

CF 2500 Hz - wavelength 400 μsec
CF 4000 Hz - wavelength 250 μsec
CF 5000 Hz - wavelength 200 μsec

Front 372

What is the fixed carrier frequency for most IFC units?

Back 372

4,000 or 5,000 Hz

Front 373

Pulse frequency (or beat frequency for interferential) for
- conventional (high rate)
- acupuncture-like (low rate)
- burst mode

Back 373

- 100-150 pps
- 2-10 pps
- generally preset in unit at 10 bursts

Front 374

Pulse duration for
- conventional (high rate)
- acupuncture-like (low rate)
- burst mode

Back 374

- 50-80 μsec
- 200-300 μsec
- generally preset and may have max of 100-300 μsec

Front 375

Amplitude for
- conventional (high rate)
- acupuncture-like (low rate)
- burst mode

Back 375

- to produce tingling
- to visible contraction
- to visible contraction

Front 376

Modulation for
- conventional (high rate)
- acupuncture-like (low rate)
- burst mode

Back 376

- use if available
- none
- generally not possible

Front 377

Treatment time for
- conventional (high rate)
- acupuncture-like (low rate)
- burst mode

Back 377

- may be worn 24 hours as needed for pain control
- 20-45 minutes every 4 hours
- 20-45 minutes every 4 hours

Front 378

Possible mechanism of action for
- conventional (high rate)
- acupuncture-like (low rate)
- burst mode

Back 378

- gating at spinal cord
- endorphin release
- endorphin release

Front 379

ES aids wound healing, particularly in conjunction with

Back 379

standard wound care

Front 380

What mechanisms are proposed to explain how ES aids wound healing?

Back 380

- increased protein synthesis and cell migration
- antibacterial effects
- increased blood flow
- improved tissue oxygenation
- attraction of appropriate cell types to area
- activation of these cells by altering cell membrane function
- modification of endogenous electrical potential of the tissue in concert with healing potentials
- reduction of edema
- enhancement of antimicrobial activity
- promotion of circulation

Front 381

For what type of wound has ES been found to work best?

Back 381

ES has been found most effective for accelerating healing of pressure ulcers

Front 382

To which pole are the following attracted:
- activated neutrophils
- inactive neutrophils
- macrophages
- epidermal cells
- lymphocytes
- platelets
- mast cells
- keratinocytes
- fibroblasts

Back 382

- activated neutrophils (-)
- inactive neutrophils (+)
- macrophages (+)
- epidermal cells(+)
- lymphocytes (-)
- platelets (-)
- mast cells (-)
- keratinocytes (-)
- fibroblasts (-)

Front 383

What electrode is used to treat inflamed, infected or acute (first 3-7 days) wounds?

Back 383

negative (cathode)

Front 384

What electrode is used to treat wounds with necrosis without inflammation and during the proliferative stage of healing?

Back 384

positive (anode)

Front 385

What types of ES have been shown to kill bacteria?

Back 385

- DC
- HVPC

(but it is likely that to inhibit bacterial growth, electrical currents must be applied either at much higher voltages or for much longer times than used in clinical settings)

Front 386

Electrode placement for wound healing

Back 386

- in or around the wound

- one electrode used if inside wound (saline-soaked gauze, surrounded by tin foil and hooked to alligator clip)

- two or more electrodes used if around wound

Front 387

Specifications for size/placement of dispersive electrode for wound healing

Back 387

large

opposite polarity to treatment electrode

placed on intact skin close to wound site

Front 388

Waveform for wound healing ES

Back 388

mainly HVPC

LIDC also found effective

Front 389

Polarity for wound healing ES

Back 389

- negative for infection/inflammation or first 3-7 days of treatment

- positive thereafter if no inflammation/infection

some recommend using negative for all treatments or switching polarity when treatment reaches a plateau

Front 390

Recommended pulse duration for HVPC for wound healing

Back 390

- 40-100 μsec (generally preset in device)

Front 391

Recommended frequency for HVPC for wound healing

Back 391

60-125 pps

Front 392

On:off time for HVPC for wound healing

Back 392

trick question

none, it's continuous

Front 393

Current amplitude for HVPC for wound healing

Back 393

to produce comfortable tingling without motor response

Front 394

What can the clinician do to determine appropriate amplitude for HVPC treatment for wound healing if the individual has reduced sensation in the area of the wound?

Back 394

find the appropriate amplitude by applying the electrode to another area with intact sensation (e.g., the other ankle)

Front 395

Treatment time and frequency for HVPC for wound healing

Back 395

45-60 minutes per day
at least 5 days per week

Front 396

Types of edema for which ES may be used

Back 396

- inflammation (red/hot) use negative electrode, submotor HVPC

- poor circulation (pale, cold) use motor level (need pump)

Front 397

What can ES do for edema caused by inflammatory response

Back 397

it can retard formation of edema, but cannot reduce the amount already present

Front 398

Theories for ES/HVPC retardation of edema formation associated with inflammation

Back 398

- negative charge repels negatively charged serum proteins
- decreases blood flow by reducing microvessel diameter
- reduction in pore size in microvessel walls, preventing large plasma protein from leaking through

Front 399

Waveform used for ES treatment of edema associated with
- inflammation
- poor circulation, lack of motion

Back 399

- HVPC
- pulsed biphasic (can use interferential if on:off time is available) or Russian protocol

Front 400

Can ES be used to treat edema caused by kidney failure?

