adapted swimming sports and rehabilitation

LOWER LIMB MUSCLES ACTIVITIES OF THE DEEP-WATER RUN-
NING AND INTERVENTION EFFECTS ON BALANCE ABILITY IN THE
ELDERLY
Koichi Kaneda, Hitoshi Wakabayashi, Takeo Nomura
University of Tsukuba, Ibaraki, Japan.
This study was intended to investigate thigh-muscle activity
during deep-water running (DWR) (Exp. 1), along with the
effects of intervention with upright-floating (UF) exercise on
balance ability in elderly (Exp. 2). Exp. 1: Nine healthy males
(25.0 ± 0.5 yrs) performed DWR and water walking (WW).
The surface electromyogram (EMG) electrodes were placed on
the rectus femoris (RF) and biceps femoris (BF). The mean
electromyogram (mEMG) of the BF during the DWR showed
significantly higher values than that during the WW. Exp. 2:
Fourteen healthy elderly persons (60.8 ± 5.3 yrs) participated
in a once-a-week water exercise program of 12 weeks. They
were separated into a normal and an UF group. The UF group
improved the body-sway area (30 s, eyes open) and tandem
walk time (10 steps). It was considered that the high stimulus
of the BF during DWR affected the improvement of the balance
ability in UF.
Key Words: deep-water running, upright-floating, thigh muscles,
EMG, balance ability, elderly.
INTRODUCTION
Various water exercises exist for rehabilitation or fitness maintenance.
In water, buoyancy acts against the body to reduce the
load at the joints, while water viscosity requires the subject to
exert greater force than when moving on land (3).
An upright-floating situation in a water environment (feet separated
from the swimming pool floor) is hard to experience in
any other exercise environment. The typical form of uprightfloating
(UF) exercise in water is deep-water running (DWR).
The advantages of this exercise are that it reduces the impact
stress for lower limb joints and maintains aerobic fitness (7).
Studies have investigated motion analysis and aerobic fitness
during DWR and suggested its characteristics. Moening et al.
(4) described that when comparing DWR and treadmill running,
the subject leans forward in the DWR at the trunk to
counteract the buoyancy effect on the lower limbs. They also
described that the DWR is an open kinetic chain compared to
the closed kinetic chain of treadmill running. Another study of
DWR reported that the maximal oxygen uptake ( V O2) and
the heart rate (HR) were lower than those for running on
land, but the ratings of perceived exertion (RPE; legs and
breathing) and the respiratory exchange ratio (RER) were
greater during submaximal, whereas ventilation (l/min) was
similar with younger males (10).
However, no studies have investigated thigh muscle activity
during DWR and its intervention effects for elderly persons.
This study was intended to investigate lower limb muscle activity
during DWR and the effects of intervention of UF exercise on
balance abilities of elderly persons. We established two experiments
to explore these issues mentioned above. The first experiment
investigated thigh muscle activity during DWR in young
males (Exp. 1). The second experiment conducted short-time
water exercise intervention for elderly persons and investigated
their balance ability before and after intervention (Exp. 2).
·
ADAPTED SWIMMING SPORTS AND REHABILITATION
METHODS
Exp. 1:
Nine healthy young males participated in this experiment as
subjects. Their respective mean age, height, weight and %fat
were 24.9 ± 2.2 yrs, 172.0 ± 3.8 cm, 69.3 ± 3.7 kg, and
19.4 ± 4.1%. Informed consent was obtained for this experiment.
Subjects practiced to familiarize themselves with water
walking (WW) and DWR before the experiment. The subjects
underwent WW and DWR at their comfortable speeds for 8 s
with two repetitions. An aqua jogger (Aqua Jogger; Excel
Sports Science Inc., Japan) was attached to the subject’s waist
during DWR.
The left thigh muscle activities of rectus femoris (RF) and biceps
femoris (BF) were measured during trials using surface electromyography
(EMG). The skin cuticle was removed carefully
using a blood lancet (Blood Lancet; Asahi Polyslider Co. Ltd.,
Japan) and cleaned with alcohol wipes so that the inter-electrode
impedance was less than 20 kΩ. A pair of surface EMG electrodes
(5 mm diameter) was placed in the middle of the belly of
the RF and BF. Electrodes were covered with transparent film
(Dressing tape No. 100; As One Corp., Japan) for waterproofing.
