According to Ohm’s law, which of the following statements is most accurate?
Current flow will decrease when voltage decreases regardless of resistance.
Current flow is indirectly proportional to voltage.
Current flow is directly proportional to voltage.
Current flow is not related to voltage; it is related to resistance.
What is meant by the term “capacitance,” and what biologic tissue has this quality?
The ability to store charge in an electric field and oppose change in current flow; muscle membranes
The ability to resist the flow of current in an electric field; adipose tissue
The ability to conduct charge in an electric field; nerve
None of the above
Impedance changes in the presence of injury and disease and will increase with which of the following?
Edema, ischemia, atherosclerosis, scarring, and denervation
Abrasions
Open wounds
All of the above
What two conditions are necessary for current to flow?
An energy source that creates a difference in electrical potential and a capacitor
Current and ions
An energy source that creates a difference in electrical potential and a conductor
Current and a conductor
What chemical reaction takes place at the interface between the negative electrode and underlying tissue?
The formation of hydrochloric acid, which softens tissues
The formation of sodium hydroxide, which softens tissues
The formation of sodium hydroxide, which hardens tissues
The formation of hydrochloric acid, which hardens tissues
Which of the following definitions best describes direct current?
The unidirectional or bidirectional flow of charged particles periodically ceasing for less than one second before the next electrical event
The unidirectional uninterrupted flow of charged particles with a duration of at least one second
A monophasic pulse that changes phase at least twice within one second
The bidirectional uninterrupted flow of charged particles changing direction at least once per second
Which of the following definitions best describes alternating current?
A monophasic pulse that randomly changes phase at least twice within one minute
Why does the diagram of the waveform rarely reflect what the patient is actually receiving?
It is affected by the capacitance and reactance of the tissue.
It is affected by the intensity of the stimulation.
It is not affected; it will be the same.
It is affected by the capacitance and intensity of the stimulation.
Which type of waveform is most likely to produce a net charge in the underlying tissue?
An asymmetrical waveform
A symmetrical waveform
An unbalanced waveform
A balanced waveform
Which waveform has the ability to activate peripheral nerves with minimal electrical charge and has minimal potential for skin reactions?
Symmetrical biphasic
Monophasic
Asymmetrical biphasic
Asymmetrical monophasic
Which of the following statements is most accurate regarding the stimulation of nerve fiber?
Larger diameter fibers require lower levels of stimulation to elicit a response.
Larger diameter fibers require higher levers of stimulation to elicit a response.
Smaller diameter fibers require lower levels of stimulation to elicit a response.
Nerve fiber stimulation with electrical stimulation is uncomfortable.
What is the potential clinical significance for an off ramp on a biphasic stimulator?
The off ramp prevents the clinician from turning the stimulus up too quickly.
If a muscle contraction is elicited, the off ramp provides the patient with the opportunity to hold the contraction after the stimulus has ended.
If a muscle contraction is elicited, the off ramp provides the patient with a warning that the stimulus will be getting stronger.
The off ramp prevents the clinician from turning the stimulus off too quickly.
Which of the following terms is not a synonym for frequency?
Intensity
Cycles per second
Rate
Hertz
Duty factor
What are the indications for clinical electrical stimulation?
Pain management
Stimulation of denervated muscle
Muscle strengthening
Muscle spasm/guarding
What is the normal pH of the skin?
5 to 6
1 to 2
7 to 8
3 to 4
What effect does tissue hydration have on the impedance value of the skin?
Higher hydration results in higher impedance.
Higher hydration results in reduced impedance.
Lower hydration results in reduced impedance
Lower hydration results in no change in impedance.
The term “iontophoresis” implies which of the following?
The use of large amounts of physiologically acceptable electric current to deliver drugs into the body
The use of electrical stimulation to deliver medication into the body
The use of small amounts of physiologically acceptable electric current to deliver drugs into the body
The use of ultrasound to deliver medication into the body
When using iontophoresis to enhance the transcutaneous permeation of ionic drugs into the skin, what polarity must the electrode be in relationship to the medication?
The polarity of the medication and the electrode should be the opposite of each other.
The polarity of the medication and the electrode should be the same.
As long as the electrode with the medication is hydrated, the polarity of the electrode makes no difference.
There is no relationship between the polarity of the medication and the electrode.
What type of current output is necessary for iontophoretic devices to be able to accomplish the delivery of a medication to a patient?
Pulsed current
Alternating current
Direct current
Either alternating or direct current, depending upon the manufacturer
What parameters are adjusted to determine the dosage for iontophoresis to accomplish therapeutic treatment goals?
Treatment time and strength of medication
Strength of medication and pulse duration
Intensity and pulse duration
Treatment time and intensity
Which of the following is the most important consideration and is also a contraindication to iontophoresis that must be considered by everyone involved in the administration of the treatment prior to the application of iontophoresis?
