Modalities Exam III - Intro to E-Stim

Which of the following definitions BEST describes Direct Current?

The unidirectional, uninterrupted flow of charged particles with a duration of at least one second

Which of the following definitions BEST describes alternating current?

The bidirectional uninterrupted flow of charged particles changing direction at least once per second

Which of the following definitions BEST describes pulsed current?

The unidirectional or bidirectional flow of charged particles periodically ceasing for less than one second before the next electricity event

Which waveform has the ability to activate peripheral nerves with minimal electrical charge and has minimal potential for skin reactions?

symmetric biphasic

Which of the following statements is MOST accurate regarding the stimulation of a nerve fiber?

A. Larger diameter fibers require lower levels of stimulation to elicit a response
B. Smaller diameter fibers require lower levels of stimulation to elicit a response
C. Nerve fiber stimulation with electrical stimulation is uncomfortable
D. Larger diameter fibers require higher levels of stimulation to elicit a response

Larger diameter fibers require lower levels of stimulation to elicit a response

Which type of waveform is most likely to produce a net charge in the underlying tissue?

an unbalanced waveform

Which of the following terms is NOT a synonym for frequency?

A. hertz
B. duty factor
C. rate
D. cycles per second

duty factor

What happens to current density when two electrodes from one channel of an electrical stimulation unit are different sizes?

There will be a greater concentration of current under the smaller electrode

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?

quadripolar

Which technique for the application of electrodes involves the use of two electrodes from one channel within the target treatment area?

bipolar

Which of the following terms describes the period of time after an action potential when the nerve can NOT be further excited?

A. ionic effect period

B. relative refractory period

C. resting membrane potential

D. absolute refractory period

absolute refractory period

Which of the following causes an action potential to travel faster?

myelin and large diameter fibers

Which of the following is NOT a contraindication to the use of electrical stimulation?

A. a patient with a pacemaker if the electrical stimulation is on the lower half of the body

B. in or around open wounds

C. over or near abdomen in pregnancy

D. an area near a thrombus

in or around open wounds

During resting membrane potential, the inside of the nerve membrane is relatively more _______ charged.

negatively

During depolarization, the Na+ ions move rapidly ____ while the K+ ions move slowly ____ of the cell membrane making the inside of the cell relatively _____________ charged.

in

out

positively

The period of time when a nerve cannot be further excited is known as the __________________.

absolute refractory period

The period of time after an action potential where the nerve membrane is hyperpolarized and requires a greater stimulus is known as ________________.

relative refractory period

Which fibers require a longer pulse width and higher currents to fire?

Motor

Sharp

Denervated muscle

Which waveforms are continuous?

AC

DC

IFC

Which waveforms are not continuous?

Burst

HVPC(mono or biphasic)

Pulsed biphasic

How long is the pulse width for denervated muscles to fire?

10 msec

Pulse width of <80 us produce ________ stimulation

sensory

Pulse width of 200-300 us produces ______ contractions.

muscle

Pulse width can be painful at _____ msec.

1

What is the term used when a nerve becomes gradually less responsive to stimulation?

accommodation

Which muscle fibers do not accommodate?

denervated muscle fibers

What term is used to describe that when an action potential is generated, it triggers an action potential in the adjacent area (also known as conduction)?

propagation

Action potentials travel faster in __________ nerves.

myelinated

Small, unmyelinated gaps in the myelin sheath are known as ________.

nodes of Ranvier

Action potentials travel slower in ________ diameter fibers.

small

What type of current has ionic effects?

DC

An example of DC current forcing drug molecules to increase drug penetration across skin is called ____________.

iontophoresis

The cathode attracts _________ charged ions and repels _________ charged ions.

Positively

negatively

The anode attracts _________ charged ions and repels _________ charged ions.

Negatively

positively

With normal muscle contraction, _____________ fibers activate first and _____________ fibers fatigue first.

Slow, type I

slow, type I

With electrical stimulation, ____________ fibers activate first and ____________ fibers fatigue first.

Large diameter, type II

large diameter, type II

The greater the load placed on muscle, the higher force contraction it produces and the more strength it will gain can be described as the ____________ principle.

overload

To gain strength, healthy muscle needs at least _____ percent max voluntary isometric contraction (MVIC).

50

Injured muscle requires at least ____ percent max voluntary isometric contraction (MVIC).

10

Application of an electrical current to motor nerves to produce contractions of the muscle they innervate is known as NMES or ________________________.

neuromuscular electrical stimulation

____________________ is stimulating a contraction at the time during an activity when a muscle should contract.

Functional electrical stimulation (FES)

There has been conflicting evidence of the efficacy of electrical stimulation for ______________ including Bell's palsy.

denervated muscle

Electrodes should be placed over motor points ________ to the direction of the muscle fiber.

parallel

For strengthening, pulse duration should be between ______ and ______ us.

150

350

For strengthening, pulse frequency between ___________ is recommended and may be increased to ____ pps if needed for comfort.

30 & 50 pps

80

The recommended on-time for muscle contraction is _____ sec on and _________ sec off.

6-10

50-120

Ramp time is generally ____ sec.

1-4

Treatment time should allow for 10-20 contractions, which takes approximately _______ minutes.

10-20

A SMALL electrode has ______ current density, ______ impedance, and ________ current flow.

increased

increased

decreased

A LARGE electrode has _______ current density, _______ impedance, and _______ current flow.

decreased

decreased

increased

A patient is more susceptible to pain and potential tissue damage when a ______ sized electrode is used.

small

Interferential Current (IFC) is used for ______________________.

pain management and muscle contraction

What constitutes Russian Current:

pulsed biphasic current

Indications for Russian Current are:

strength gains in healthy muscle

HVPC (High Volt Pulsed Current) is also known as ______________.

monophasic pulsed current

Indications for HVPC are:

Wound healing

Edema due to inflammation

The type of pain control that interferes with the transmission of pain c-fibers at the spinal cord level is known as the ___________ theory.

gate control

The most comfortable frequencies for pain control are ____ us to _____ us, known as transcutaneous electrical current.

100

150

How long may sensory level TENS be applied?

continuously

_______________ is needed for pain relief in order to stimulate endorphin production.

muscle contraction

Pain modulation that stimulates endorphin productions should last how long?

20-30mins

TENS can use _________ waveform or _________ current.

pulsed biphasic

interferential

Interferential current must have _____ electrodes.

four

For pain modulation at sensory level, the frequency is _______ pps. For muscle contraction, frequency is set to _____ pps. The burst mode, the frequency is generally preset.

100-150 pps

2-10 pps

The on:off time for pain control is ____________.

continuous

Treatment time for portable tens is __________. For muscle contraction, the treatment time is _________.

continuous, 20-30min