The EMG signals were telemetered via a multi-channel telemetry
system (WEB-5500 Nihon Kohden multi-telemeter system;
Nihon Kohden Corp., Japan) using a time constant of 0.03 s,
2 kHz sampling rate, and 500 Hz hi-cut filter.
The trials were videotaped with synchronization to the EMG. A
digital video camera was placed on the left side of the subject;
it allowed coverage of one cycle at a 30 Hz frame rate. Data
were collected from one cycle of the videotaped picture, from
heel contact to the next heel contact in WW and from the maximum
knee drive (as a maximal hip flexion) to the next maximum
knee drive at DWR. Then, the mean electromyogram
(mEMG) was calculated during one cycle. The water temperature
was set at 27 ± 2°C and the water depth was set at 1.1 m
throughout the experiment.
Paired Student’s t-tests were used to compare differences
between WW and DWR. Statistical significance was inferred at
p < 0.05.
Exp. 2:
Fourteen healthy elderly volunteers (mean age 60.9 ± 5.3 yrs.:
2 males and 12 females) were separated into two groups: a
normal water exercise group (NW, n = 7: 1 male and 6
females) and an upright-floating exercise group (UF, n = 7: 1
male and 6 females). Their mean height, weight and BMI were
respectively 150.9 ± 6.6 cm, 56.2 ± 10.9 kg and 24.5 ±3.2 in
NW, 153.2 ± 8.6 cm, 61.3 ± 7.3 kg and 26.1 ± 2.0 in UF. They
had already become accustomed to water exercise, but did not
engage in other water exercise programs. Informed consent
was obtained for this experiment program. Subjects participated
in a 60 min water exercise program, including 30 min divided
into two groups in one session, once a week, for 12 weeks.
The NW participants underwent WW, resistance training and
other ordinary water exercises using a kick board (Fig. 1A).
The UF participants performed locomotive motions, mainly
DWR with feet separate from the bottom of the swimming
pool, using a water noodle (Fig. 1B). The pool depth was
1.1–1.3 m; it was 25.0 m long and 3.6 m wide, with water temperature
maintained at 30°C throughout the 12 weeks. A bodysway
test for static balance ability (12) and a tandem walk test
for dynamic balance ability (2) were conducted before and after
12 weeks. The body-sway test was conducted using a posturo-
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ADAPTED SWIMMING SPORTS AND REHABILITATION
graphic meter (Gravicoda GS-10, type-C; Anima Co., Japan).
Subjects stood silently on the posturographic meter staring at a
point marked on the wall (distance was 3 m forward, height
was 1.5 m) with their feet bared and kept together. Tests were
conducted for 30 s with eyes open. Body-sway distance and
body-sway area were analyzed in this study. A tandem walk
test was conducted for two trials. Subjects were required to
walk heel to toe along a 10-step line as quickly as they could
without mis-stepping. A misstep occurred when subjects
stepped completely off the line or failed to follow a heel-to-toe
pattern. The 10-step tandem walk time measured using a stopwatch
of two trials without mis-stepping was then averaged.
Wilcoxon’s signed-rank test was used to detect differences in
the two tests taken by each group for the conditions before and
after 12 weeks. A Mann-Whitney U-test was used to assess differences
in two tests between two groups before and after 12
weeks. The statistically significant level was set as p < 0.05.
Figure 1. Typical exercise forms of respective groups.
RESULTS
Exp. 1:
Figure 2 shows the mean ± SD values of the time for 1 cycle in
each trial. The time for 1 cycle was 2.45 ± 0.23 s for WW and
1.51 ± 0.27 s for DWR. A significant difference in the 1 cycle
time was found between WW and DWR (p < 0.05). Figure 3
shows mean ± SD values of the mEMG of RF and BF. The
mEMG values of RF were 9.90 ± 2.96 µV in WW and 8.20 ±
2.81 µV in DWR. The mEMG values of BF were 11.46 ± 3.39 µV
in WW and 22.85 ± 14.06 µV in DWR. The mEMG value of BF
during DWR was significantly higher (p < 0.05) than that during
WW, but no difference was apparent in the mEMG value of RF.
