Ageing Flashcards
What happens to strength as ageing occurs?
Decreases.
At what ages is a decrease in strength clear?
After 60yrs
What is the steady decline in strength per year after 60yrs?
1-2% steady decline
What happens on average in 70-80yrs olds in regards to strength?
20-40% lower on tests of isometric strength than young adults.
Conclusion of muscles that control leg multi-joint movements in ageing
⬆️ age = ⬇️ in force-generating capacity
⬆️ age = NO change in max shortening velocity of muscles
== Relevant to muscles controlling leg multi-joint movements
Does age-related decline in muscular power performance have a larger or smaller effect on the force than on the shortening velocity of muscles?
Larger effects on the force
smaller effect on the shortening velocity of muscles
Age related decline in muscular power performance has a larger effect on the force than on the shortening velocity of muscles.
What does this finding suggest?
⬇️ in muscle force-generating capacity + power w/ ageing may lead to the loss of mobility
At what ages do muscle-fibre loss of motor units begin?
Near 50-60yrs
When does muscle size begin to decrease?
~30 yrs
What happens to muscle size between the ages of 30 to 50?
⬇️ by 10%
Why does muscle area decline a lot after 50yrs?
Due to ⬇️ in total no. of fibres that receive stimulation.
Which deteriorates quicker?
Leg or arm strength?
Leg
How does metabolic rate decrease after 40 yrs old?
Metabolic rate ⬇️ 5% after each decade after 40.
Which leads to a ⬇️ in muscle mass.
What are the 2 biggest reasons as to why we see a decline in neural function with ageing?
Due to:
- 40% ⬇️ in spinal cord axons
- 10% ⬇️ in nerve conduction velocity
Why does the nerve conduction velocity decrease as we age?
Due to:
- Structural changes in myelinated neurons = ⬆️ internal distances
- Preferential loss of fastest conducting axons
- ⬇️ In soma size
