Electrical Stimulation for Muscle Contraction

Question 1

What are the two different types of waveformsformusclecontraction

Answer 1

NMES and Russian

Question 2

whatypeofcurrentis NMES

Answer 2

a monophasic or biphasic pulsed current

Question 3

Why would you choose monophasic or a biphasic pulsed current

Answer 3

there is no relevant reason to chose one over the other, other than just patient preference

Question 4

what type of current can be used in a monophasic set up with the cathode over the motor pooint

Answer 4

monophasic pulsed current

Question 5

what is Russian stimulation

Answer 5

• aka. burst modulated alternating current is the third type of waveform that is used with NMES.
• it uses alternating current meaning it also has no true polarity.
• the continuous wave of alternating current is broken into bursts of many cycles grouped together
• frequency of these units refers to the frequency of the bursts

Question 6

what is carrier freqeuncy

Answer 6

refers to the rate at which the current is cycling within the the bursts.

Question 7

what is the usually carrier frequency for Russian stimulation

Answer 7

2000-5000 hz

Question 8

what can you control with Russian stimulation

Answer 8

ramp, on-off time, treatment time, intensity, and how many channels you want to use

Question 9

what is the optimal rate for muscle contraction

Answer 9

dependent on muscle size, smaller muscles 30 pps, large muscles 50-80 pps

Question 10

what is the optimal amplitude for muscle contraction

Answer 10

turn as high as the patient can tolerate to achieve good muscle contraction

Question 11

what is the optimal phase duration for muscle contaction

Answer 11

100-300 microseconds

Question 12

what is the optimal ramp for muscle contraction

Answer 12

1-2 seconds, slower 3-6 second for spastic muscles

Question 13

what is the optimal on/off time for muscle contraction

Answer 13

1/5 to avoid fatiue

Question 14

what is the optimal number of channels for muscle contraction

Answer 14

larger muscles may be best stimulated with two channels

Question 15

what is the optimal treatment time for muscle contraction

Answer 15

at least 210 contractions at max tolerable intensity

Question 16

what should you disontinue esteem for muscle contraction

Answer 16

when you can get voluntary contraction at a higher % of MVC

Question 17

where should electrodes be placed

Answer 17

firmly over the belly of the muscle and run longitudinally or parallel to the line of the origin or insertion

Question 18

what happens if electrodes are farther apart

Answer 18

the deeper the current goes

Question 19

what is usually the biggest issue with trying to generate force production >60% MVV

Answer 19

patient discomfort

Question 20

how can you decrease discomfort for a patient when using E-stim

Answer 20

try increasing pad size, change locations of pad, ensure good contact, add another channel, or try longer duration of different wave form

Question 21

when is there a strengthening effect with ES

Answer 21

if the dosage is adequate vs, no intervention at all

Question 22

is there a difference between the training effect of ES and exercise in healthy patients if the training intensity is the same

Answer 22

no

Question 23

is there an added benefit of using ES and exercise in healthy individuals

Answer 23

no

Question 24

when have studies shown ES to be the most effective

Answer 24

early in the rehab process, perhaps due to the selective recruitment of type II fibers

Question 25

what are patients with ACL repair and children with CP examples of

Answer 25

patient populations with type II muscle atrophy

Question 26

what muscle fiber has been shown to shrink with aging

Answer 26

type II