Exp. 2:
The mean ± SD values of body-sway and tandem walk tests at
baseline and after 12 weeks are shown in Table 1. The values of
body-sway distance were 45.70 ± 14.54 cm in NW and
46.54 ± 11.28 cm in UF at baseline, 53.97 ± 21.19 cm in NW
and 42.80 ± 7.74 cm in UF at after 12 weeks. A significant
increase of the body-sway distance was apparent in NW (p <
0.05). In the body-sway area, the values were 1.94 ± 1.23 cm 2
in NW and 2.59 ± 1.28 cm 2 in UF at baseline, 2.96 ± 2.06 cm 2
in NW and 1.91 ± 0.62 cm 2 in UF at after 12 weeks. The tendency
of the body-sway area was apparent in each group, but
increasing in NW (p = 0.06) and decreasing in UF (p = 0.09).
The tandem walk times were 7.3 ± 1.4 s in NW and 7.4 ± 1.1
s in UF at baseline, 6.9 ± 1.1 s in NW and 6.6 ± 0.8 s in UF at
after 12 weeks, respectively. A significant decrease of the tandem
walk time was detected in UF (p < 0.05).
Rev Port Cien Desp 6(Supl.2) 351-357
DISCUSSION
The first objective of this study was to compare the thigh
muscle activities of WW and DWR. For that purpose, the first
experiment was designed to collect the RF and BF activity
data using surface EMG and mEMG during 1 cycle at each
trial and compare them. The mEMG of BF was significantly
higher in DWR than that of WW (p = 0.05), but the mEMG
of RF was similar.
No studies have compared WW to DWR directly in motion
analysis. Moening et al. (4) described that trunk flexion was
larger for DWR than for treadmill running on land. In addition,
the joint angle of hip maximum flexion in the knee drive was
about 60° greater in DWR than that in treadmill running. At
the knee joint, the range of motion from the back swing to the
knee drive was about 55° greater in DWR than that in treadmill
running. Hip and knee flexion are greater in DWR than
that in treadmill running. Miyoshi et al. (3) reported that the
range of motion at the hip joint in WW was similar to land
walking at comfortable speed, and that the range of motion at
the knee joint in WW was smaller than that of land walking.
Regarding treadmill walking and running, Nilsson et al. (6)
reported that the net hip angle was somewhat larger during
walking than running at the same speed. The net amplitude of
the hip joint was four times larger during running than walking
when the speed was changed from low to high. They also
reported a significantly larger net knee flexion amplitude during
running than during walking.
This study measured the RF and BF muscle activities and compared
WW to DWR. The RF activates hip flexion and knee
extension. The BF activates hip extension and knee flexion. We
hypothesized that muscle activities of RF and BF were higher
in DWR than in WW, but this study showed a similar value on
RF activity, probably because buoyancy served to assist hip
flexion, although maximum flexion in the knee drive was
greater in DWR than in WW. The higher muscle activity of BF

in DWR than in WW was attributable to the greater range of
motion at the knee joint in DWR. Experiments of motion
analysis that are synchronized to EMG are required to elucidate
this aspect more precisely.
The second objective of this study was investigation of the
intervention effects of UF exercise on balance ability in elderly.
For that purpose, we designed a once-a-week water exercise
program lasting 12 weeks and established NW and UF exercise
groups. The body-sway distance and area were increased in
NW, but the body-sway area was decreased in UF and the tandem
walk time of 10 steps was decreased in UF.
It is widely acknowledged that body-sway as a static balance
ability reflects the center of gravity (COG) during standing (5).
Tandem walking is often used as a dynamic balance ability (2).
