Chu (2004) A randomized controlled trial of water-based exercise for cardiovascular fitness in individuals with chronic stroke

A randomized controlled trial of water-based exercise for
cardiovascular fitness in individuals with chronic stroke
Kelly S Chu, MSc 1,2
, Janice J Eng, PhD, PTOT 1,2
, Andrew S Dawson, MD, FRCP(c) 3
,
Jocelyn E. Harris, BHSc, OT 1,2
, Atila Ozkaplan, BHK 2
, and Sif Gylfadttir, BSc, PT 1
1 Department of Physical Therapy, University of BC, Vancouver, Canada
2 Rehabilitation Research Laboratory, GF Strong Rehab Centre, Vancouver, Canada
3 Acquired Brain Injury Program, GF Strong Rehab Centre, Vancouver, Canada
Abstract Objective To evaluate the effect of an 8-week water-based exercise program (experimental
group) over an upper extremity function program (control group) to increase cardiovascular fitness
within a community setting for individuals with stroke.
Design Single-blind randomized controlled trial
Setting Public community centre
Participants 12 community-dwelling individuals who have had a stroke with mild to moderate
motor deficits; volunteer sample
Intervention Experimental and control groups participated in group exercise programs
undertaken in one hour sessions, three times per week for 8 weeks. The experimental group
undertook chest deep water exercises at targeted heart rates. The control group performed arm and
hand exercises while sitting.
Main Outcome Measures The primary outcome measure was cardiovascular fitness
(VO 2max). Secondary measures were maximal workload, muscle strength, gait speed, and the
Berg Balance Score.
Results The experimental group attained significant improvements over the control group in
cardiovascular fitness, maximal workload, gait speed, and paretic lower extremity muscle strength.
The relatively short program (8 weeks) of water-based exercise resulted in a large improvement
(22%) in cardiovascular fitness in a small group of individuals with stroke with relatively high
function.
Conclusions A water-based exercise program can be undertaken in the community as a group
program and may be an effective means to promote fitness in individuals with stroke.
Keywords endurance; stroke; randomized trial; exercise; cardiovascular fitness; clinical trial
For correspondence, please address to the second author (J Eng). Janice Eng, Department of Physical Therapy, University of BC
212-2177 Wesbrook Mall, Vancouver, BC, Canada, V6T 1Z3, Janice.Eng@ubc.ca, work phone: (604) 714-4105, fax: (604) 714-4168.Pub Med Central CANADA
Author Manuscript Manuscrit d'auteur
Arch Phys Med Rehabil . Author manuscript; available in PMC 2011 September 27.
Published in final edited form as:
Arch Phys Med Rehabil. 2004 June ; 85(6): 870874.
PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada Author Manuscript

IntroductionIncreasing exercise capacity following a stroke can help prevent deterioration to the
cardiovascular system. Such effects are important given that cardiovascular disease is the
leading prospective cause of death in individuals with stroke1 ,
2. Furthermore, increasing
exercise capacity in persons with stroke may improve the ability to perform functions of
daily living, which might be limited by weakness and fatigue secondary to the stroke.
Recommendations for physical activity levels outlined by the American College of Sports
Medicine (ACSM)indicate that adults should engage in moderate levels of physical activity
for a total of 30 minutes on most days to maintain health3. To see improvements in
cardiovascular fitness, moderate to high intensity exercise needs to be performed at least 3
times per week for 30 minutes per day4. Given these recommendations, it is important to
develop a variety of exercise protocols that can accommodate the diverse levels of function
that are found in individuals with stroke.
Cardiovascular fitness has been improved (as measured by increases in VO 2max, workload,
exercise time, or gait efficiency) in individuals with stroke using treadmill training5 ,
6,
modified cycle ergometer training7, and circuit training8. A water-based exercise program
(WBE) is potentially another viable exercise medium given that water is 700 times the
density of air9 allowing for increased energy expenditure per work done10, reduction in
joint impact loading and partial weight support provided by the buoyancy of water, and
ability to undertake the exercise in local recreation centers without expensive equipment.
Eight to twelve weeks of WBE have been shown to improve cardiovascular fitness and
strength in healthy older adults11 ,
12 and individuals with rheumatoid arthritis13. No studies
have previously examined WBE in individuals with stroke and it is not known whether
impairments might limit the ability to undertake intensive exercise in the water. It was the
purpose of this study to determine the effectiveness of an 8-week WBE in improving
cardiovascular fitness and functional mobility in individuals with chronic stroke.
