Decreased Use Flashcards
What are some models of decreased use
- immobilization
- spinal cord transection
- unloading
- tenotomy
- Denervation
- aging
Why is immobilization relevent for PT
surgery
Will type 1 or type 2 muscles look more muscle mass with immobilization
type 1
is soleus a type 1 or 2
1
is gastroc a type 1 or 2
2
will a muscle lose more mass with a lengthened or shortened position
shortened
_______ muscles atrophy to a greater extent than _____ muscles
slow (1)
fast (2)
_________ muscles atrophy to a greater extent than their antagonists
antigravity
T or F: due to a lack of muscle length control in many studies there are many exceptions in immobilization research
T
T or F: muscle length plays a role in immobilization mass loss
T
Which quad is mostly fast twitch
VL
_____ joint muscles atrophy faster than _____ joint muscles
2
1
_____ fiber atrophy was VM = VL> RF
______ fiber atrophy was VM>VL>RF
fast
slow
_________ endomysium and perimysium in VM and VL study
increased
most susceptible to atrophy with immobilization
antigravity, single joint, large proportion of slow fibers
less susceptible to muscle atrophy with immobilization
antigravity muscles, predominately slow, cross multiple joints
least susceptive to atrophy with immobilization
phasically activated, predominately fast
examples of most susceptible muscles
VM, soleus, VI, multifidus
examples of less susceptible muscles
RF, gastroc, longissimus, erector spinae
examples of least susceptible muscles
EDL, TA, biceps
_______ is proportional to the total amount of contractile material
mass
strength is a function of _________
CSA (architecture)
muscle fiber CSA correlates to ____________ in the immobilized then remobilized model
muscle tension
T or F: there is a greater loss of muscle at 3 weeks with exercise than there is at 2 weeks with no exercise
T
type ______ shifts to type ____ with immobilization
1
2
why is it important to know type 1 fibers shift to type 2 fibers with immobilization
the pt will be able to meet force but not endurance demands post surgery. they have increased fatigability which is when more injuries occur
when you have a spinal cord transection you are…
weaker, activate faster, and are more easily fatigued
contractile properties after long-term cordotomy
- soleus increased contractile speed, EDL didn’t
- specific tension increased 100% (because soleus had smaller CSA but same force output)
is stepping or stand alone training better after a cordotomy
stepping (has higher force and intermittent loading)
(stand alone has lower and constant loads which is why stepping is better)
T or F: post cordotomy there is nearly normal rhythmic activity of the locomotory muscles
T
changes that occured in muscle with training post cordotomy
- decrease tetanic tension
- increase velocity
- decrease % of slow fibers
T or F: type 2 muscle loses more mass than type 1 with unloading
F - type 1 loses more mass
T or F: you continuously lose muscle mass with unloading
F it plateaus after about 30 days
what are changes in slow twitch muscles with unloading
- decrease fiber diameter
- decrease specific tension
- increase velocity
what are changes in fast twitch muscles with unloading
- decrease fiber diameter
- decrease specific tension
*no change with velocity
T or F: changes in fast AND slow fibers in muscles during unloading will be dependent on levels of activation
T
(if unloaded but can still activate ex. space will preserve more muscle than unloaded and can’t activate ex. coma)
there is a _________ in force with unloading
decrease
glycolytic capacity _________ with unloading
increases because type 1 shifts to type 2
what happens to muscle mass and force generation post tenotomy
- anti-gravity atrophys more
- with intact innervation, slow converts to fast fibers
what happens to connective tissue post tenotomy
it increases
what happens to capillaries post tenotomy
decrease esp in slow twitch
what happens to sarcomeres post tenotomy
shorter sarcomeres to optomize the contractile function of each sarcomere
loss of __________ over time in tenotomy results in return to normal sarcomere length
sarcomeres