In the present study, the static balance declined in NW, but
static and dynamic balance improved in UF. No studies have
reported the decline of body-sway through exercising for the
elderly. Simmons et al. (8), who reported enhancement of functional
reach in water exercise group, explained two characteristics
during water exercise. First, the buoyancy provided by
water can be considered destabilizing because it will tend to lift
a subject up. Second, because water exercise was conducted for
a group, this created turbulence, which might have increased
the variability of the factors influencing each participant’s
movement. Destabilizing buoyancy and turbulence that
occurred during water exercise might have affected the
increased body-sway distance and area in NW.
Improvement of body-sway in women with lower extremity
arthritis was demonstrated in water exercises (9). In the present
study, UF improved the body-sway area. Tandem walking also
improved only the UF group. Experiment 1 revealed that BF
mEMG increased significantly in DWR compared to WW. The
high stimulus of the BF during DWR was inferred to improve
the balance ability in UF. Other possibilities are coordination
between the legs and body or adjustment of body balance, as
seen in Tai Chi Chuan (1), but further research is required.
The static and dynamic balance ability improved in UF in the
present study. In general, the balance ability declines with age;
it is an important function that prevents fall accidents because
it is associated with postural control (11). Results of the present
study suggest that UF exercise might be useful for elderly
persons to prevent fall accidents because the balance ability
was improved after 12 weeks’ intervention.
CONCLUSION
This study suggests that UF exercise can improve the balance
abilities of elderly persons. It might be affected by the high
muscle activity of BF during DWR. Furthermore, because balance
abilities were improved after 12 weeks, UF exercise in the
water might be useful to prevent elderly persons’ fall accidents.
ACKNOWLEDGEMENTS
Support of the staff of the Swim Laboratory at the University
of Tsukuba is greatly appreciated. We also thank all 9 young
men of Exp. 1 and 14 elderly men and women of Exp. 2 for
participating enthusiastically in this study.
REFERENCES
1. Jin C, Watanabe K (2003). The practice of Tai Chi Chuan in
middle and elderly person and its effect to static and dynamic
postural stability. Jpn J Phys Fitness Sports Med, 52: 369-80, in
Japanese
ADAPTED SWIMMING SPORTS AND REHABILITATION
2. Medell JL, Alexander NB (2000). A clinical measure of maximal
and rapid stepping in older women. Journal of
Gerontology: Medical Sciences, 55A(8): M429-33
3. Miyoshi T, Shirota T, Yamamoto S, Nakazawa K, Akai M
(2004). Effect of the walking speed to the lower limb joint
angular displacements, joint moments and ground reaction
forces during walking in water. Disability and Rehabilitation,
26(12): 724-32
4. Moening D, Scheidt A, Shepardson L, Davies GJ (1993).
Biomechanical comparison of water running and treadmill running.
Isokinetics and Exercise Science, 3(4): 207-15
5. Murray MP, Seireg A, Scholz RC (1967). Center of gravity,
center of pressure, and supportive forces during human activities.
J Appl Physiol, 23(6): 831-8
6. Nilsson J, Thorstensson A, Halbertsma J (1985). Changes in
leg movements and muscle activity with speed of locomotion
and mode of progression in humans. Acta Physiol Scand, 123:
457-75
7. Reilly T, Dowzer CN, Cable NT (2003). The physiology of
deep-water running. Journal of Sports Sciences, 21: 959-72
8. Simmons V, Hansen PD (1996). Effectiveness of water exercise
on postural mobility in the well elderly: An experimental
study on balance enhancement. Journal of Gerontology:
Medical Sciences, 51A(5): M233-8
9. Suomi R, Koceja DM (2000). Postural sway characteristics in
women with lower extremity arthritis before and after an
aquatic exercise intervention. Arch Phys Med Rehabil, 81: 780-
5
10. Svedenhag J, Seger J (1992). Running on land and in water:
comparative exercise physiology. Med Sci Sports Exerc, 24(10):
1155-60
11. Woollacott M (1993). Age-related changes in posture and
movement. The Journal of Gerontology, 48: 56-60
12. Yoneda T, Muraki T, Taketomi Y (1994). Influence of aging
on standing balance. Bulletin of Allied Medical Sciences, Kobe
10: 61-68.
