Changes Acoss The Lifespan Flashcards
What areas are changed by ageing?
Strength, ROM, Bone Density, Fitness, Cognition
When is loss of strength evident?
after 50 yrs
When does loss of strength occur rapidly?
after70 yrs
When does loss of strength occur?
evident after 50
increases rapidly after70
What is the extent of loss of strength? and where?
65- 89 yr loss 1-2% per year in
- elbow flexors, handgrip, an knee extensors
What age do people lose 1-2% of strength per year?
65-89
How much strength does vastus lateralis lose?
up to 40%
How much strength do plantarflexors lose?
Up to 60%
How much strength do ankle dorsiflexors loe?
20-30%
When do ankle dorsiflexors lose strength?
Later than plantarflexors
What mode of contraction is affected most with age?
Loss of concentric and isometric strength is much more sever than loss of eccentric strength
Is power or strength reduced more with age?
Power
How is endurance affected by age?
Decrease in mucle endurance
Decreased ability to maintain a force at a given intensity
What are the muscular changes that occur with age?
Decreased muscle mass
Decreased specific tension of muscle fibres
Decreased shortening velocity
Decreased number of motor units
How do he motor units of tibialis anterior change across the lifespan?
27 yo 43 motor units
older participants (66 yo) - 22 motr units
very old participant (82 yo) had 15 motor units
What muscle fibre is thought to be lost?
Repots of more loss of Type II motor units ( unclear whether due to age or inactivity
How does muscle mass change with age?
20-40% between 30 and 80 yo
What is reduced specific tension and reduced shortening velocity?
Reduced length ad mass of individual fibres
Reduced myosin concentraton
What neural changes occur with ageing? (6)
Decreased motor neurones Decreased conduction velocity Decreased motor neurone excitability Decreased motor neurone firing rate Decreased voluntary activation of motor units Excessive co-contraction of muscles
Which motor neurone decrease with age?
Upper and lower
What rate do motor neurones decrease with age?
Decrease of up to 35% of UMN after 50 yr
Decrease of up to 25% LMN after 80yr
Decreased capacity for motor neurone sprouting
How much is conduction velocity reduced wit age?
Reduced byup to 29% in older (65-80 yo) compared to younger participants
How does firing rate change with age?
Reduced by 20% in 80yo compared to 20 yo
What has been found about activation capcacity and cocontraction with ageing?
Controversial - different studies have produced different results
A study on plantarflexors:
78% activation capacity in older participants
99% in younger
However, another study on dorsiflexor muscles found no significant difference
Clear defecit in older people who are less active or affected by disease
What are the differences in results found in studies of activation capacity likely due to?
Different participant groups
Difference muscles measured
Why is there less muscular endurance with ageing?
Less motor units to share the load
Why is there more loss of power than strength?
Less type II muscle fibres
What is important in determining the walking speed in normal ageing?
Leg strength
What is the impact of normal ageing on standing up?
Older people use significantly more of their available strength to rise from a chair.
At lowest hight, - 97% of available knee extensor strength being used.
What does decreased strength result in?
Decreased ability to perform everyday tasks
- standing up
-walking
Slower recovery from repetitive daily tasks
Increased risk of falling
How much hip ROM is lose with age?
20-30%
How much spine ROM is lost with age?
20-30%
How much ankle ROM is lose with age?
30-40%
What connective tissue changes occur with ageing?
Collagen becomes thicker and rougher
Elastin more intertwined and accumulates mineral deposits
What changes occur at joints with age?
Decreased synovial fluid volume and viscosity
Fibrotisation of the synovium
Changes in water content and elasticity in cartilage
Narrowing of joint space
What is the impact of decreased ROM?
Links between poor ROM, mobility and physical independence.
At what age is peak bone mass?
20
When does bone density decline?
After 30 yo - los of 0.5%/yr
After menopause - 2-3%/yr
What is osteopenia and what is the risk associatedwith?
1-2.5 SD below controls
Increases fracture risk
What are the changes in cardiovascular fitness in normal ageing?
Decreased cardiac output
Slower HR response to exercise
Decreased V02 max - loss of 5-15 % each decade after 30yo
What changes occur in the arteries with age?
Increased stiffness
Plaque accumulation
Less vasodilation
What does decreased vasodilation mean?
Older people are more affected by the heat
What changes occur to pulmonary function in normal ageing?
Stiffer chest wall
Increased risk of atelectasis
Reduced surface area for gas exchange
Increased work of breathing
What is the impact of chanes in cardiovascular fitness in normal ageing?
