Park JS. (2011). Comparison of the Effects of Exercise by Chronic Stroke Patients in Aquatic and Land Environments.

Purpose: The purpose of this study was to compare the effects of land exercise and aquatic exercise onchronic stroke patients.

Subjects and Methods: The subjects were randomly divided into a land exercise group (12males and 10 females; average age: 56.09 ± 7.22 years) and an aquatic exercise group (15 males and 7 females;average age: 51.55 ± 8.27 years). Subjects from both groups received general conventional treatment during theexperimental period. In addition, all subjects engaged in extra treatment sessions. This extra treatment consisted oftrunk stability strengthening exercises and balance training exercises in the land exercise group, whereas in theaquatic exercise group subjects participated in balance board exercises and walking exercises using buoyancyequipment in the hospital swimming pool.

Results: The joint position sense test and performance oriented mobilityassessment showed significant improvements in both groups. However, the joint position sense test and performanceoriented mobility assessment showed there was more improvement in the aquatic exercise group than in the landexercise group.

Conclusion: The results suggest that aquatic exercise is more effective than land exercise atimproving the joint position sense and clinical functions of stroke patients.Key words: Aquatic exercise, Joint position sense, Performance oriented mobility assessment

J.Phys. Ther. Sci
23: 905-908, 2011
Postural Balance of Stroke Survivors in Aquatic and
Land Environments
Jungseo Park, Ms, PT1), Hyolyun roH, PhD, PT2)
1) Department of Rehabilitation Science, Graduate School Daegu University2) Department of Occupational Therapy, Kangwon National University: Hwangio-ri, Samcheok-si,
Gangwondo, 240-907 Republic of Korea.
TEL: +82 33-540-3481, FAX: +82 33-540-3489, E-mail:
Abstract. Purpose The purpose of this study was to investigate the effect of an aquatic environment on the
balance of stroke patients compared to a land environment. Subjects and Methods Forty-six subjects participated
in this study. They were divided into a land exercise (LE) group (13 males, 10 females) and an aquatic exercise (AE)
group (12 males, 11 females). Exercises were conducted six times a week for six weeks. Balance was assessed
through parameters of sway of the center of pressure. Results The exercises improved the balance abilities of both
groups with eyes open. With eyes closed, balance ability improved more in the AE group, and AE was more
important than vision for improving the balance ability of stroke patients. Conclusion This study found that stroke
patients had better balance in an aquatic environment than in a land env\ironment.
Key words: Aquatic environment, Posrural balance, Stroke
(This article was submitted Jul. 5, 2011, and was accepted Jul. 22, 2011)
Stroke survivors have poor balance and decreased
loading on the hemiparetic leg. Deficits in balance control
can contribute to low performance in functional activities
and to a high incidence of falls among stroke survivors
1). To
date, many therapeutic exercise interventions have been
u s e d t o p r e v e n t p h y s i c a l i n a c t i v i t y a n d t h e r e s u l t a n t
secondary complications in chronic stroke patients
Aquatic therapy has gained a wide level of acceptance as a
method of treatment for musculoskeletal and neurological
disorders, disabling pain conditions, and balance disorders
a s i t a l l o w s a p a t i e n t t o p e r f o r m a c o m p r e h e n s i v e
rehabilitative program
3). The water provides resistance but
minimizes biomechanical stress on muscles and joints,
which is important for such individuals when exercising
The support offered by water allows more independent
upright postures. There may be an increase in afferent
stimulation from greater cutaneous inputs, muscles may fire
more freely because patients are less fearful of movement,
and activity in water may facilitate vestibular inputs
When submerged, hydrostatic pressure promotes equal
resistance to all muscle groups being worked and provides
a greater sense of stability. It has been suggested that
because there is no stationary resting position in water,
muscles are activated continuously to stabilize the position
of the body
3). This stabilization may allow a patient to gain
more strength, flexibility, and more importantly, improve
6). Balance, which is the ability to maintain a
position and react to a perturbating force, is important in
7). Also, balance training may offer better outcomes when performed in an aquatic environment
Therefore, we investigated the effects of aquatic exercise
programs on the balance ability of stroke survivors.
The subjects who participated in this study were 46
s t r o k e p a t i e n t s h o s p i t a l i z e d i n H h o s p i t a l l o c a t e d i n
Daejeon, Korea. The inclusion criteria were that participants
h a d e x p e r i e n c e d a s t r o k e a t l e a s t s i x m o n t h s b e f o r e
enrollment, had hemiparesis secondary to a first stroke,
were medically stable, had no internal medical disease such
a s d i a b e t e s , h a d n o h e a r t d i s e a s e , h a d n o o r t h o p e d i c
problems, scored 24 or higher in the Mini Mental State
Examination-Korea, had no visual problems, and could
walk at least 15 m by themselves. These subjects were
given explanations until they sufficiently understood the
objectives and method of this experiment. Ethical approval
was given by the Hansalang Hospital Committee of Medical
Ethics, and consent was obtained from subjects or their
guardians prior to their inclusion in the study. Exclusion
criteria were uncontrolled hypertension, arrhythmia, and
u n s t a b l e c a r d i o v a s c u l a r s t a t u s . T h e e x p e r i m e n t w a s
conducted with the subjects divided into a land exercise
(LE) group and an aqua exercise (AE) group. Participants
were randomly assigned to either the LE group or the AE
group. The LE group consisted of 13 males and 10 females; age
(mean SD) 56.6 3.9 years, height 165.1 7.1 cm, body
weight 62.8 6.5 kg. The cause of stroke was cerebral
infarction for 9 subjects and cerebral hemorrhage for 14

