Decreased Use

Question 1

What are some models of decreased use

Answer 1

• immobilization
• spinal cord transection
• unloading
• tenotomy
• Denervation
• aging

Question 2

Why is immobilization relevent for PT

Answer 2

surgery

Question 3

Will type 1 or type 2 muscles look more muscle mass with immobilization

Answer 3

type 1

Question 4

is soleus a type 1 or 2

Answer 4

1

Question 5

is gastroc a type 1 or 2

Answer 5

2

Question 6

will a muscle lose more mass with a lengthened or shortened position

Answer 6

shortened

Question 7

_______ muscles atrophy to a greater extent than _____ muscles

Answer 7

slow (1)
fast (2)

Question 8

_________ muscles atrophy to a greater extent than their antagonists

Answer 8

antigravity

Question 9

T or F: due to a lack of muscle length control in many studies there are many exceptions in immobilization research

Answer 9

T

Question 10

T or F: muscle length plays a role in immobilization mass loss

Answer 10

T

Question 11

Which quad is mostly fast twitch

Answer 11

VL

Question 12

_____ joint muscles atrophy faster than _____ joint muscles

Answer 12

2
1

Question 13

_____ fiber atrophy was VM = VL> RF
______ fiber atrophy was VM>VL>RF

Answer 13

fast
slow

Question 14

_________ endomysium and perimysium in VM and VL study

Answer 14

increased

Question 15

most susceptible to atrophy with immobilization

Answer 15

antigravity, single joint, large proportion of slow fibers

Question 16

less susceptible to muscle atrophy with immobilization

Answer 16

antigravity muscles, predominately slow, cross multiple joints

Question 17

least susceptive to atrophy with immobilization

Answer 17

phasically activated, predominately fast

Question 18

examples of most susceptible muscles

Answer 18

VM, soleus, VI, multifidus

Question 19

examples of less susceptible muscles

Answer 19

RF, gastroc, longissimus, erector spinae

Question 20

examples of least susceptible muscles

Answer 20

EDL, TA, biceps

Question 21

_______ is proportional to the total amount of contractile material

Answer 21

mass

Question 22

strength is a function of _________

Answer 22

CSA (architecture)

Question 23

muscle fiber CSA correlates to ____________ in the immobilized then remobilized model

Answer 23

muscle tension

Question 24

T or F: there is a greater loss of muscle at 3 weeks with exercise than there is at 2 weeks with no exercise

Answer 24

T

Question 25

type ______ shifts to type ____ with immobilization

Answer 25

1 2

Question 26

why is it important to know type 1 fibers shift to type 2 fibers with immobilization

Answer 26

the pt will be able to meet force but not endurance demands post surgery. they have increased fatigability which is when more injuries occur

Question 27

when you have a spinal cord transection you are...

Answer 27

weaker, activate faster, and are more easily fatigued

Question 28

contractile properties after long-term cordotomy

Answer 28

- soleus increased contractile speed, EDL didn't - specific tension increased 100% (because soleus had smaller CSA but same force output)

Question 29

is stepping or stand alone training better after a cordotomy

Answer 29

stepping (has higher force and intermittent loading) (stand alone has lower and constant loads which is why stepping is better)

Question 30

T or F: post cordotomy there is nearly normal rhythmic activity of the locomotory muscles

Answer 30

T

Question 31

changes that occured in muscle with training post cordotomy

Answer 31

- decrease tetanic tension - increase velocity - decrease % of slow fibers

Question 32

T or F: type 2 muscle loses more mass than type 1 with unloading

Answer 32

F - type 1 loses more mass

Question 33

T or F: you continuously lose muscle mass with unloading

Answer 33

F it plateaus after about 30 days

Question 34

what are changes in slow twitch muscles with unloading

Answer 34

- decrease fiber diameter - decrease specific tension - increase velocity

Question 35

what are changes in fast twitch muscles with unloading

Answer 35

- decrease fiber diameter - decrease specific tension *no change with velocity

Question 36

T or F: changes in fast AND slow fibers in muscles during unloading will be dependent on levels of activation

Answer 36

T (if unloaded but can still activate ex. space will preserve more muscle than unloaded and can't activate ex. coma)

Question 37

there is a _________ in force with unloading

Answer 37

decrease

Question 38

glycolytic capacity _________ with unloading

Answer 38

increases because type 1 shifts to type 2

Question 39

what happens to muscle mass and force generation post tenotomy

Answer 39

- anti-gravity atrophys more - with intact innervation, slow converts to fast fibers

Question 40

what happens to connective tissue post tenotomy

Answer 40

it increases

Question 41

what happens to capillaries post tenotomy

Answer 41

decrease esp in slow twitch

Question 42

what happens to sarcomeres post tenotomy

Answer 42

shorter sarcomeres to optomize the contractile function of each sarcomere

Question 43

loss of __________ over time in tenotomy results in return to normal sarcomere length

Answer 43

sarcomeres