Week 6 - Laboratory-Based Physiological Assessment of OA Flashcards
What are the best predictors of longevity?
Age, gender, cardiorespiratory fitness
Which organs comprised the cardiovascular function?
Heart and blood vessels
Which organs comprised the respiratory function?
Lungs and airways
What are synonyms of cardiorespiratory function (CRF)?
- Aerobic fitness
- Aerobic endurance
- Cardiorespiratory endurance
What are 2 good reasons for testing CRF?
- Provides baseline values prior to commencing a fitness program
- Key determinant of maintaining independent living (basic ADLs and instrumental ADLs)
What are 2 ways to measure CRF in a lab setting?
- Direct method: measurements taken during maximal-intensity exercise tests
- Indirect method: measurements taken without the use of sophisticated methods. Equations are used to estimate VO2 levels
Which is better for OA, direct or indirect method of CRF testing?
Indirect. Direct is more appropriate for younger, healthy people or athletes
What are the advantages of using the direct method?
- more accurate (typical error = 3%)
- better estimation of desired exercise intensity
What are the disadvantages of direct method?
- require expensive and sophisticated equipment
- higher risk of adverse events (increase stress on participants)
- physician supervision can be required
Example of higher risk of adverse event: putting the O2 mask is not as comfortable or people don’t want to be pushed to the max
What are the advantages of using the indirect method?
- easier to make measurements
- lower risk for technical issues
- test is shorter to perform
- test is less expensive
What are the disadvantages of indirect method?
- less accurate: typical error is 5 to 7 % in CRF max prediction
Name 4 equipments for submaximal CRF tests.
treadmill, leg ergometer, arm ergometer, recumbent stepper
What are the disadvantages of the treadmill test?
- expensive
- not portable
- more difficult to measure BP accurately (bc participants move arms when using treadmill)
- may not be appropriate for OA with balance, gait, or weight problems
What are the advantages of the treadmill test?
functionally relevant activity (we walk all day and therefore use the same muscle). Movement novelty doesn’t interfere with the test.
What are the advantages of the leg cycle ergometer?
- preferred testing (vs treadmill) for OA with balance, gait or weight problems
- easy to obtain CRF measurements - blood pressure (BP) & heart rate (HR)
- more portable than treadmill
What are the disadvantages of the leg cycle ergometer?
- not necessarily funtional exercise
- can develop localized muscle fatigue (bc participants aren’t used to using these muscles, they get tired before hitting VO2 max, making it a limiting factor to CRF test)
What is the VO2 max difference between treadmill and leg cyclo ergometer for a non initiated OA?
VO2 max is ~10% lower on leg cycle than treadmill bc of localized muscle fatigue
What are the advantages of the recumbent stepper?
- preferred testing for OA with balance, gait, weight problems, impaired motor coordination in upper and/or lower limbs (ex: spinal cord injury, stroke, multiple sclerosis, Parkinson’s)
What are the disadvantages of the recumbent stepper?
- not necessarily functional exercise
- expensive + not portable
- difficult to take BP during test
- quite recent = limited exercise protocols for testing
Can you design your own testing protocol for OA?
Yes, especially for submax effort
What are the advantages of the arm cycle ergometer?
- ideal for OA with difficulty in ambulation (wheelchair or bed restrictions). Ex: stroke, spinal cord injuries, MS, etc.
- can be portable
- relatively expensive for portable units
What are the disadvantages of the arm cycle ergometer?
- localized muscle fatigue in smaller arm muscles
- lack of functional specificity (doesn’t mimic movement they do in a wheelchair)
- difficult to take the BP during test (arms are moving all the time)
How many testing protocols are available for each test?
- several protocols for treadmill, leg ergometer and arm ergometer + 1 protocol for recumbent stepper
Which types of tests are recommended for OA and why?
- submaximal tests
it’s an indirect measurement of the volume of oxygen consumed per min
participants much reach ~75% of max age-predicted HR
How is predicting VO2 max done and what is the accuracy of prediction?
Based on assumption that HR increases at the same rate.
error of 5 to 7%
Which is the better method to compare workload (or VO2)
for a given HR see if improvements occurred when repeating a 75% intensity. (ex: increased speed or resistance)
Name a treadmill test and what it consists of.
Modified Balke-Ware treadmill test: uses a slow and constant walking speed (3.2 km/h or 0.9 m/s) with small increases (1%) in grade (incline) every minute
For which population is the Modified Balke-Ware test more appropriate?
OA with good ambulation. It has also been successfully used in participants with stroke and PD’s.
- healthy and frail OA
- Participants with cardiac problems
- Participants with chronic disease and disabilities
What to do if the Modified Balke-Ware test is too easy/too long for fit OA?
modify test:
- increase walking speed
- increase grade increments (instead of 1% per min, maybe 2% per min)
What are reasons for stopping a test?
- angina-like symptoms (chest pain bc some parts don’t receive enough blood)
- participants is:
- is not sweating
- feels light-headed
- feels confused or unsteady
- looks pale
- has blue lips
What are reasons related to BP for stopping a test?
- BP drops below 20 mmHg from rest –> could be indicator of arrhythmia
- no increase in systolic BP with increase in exercise intensity
- excessive rise in systolic BP > 250 mmHg and/or rise in diastolic BP > 115 mmHg
What are reasons related to heart for stopping a test?
- HR does not rise with increase exercise intensity
- Participants have a noticeable change in heart rhythm (arrhythmia)
What are additional reasons for stopping a test?