906J. Phys. Ther. Sci. Vol. 23, No. 6, 2011
subjects. Ten subjects had right hemiplegia and 13 had left
hemiplegia. The modified barthel index was 8083 for 4
subjects and above 84 for 19 subjects.
The AE group consisted of 12 males and 11 females;
age (mean SD) 54.56 8.27 years, height 169.25
8.40 cm, body weight 66.92 8.91 kg. The cause of
stroke was cerebral infarction for 9 subjects and cerebral
hemorrhage for 14 subjects. Eleven subjects had right
hemiplegia and 12 had left hemiplegia. The modified
barthel index was 8083 for 5 subjects and above 84 for
18 subjects. This experiment was conducted over six weeks during
June and July 2010. Exercises were conducted six times
a week for six weeks (35-minute sessions). Three sets
were implemented for each type of exercise, with ten
repetitions per set. The land exercises were carried out in
the exercise therapy room at the hospital, and the aquatic
exercises were performed in the indoor aquatic exercise
therapy room at the hospital. The subjects in both groups
also received conventional exercise therapy six times a
week. Different exercise programs were performed by
the LE group and the AE exercise group. The LE group used the exercise methods of Dean
a n d E v e r t e t a l .9 ) T h e f o l l o w i n g e x e r c i s e s w e r e
performed by the land exercise group. 1. Improving the stability of the lower trunk using the
upper limbs. In the supine position, a square pillow
was placed under the knee joint so that the angles
of the hip joint and the knee joint were at 90
degrees. The muscle at the back of the neck was
lengthened and the epigastric region was pushed to
the distal part, elevating the head of the patient.
Then, both scapulae were displaced in the anterior
direction, and the upper limbs were abducted. At
the same time, the head was directed to the knees,
and the trunk was maintained straight.
2. Walking back and forth, walking right and left, and
standing still.
3. Anterior tilt and posterior tilt of the pelvis in a
sitting position. A therapist moved the pelvis of the
patient in front of the patient, holding the outer
sides of the pelvis.
4. S t r e t c h i n g t h e a r m s f o r w a r d , d o w n w a r d , a n d
toward both sides in the sitting position.
5. Standing with both feet together.
6. Repeated lifting and lowering of the heels within a
range in which the patient would not fall down,
standing in a comfortable position and keeping
both feet wide.
The exercises carried out by the land exercise group
followed to the exercise methods of Itshak et al.
10), Peter
et al.11), and Carin et al.12) The following exercise
programs were performed by the aquatic exercise group. 1. Standing on a board while maintaining balance in
the water.
2. If a stable state could be maintained in Exercise 1,
the patient bent and spread the hip and knee joints
as slowly as possible in the water.
3. Walking while wearing a floating cuff in the water.
4. Moving the hip and knee joints around while holding
a water noodle between the legs as if riding a bicycle
in the water..
5. Standing on a balance board while keeping the eyes
closed and wearing a floating cuff in the water.
6. Jumping in a given area of the pool while wearing a
floating cuff and keeping both feet together.
For the aquatic exercises, a floating cuff, belt, balance
board and water noodle were used. The cuff provides
buoyancy in the lower extremity and the belt helps subjects
to maintain an independent standing posture in the water.
The balance board helps subjects with sitting balance,
coordination and pelvis stability exercises in the water. The
w a t e r d e p t h w a s c o n s t a n t a t 1 . 3 m , a n d t h e w a t e r
temperature was kept at 3335C for the aquatic exercises. Static balance assessed with parameters of sway of the
center of pressure (COP) which were measured by the Good
Balance System (Metitur Ltd, Jyvskyl, Finland). The
subjects were instructed to stand on the force platform in
the most comfortable posture while maintaining a distance
of 56 cm between their heels. Each measurement was
carried out for 30 seconds. Each measurement was carried
out three times with the eyes open and then three times with
the eyes closed, and average values were obtained. For the
measurements, the environment was kept warm, calm and
bright, and the subjects wore simple clothes. The force
p l a t f o r m i s c o n s t r u c t e d i n t h e s h a p e o f a t r i a n g l e
(800800800 mm). The signals from the amplifier were
i n p u t t o a c o m p u t e r v i a a 1 2 - b i t t r a n s d u c e r, a n d t h e
sampling frequency of each channel used to record the
information was 50 Hz. In this experiment, the mediolateral
movement distance and the anteroposterior movement
distance of the COP of each subject were assumed as the
X-axis and Y-axis of the subject respectively. The values for
e a c h a x i s w e r e d i v i d e d b y t h e m e a s u r e m e n t t i m e t o
calculate the average speed. The velocity moment is the
area described by the movements of the COP per second
and this value is related to the distance from the geometrical
center point of the entire test and the velocity of the
movement during the same period of time
13). Consequently,
the moments were interpreted as the total COP sway. The
independent t-test was used to determine within-subject
changes between baseline and follow-up. For group and
v i s i o n i n f o r m a t i o n , d i ff e r e n c e s i n o u t c o m e v a r i a b l e s
meeting mathematical assumptions were examined using
two-way ANOVA. Duncans post hoc test was then used to
determine whether differences existed across each group.
All statistical analyses were performed using SPSS (version
12.0 for Windows, SPSS Inc., Chicago, IL, USA). Values of
p0.05 were considered significant.
The LE group and the AE group showed significant
improvements with eyes open in X-speed, Y-speed and
Velocity Moment after the exercises (p0.05). Therefore,
the exercises improved the balance abilities of both groups
( Ta b l e 1 ) . Wi t h e y e s c l o s e d , t h e A E g r o u p s h o w e d
significant improvements in X-speed, Y-speed and Velocity
Moment after the exercises (p0.05), but the LE group did