Whether or not the patient has a signed consent for treatment
Whether or not the patient has insurance coverage for treatment
Whether the time the patient has allotted for treatment is long enough to accomplish the treatment goals
Whether or not the patient has an allergy to the medication to be administered
What seemingly simple fact must be true for the passing of current through an electrode into the skin via an electrode?
The electrodes must have an electrically conductive surface.
The electrodes must be connected to the patient and a stimulator and have an electrically conductive surface.
The electrodes must be connected.
The electrodes must be the same size and connected to a lead wire and a stimulator.
Why is distilled water an inappropriate choice to hydrate electrodes?
Electrodes do not need to be hydrated to be conductive.
There are too many free ions in tap water to transmit charge.
There are no free ions in distilled water to transmit charge.
It is an appropriate choice and is better than tap water to transmit charge.
Self-adhering single-use or reusable electrodes are composed of flexible conductors that are covered with an electrically conductive interface. When would the use of this type of electrode be advantageous?
Whenever they are more convenient to adhere to the treatment area
Whenever strapping electrodes or taping electrodes on a patient is difficult
To prevent the risk of cross contamination between patients if the electrodes are used for only one patient
What is a potential disadvantage of self-adhering electrodes?
The resistance exhibited by self-adhering electrodes may be too high.
They may be too large. The sizes of self-adhering electrodes are limited, which is potentially disadvantageous.
Their availability may be limited. If the patient's insurance doesn't cover the use of self-adhering electrodes, this could be a disadvantage.
The resistance exhibited by self-adhering electrodes may be too low.
Current density describes the amount of current concentrated under an electrode and is a measure of the quantity of charged particles moving through a specific cross-sectional area of body tissue. What is the relationship between electrode surface area and total current flow?
When the electrodes are small, the current density is high.
Current flows more easily in smaller electrodes.
There is no relationship between electrode surface area and total current flow.
When the electrodes are large, the current density is high.
What happens to current density when two electrodes from one channel of an electrical stimulation unit are different sizes?
There will be no sensation under the electrodes
It is contraindicated to use different size electrodes on one channel.
There will be a greater concentration of current under the smaller electrode.
There will be a greater concentration of current under the larger electrode.
What is the difference between percutaneous and transcutaneous electrodes?
There is no difference between transcutaneous and percutaneous electrodes.
Percutaneous electrodes are surface electrodes applied to the skin, and transcutaneous electrodes are needle electrodes inserted under the surface of the skin.
Percutaneous electrodes are applied to the surface of skin, and transcutaneous electrodes are inserted into the skin.
Percutaneous electrodes are inserted into the skin, and transcutaneous electrodes are applied to the surface of the skin.
Which technique for the application of electrodes involves a single electrode from a channel, usually smaller in size, placed over the target area called the active electrode?
Criss-cross technique
Quadripolar technique
Monopolar technique
Bipolar technique
Which technique for the application of electrodes involves electrodes from two or more channels, each lead with two electrodes, with all four of the electrodes placed in the target treatment area?
All of the following could cause a patient to not feel electrical stimulation underneath one of the electrodes from a channel of an electrical stimulator except which one?
The current density may be too low under one of the electrodes.
One of the electrodes has become disconnected from a lead wire.
The skin resistance may be too high under one of the electrodes.
The patient may have decreased sensation under one of the electrodes.
Which of the following terms is used to describe the use of electrical stimulation for activation of muscle through stimulation of the intact peripheral nerve?
Functional electrical stimulation
Transcutaneous electrical nerve stimulation
Electrical stimulation
Neuromuscular electrical stimulation
Which of the following terms is used to describe the use of electrical stimulation to facilitate muscle contractions for the purpose of performing an activity?
Which of the following terms is used to describe the use of electrical stimulation for pain management with portable stimulators?
For patients who are obese, it may not be possible to achieve the desired muscle response with NMES. Why?
The statement is false.
The depth of the myoneural junction in patients with significant adipose is prohibitively deeper than in patients who are not obese, making stimulation of the motor nerve virtually impossible.
The motor nerve may be too “insulated” by the intervening layer of adipose to allow sufficient stimulation without painful stimulation of the sensory nerves in the skin.
Appropriate timing modulation for electrically elicited muscle contractions can facilitate the accomplishment of therapeutic treatment goals. Which of the following would be considered a more appropriate form of documentation for the on-off ratio of electrical stimulation, and why?
10 contractions in 15 minutes since both the number of contractions and treatment time are included.
20% duty factor for 15 minutes since the percentage of overall on time and the treatment time is included.
1:5 for 15 minutes since both the ratio and treatment time are included.
2 seconds on, 10 seconds off or 1:5 for 15 minutes since contraction times, relaxation times, and the treatment times are all included.
What is the relationship between frequency and the quality of a motor response?
When the frequency is lower than 50 Hz, the quality of the motor response is optimal for most large muscles.
When the frequency is higher than 50 Hz, the quality of the motor response is less than optimal.
When the frequency is 50 Hz, the quality of the motor response is optimal for most large muscles.
Frequency and the quality of motor response are not related to each other.
