Early Aerobic Exercise Intervention After Stroke

91 Pages·2009·0.51 MB·English

by  Jake Yoon

Early Aerobic Exercise Intervention After Stroke:
Improving Aerobic and Walking Capacity

by

Jake Jangjin Yoon

A thesis submitted in conformity with the requirements
for the degree of Master of Science
Graduate Department of Rehabilitation Science
University of Toronto

© Jake Jang Jin Yoon 2009
Abstract

Early Aerobic Exercise Intervention After Stroke:
Improving Aerobic and Walking Capacity

Jake Jang Jin Yoon Advisor:
Master of Science, 2009 Dr. Dina Brooks
Graduate Department of Rehabilitation Science
University of Toronto

The benefits of brief-duration, early exercise programs in stroke have been shown, but the
effects of longer-duration aerobic training early after stroke have not been examined. The
purpose of this study was to determine the effects of an early aerobic exercise program that
extended beyond inpatient into outpatient rehabilitation on aerobic capacity, walking
parameters (walking distance, speed, and symmetry), health-related quality of life, and
balance. Patients in the subacute phase after stroke (n = 15) with mild to moderate
impairment received aerobic exercise in addition to conventional rehabilitation. The study
participants demonstrated significant improvement in aerobic and walking capacity, peak
work rate, quality of life, balance, and gait velocity from baseline to midpoint. However,
no difference was found between midpoint and final. This early aerobic exercise program
following stroke significantly improved aerobic capacity, walking ability, quality of life
and balance during the inpatient period although no further improvement was observed
during the outpatient period.

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Acknowledgements

First of all, I would like to thank my supervisor, Dr. Dina Brooks, for her ongoing support
throughout my study. My thesis would not have been possible to complete without your
guidance, and you are one of the most influential people who made my graduate
experience fun and memorable. I cannot express my gratitude enough to you and I feel
extremely lucky to have you as my supervisor.

I would also like to thank Dr. Bill McIlroy for his guidance and patience. He has guided
me through my graduate studies along with Dina when I felt overwhelmed with many
questions. He is also one of the reasons why my graduate experience has been such a
enjoyable experience. You have been such a great leader and a great mentor, and it has
been my honour to work with you.

I am grateful to Dr. Scott Thomas for his guidance and feedback. You have taught me how
to think critically and made me become better at research.

I would like to thank everyone at the Mobility Team for their support, especially Hannah
Cheung, Sanjay Prajapati, Bimal Lakhani, and Ada Tang for their wisdom and laughter. I
thank everyone at Toronto Rehab who made this work possible including Lou Biasin,
Janice Komar, Jackie Lymburner, Chris Peppiatt, Dr. Mark Bayley, Dr. Denise
Richardson, Dr. Lisa Becker, and all the study participants.

Finally, I would like to thank my family and friends for their unconditional support and
love. I truly believe that I would not have accomplished many of my goals if I did not have
their support and belief in my ability. You are the source of my inspiration and drive to
excel in what I do. Thank you.

I am extremely fortunate to be surrounded by many inspirational and supportive people,
and I sincerely apologize to you if I have missed you here. But, I am truly grateful to all of
you who have guided and supported me.

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Table of Contents

Abstract ii
Acknowledgements iii
Table of Contents iv
List of Tables vi
List of Figures vii
Abbreviations viii
1.0 Introduction 1
2.0 Background 5
2.1 Epidemiology of Stroke 5
2.2 Stroke Risk Factors 5
2.3 Impairments and Disabilities Following Stroke 7
2.3.1 Walking Capacity 9
2.3.2 Aerobic Capacity 11
2.4 Aerobic Training in Chronic Stroke Population 13
2.5 Aerobic Training in Subacute Stroke Population 20
2.6 Aerobic Exercise and Conventional Stroke Rehabilitation 24
2.7 Research Rationale and Objectives 24
2.8 Hypothesis 25
3.0 Methods 26
3.1 Participants 26
3.2 Measurements 26
3.3 Training Protocol 31
3.4 Data Analysis 32
4.0 Results 33
4.1 Demographics and Training Parameters 33
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4.2 Aerobic Capacity 37
4.2.1 Peak Work Rate (WRpeak) 38
4.2.2 Peak Heart Rate (HRpeak) 40
4.3 Six-Minute Walk Test 41
4.4 Secondary measurements 45
5.0 Discussion 54
5.1 Clinical Implications 58
5.2 Limitations 58
5.3 Future Directions 59
6.0 Conclusion 61
7.0 References 62
8.0 Appendices 73
8.1 Chedoke-McMaster Assessment Scale 73
8.2 VO2peak Assessment Form 75
8.3 Modified Borg Rating of Perceived Exertion Scale 76
8.4 Stroke Impact Scale 77
8.5 Berg Balance Scale 83