Methods
Study Participants We recruited individuals on a volunteer basis who were community-dwelling and had
residual unilateral weakness secondary to stroke. The study was approved by the local
university and hospital research ethics committees and participants provided their informed
consent. The participants and the inclusionexclusion criteria have been described
previously14 and are briefly described here. The initial screening criteria was queried with a
telephone interview: 1) have a history of only one cerebrovascular accident of at least one
year post stroke, 2) independent in walking (with or without assistive device), 3) medically
stable (i.e., exclusion criteria were uncontrolled hypertension, arrhythmia, or unstable
cardiovascular status, 4) no previous myocardial infarction, and 5) no significant
musculoskeletal problems from conditions other than stroke. Participants then attained
written permission to participate in the study from a primary care physician who was
informed about the screening criteria and the study protocol. Participants were then assessed
in the lab to meet the next screening criteria which was to pedal a cycle ergometer and reach
60% of their age-predicted heart rate maximum (220 beatsmin minus their age).
Research Design Individuals with chronic stroke were randomized to one of two eight-week group programs:
a) water-based exercise program focused on leg exercises to improve cardiovascular fitness
(experimental group) and b) arm exercise group (control group). Participants were only
aware that they were involved in either a leg or arm training programs (partial subjectChu et al. Page 2
Arch Phys Med Rehabil. Author manuscript; available in PMC 2011 September 27.
PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada Author Manuscript

blinding since they did not know that cardiovascular fitness was the main outcome
measure). For group assignment, stratified randomization was undertaken. First, subjects
were identified for two levels of two strata (stratum1=VO 2max: less than group median
greater than or equal to the group median, stratum2=age: 5059 years60+ years). Then,
subjects were randomly assigned such that there were equal numbers of subjects for each
level of stratum in the experimental and control groups15 ,
16. One researcher undertook all
randomization procedures while assessments were undertaken by testers who had no
knowledge of the participants grouping (researcher blinding).
Descriptive Measures Descriptive measures of the subjects were taken: age, duration of injury, type of stroke,
severity of lower extremity physical impairment, and the American Heart Association
Stroke Functional Classification17. Chedoke-McMaster Stroke Assessment was measured to
determine the severity of lower limb physical impairment and has been shown to be valid
and reliable in individuals with stroke18. The lower extremity score of the Chedoke-
McMaster Assessment (maximum 14) was evaluated from a structured physical assessment
of the subject and consists of a leg score (1=no active movement and maximum 7=can
complete normal age appropriate complex movements like rapid stepping) and foot score
(1=no active movement and maximum 7=can complete normal age appropriate complex
movements like rise on toes) 18.
Outcome Measures The primary outcome measure was VO 2max which is the gold standard criterion of
cardiovascular fitness19 and was measured during a symptom-limited graded cycle
ergometer test. Secondary measures were 1) maximal workload (watts) assessed during the
symptom-limited ergometer test, 2) self-selected gait speed (ms) over 8 m, 3) 14-item Berg
Balance Scale20 ,
21 and 4) muscle strength (Nkg). All assessments were performed over 3
days, with at least 2 days rest between each test session. We have shown that measurements
of gait speed and muscle strength have excellent reliability in individuals with stroke and
their protocols have been described in detail previously22 ,
23. Gait speed was measured with
subjects using their usual assistive device (see Table 1). Self-paced gait speed was
calculated from the mean of three walking trials. The cumulative distance and time of
consecutive strides (i.e., foot contact to the next foot contact of the same leg) were recorded
by infrared emitting diodes a
attached to the foot during the middle section (i.e.,
approximately a 4 m section representative of constant gait speed) of the 8-meter walkway.
The Berg Balance Test consists of 14 tasks which challenge balance while sitting, standing
or stepping (minimum score = 0 and maximum score = 56 with higher scores indicating
better balance performance) and has been shown to be a valid and reliable measure20 ,
21.
