Quiz 1

Question 1

What is the goal of most therapeutic electrical stimulation?

Answer 1

to produce action potentials in intact sensory or motor neurons

Question 2

How can you deliver current?

Answer 2

externally
internally
percutaneously

Question 3

What is resting potential?

Answer 3

difference between outside and inside of the nerve cell

Question 4

What does a negative electrode do?

Answer 4

it is a better depolarizer of axons in the body: draws positive charge away from membrane

Question 5

Where are action potentials in motor neurons created?

Answer 5

proximally in spinal cord and travel distally to muscles they innervate

Question 6

What is amplitude?

Answer 6

strength

Question 7

What is duration?

Answer 7

time

Question 8

What is DC current used for?

Answer 8

iontophoresis

stimulating denervated muscle

Question 9

What direction does DC current flow?

Answer 9

in one direction and continously

Question 10

What is AC current used for?

Answer 10

• pain control (interferential): beat modulated

- muscle contraction (Russian): burst modulated AC

Question 11

What are the 3 frequencies of AC?

Answer 11

low (10,000 Hz)

Question 12

What frequency of AC is used?

Answer 12

medium; transformed into interferential or Russian

Question 13

What is pulsed current used for?

Answer 13

pain control
muscles contraction
tissue healing

Question 14

What is monophasic?

Answer 14

only above the line, current is delivered only in one direction; one electrode is always negative and one is positive and it does not change

Question 15

What is monophasic used for?

Answer 15

promote tissue healing

manage acute edema

Question 16

What is biphasic?

Answer 16

currents that switch direction in the middle of the pulse (2 directions)

Question 17

What is biphasic used for?

Answer 17

promote pain relief
promote muscle contraction
manage chronic edema

Question 18

Biphasic can be:

Answer 18

symmetrical

assymetrical

Question 19

Symmetrical current is:

Answer 19

equally strong and equally lone

Question 20

Assymetrical current is:

Answer 20

balanced

unbalance

Question 21

Balanced:

Answer 21

strength and duration in one direction is equal to the other

Question 22

Unbalanced:

Answer 22

strength and duration in one phase in greater than the other

Question 23

Shorter pulse duration for:

Answer 23

pain control

tissue healing

Question 24

Longer pulse duration for:

Answer 24

muscle contraction

Question 25

Pulse duration

Answer 25

entirety of one electrical event

Question 26

Phase duration

Answer 26

current flow in one direction

Question 27

On time

Answer 27

what period of time the stimulator is on

Question 28

Off time

Answer 28

time stimulator lets tissue rest

Question 29

Ramp up

Answer 29

stimulator is controlling increase of amplitude from 0 to wherever it is set

Question 30

Ramp down

Answer 30

time that passes when stimulator is turning down

Question 31

Short duration pulses for ______ axon?

Answer 31

sensory (60-80 usec)

Question 32

Long duration pulses for ____ axon?

Answer 32

motor (150-300usec)

Question 33

Very long duration pulse for _____?

Answer 33

muscle fiber (>10ms)

Question 34

NMES

Answer 34

depolarization of motor neuron

Question 35

EMS

Answer 35

depolarization of muscle fiber directly

Question 36

Contraindications for Electrical Current:

Answer 36

pacemaker or unstable arrhythmia over carotid sinus blood clot pregnancy

Question 37

Precautions for Electrical Current:

Answer 37

cardiac disease impaired sensation or mentation malignant tumors skin irritation or open wounds

Question 38

Adverse effects of electrical currents:

Answer 38

burns skin irritation or inflammation perception or discomfort

Question 39

Under which of the following conditions would a physical therapist choose to set the “ramp up” time to eight (8) seconds when using NeuroMuscular Electrical Stimulation?

Answer 39

when contracting the antagonist to a spastic (hyperreflexive) muscle

Question 40

For which of the following therapeutic objectives would the current commonly called “Russian” be the best choice?

Answer 40

strong contraction of the knee extensors

Question 41

Which of the following neurons would be the easiest to depolarize with a biphasic, symmetrical pulsed current that is applied to the surface of the skin with self-adhesive surface electrodes?

Answer 41

large diameter and located shallow under skin

Question 42

An asymmetrical biphasic waveform would be the best choice for stimulating contraction of a __________ muscle group because it __________

Answer 42

small; concentrates depolarization under one electrode