v
List of Tables

Table 1. Summary of literature: effects of aerobic training in chronic stroke 15
Table 2. Summary of literature: effects of aerobic training in sub-acute stroke 21
Table 3. Participant eligibility criteria 26
Table 4. Participant demographics at baseline 36
Table 5. Training parameters 36
Table 6. Gait symmetry values obtained during fast- and preferred-gait for
all participants 50
Table 7. Gait symmetry values obtained during fast- and preferred-gait for
participants with complete data 51
Table 8. Main outcome comparison between current and previous studies 52
Table 9. Patient characteristics from current and previous studies at baseline 53

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List of Figures

Figure 1. Study timeline summary 27
Figure 2. Reason for exclusion 34
Figure 3. Flowchart depicting participants through each stage of the study 35
Figure 4. Baseline, midpoint and final values for VO peak 37
2
Figure 5. Relationship between change in VO and number of training sessions 38
2
Figure 6. WRpeak obtained during max tests 39
Figure 7. Relationship between change in WR and number of training sessions 40
Figure 8. HRpeak obtained during max tests 41
Figure 9. Baseline, midpoint and final values for 6MWT with non-ambulatory
participants (SA02, SA04, SA14, SA18, and SA25) given a score of 0m 42
Figure 10. Relationship between change in 6MWD and number of training sessions 43
Figure 11. Baseline, midpoint and final 6MWT values for participants excluding
non-walkers at baseline 44
Figure 12. Relationship between change in 6MWD and number of training sessions
excluding non-walkers 45
Figure 13. Scores for the SIS 46
Figure 14. Scores for the BBS 47
Figure 15. Baseline, midpoint and final gait velocity values for all participants 48
Figure 16. Baseline, midpoint and final gait velocity values for participants with
complete data 49
Figure 17. Relationship between change in 6MWD and change in VO peak 51
2
Figure 18. Comparison between current and previous study 53

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Abbreviations

6MWT Six-minute walk test
ACSM American College of Sports Medicine
ADL Activities of daily living
ATP Adenosine triphosphate
BBS Berg Balance Scale
BP Blood pressure
bpm Beats per minute
CAD Coronary artery disease
CMSA Chedoke McMaster Stroke Assessment
DM Diabetes Mellitues
ECG Electrocardiogram
HR Heart rate
HRpeak Peak heart rate
HRR Heart rate reserve
NIH National Institutes of Health Stroke Scale
RER Respiratory exchange ratio
RPE Rating of perceived exertion
RPM Revolutions per minute
SD Standard deviation
SIS Stroke Impact Scale
TM Treadmill
TRI Toronto Rehabilitation Institute
VO peak Peak oxygen consumption
2
VO Oxygen consumption, oxygen uptake
2
W Watts
WR Work rate
WRpeak Peak work rate

