Electromyography - EMG Flashcards Preview

DPT Biomechanics > Electromyography - EMG > Flashcards

Flashcards in Electromyography - EMG Deck (19):
1

If the amplitude is increased on an EMG, what does that mean?

more MUs recruited

2

If the frequency decreases on an EMG, what does that mean?

MUs firing slower

3

What can we interpret from the amplitude of an EMG signal

muscle force, muscle activation

4

What can we interpret from the frequency of an EMG signal

muscle fatigue, muscle biomechanics

5

Where should the electrode be placed?

over the muscle belly

6

The electrode pair should be ____ to the muscle fiber

parallel

7

The individual electrode should be _______ to the muscle fiber (if not round)

perpendicular

8

EMG _____ neural impulse

follows

9

EMG ______ contraction and tension development

precedes

10

Frequency Content of EMG is mostly between ____ and ____ Hz

10,500

11

What happens to Mean Power Frequency with fatigue

downward shift of 20-40 Hz with fatigue
(a normal MPF = 80-120 Hz

12

Linear envelope is a force

APPROXIMATION

13

North American Electrical Grid Frequency

60 Hz

14

Frequency of Human movement

6-10 Hz

15

European Electrical Grid Frequency

50 Hz

16

indwelling EMG frequency

10-1500

17

ECG frequency

1-150 Hz

18

What info can we get from EMG

Is the muscle active?
What percentage of muscle capacity is being used?
Timing/sequencing of muscle activation relative to each other
Fatigue?

19

It is important to normalize EMG to %MVC or %RVC so that we can

make comparisons between people
make comparisons between muscles
make comparisons between days