Transcript L5-stroke-and-physical-fitness-Nov11

EXERCISE AFTER STROKE
Specialist Instructor Training Course
L5
Physical fitness after stroke
background
Content
• Physical activity and fitness defined
• Components of physical fitness
• Impact of stroke on fitness
• Relation between fitness and function after
stroke
• The need for exercise!
Learning outcomes
After this session you should be able to:
• Define “physical fitness”
• Describe and explain the impact of stroke on
fitness
• Describe and explain the impact of reduced
fitness on function after stroke
Physical activity
• All bodily movement produced by the
contraction of skeletal muscle and which
substantially increases energy expenditure
(USDHHS 1996)
• Includes the muscular work required for;
– Walking
– Maintaining posture
– Activities of daily living
– Occupational, leisure and sporting activities
What happens to physical activity after
stroke?
• After major stroke, patients are often immobile
due to the neurological effects of stroke
• Stroke in-patients: only 13% of time engaged in
physical activity (Bernhardt 2004)
• Even relatively minor neurological deficits may
lead to a reduction in physical activity
• Paucity of literature on levels of physical activity
after stroke, particularly after minor stroke
ActivPalTM physical activity monitoring
Physical fitness..
..Is a set of attributes, which people
have or achieve, that relate to the ability
to perform physical activity
(USDHHS 1996)
..Is improved by activity, and reduced by
inactivity
Components of physical fitness
Cardiorespiratory fitness;
• Relates to an individual's ability to perform
physical activity for an extended period.
Conferred by Central capacity of the circulatory
and respiratory systems to supply oxygen
(USDHHS 1996)
• Peripheral capacity of skeletal muscle to utilise
oxygen
(Saltin & Rowell 1980)
Components of physical fitness cont
Muscle strength;
Maximum force that can be generated by a muscle or
muscle group.
Ability to sustain repeated muscular actions or a single
static contraction is 'muscular endurance' (USDHHS 1996)
Muscle power;
Rate of generation of strength
Body composition;
Includes total and regional bone mineral density, and the
relative amounts and distribution of adipose tissue, muscle
and other vital parts of the body (USDHHS 1996).
What happens to physical fitness after
stroke?
• Physical fitness is related to physical activity
• After stroke, activity falls
• So might physical fitness be reduced?
Aerobic fitness (endurance) after stroke
Peak V02 synthesised from 16 studies (Dave
Saunders 2007 unpublished)
Muscle strength and power after
stroke
We recruited 11 patients who had made an apparently full
neurological recovery several months after their stroke
We measured;
– Muscle strength
– Power output of both lower limbs
We found that muscle strength and power output in both
limbs were significantly lower than age and sex matched
values from the population
Greig et al 2001
Measurement of maximum voluntary isometric knee
extensor strength
Measurement of lower limb extensor power during
a single maximal leg extension
Might these impairments in aerobic
fitness, muscle strength and muscle
power have consequences for function,
mobility, quality of life?
Influence of impaired leg extensor power on
function after stroke?
• In 66 ambulatory patients, who had completed their
rehabilitation, there were associations between impaired
LEP in both the affected and unaffected limbs and
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Timed up and go
Sit to stand
Functional reach
Comfortable walking velocity
FIM
Rivermead motor index
Nottingham extended ADL
SF36
Elderly mobility scale
(Saunders et al 2008)
LEP and function in 66 people after stroke
(STARTER)
Timed 3-m up and go (sec)
Functional reach (cm)
40
30
20
10
0
0
1
2
60
40
20
0
3
0
-1
2
3
LEP (WKg-1)
LEP (WKg )
1.2
7
1.0
6
Chair rise time (sec)
Walking Velocity (m.sec -1)
1
0.8
0.6
0.4
0.2
5
4
3
2
1
0
0.0
0
1
2
LEP (WKg-1)
3
0
Affected (■) and unaffected (□) legs
1
2
LEP (WKg-1)
3
Relationship between aerobic fitness
and function
• 74 people with chronic hemiparetic stroke
demonstrated that walking ability was
independently related to;
– Cardiovascular fitness
– balance
– paretic leg strength
Patterson 2007
Why is fitness impaired after stroke?
• Reduced physical activity after stroke
• Reduction in fitness may pre-date stroke
(age and co-morbidities)
• Direct effect of hemiparesis
Mechanisms of reduced fitness after
stroke
Increasing Age
Comorbid Disease
STROKE
Pathology
Fitness
Impairments
Cycle of
Detraining
Physical
Inactivity
Direct Effect
of Stroke
Functional
Limitations
Other
Impairments
Process of
Disablement
DISABILITY
Courtesy Dave Saunders 2008
Summary
• Physical fitness is reduced after stroke
– Muscle strength
– Muscle power
– Aerobic fitness
• Mechanisms include
– Direct effect of hemiparesis
– Pre-stroke impairments
– Reduced physical activity after stroke
• Impairments in physical fitness are
associated with reductions in functional
ability
Physical fitness essential for
physical activity
Cardiorespiratory
Muscle strength and power
Essential Reading
Further detail about the topics discussed in this
session can be found in section L5 of the
course syllabus.