For the measurement of VO 2max, all subjects were required to refrain from alcohol and
strenuous exercise 24 hours and caffeine and food intake 4 hours prior to the test. For the
maximal cycle test, subjects began pedaling on a stationary bike b
between 5070 rpm at 0
watts with workload increments of 20 wattsmin and oxygen consumption (VO 2) was
measured using a metabolic cart c
and cardiovascular stability measured using a 12-lead
ECG d
.. All subjects were familiarized with Borgs 16-point Rating of Perceived Exertion
Scale (RPE)24 to assess how hard they felt they were working. Blood pressure was
monitored before and immediately after the test session. Determination of whether maximal
a Optotrak, Northern Digital, 103 Randall Drive, Waterloo, ON, Canada, N2V 1C5.
b Excalibre bike, Lode Medical Technology, Zernikepark 16, 9747 AN Groningen, The Netherlands.
c CPX-D Metabolic System, Medical Graphics Corporation, 350 Oak Grove Parkway, St. Paul, Minnesota, USA, 55127.
d Schiller AT10i, Schiller AG, Altgasse 68, PO Box 1052, CH-6341 Baar, Switzerland.
Chu et al. Page 3
Arch Phys Med Rehabil. Author manuscript; available in PMC 2011 September 27.
PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada Author Manuscript

effort was achieved during this test followed the criteria outlined by the ACSM4: 1)
respiratory exchange ratio 1.15, 2) no increase in HR following increases in workload, 3)
a plateau of VO 2 defined by 1.5mlkgmin increase in VO
2 with workload increases, or 4)
volitional fatigue. Our VO 2max found test-retest intraclass correlations over 0.90 for these
same subjects which was reported previously14.
Isokinetic flexor and extensor muscle strength of the paretic and non-paretic knee and hip
joints were measured on a KinCom strength dynamometer e
at 60sec as these muscle
groups are thought be largely activated during water running9 and improvements have been
reported following water-based training programs in adults12. The exact strength testing
protocol is reported in Eng et al.22 Muscle torques normalized to body mass were summed
over each body side to generate a composite muscle strength score for the paretic and non-
paretic side. Composite lower extremity strength scores have been reported to be sensitive to
muscle strengthening and physical conditioning programs in persons with stroke.25 ,
26
Experimental group: Water-based endurance program The main objective of this program was to improve cardiovascular fitness in individuals
with stroke following eight weeks (three daysweek, one hrsession) of intensive water-
based exercises in chest level water at a local community centre swimming pool (water
temperature between 2628C). Participants wore a heart rate monitor f
and either a flotation
belt g
or lifejacket h
. The exercise intervention consisted of: 10 minutes of land-based
stretching, 5 minutes of light aerobic warm-up in the water (marching on the spot, single and
double legged hopping holding onto the pool edge), 30 minutes of moderate to high aerobic
activities (shallow water walking, running, side stepping) at the target heart rate prescribed
for that week, 5 minutes of a light cool down (marching on the spot), and 10 minutes of
gentle stretching in the water. Target heart rates were set at 5070%, 75%, and 80% heart
rate reserve 5 beatsmin (as determined by the initial maximal exercise test) for weeks 1
2, 35, and 68, respectively. Subjects were instructed to stop or reduce their exercise
workload if the following occurred: 1) lightheadedness or dizziness, 2) chest discomfort
pain, or 3) RPE value 15. All exercise sessions were supervised by one physical therapist
and two exercise physiologists.
Control group: Arm function program Participants in the control group attended the same amount of time as the experimental
group (eight weeks, three daysweek, one hrsession). The main objective of this program
was to improve upper extremity function. Each session commenced with a five minute
warm-up of active upper extremity movements. A six station circuit then focused on gross
upper limb movement (e.g., reaching), fine motor movement (e.g., adjusting small screws
bolts) and muscle strengthening of the shoulder, elbow, wrist, and fingers (e.g., exercises
using hand putty, theraband and weights). Participants focused primarily on the paretic
upper extremity unless there was remaining time within each of the 7-minute stations.
Participants were seated at each station, but had to stand and walk a few steps to the next
station. The program ended with a 5 minute cool-down of active upper extremity exercises.
All exercise sessions were supervised by 1 occupational therapist and exercise physiologist.
e Chattanooga Group Inc., 4717 Adams Road, Hixson, TN, USA, 37343.
f Polar Electro Inc., 370 Crossways Park Drive, Woodbury, NY, USA, 11797-2050.
g Aquam Inc., 1320 Route 9, Champlain NY, USA, 12919.
h Mustang Survival Canada, 3810 Jacombs Road, Richmond, BC, Canada, V6V 1Y6.
