Physical Inactivity / Bed Rest

Question 1

What is the impact of bed rest on muscle force ?

Answer 1

Important decrease of muscle force up to 46%

Question 2

What can one observe after 20 days of bed rest ?

Answer 2

Increase in tendon compliance
Decrease in the installation of force
It is more proeminant in gastrocnemius (different muscle composition : essentially fast MU)

Question 3

Describe the course of muscle atrophy in case of cast

Answer 3

Progressive atrophy of the muscle at 4 weeks and 8 weeks of cast
10 weeks after cast removal muscle mass is almost recovered

Question 4

Explain the relation between muscle atrophy and muscle lengths

Answer 4

• the loss is greater when the muscle is in a shorten position

Question 5

Explain the relation between muscle atrophy and protein loss

Answer 5

Muscular atrophy is the loss of contractile proteins.
It means an increase in contractile protein degradation and a decrease in contractile protein synthesis
The loss is important during the first 15 days then there is a plateau

Question 6

What are the consequences of soleus immobilization on the H-Reflex ?

Answer 6

There is an increase in H-Reflex amplitude after immobilization

Question 7

How to diminish the negative effects of immobilization ?

Answer 7

Perform max 30 isometric contractions per day of the quads for 20 days of bed rest