not. Therefore, the exercises improved the eyes closed
balance ability of the AE group (Table 1). Changes in balance ability were determined by vision
i n f o r m a t i o n i n t h e L E a n d A E g r o u p s . T h e r e w e r e
significant differences related to visions between the groups
(Table 1). Therefore, balance ability changed with group
and also with vision information. Post hoc analysis of the
groups showed significant differences in the X-speed and
Ve l o c i t y M o m e n t i r r e s p e c t i v e o f v i s i o n i n f o r m a t i o n
(p=0.01). Y-speed showed significant differences in the AE
group with the eyes closed and in both vision conditions in
the LE group (p0.01) (Table 1).
This study demonstrated that six weeks of aquatic
therapy improved the static balance of stroke survivors. The
buoyancy of the water may allow stroke patients to move
with less effort and in movement planes that would be
impossible on land without assistance
13). Thus, the subjects
may be able to perform some activities in the water more
readily than they are able to on dry land. Repeated and
intensive movement training in the water environment may
produce substantial changes, leading to improved balance
In this study, we did not measure dynamic balance,
because the subjects balance ability was poor. The effects
of exercise group and vision on balance were examined.
The results indicate that balance ability is affected by
exercise group rather than by vision. Both groups had better
open-eye, mediallateral, anteriorposterior, and overall
balance after the exercises. However, the aquatic exercise
group had a greater increase in balance ability than the land
exercise group. These results are similar to those presented in a report
w h i c h i n d i c a t e d t h a t b a l a n c e a n d g a i t a b i l i t i e s w e r e
improved more in an aqua exercise group than in a land
exercise group
14), and a report that indicated that there were
m o r e i m p r o v e m e n t s i n b a l a n c e a n d l o w e r e x t r e m i t y
muscular force in an aqua exercise group than in a land
exercise group
2). However, another study of elderly persons
reported no difference in balance between an aqua exercise
group and a land exercise group
5). Willen4) et al. reported on changes in muscular force, gait and balance induced by
aqua tasks on adult patients with infantile paralysis and
found only slight improvements, while a control group that
received only conventional physical therapy only showed
some differences in the degree of pain without any other
changes. Their results were also somewhat different from
the results of this study.
In this study, the degrees of mediallateral, anterior
posterior and overall sway decreased in the aqua exercise
group but not in the land exercise group. The degrees of
mediallateral and overall balance improved only in the
aqua exercise group. Visual information serves a primary
role in maintaining orientation, dynamic balance and static
15), and postural sway increases by 2070% when
visual information is lacking, that is, when standing with
the eyes closed
16). In this study, too, the degree of sway was
greater with the eyes closed than with the eyes open in both
groups. This study also showed that balance abilities were
affected by aquatic or land exercises much more than by
vision. Therefore, it seems likely that aquatic exercises
contribute to the improvement of balance ability regardless
of whether or not there is visual information. Therefore, it
can be said that the physical conditions of the water
environment stimulated patients more effectively than
exercise on land and, as a result, stroke patients balance
abilities improved.
1) Teasell R, McCrae M, Foley N, et al.: The incidence and consequences of
falls in stroke patients during inpatient rehabilitation: Factors associated
with high risk. Arch Phys Med Rehabil, 2002, 83: 329333.
2) Noh DK, Lim JY, Shin HI, et al.: The effect of aquatic therapy on postural
balance and muscle strength in stroke survivors. Clin Rehabil, 2008, 22:
3) Geigle P, Daddona K, Finken K, et al.: The effects of a supplemental aquatic
physical therapy program on balance and girth for NCAA division 111
athletes with a grade I or grade I1 lateral ankle sprain. J Aquat Phys Ther,
2001, 9: 1320.
4) Wi l l e n C , S u n n e r h a g e n K S , G r i m b y G : D y n a m i c w a t e r e x e r c i s e i n
individuals with late poliomyelitis. Arch Phys Med Rehabil, 2001, 82: 66
5) Peter D, Veronica S, Celia V, et al.: The effect of land and aquatic exercise
Table 1. A comparison of balance by group and vision information (M SD) (unit: mms)
Balance Group Condition Pre Post Duncan
eyes closed
a 12.5 5.3a 11.5 4.8
Land group
eyes openb* 14.3 3.7a 12.5 3.0
X-speed*** c,da,b
eyes closedc* 12.5 5.5 8.6 4.0
Aqua group
eyes opend** 13.8 5.5 8.7 3.5
eyes closed
a 14.7 3.7 13.4 3.8
Land group
eyes openb* 16.9 4.7 15.3 4.8
Y-speed** d,cc,aa,b
eyes closedc 14.5 4.3 11.4 3.4
Aqua group
eyes opend** 15.4 4.4 10.2 3.0
eyes closed
a 62.6 22.4 57.8 20.1
Land group
eyes openb* 72.0 22.8 61.9 29.2
Velocity Moment** d,ca,b
eyes closedc** 61.1 36.6 36.9 24.7
Aqua group
eyes opend** 65.8 29.2 34.2 14.0
*p0.05, **p0.01, *** p=0.01; X-speed, mediolateral sway; Y-speed, anteroposterior sway.