Chu et al. Page 4
Arch Phys Med Rehabil. Author manuscript; available in PMC 2011 September 27.
PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada Author Manuscript

Statistical AnalysisIndependent T-tests compared baseline measures between the experimental and control
group. A two-way ANOVA compared differences between groups over time (pre-testpost-
test). The alpha value was 0.05.
Results Twenty-seven individuals with stroke met the initial telephone screen criteria. Fourteen
subjects were then excluded for a remaining 13 participants. The reasons for exclusion were:
written permission from the family physician was not acquired because the subjects
physician found their patient to be medically unstable (n=2), unable to position leg on the
cycle ergometer due to leg adductor spasticity, muscle weakness or reduced joint range
(n=5), inability to generate sufficient leg force during cycling to elicit a HR of at least 60%
age-predicted heart rate maximum (n=5), dysphagia which caused frequent coughing and
disruption to the subjects performance (n=1), and unable to complete all exercise tests due
to time commitments (n=1). The remaining 13 subjects then performed the maximal cycle
test of which none were excluded as all reached maximal effort as defined by the ACSM
guidelines4 and satisfied a minimum of three of the four criteria: 1) respiratory exchange
ratio 1.15, 2) failure of HR to increase with further increases in exercise intensity, 3) a
plateau in VO2 or 1.5 mlkgmin increase in VO2 following workload increases, or 4)
volitional fatigue. Subjects reached a mean 95% of their age-predicted HR maximum during
the symptom-limited graded exercise test and all but one subjects actual HR maximum was
within 10% of their age-predicted HR maximum. These thirteen subjects were then
randomized into an experimental (n=7) and control group (n=6). One subject withdrew from
the control group after week 2 as she found the program too fatiguing. Other then this one
subject, no other adverse effects occurred during the testing or training sessions. Subject
characteristics for the remaining 12 participants are presented in Table 1. Subjects were
currently taking prescribed medications to control for hypertension (peripheral vasodilators,
n=1; diuretics, n=1; ACE inhibitors, n=8; and depression, n=5).
Subjects attended 157 out of a possible 168 classes for the experiment group and 111 out of
a possible 120 classes for the control group. There were no significant group differences for
the descriptive characteristics or baseline outcome measures (Table 2). A significant time
group interaction showed greater improvements of VO 2max, self selected gait speed, and
composite paretic muscle strength for the experimental group compared to the control group
following the 8 week intervention. The observed power when the alternative hypothesis was
set based on the observed values was greater than 0.80 for the primary outcome measure,
VO 2max. A 22% improvement in VO
2max and 19% in gait speed was observed in the
experimental group following 8 weeks of water-based exercise, while these measures did not
change for the control group (Table 2). The time group interaction for the Berg Balance
Score approached significance (0.094) with a greater improvement for the control group
following the intervention.
Discussion Despite the relatively mild impairments of these subjects, their baseline cardiovascular
fitness is considered poor for their gender and age27 but comparable to studies reporting
cardiovascular fitness in individuals with chronic stroke5 ,
7 ,
8 ,
28. Although exercise capacity
was low in this sample, exercise tolerance was excellent, as all subjects in the water-based
program were able to exercise at 7080% of their baseline age-predicted HR maximum
without discomfort. Adherence was also very good for both programs with over a 92%
attendance rate. Surprisingly, the only subject to withdraw from the program was from the
control group and she felt that the exercises were too fatiguing. Three instructors wereChu et al. Page 5
Arch Phys Med Rehabil. Author manuscript; available in PMC 2011 September 27.
PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada Author Manuscript

required for the first week of the water-based program as one subject required one-on-one
supervision due to his fear in the water, in addition to his low functional status. However,
even one instructor would have been sufficient for the seven water-based program
participants following that first week
The findings from this study demonstrated that a relatively short program (8 weeks) of
water-based exercise improved cardiovascular fitness (VO 2max) by 22% in chronic stroke
survivors. These findings have important clinical implications for stroke rehabilitation as it
has been well documented that improvements in VO 2max are related to improvements in
risk factors associated with cardiovascular disease29. The improvement in cardiovascular
fitness found in our study is much greater than the 8 to 14% improvements reported
previously for individuals with stroke following cycle-ergometer, treadmill and circuit-based
protocols5 ,
7 ,
8. The combination of a higher prescribed exercise intensity and greater
resistance (compared to land-based programs) likely contributed to the enhanced
cardiovascular improvements found in this study. In addition, the lower the initial level of
cardiovascular fitness, the greater the potential gain in VO 2max31.