Which of the following statements is most accurate regarding NMES and isometric muscle contraction?
Simultaneous stimulation of the agonists and antagonists is discouraged with the use of NMES for muscle contraction.
There was no difference between volitional isometric strength gains and NMES isometric strength gains.
Superior isometric strength has been accomplished with NMES in comparison to volitional isometric contraction strength gains.
Patients receiving NMES should be permitted to move through the entire available range of motion for the therapeutic exercise that is augmented by the NMES.
According to a normal strength duration (SD) curve, what would be the first sensation that a patient would perceive as the intensity was slowly increased and if the pulse duration of the stimulator was set at 250μsec (250 microseconds)?
An achy sensation
Pins and needles or tingling
Pain
A muscle twitch or contraction
Which of the following most accurately represents the sequence for tissue repair?
Remodeling, proliferation, inflammation
Inflammation, proliferation, remodeling
Inflammation, remodeling, proliferation
Proliferation, inflammation, remodeling
Which of the following is the most accurate definition of the term “current of injury”?
“Current of injury” is the electrical stimulation that caused injury to the underlying tissue.
When the skin is damaged, the polarity of the skin changes from negative to positive.
When the skin is damaged, the polarity of the skin changes.
When the skin is damaged, the polarity of the skin changes from positive to negative.
What is meant by the term “Galvanotaxis”?
The process in which cells possessing a positive or negative charge are carried in an electric field
The process in which cells possessing a positive or negative charge are attracted to an electric field of opposite polarity
The process in which cells possessing a positive or negative charge are found in an electric field
The process in which cells possessing a positive or negative charge are repelled in an electric field of opposite polarity
The positive pole in an electric field attracts all except which of the following types of cells?
Macrophages
Cytokines
Negatively charged free ions
Neutrophils at higher pH values
The literature regarding the effects of electrical stimulation for increasing blood flow to an area has been plagued by many irregularities and discrepancies. Which of the following statements is true?
The use of electrical stimulation has been associated with increases in transcutaneous oxygen levels in individuals with spinal cord injuries.
Sufficient oxygen is required for all phases of wound healing.
Diminished oxygen levels show a trend of being associated with the presence of pressure ulcers in individuals with spinal cord injuries.
Which of the following statements is least accurate regarding the use of electrical stimulation for tissue repair?
Electrical stimulation may be used to solubilize necrotic wound tissue.
Electrical stimulation has no effect on necrotic tissue.
Electrical stimulation may be used to facilitate autolytic debridement.
Electrical stimulation may initiate the attraction of negatively charged neutrophils to promote autolysis in a wound.
What was the significance of the decision of the Centers for Medicare and Medicaid Services (CMS) regarding electrical stimulation in 2002?
Electrical stimulation for tissue repair now can be claimed to be a contributing factor in the treatment of chronic wounds.
Electrical stimulation is now considered a covered charge for the treatment of chronic wounds.
Electrical stimulation was considered ineffective and non-reimbursable for the treatment of chronic wounds.
Electrical stimulation cannot be billed as a treatment modality for the treatment of chronic wounds.
Which of the following statements is most accurate regarding the polarity of wounds?
The polarity of healing wounds is usually positive
As healing progresses, the polarity of a wound usually changes.
The use of currents that are capable of producing polar effects may be a factor in facilitating a healing response.
Which of the following terms is best described as something that is capable of eliminating pain, edema, loss of function, heat, and erythema?
Anesthesia or anesthetic
Analgesia or analgesic
An anti-inflammatory
An endogenous opiate
Which of the following terms is best described as something that is administered to provide temporary relief of pain?
Which of the following terms is best described as something that is capable of providing complete relief of pain and all sensation?
Which of the following terms is best described as something that the body produces that is capable of providing temporary relief of pain?
What is the potential purpose for providing sensory stimulation along the corresponding dermatome of a painful site?
The sensory stimulation may block painful sensation from that corresponding area from ascending to the brain.
The sensory stimulation will enhance perception of that area.
The sensory stimulation may enhance the perpetuation of the painful stimulus from that area.
What characteristics determine whether an electrode placement site is considered optimal for pain management with TENS?
The area is a trigger point.
The area is located on a sensory nerve that is segmentally related to the spinal cord nerve root for that area.
The area is an acupuncture point.
What fiber type would potentially need to be stimulated with electrical stimulation to cause the liberation of the longest lasting endogenous mechanisms for pain management?
C fibers
A-delta
Motor
A-beta
Pain is perceived differently by each individual and we need to recognize that difference during treatment.
The formation of new blood vessels to a wound is called hemostasis.
A-beta fibers transmit discriminative touch stimuli from the skin.
What effect does the amount of adipose tissue have on the impedance of the underlying tissues?
Adipose tissue has no effect on impedance.
The smaller the amount of adipose tissue, the higher the impedance of the tissue.
The smaller the amount of adipose tissue, the lower the impedance of the tissue.
The larger the amount of adipose tissue, the lower the impedance of the tissue.