Slowed HR response- takes longer to reach training HR
For given workload-working at a higher proportion of V02 max
What is fluid intelligence?
Relies on short term memory storage while processing information.
- Novel problem solving
- spatial manipulation
- speed of processing
- identifying complex relation among patterns
What is crystallized intelligence?
Relies on long term memory - accumulated knowledge and expertise
How does ageing affect memory?
Affects fluid intelligence.
- slower information processing
- difficulty selectively attending to information and inhibiting irrelevant information.
Deficits in information processing and attention impact of working memory and short term memory.
What happens to crystallized intelligence across the lifespan?
Increases due to
education
occupational, cultural cultural experience
cultural, intellectual pursuits
33 item vocab test 25 yo and 70 yo
No difference
25 yo and 70 yo recall of digits in order presented
25 recalled about seven
70 recalled about 5
25 yo and 70 yo coding speed within a time limit
25 coded about seventy eight items correctly
70
About 51 items correctly
What is MMSE
Mini mental state exam
<24/30 used to indicate cognitive impairment
Limitation of MMSE
Reliant on English literacy and numeracy skills
Differentiating normal ageing from cognitive impairment requires formal assessment by neurologist, geriatrician or neuropsychologist
What happens to physical activity with age
Declines
- measures by self report, interview, body motion sensors, daily caloric expenditure
Lesser intensity
Ie walking, golf, low impact activities
Survey of activity in older adults
32 % no exercise in last year
40% one type of activity
53 % exclusively walking
What chronic diseases are more likely in older age that can be reduced with exercise
Cardiovascular disease
Diabetes
Cancer
MSK condition:
Osteoporosis, arthritis, sarcopenia
Three characteristic behaviours for longevity
Regular exercise
Maintaining a social network
Maintaining a positive mental attitude
Physiological factors for longevity
Low BP Low bmi Low central adiposity Preserved glucose tolerance Low cholesterol levels
(Physical activity influences all of these(
Regular physical activity increases average life expectancy by
- Decreasing the development of chronic disease
- Restoring/ maintaining functional
Capacity in older people
What happens to older athletes
Thinner and fitter
Cardio protective
Also
30-50% stronger than sedentary peers
Faster nerve conduction velocity
Retention of type II fibres
Aerobic training leads to
Improved vo2 max Improved sub maximal metabolic responses Improved exercise tolerance Lower resting hr Lower HR for given workload Less increases in BP at a given workload Improved vasodilator and O2 capacity of trained muscles Numerous cardio protective
Caution physical activity in older adults
Older people may take longer to reach same levels of improvement as younger person
- Increased risk of heat/cold illness or injury
Cessation of aerobic training leads to rapid loss of cardiovascular fitness
Benefits training for bone density
Low intensity weight bearing activities ie walking
- counteract age related loss of bone density
Reduce hip fracture risk
High intensity eg jogging
- more significant effects
Resistance training leads to
Increased muscle strength, endurance,size, power, activity
Capacity of older adults to adapt to training and increase strength
Equal to younger adults
How can resistance training be more functional for older adults
Muscle power (force x velocity) is more strongly associated with function than strength
Using higher velocity training protocols- gains in power may be comparable or greater than gains in strength (include speed in training)
What does high intensity resistance training do?
Preserves or increases bone density
Benefits of walking
No change self selected speed (except frail older people)significant Change in maximum walking speed
Cessation of resistance training
Leads to loss of strength but at slower rate than loss of cardiovascular fitness
Rest of up to five weeks- no significant loss of strength
Delivery resistance training
Gym facility- high adherence
Home- drop out numbers higher
Reduced effectiveness- less supervision
Harder to ensure sufficient resistance
Benefits of balance training
Effective at reducing non injurious falls and sometimes injurious falls in people who are ar risk of falling
Specificity of training in older adults. Consider
Adaptations will mimic the Kinematics, kinetics of the training programme
Important to include higher velocity movements that mimic ADL
Psychosocial benefits exercise in older adults
Significant improvement in overall psychological well being
- moderating effects on self concept and self esteem
Decreased risk for depression or anxiety
Benefits exercise cognitive function older adults
Reduced risk cognitive decline and dementia
Combined aerobic and resistance:
Can improve some measures of cognitive functions
- especially on tasks requiring complex processing
Clinical implications increasing physical activity in older adults- general
Increase time in warm up
- slower O2 uptake in response to exercise
- slower hr response