DURATION OF ONE UNIT (80KCAL) DURING TREADMILL WALKING
IN WATER
Kumiko Ono1 , Kazuki Nishimura1 , Sho Onodera2 1Graduate School, Kawasaki University of Medical Welfare, Kurashiki,
Japan
2Kawasaki University of Medical Welfare, Kurashiki, Japan.
The number of Japanese people diagnosed with diabetes has
been increasing. Epidemiological and intervention studies of
endurance exercise training strongly support its efficacy for
improving diabetes. The purpose of the present study was to
make clear the difference of duration per expended one unit
(80kcal) during treadmill walking in water between younger
and older people. We would get the standard data by using non
diabetes people. Ten healthy young men and eight healthy
women participated in this study. Subjects walked at 1, 2 and
3km/h (30.3°C). The duration of exercise that expended one
unit of energy was calculated from VO 2. Younger and older
people’s calculated results were 41’39’’ and 39’44’’ (1km/h),
33’22’’ and 31’56’’ (2km/h) and 24’51’’ and 24’56’’ (3km/h).
There was no difference due to the difference of the age in one
unit. It might be suggested that it becomes possible to pre-
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scribe underwater exercise for older diabetes patients by using
the young’s one unit index.
Key Words: treadmill, walking water, one unit (80kcal), diabetes.
INTRODUCTION
It is believed that in Japan 7.4 million people are suspected of
having diabetes (2002). Moreover, recently the number of
Japanese people diagnosed with diabetes has been increasing.
Many diabetes patients suffer from complications, for example
diabetic renal disease, retinopathy and neurosis. As for diabetic
renal disease, it is the NO. 1 cause of artificial dialysis in Japan.
Many diabetes patients also suffer from obesity.
Epidemiological and intervention studies of endurance exercise
training strongly support its efficacy for improving diabetes.
But exercise on land causes kidney blood flow to reduce. It will
not be good for it’s patient’s kidney. In water, the amount of
kidney blood flow is maintained during exercise. And by the
action of buoyancy the weight which is loaded on the joint of
the legs decreases.
The remedy for diabetes consists of diet, exercise and medication.
For diet, the unit conversion which designates 80kcal as
one unit has been used in Japan. For diabetes patients, by using
this kind of unit conversion, they can take the calorie which is
easily decided in detail (intake per a day divided by nutrition).
So far we calculated the duration when one unit (80kcal) is
expended in young people during underwater treadmill walking.
As for diabetes, it can recognize the increase of morbidity
in older people. The purpose of the present study was to make
clear the difference of duration per expended one unit (80kcal)
between younger and older people during treadmill walking in
water, and whether or not one unit index of the young can be
adapted to older.
METHODS
In this study, in order to accomplish the above mentioned purpose,
we gathered standard data which is intended for people
who are not diabetes as the subject. Ten healthy young men
(age: 22.6±1.1 yrs, height: 171.6±5.4 cm, weight: 67.7±8.4 kg
and %fat: 19.2±4.7 %) and eight healthy women (age:
61.8±4.3 yrs, height: 152.4±3.9 cm, weight: 60.0±4.9 kg and
%fat: 34.1±2.8 %) participated in this study. We conducted
informed consent following the Helsinki declaration for participation
in this experiment.
In order to enter the water, subjects wore a swimming suit.
They took a rest by standing before walking for 5 minutes each
on land and then in water. Subjects walked at 3 velocities (1, 2
and 3km/h) on a treadmill in water. On the 1 st day, young subjects
were walking in water for 15 minutes at one velocity.
They walked the other two velocities other day. On the other
hand, older subjects completed three consecutive 7-minute
walks at progressively increasing velocity. So they walked for
21 minutes in water. Water level was set to Trochanter major.
Heart rate (HR) and oxygen uptake (VO 2) were measured. HR
was measured by bipolar lead chronologically. And we recorded
for each minute. Exhaled gas was gathered to calculate VO 2.
