DPT 634: Electrotherapy Modalities

Question 1

The time lapse from the stimulation to the onset of the comound motor unit action potential is referred to as the:

a. Neuro conduction velocity
b. Rise time
c. Amplitude
d. Distal Motor Latency

Answer 1

D

Question 2

Which of the following sttatements is true regarding externally applied stimulus during NCS

a. It takes longer for smaller diameter muscle fibers to depolarize
b. Current flows first via the Type I muscle fibers
c. Requires a supramuscular stimulus for a good test result
d. Current is applied internally via sharp needle electrodes

Answer 2

C

Question 3

All of the following are common disorders that can be diagnosed via NCS, EXCEPT:

a. Radiculopathy
b. Myopathies
c. N/M junction disorders
d. Facet joint dysfunction

Answer 3

D

Question 4

When comparing DSLs to DMLs, taken over the same distance (8cm), what would be expected?

a. DSL = DML
b. it varies throughout the body – there is no consistent relationship
c. DML > DSL
d. DSL > DML

Answer 4

C

Question 5

Which of the following statements regarding repetitive stimulation for assessment is most accurate?

a. If a N/M junction disease process is present, the amplitude of successful stimuli will increase
b. The quantal content of ACh decreases by 10% from the initial stimulus
c. A decrease in amplitude of 10% or more from the first stimulus to the 5th stimulus is considered abnormal
d. Drop in ACh combined with decreased receptors results in an increased amplitude in the CMAP

Answer 5

C

Question 6

All of the following are reasons to require supramaximal stimulus during NCS, EXCEPT:

a. Create a sudden and rapid alteration in the resting membrane potential of the nerve being evaluated
b. Bring a small sample of axons of that nerve to threshold
c. So you obtain a representation of the capabilities of the peripheral nerve
d. To provide reproducible results

Answer 6

B

Question 7

The H-reflex is physiologically similar to a muscle stretch reflex, in that an AP is carried proximally via afferent axons to the spinal cord, where the combined potential enters the dorsal horn, passing through at least one synapse and is then carries via efferent axons to the appropriate distal muscle

a. True
b. False

Answer 7

True

Question 8

Which of the following best represents the role of a patient history and physical examination, in relation to electrophysiologic testing?

a. A history can assist with items such as the potential for inherited traits, but there is no compelling need to perform a physical examination
b. The electrophysiologic testing stands along as an objective assessment of nerve function
c. If lab tests and preceding assessment measures (such as MRI) have been obtained, it is redundant to take a patient history or physical examination
d. Electrophysiologic testing is based on a sound history and physical examination

Answer 8

D

Question 9

With a compression of the superficial branch of the ulnar nerve at Guyon’s canal, which of the following would be expected?

a. Prolonged distal latency to the 5th digit
b. Decreased recruitment of the abductor digit minimi and first dorsal interossei
c. Faster conduction velocity of the motor fibers
d. Increased amplitude of the ulnar SNAP

Answer 9

A

Question 10

What is the typical minimum NCV speed of a normal mixed nerve (motor & sensory) in the upper extremity?

a. 60 m/s
b. 40 m/s
c. 50 m/s
d. 70 m/s

Answer 10

C

Question 11

An electrical stimulator set up with a pulse rate of 65, a 3-second ramp time, current amplitude sufficient to achieve 60% of maximum, voluntary isometric contraction (MVIC), a 10 second on time, a 50-second off time and total treatment of 12 minutes would be appropriate to accomplish which physiologic response?

a. pain modulation via endorphin production
b. muscle re-education
c. pain modulation via endorphin production
d. muscle strengthening

Answer 11

D

Question 12

All of the following are proposed advantages of using IFC, EXCEPT:

a. can target an area between the electrodes
b. improved ability to produce muscle contractions
c. increased patient comfort
d. large treatment area

Answer 12

B

Question 13

You want to use electrical stimulation for pain modulation and want the current to penetrate as deep as possible. To _______ current density in deeper tissue, the electrodes must be placed ________.

a. decrease, further apart
b. increase, closer
c. increase, further apart
d. decrease, closer

Answer 13

C

Question 14

Muscles that are stimulated using NMES generally fatigue more rapidly than muscles that are voluntarily contracted. This is possibly due to:

a. asynchronous fiting of the same motor units during a voluntary muscle contraction
b. synchronous firing of the same motor units when stimulated by NMES
c. asynchronous firing of motor units when stimulated with NMES
d. synchronous firing of the same motor units during voluntary muscle contraction

Answer 14

B

Question 15

How could a pulse duration of a current be decreased without changing the frequency?

a. the interpulse interval must increase
b. this is not possible for any type of current
c. the rise time must increase
d. this is only possible for a monophasic current

Answer 15

A

Question 16

A patient is being treated with IFC. One of the circuits has a frequency of 4000 Hz. The other circuit has a frequency of 4150 Hz. What is the resultant beat frequency or treatment frequency?