Back 400

no

only for edema caused by inflammation or by poor circulation/lack of movement, not for other causes

Front 401

Electrode placement for HVPC treatment for retarding formation of edema due to inflammation

Back 401

- negative electrode directly over the edema

- dispersive electrode more proximal

Front 402

Electrode placement for treating edema due to lack of muscle contraction/disuse

Back 402

- place electrodes on the muscle around the main veins draining the area

- same way as recommended for muscle contractions

Front 403

Polarity used for ES treatment of edema associated with
- inflammation
- poor circulation, lack of motion

Back 403

- negative

- NA

Front 404

Pulse frequency used for ES treatment of edema associated with
- inflammation
- poor circulation, lack of motion

Back 404

- 100-120 pps

- 35-50 pps with 2-5 (1-2) second 1:1 on:off times

Front 405

Pulse duration used for ES treatment of edema associated with
- inflammation
- poor circulation, lack of motion

Back 405

- usually preset for HVPC at 40-100 μsec

- 150-350 μsec

Front 406

Amplitude used for ES treatment of edema associated with
- inflammation
- poor circulation, lack of motion

Back 406

- to produce comfortable tingling

- to visible contraction

Front 407

Treatment time used for ES treatment of edema associated with
- inflammation
- poor circulation, lack of motion

Back 407

- 20-30 minutes, may be used more than once per day

- 20-30 minutes, may be used more than once per day

Front 408

Theories on how iontophoresis works

Back 408

- like charges repel and drive medication through skin

- may increase permeability of stratum corneum, the main barrier to transdermal drug uptake

Front 409

What causes declining drug concentration with distance?

Back 409

possibly clearance from the site of application by skin's microcirculation, resulting in systemic uptake of the drug

Front 410

What is required to facilitate transdermal drug penetration?

Back 410

the current must be at least sufficient to overcome the combined resistance of the skin and electrode being used

Front 411

What is the most common iontohoresis treatment (mA-min)?

Back 411

40 mA-min

some have 80 mA-min, however

Front 412

How is amplitude set for iontophoresis delivery?

Back 412

- to patient comfort (1-4 mA)

- then adjust time to produce the desired result (40, 20, 13.3, 10 mins)

Front 413

What can happen under the negative electrode during iontophoresis?

Back 413

sodium hydroxide can form and cause discomfort, skin irritation, or chemical burns (alkaline reaction)

Front 414

How can the clinician reduce the likelihood of an alkaline reaction during iontophoresis?

Back 414

reduce the current density

(either by increasing the size of the negative electrode or reducing the current amplitude)

Front 415

What can happen under the positive electrode during iontophoresis?

Back 415

hydrochloric acid can form (acidic reaction)

this is generally less uncomfortable than the alkaline reaction

Front 416

What is dexamethasone?

Back 416

corticosteroid with anti-inflammatory properties recommended for treatment of inflammatory conditions such as tendonitis or bursitis

Front 417

What is lidocaine?

Back 417

an anesthetic drug

Front 418

How are electrodes placed for iontophoresis?

Back 418

delivery electrode over the area of pathology, dispersive or return electrode a few inches away, at a site of convenience over a large muscle belly

Front 419

The electrodes should be large enough that their current densities do not exceed

Back 419

0.5 mA/cm sq (cathode delivery)

1.0 mA/cm sq (anode delivery)

Front 420

Why should use of ES over open or damaged skin (except when treating the wound) be avoided?

Back 420

open or damaged skin has lower impedance and less sensation than intact skin and this may result in too much current being delivered to the area

Front 421

Why should iontophoresis not be applied after the application of another modality that may alter skin permeability?

Back 421

heat, ice, ultrasound, etc. alter skin permeability

heat will cause vasodilation and increased blood flow that can accelerate dispersion of the drug

Front 422

How can the risk of burns be minimized with IFC?

Back 422

use at least 2 X 2 inch electrodes and only electrodes that adhere well to skin

Front 423

Why may poor adhesion of electrodes cause burns?

Back 423

because the current density then increases in portions of the electrode that are sticking and can cause burns

Front 424

When applying ES for muscle strengthening, why should the limb be secured?

Back 424

to prevent motion through the range

you want the joint in midrange where the patient can perform a strong isometric contraction, rather than having them move through the ROM and applying maximum force at the end of the ROM

Front 425

Upon what does selection of electrode depend?

Back 425

- desired size, shape, and type
- treatment goals
- area to be treated
- amount of tissue or bulk targeted

Front 426

Current density is inversely proporational to

Back 426

size of electrode

thus larger electrodes are more comfortable, but cannot target small areas

Front 427

Why shouldn't electrodes be placed over bony prominences?

Back 427

- higher resistance of bone
- poor adhesion of electrodes to highly contoured surfaces

increases risk of burns and is less likely to produce therapeutic benefits