LECTURE 29 Flashcards
What is sarcopenia?
The age associated loss of skeletal muscle mass and function
When should diagnosis of sarcopenia be considered?
In all older patients with observed declines in physical function, strength or overall health.
It should be considered in patients who are bedridden, cannot independently rise from a chair or who have measured gait speed of
What is a diagnosis of sacopenia?
criterion 1 (low muscle mass) + criterion 2 (low muscle strength) or criterion 3 (low physical performance)
When does performance/speed begin to decline?
From peak at 20-30 it begins to decline
When does a steep decline in muscle strength and motor units occur?
50
Which muscles are more affected by ageing?
Fast muscles - can’t do quick daily activites
What are the neural mechanisms of ageing?
- denervation of type II motor units, muscle volume decreases
- muscle is more type I fibres (slow)
When does slowing of contraction occur and what is it caused by?
Before severe muscle wasting and occurs due to impaired release and reuptake of calcium, changes in calcium handling (resulting in balance, movement and response actions)
What are the most susceptible motor units and what happens when these are lost?
Type IIB, prolonged contraction time
What happens to motor neurons as they cease functioning?
Die or send out new branches (sprouts) - often reinnervate fast muscles and make them slow
What happens to the NMJ with ageing?
Widening of end plate, longer nerve terminals and fewer side branches
What happens to elite athlete performance with age?
- Elite athlete status does not protect muscles from gradual losses in fibres and motor units
- Motor skills for elite athletes are not lost with age, just physical skills such as agility and speed
When do elite athletes begin to show a decline in performance?
Early 30s
What can strength training do for the elderly?
Increase muscle strength, hypertrophy and protein turnover, adaptations due to combination of neural and muscle adpatations, increase type II fibres
What aspects of training are important to minimise sarcopenia?
Balance, flexibility, strength and aerobic