Our outcome measures did not allow us to partition factors which contributed to the
improvements in VO 2max resulting from peripheral muscle mechanisms (e.g., muscle
oxidative capacity) or central cardiovascular mechanisms (e.g., cardiac output). We found
only a modest improvement (9%) in maximal workload compared to others who have
reported between 28 to 44% increase in maximal workload5 ,
7 ,
8. These studies used the
same task to assess and train cardiovascular fitness and thus, task-specific motor learning
might account for these large improvements in maximal workload. Our subjects
demonstrated more modest improvements in maximal workload which can be attributed to
the fact that we used different tasks to assess (cycle ergometer) and train (water-based
exercise) cardiovascular fitness. Thus, our subjects did not experience the cycling practice
which might have improved their ability to pedal more efficiently in light of the well known
impairments in motor coordination in stroke32, the task-specificity of the muscular
responses33 and the neural changes (e.g., motor unit recruitment and rate coding) that take
place with practice34 which might enhance force output. It would be interesting to compare
a land-based versus water-based exercise program on cardiovascular fitness when exercising
at similar intensities.
Improvements in strength and gait speed suggest that the water-based exercise can improve
lower extremity muscle function and functional mobility. The gains in muscle strength may
have contributed to the improvements in gait speed. The trend towards balance improvement
in the control group may have resulted from the mobility required between the stations or
from improved trunk and leg weight-bearing function from the reaching movements. For
example, Dean et al.30 demonstrated improved leg weight-bearing and sit-to-stand ability
with the practice of seated reaching tasks. The lack of balance improvement for the water-
based exercise group was not a surprise considering that balance training was not a focus in
this study. Furthermore, the buoyancy characteristic of the water, combined with the
flotation device, may not have allowed balance to be challenged during the water-based
program.
The findings of this pilot study are promising considering the short length and large
magnitude of improvement in cardiovascular fitness and functional mobility. This study
demonstrates that feasibility of the protocol in that subjects could tolerate moderate to high
intensity exercise programs using a water-based program. A water-based program can be
undertaken in the community as a group program and is therefore a cost-effective and
convenient means to promote fitness in individuals with stroke. This study is the first to
evaluate a water-based community program for individuals with stroke. Given the smallChu et al. Page 6
Arch Phys Med Rehabil. Author manuscript; available in PMC 2011 September 27.
PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada Author Manuscript

sample size and relatively high function of this sample, caution needs to be taken when
generalizing these results to the wider stroke population.
Acknowledgments Funding sources: This study was supported by a grant-in-aid from the Heart and Stroke Foundation of BC and
Yukon and a career scientist award to JJE from the Canadian Institute of Health Research (MSH-63617) and the
Michael Smith Foundation for Health Research.
We thank Dr. Don McKenzie and Ms. Diana Jespersen for their expertise and use of the Allan McGavin Sports
Medicine Centre.
References 1. Roth EJ. Heart disease in patients with stroke: incidence, impact, and implications for rehabilitation.Part I: classification and prevalence. Arch Phys Med Rehabil. 1993; 74:75260. PubMed:
8328899
2. Sacco RL, Wolf PA, Kannel WB, McNamara PM. Survival and recurrence following stroke: the Framingham Study. Stroke. 1982; 13:2905. PubMed: 7080120
3. Pate RR, Pratt M, Blair SN, Haskell WL, Macera CA, Bouchard C, et al. Physical activity and public health: A reommendation from the centres for disease control and prevention and the
American collect of sports medigin. JAMA. 1995; 273:4027. PubMed: 7823386
4. American College of Sports Medicine. Guidelines for Exercise Testing and Prescription. 6. Baltimore: Williams and Wilkins; 2000. p. 104-117.
5. Macko RF, Smith GV, Dobrovolney CL, Sorkin JD, Goldberg AP, Silver KH. Treadmill training improves fitness reserve in chronic stroke patients. Arch Phys Med Rehabil. 2001; 82:87984.