We set 5 points to gather. It’s rest on land for 5 minutes, rest
in water for five minutes and walking in water for 2 minutes by
each velocity. The duration of exercise that expended one unit
of energy was calculated from oxygen uptake. Energy used per
liter of expended oxygen is about 5 kcal, so we used the following
formula (duration of one unit=16/VO 2).
Rev Port Cien Desp 6(Supl.2) 351-357
Water temperature, room temperature and humidity during the
experiments were 30.3±0.3°C, 26.9±0.7°C and 76.6±2.3%.
RESULTS
The young’s average HR at rest was 72.2±8.6 bpm on land and
64.3±8.2 bpm in water. Older people’s average HR at rest was
81.2 ±10.4 bpm on land and 76.2±9.3 bpm in water. Average
HR for older people was significantly higher than the young’s
on land and in water respectively (p

Table 1. The Duration of Expending One Unit (80kcal) during
Treadmill Walking in Water.
velocity (km/h) young subjects (min) Olderly subjects (min)
1 41.66±4.56 (41’39’’) 39.73±6.54 (39’44’’)
2 33.37±4.59 (33’22’’) 31.94±4.49 (31’56’’)
3 24.86±5.23 (24’51’’) 24.93±4.18 (24’56’’)
DISCUSSION
It was made clear that older people’s HR on land at rest was
higher, the rate of decease in HR in water at rest was lower and
the rate of increase in HR while exercising was higher than the
young’s. From this, it was suggested that older people’s Venous
Return could prevent promotion by comparison with the young.
The aerobic ability of older people has decreased by comparison
with the young. As a result, we thought that older people’s
absolute VO 2 became the same as the young’s. So we could
have to consider the duration of exercise for the patient whose
body weight deviates from these subjects. For example, if
patient’s weight is too high when compared with the young
subjects’ we should change the duration by decreasing it.
When introducing exercise we should start at lower durations,
too. The Ministry of Health, Labour and Welfare in Japan
advises that diabetes patients should exercise enough to sweat
a little while having a conversation with their neighbor easily
for about 30 minutes per day. So we could say that our index is
fit for these patients.
As said in the introduction it is clear that exercise on land
reduces the renal blood flow rate but that in water it is maintained.
By exercising on land or in water our muscles can use
glucose easily and glucose metabolism is improved; so they
should exercise. Including diabetes patients that may develop
diabetic renal disease, we could say that for diabetes patients
exercise in water is the best choice of training for preventing
deterioration of diabetes.
Almost all Japanese people live on rice. The energy of a half
cup of rice is about 80 kcal. So, in the diet of diabetics in
Japan, the unit conversion which designates 80 kcal as one unit
has been used. It suggests that the index calculated in this
study is useful for the patients exercising by themselves, too.
We calculated the duration of water level that is at Processus
xiphoideus, too. The results were 62’41’’ (1km/h), 50’33’’
(2km/h) and 37’51’’ (3km/h). If the water level goes up to the
Processus xiphoideus, the duration for expending one unit
becomes long. It is showed that the strength of the exercise is
lower than at Trochanter major. So introducing exercise for the
patients we should start at the Processus xiphoideus level.
CONCLUSION
In this study we calculated the duration of expending one unit
(80kcal) of energy during treadmill walking in water to obtain
the standard data to improve diabetes. Older people’s one unit
data was equal to the young’s. We could expect to prevent the
health of those with aggravation of diabetes or improve it using
the one unit index. Using this index, we can connect it to the
QOL maintenance or the improvement of life for patients with
diabetes patients who also are at an advanced age.
ACKNOWLEDGEMENTS
For his assistance with the study the authors would like to
thank Michael J. Kremenik, an associate professor at the
Kawasaki University of Medical Welfare, Kurashiki.
ADAPTED SWIMMING SPORTS AND REHABILITATION
REFERENCES
1. Ono K, Ito M, Kawaoka T, Kawano H, Shiba D, Seno N,
Terawaki F, Nakajima M, Nishimura K, Onodera S (2005).
Changes in heart rate, rectal temperature and oxygen uptake
during treadmill walking in water and walking in a pool.
Journal of Kawasaki Medical Welfare Society 14: 323-330.
