Electrotherapy and Muscle Contraction Flashcards Preview

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Flashcards in Electrotherapy and Muscle Contraction Deck (81)
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1

When do we use accomodation

Chronic pain syndromes

2

True or False:
AP of muscle developed by electrically stimulated motor nerve is similar to that produced physiologically

True

3

How are motor units recruited during a contraction caused by E-stim

Large motor units are recruited first then small motor units

4

What does motor units being recruited from large motor to small units cause in terms of strength

The patient is weaker because the small motor units are not activated to help the large motor units

5

How are motor units recruited during a voluntary muscle contraction

Progressive recruitment of small, slow motor units to large fast motor units

6

What type of contraction has an increased rate of fatigue E-stim or voluntary

E-stim

7

True or False:
Longer rest times are needed between contractions to allow the muscle to be able to produce the same strength

True

8

What are the factors that influence the force-frequency relation for E-stim or voluntary contractions (4)

1. Muscle length
2. Muscle temperature
3. Fatigue state
4. Degree of potentiation of the muscle

9

What is low frequency stimulation of muscle with E-stim

1-2 stimuli per second

10

What does low frequency stimulation of muscle with E-stim cause

Twitch contraction

11

At what frequency will the AP start to summate causing unfused tetanus

15 pps

12

At what frequency will sustained contraction or tetanus occur

30 pps

13

What is the spatial motor unit recruitment for E-stim and voluntary muscle contraction

E-stim: Large to small
Voluntary: Small to large

14

What is the temporal motor unit recruitment for E-stim and voluntary muscle contraction

E-stim: Synchronous
Voluntary: Asynchronous

15

What is the muscle loading to increase strength for E-stim and voluntary muscle contraction

Both against resistance

16

What is the strengthening for E-stim and voluntary muscle contraction

E-stim: Increased motor unit recruitment and increased muscle hypertrophy
Voluntary: Increased motor unit recruitment and increased muscle hypertrophy

17

True or False:
E-stim can accelerate rehab by increasing muscle strength and endurance

True

18

What needs to happen to increase strength in healthy muscle

Stimulated contraction needs to be at least 50% of max voluntary isometric contraction (MVIC)

19

What needs to happen to increase strength in injured muscle

Stimulate contraction need to be only 10% of MVIC

20

Why do you not want a stronger contraction for injured muscle

It will produce greater pain and potential damage the tissue further

21

What is the overload theory

The larger the load placed on a muscle the greater the force of contraction the muscle will produce, thus strength will be greater than if smaller loads are applied

22

When does the overload theory apply to E-stim and voluntary muscle contractions

When the same force is applied

23

What is the specificity theory

E-stim stimulates large fast twitch type II motor units before small slow twitch motor units

24

True or False:
E-stim should produce greater strength gains than exercise alone with the same force contraction

True

25

Why is E-stim able to produce greater strength gains than exercise alone

Because it stimulates large motor units first which are the stronger motor units

26

What is the smoothness of onset of contraction for E-stim

Rapid and more jerky onset of contraction where all motor units of a given size contract simultaneously

27

True or False:
E-stim can support or assist with joint positioning

True it was able to reduce shoulder subluxations

28

True or False:
E-stim can increase blood flow

True

29

What frequency E-stim caused increased blood flow in the extremties

High frequency E-stim

30

How does blood flow increase because of E-stim

Muscle contraction increases venous return and muscles need more blood so heart pumps faster