PubMed: 11441372
6. Macko RF, DeSouza CA, Tretter LD, Silver KH, Smith GV, Anderson PA, et al. Treadmill aerobic exercise training reduces the energy expenditure and cardiovascular demands of hemiparetic gait in
chronic stroke patients: a preliminary report. Stroke. 1997; 28:32630. PubMed: 9040684
7. Potempa K, Lopez M, Braun LT, Szidon JP, Fogg L, Tincknell T. Physiological outcomes of aerobic exercise training in hemiparetic stroke patients. Stroke. 1995; 26:1015. PubMed:
7839377
8. Rimmer JH, Riley B, Creviston T, Nicola T. Exercise training in a predominantly African-American group of stroke survivors. Med Sci Sports Exer. 2000; 32:19906.
9. Moening D, Scheidt A, Shepardson L, Davies GJ. Biomechanical comparison of water running and treadmill running. Iso Exer Sci. 1993; 3:20715.
10. Costill DL. Energy requirements during exercise in water. J Sports Med Phys Fitness. 1971; 11:8792. PubMed: 5098427
11. Taunton JE, Rhodes EC, Wolski LA, Donelly M, Warren J, Elliot J, et al. Effect of land-based and water-based fitness programs on the cardiovascular fitness, strength and flexibility of women aged
6575 years. Gerontology. 1996; 42:20410. PubMed: 8832268
12. Takeshima N, Rogers ME, Watanabe E, Brechue WF, Okada A, Yamada T, et al. Water-based exercise improves health-related aspects of fitness in older women. Med Sci Sports Exer. 2002;
33:54451.
13. Danneskiold-Samse B, Lyngberg K, Risum T, Telling M. The effect of water exercise therapy given to patients with rheumatoid arthritis. Scand J Rehabil Med. 1987; 19:315. PubMed:
3576139
14. Eng JJ, Dawson AS, Chu KS. Submaximal exercise in individuals with stroke: Test-retest reliability and concurrent validity with VO2max. Arch Phys Med Rehabil. In press.
15. Domholdt, E. Physical Therapy Research: Principles and Applications. 1. Philadelphia: W.B. Saunders Company; 1993.
16. Tate DG, Findley TJ, Dijkers M, Nobunaga AI, Karunas RB. Randomized clinical trials in medical rehabilitation research. Am J Phys Med Rehabil. 1999; 78:48699. PubMed: 10493460Chu et al. Page 7
Arch Phys Med Rehabil. Author manuscript; available in PMC 2011 September 27.
PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada Author Manuscript

17. Kelly-Hayes M, Robertson JT, Broderick JP, Duncan PW, Hersey LA, Roth EJ, et al. TheAmerican Heart Association Stroke Outcome Classification: executive summary. Circulation.
1998; 97:24748. PubMed: 9641702
18. Gowland C, Stratford P, Ward M, Moreland J, Torresin W, Van Hullenaar S, et al. Measuring physical impairment and disability with the Chedoke-McMaster Stroke Assessment. Stroke. 1993;
24:5863. PubMed: 8418551
19. Franklin, BA. ASCMs Resource Manual for Guidelines for Exercise Testing and Prescription. 4. Philadelphia: 2001. Normal Cardiorespiratory Responses to Acute Aerobic Exercise; p. 145
20. Berg K, Wood-Dauphinee S, William JI, Gayton D. Measuring balance in the elderly: preliminary development of an instrument. Physiother Can. 1989; 41:30411.
21. Berg K, Maki BE, Williams JI, Holliday J, Wood-Dauphinee SL. Clinical and laboratory measures of postural balance in an elderly population. Arch Phys Med Rehabil. 1992; 73:107380.
PubMed: 1444775
22. Eng JJ, Kim CM, MacIntyre DL. Reliability of lower extremity strength measures in persons with chronic stroke. Arch Phys Med Rehabil. 2002; 83:3228. PubMed: 11887111
23. Eng JJ, Chu KS, Dawson AS, Kim CM, Hepburn K. Functional walk test in individuals with stroke: relationship to perceived exertion and myocardial exertion. Stroke. 2002; 33:75661.
PubMed: 11872900
24. Borg G. Perceived exertion as an indicator of somatic stress. Scand J Rehabil Med. 1970; 2:928. PubMed: 5523831
25. Teixeira-Salmela LF, Olney SJ, Nadeau S, Brouwer B. Muscle strengthening and physical conditioning to reduce impairment and disability on chronic stroke survivors. Arch Phys Med
Rehabil. 1999; 80:2118.