908J. Phys. Ther. Sci. Vol. 23, No. 6, 2011
on balance scores in older adults. J Geriatr Phys Ther, 2003, 26: 13.
6) Aimee ER, Michael GM, Marc R, et al.: Comparisons of static and dynamic
balance following training in aquatic and land environments. J Sport
Rehabil, 2006, 15: 299311.
7) Genuario SE, Vegaso JJ: The use of a swimming pool in the rehabilitation
and reconditioning of athletic injuries. Contemp Orthop, 1990, 20: 381\387.
8) Dean CM, Richards CL, Malouin F: Task-related circuit training improves
performance of locomotor tasks in chronic stroke: A randomized controlled
pilot trial. Arch Phys Med Rehabil, 2000, 81: 409417.
9) Evert V, Bobbert M, Inklaar M, et al.: The effect of a balance training
programme on centre of pressure excursion in one-leg stance. Clin Biomech
(Bristol, Avon), 2005, 20: 10941100.
10) Itshak M, Ori E, Irit T, et al.: A water-based training program that include
perturbation exercises to improve stepping responses in older adults: study
protocol for a randomized controlled cross-over trial. BMC Geriatr, 2008, 8:
11) Peter D, Veronica S, Celia V, et al.: The effect of land and aquatic exercise
on Balance Scores in older adults. J Geriatr Phys Ther, 2003, 26: 36. 12)
Carin W, Datharina SS, Gunnar G: Dynamic water exercise in individuals
with late poliomyelitis. Arch Phys Med Rehabil, 2001, 82: 6672.
13) Suomi R, Koceja DM: Postural sway characteristics in women with lower
extremity arthritis before and after an aquatic exercise intervention. Arch
Phys Med Rehabil, 2000, 81: 780785.
14) Lee DJ: Effect of the Aquatic Training on Balance and Walking in Stroke
Patients. Journal of Special E Education & Rehabilitation Science, 2008, 47:
15) Nichols DS, Glenn TM, Mutchinson KJ: Changes in the mean center of
balance during balance testing in young adults. Phys Ther, 1995, 75: 699
16) Magnusson M, Enbom H, Johansson R, et al.: Significance of pressor input
from the human feet in anterior-posterior postural control. The effect of
hypothermia on vibration-induced body-sway. Acta Otolaryngol, 1990, 110:

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