a. 150 Hz
b. 300 Hz
c. 0-150 Hz
d. 80-150 Hz

Answer 16

A

Question 17

All of the following are examples of the appropriate use of Functional Electric Stimulation (FES) in treatment, EXCEPT:

a. to stimulate ankle dorsiflexors during gait in a patient with foot drop
b. to substitute for an orthotic device
c. to control pain in a hemiplegic shoulder in a patient that had a recent stroke
d. to stimulate wrist extensors for a tenodesis grip in a patient with a spinal cord injury

Answer 17

C

Question 18

You are using NMES to facilitate muscle contraction in the quadriceps for muscle re-education in a patient with an ACL reconstruction. In this scenario, which of the following “On-Off” ratios would lead to faster muscle fatigue?

a. 1:3
b. 1:5
c. 1:1
d. 1:10

Answer 18

C

Question 19

A patient reports the sensation of greater intensity under one of the two treatment electrodes. if that is not a desired treatment goal, which of the following steps could be taken to make the sensation equal under both electrodes?

a. increase pulse duration
b. decrease the size of the electrodes where the greatest intensity is felt
c. increase the intensity until it is the same for both electrodes
d. increase the size of the electrodes where the greatest intensity is felt

Answer 19

D

Question 20

When the current increases gradually to a maximum amplitude, it is known as:

a. ramping
b. galvanic
c. modulation
d. burst

Answer 20

A

Question 21

During the absolute refractory period the cell is not capable of:

a. depolarization
b. an action potential
c. twitch muscle contraction
d. all of the above
e. none of the above

Answer 21

D

Question 22

While providing TENS treatment for your patient, you’ve chosen to use conventional TENS. Your patient happens to be a medical student who asks you to describe what ‘conventional TENS’ means. The most appropriate response would be:

a. The motor nerves are continually stimulated, creating pain relief
b. A-beta sensory nerves are stimulated, providing pain relief during treatment
c. A-beta sensory nerves are stimulated, providing pain relief 4-5 hours after treatment
d. Stimulus creates endogenous opiod production and release

Answer 22

B

Question 23

When using interferential current for pain relief, what characteristic(s) must be present within your machine of choice?

a. 350 Hz carrier frequency
b. The ability to have direct current
c. The ability to have 2 channels and 4 electrodes
d. Carrier frequency of at least 2500 Hz, more frequently 4000Hz

Answer 23

C & D

Question 24

Chronic pain is considered to be pain that lasts 6 months or longer. Arthritis is a pathology that can create chronic pain . Which of the following terms describes the reason for this?

a. neuropathic input
b. mixed pain syndrome
c. nociceptive input
d. complex regional pain syndrome
e. none of the above

Answer 24

A & B & C & D

Question 25

While performing a brief sensory eval on a patient that presents with shoulder pain, the sensory examination reveals hyperalgesia and paresthesia throughout the C4 dermatome. What centered language would you use to describe these findings to your patient?

a. increased temperature and decreased motion sensations
b. increased sensitivity to pain and sensory perversion
c. increased painful sensation to touch and sensory perversion feeling
d. decreased sensitivity to joint motion and paralysis of nociceptive fibers

Answer 25

B

Question 26

Conventional TENS (aka high rate) has:

a. ability to work using the gate control theory of pain modulation
b. low frequency
c. long duration of pulses
d. the ability to produce endogenous opiod release

Answer 26

A

Question 27

When using low rate/acupuncture-like TENS, small muscle contractions should be avoided.

a. True
b. False

Answer 27

False

Question 28

Burst mode TENS is another form of TENS used for pain modulation. It is thought to work by the same mechanisms as low rate TENS but may be more comfortable for some individuals since the stimulation is delivered in bursts

a. True
b. False

Answer 28

True

Question 29

When explaining to your paitent why they may not wear a portable TENS unit with a low-rate/acupuncture like setting for the majority of the day, you may state:

a. The risks associated with continuous electrical current are well documented, thus a short duration is better
b. Low-rate TENS is meant to create a small muscle contraction, thus wearing it longer than 45 minutes can create delayed onset muscle soreness
c. it’s a fashion pas
d. there is a risk of adaptation, that is, your body will get used to stimulus and pain modulation will not occur

Answer 29

B

Question 30

What is the clinical significant of adaptation, when referring to the use of conventional TENS?

a. Modulating frequency, pulse duration, or current amplitude can be effective in preventing adaptation
b. All of the stimulation parameters must be modulated at once in order to prevent adaptation
c. It is not possible to prevent adaptation with conventional TENS use

Answer 30

A

Question 31

When using a biphasic waveform for conventional TENS, the pulse duration should be between 50 and 80 µs to depolarize only the:

a. Motor Nerves
b. A-Delta Nerves
c. A-Beta sensory Nerves
d. C Fibers

Answer 31

C