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Chapter 1

1.0 Introduction
Stroke is the leading cause of neurological disability in adult Canadians (Heart and
Stroke Foundation of Canada, 2008), leaves many individuals post stroke with social
isolation and reduced quality of life (Schepers, Visser-Meily, Ketelaar, & Lindeman,
2005), and puts a strain on the Canadian economy (Heart and Stroke Foundation of
Canada, 2008). Every year, 35,000 – 50,000 Canadians suffer strokes, and there are
approximately 300,000 individuals with stroke (Heart and Stroke Foundation of
Canada, 2008). Unfortunately, these individuals have a 20% chance of having another
stroke within 2 years of their first stroke (Heart and Stroke Foundation of Canada,
2008). Over the past decade, there has been a 30% increase in individuals with stroke
worldwide, and this number may increase because of the combination of aging
demographics, advances in medical care and improved stroke management (Patten,
Lexell, & Brown, 2004). These individuals often experience interruptions in
communication and cognition in addition to physical impairment, making it hard for
them to integrate into the community (MacKay-Lyons & Howlett, 2005a). Hence,
individuals post stroke often experience limited social participation and reduced quality
of life (Jorgensen et al., 1995).
Furthermore, the loss of individuals with stroke from the work force and their extended
hospitalization following stroke has a large economic impact, costing the Canadian
economy $2.7 billion a year (Heart and Stroke Foundation of Canada, 2008). For
example, the average cost of acute care is about $27,000 per patient with stroke, and
Canadians spend a total of 3 million days in hospital because of stroke (Heart and
Stroke Foundation of Canada, 2008). To reduce the heavy economic burden on our
economy, it is important to establish both effective and economic stroke programs
which address stroke prevention and management. Aerobic exercise may be an
effective way to manage and modify many risk factors of stroke and it may also be
useful in effectively reducing stroke-related impairments since aerobic exercise has the
potential to improve aerobic and walking capacity, prevent a cycle of inactivity, and
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improve quality of life. However, aerobic exercise has not been adequately
implemented in stroke rehabilitation, and further studies are needed to elucidate the
effects of aerobic exercise, especially during the inpatient rehabilitation period.
Several authors have demonstrated the beneficial effects of aerobic exercise in stroke
recovery using various exercise modalities including treadmill (Macko et al., 2005;
Pohl, Mehrholz, Ritschel, & Ruckriem, 2002; Teixeira-Salmela, Olney, Nadeau, &
Brouwer, 1999), cycle ergometer (Lennon, Carey, Gaffney, Stephenson, & Blake,
2008), and recumbent cross trainer (Page, Levine, Teepen, & Hartman, 2008).
Improvements following aerobic exercise have been observed in cardiorespiratory
fitness (Rimmer, Riley, Creviston, & Nicola, 2000), walking distance (Ada, Dean, Hall,
Bampton, & Crompton, 2003; Pang, Eng, Dawson, McKay, & Harris, 2005) and
velocity (Ada et al., 2003; Pohl et al., 2002), quality of life (Teixeira-Salmela, Nadeau,
Mcbride, & Olney, 2001), balance (Page et al., 2008), stride length (Pohl et al., 2002),
muscle strength of affected lower limb (Pang et al., 2005), body composition (Rimmer
et al., 2000), and flexibility (Rimmer et al., 2000). Exercise training also has the
potential to prevent recurrent strokes by managing many stroke risk factors including
hypertension (Pescatello et al., 2004), hyperlipidemia (Stone, Bilek, & Rosenbaum,
2005), obesity (Villareal et al., 2006), insulin resistance (Villareal et al., 2006), and
inflammation (Dekker et al., 2007).
Cardiovascular fitness and walking capacity were of particular interest in this study
because they have been shown to be significantly impaired following stroke, possibly
resulting in inactivity and low quality of life. Cardiorespiratory fitness is severely
reduced early after stroke, falling to 50% to 70% that of age- and sex-matched values of
sedentary individuals (Kelly, Kilbreath, Davis, Zeman, & Raymond, 2003; MacKay-
Lyons & Makrides, 2002b; Mackay-Lyons & Makrides, 2004). For instance,
individuals in the subacute phase after stroke often do not satisfy the minimum oxygen
uptake (VO ) value of 15 ml/kg/min to meet the physiologic demands for independent
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living (MacKay-Lyons & Makrides, 2002b). Furthermore, these individuals require
greater oxygen uptake at a given workload than healthy age-matched individuals
possibly due to reduced mechanical efficiency in movement and the effects of spasticity
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