- participant requests to stop
- participant shows physical or verbal signs of severe fatigue
- failure of the testing equipment
What is the formula for predicted target HR at 75% of max?
755 of max = (220 - age) x 0.75
Is it true that CRF tests for OA do not have to be as vigorous and demanding as it is for a 21 year old?
True, because it takes OA less bpm to reach 75% of max HR.
What is the formula used to calculate the 75% HRmax for the Modified Balke-Ware Treadmill test?
75% of HRmax = (207 - 0.7 x age) x 0.75
What should you do before the Modified Balke-Ware Treadmill test?
- Record baseline HR and BP
- Calculate and record the 75% HRmax
- Let client get used to walking on treadmill
What should you do during the Modified Balke-Ware Treadmill Test?
- set treadmill for 3.2 km/h (or 4 to 4.8 km/h for fit clients)
- increase grade by 1% (or 2%) every minute
- record HR and RPE every min
- Try to record BP every 2 min
- stop test when client reaches 75% of HRmax or client asks or if we see any signs of stopping
- record HR and RPE immediately after stopping
What should you do after the Modified Balke-Ware Treadmill test?
- reduce grade to 0% and keep client walking for 4 min
- record HR and RPE
- record BP at the end of the 4 min
Specific studies have found pedestrian walking speeds ranging from __ km/h to __ km/h for OA and __ km/h for younger adults?
4.5 to 4.8 for OA and 5.4 for YA
What is the equation for calculating/estimating the oxygen consumption?
VO2 = 0.1 x speed [of treadmill] + 1.8 x speed [of treadmill] x grade + 3.5
What is the resting 02 consumption?
3.5 ml/kg/min
Which predicted 75% HRmax equation is more conservation? the 0.75x (207-0.7xage) or 0.75 x (220-age)
0.75 x (220-age)
Pretest-posttest comparison after exercise training. What will normall change as a result of training?
Recall: 0.1 x speed + 1.8 x speed x grade + 3.5 = VO2
Overtime, increase in VO2 at the same HR level –> your participants’s CRF is improving
Why? Bc of increase of speed and grade
Why is muscular strength important in OA?
Allows them to stay independent at home
Which muscular strength tests are recommended and for which population?
- 1 RM (rep max) Test: for healthy OA
- Submax alternative to 1 RM: for frail OA or participants with physical impairments and disabilities (don’t want them to be too fatigued and it decreases risk of injury)
How to perform the 1RM test?
- Instruct participants to warmup, half of predicted max
- Tell client to complete 3 to 5 repetitions with a higher weight 60-80% of perceived max
- 1 min rest + light stretching
- add 2.5-5lbs every time lift is completed with no assistance. 3-5 min rest between lifts. Continue until client can’t complete more than 1 rep
Why is the submaximal alternative to 1RM test performed?
- concern about pushing inexperienced or frail clients to their limits
- when contraindications to max intensity (osteoporosis, hypertension, frailty, etc.)
Give an example of a submaximal alternative to 1RM.
Can be repeated in time to measure the effect of a training program.
Ex: 6-RM for arm curls.
Pretest = 6 RM = 10kg
Posttest = 6 RM = 15 kg
Why is balance testing important in OA?
To evaluate risk of falls
What is balance?
ability to control the body’s center of mass relative to the base of support (BOS: feet), whether that base is stationary or moving
What is the limits of stability (LOS)?
Max distance an OA can move beyond a centered position without altering the BOS
Name the 4 measurements of balance.
- Static balance
- Dynamic balance
- Reactive balance
- Sensory integration and organization
Define static balance
ability to maintain the center of mass directly over the base of support
What differs in static balance between OA and YA?
OA have a greater postural sway (movement over their BOS) than YA
What are some static balance assessment?
Stand still for a designated period of time (20-30s)
- eyes open-closed
- feet heel-to-toe
-one-legged stance
What is the purpose of a force plate?
it’s a static balance assessment that measures the magnitude and velocity of the postural sway
What does the center of pressure (COP) displacement and velocity tests reveal in YA, non-faller OA and faller OA?
max COP displacement (they sway more): fallers > non-fallers > YA
max COP velocity (they move faster): fallers > non-fallers > YA
What is dynamic balance?
Ability to control the center of mass (COM) while leaning through or moving beyond the limits of stability (LOS)
Name the purpose of a dynamic balance assessment. (What does the subject do?)
Lean toward visual targets as quickly and accurately as possible.
What do dynamic balance assessment measure?
- distance reached forward, backward, laterally, diagonally
- time of reaction
- movement accuracy
What is reactive postural control?
ability to respond automatically to a loss of balance
How is reactive postural control tested?
Perturbation (tilt forward or backward) is elicited through a moving force plate
What does the force plate measure in reactive postural control?
time + magnitude of reaction to the perturbation
What do we expect of a participant with good balance in a reactive postural control test?
quick response with a countermovement opposite to the direction of the plate movement
What is the sensory integration and organization?
ability to integrate and organize sensory information provided by the visual, somatosensory, and vestibular systems
What do the sensory integration and organization test measure?
- how well each sensory system is functioning
- how well the participant maintains upright balance when the information coming from the 3 systems is not in agreement
What do the results for the sensory integration and organization test indicate?
can indicate if an OA is at risk of falls in certain sensory conditions (ex: low lighting, compliant surface, busy visual environments)