26. Kim CM, Eng JJ, MacIntyre DL, Dawson AS. Effects of isokinetic strength training on walking in persons with stroke: a double-blind controlled pilot study. J Stroke Cerebrovasc Dis. 2001;
10:26573. PubMed: 17903837
27. Brooks, GA.; Fahey, TD.; White, TP. Exercise Physiology: Human Bioenergetics and It Applications. 2. Mountain View: Mayfair Publishing; 1996. p. 589
28. Ryan AS, Dobrovolny CL, Silver KH, Smith GV, Macko RF. Cardiovascular fitness after stroke: role of muscle mass and gait deficit severity. J Stroke Cerebrovasc Dis. 2000; 9:18591.
29. Rogers MA, Yammamoto C, Hagberg JM, Holloszy JO, Ehsani AA. The effect of 7 years of intense exercise training on patients with coronary artery disease. J Am Coll Cardiol. 1987;
10:3216. PubMed: 3598003
30. Dean CM, Shepherd RB. Task-related training improves performance of seated reaching tasks after stroke. A randomized controlled trial. Stroke. 1997; 28:7228. PubMed: 9099186
31. Blomqvist G, Saltin B. Cardiovascular adaptations to physical training. Annu Rev Phys. 1983; 45:16989.
32. Duncan, PW.; Badke, MB., editors. Stroke Rehabilitation: the recovery of motor control. Chicago: Year Book Medical Publishers; 1987.
33. Rutherford OM. Muscular coordination and strength training. Implications for injury rehabilitation. Sports Med. 1988; 5:196202. PubMed: 3285437
34. McComas AJ. Human neuromuscular adaptations that accompany changes in activity. Med Sci Sports Exerc. 1994; 26:1498509. PubMed: 7869885Chu et al. Page 8
Arch Phys Med Rehabil. Author manuscript; available in PMC 2011 September 27.
PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada Author Manuscript

Figure 1.
Muscle strength changes in Nmkg (plus 1 standard error) for individual muscles
(+ve=improvement)
Chu et al. Page 9
Arch Phys Med Rehabil. Author manuscript; available in PMC 2011 September 27.
PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada Author Manuscript

PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada AuthorManuscriptChu et al. Page 10Table 1
Subject Characteristics (N= 12)Experimental GroupControl GroupVariableMean or #StdRangeMean or #StdRangeGender (MF)6150Type of Stroke (ischemichemorrhage)3450Paretic Side (LR)3423AHASFC *
IIIII5232Mobility Aids
(walkercanebracenone)10240322Chedoke Score (14) 10.02.57128.62.6612Age (years)61.99.4517063.48.45172Time Since Stroke (years)3.02.0174.22.116Mass (kg)83.515.164.7113.885.313.371.7106.6Height (cm)175.97.7164.2185.7171.65.8164.8178.8Body Mass Index (kgm 2
)26.93.622.733.028.93.124.633.3*
abbreviation for American Heart Association Stroke Functional ClassificationMaximum Chedoke-McMaster Lower Extremity Score is 14None of the subject characteristics were significantly different between groups (p0.2)
Arch Phys Med Rehabil . Author manuscript; available in PMC 2011 September 27.

PMC Canada Author Manuscript PMC Canada Author Manuscript PMC Canada AuthorManuscriptChu et al. Page 11Table 2
Outcome measures: Baseline and post-test (N= 12)
Variable
Exercise GroupControl GroupBaseline.Post-testBaselinePost-test.VO 2max (mlkgmin) *17.3 (3.0)21.2(2.3)17.1(3.2)17.6(4.7)Maximal Workload (watts) *137.7(37.9)150.3(44.8)127.6(29.9)111.2(39.0)Berg Balance Score (max=56)51.6(4.7)52.0(3.3)49.8(3.9)52.2(3.6)Self selected gait speed (ms) *0.99(0.33)1.18(0.44)1.01(0.29)1.04(0.40)Strength (composite) More affected side (Nmkg) *2.75(0.86)2.97(0.91)2.12(0.41)1.96(0.59) Less affected side (Nmkg)3.79(0.72)3.82(0.65)3.29(0.44)3.24(0.37)
Means (standard deviations)
None of the baseline measures were significantly different between groups (p0.40)
* significant time group interaction, p0.05
Arch Phys Med Rehabil . Author manuscript; available in PMC 2011 September 27.