2. Hung CT (1989). Food exchange list based on 80-kilocalorie
rice unit. Taiwan yi xue hui za zhi. Journal of the Formosan
Medical Association, 88: 595-600.
3. Ministry of Health, Labour and Welfare (2005). Dietary
Reference Intakes for Japanese. Tokyo. Japan: Dai-ichi Syuppan
Publishing Co. LTD.
MOVEMENT ANALYSIS IN CAD-PATIENTS
Lutz Schega1,2 , Daniel Daly2 1Otto-von-Guericke-University Magdeburg, Institute of Sport Science,
Germany
2K.U. Leuven, Department of Rehabilitation Sciences, Belgium.
Changes in movement parameters under various load conditions
during breaststroke swimming were assessed in Coronary
Artery Disease (CAD) patients. Kinematic analysis of time-discrete
and time-continuous characteristics, and timing of the
swim-movement was made during a breaststroke “load-steptest”
in a flume for 26 male CAD-patients. Factor analysis was
applied. The path of hands, feet and hips, the pause between
propulsive phases and the angle of attack of hip-shoulder-water
surface are of crucial importance in patients with CAD. These
findings are supported by the factor analysis where comparable
parameters were found to be of relevance. Results did indicate
large individual variations in time-continues characteristics.
Key Words: swimming, rehabilitation, biomechanics, coronary
artery disease.
INTRODUCTION
The importance of physical activity in patients with Coronary
Artery Disease (CAD) is undisputable. The aim of sport related
rehabilitation is to develop an optimal specific program depending
on the current condition of the individual. Nevertheless
such programs focus primarily on physiological adaptations
although it is well known that changes in the movement may
influence this. The physiological adaptation to immersion in
various water temperatures and the duration of immersion have
often been investigated in this population (e.g. 1,2). Few scientific
reports (5, 8), however, provide information on the actual
swimming movement in patients with cardiac disease. Some
studies have provided indications of the influence of movement
changes on physiological responses from a qualitatively point of
view, for example by Bücking et al. (2) and Meyer & Bücking
(9). No quantitatively analysis has been reported however. The
goal of this study, therefore, was to assess the changes in movement
parameters of CAD patients under different load conditions
during breaststroke swimming.
METHODS
Two-dimensional movement analysis (SIMI-Motion) was made
during a flume “load-step-test” in breaststroke of 26 male
CAD-patients: age, 59yrs. (± 8.2), infarct age, 8yrs. (± 6.8),
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height, 178.3cm, (SD= 8.4), weight, 78.5kg (± 11.4), body
surface, 2.1m 2 (± 0.24). The test consisted of three 3 minute
swims at the same mean swimming speed with added, subtracted
or no extra load.
One S-VHS video camera was placed outside the flume perpendicular
to the swimming direction at 3.5-m from the swimmer.
The actual camera view in the swimming plane was 4-m
x 3-m. At the start of each video session a 1-m calibration
ruler was placed in both the vertical and horizontal direction
and recorded. Reference makers were set at eight points on
the left side of the body: toe, ankle, knee, hip, shoulder, elbow,
wrist and top middle finger. Recordings were made during
each step, in order to analyse 10 movement cycles in the middle
of each step. Sampling frequency was 50 Hz. Digitizing
was done using the SIMI-Motion “ software package 6.1 and
analysis was based on the breaststroke phase model of
Wiegand et al. (12) (Figure 1).
Figure 1. Breaststroke Phase-Model by Jähnig et al. (7).
To describe the complex movement, time-discrete (paths, durations,
velocities, angles) and time-continuous characteristics
(v x-t-progress of the hip depend on arm and leg by Federle
(4)), and timing of the swim-movement (Phase Structure
Quotient-PSQ of Blaser et al. (1)) were examined. All in all 57
movement-parameters were determined in 3 swimming situations
in each patient. Means and standard deviations were
determined. Significant changes of parameters over 10 movement
cycles between load steps were calculated using the nonparametric
Wilcoxon-test. The level of significance was set at P
< 0.05. A factor analysis (principle –component analysis) was
performed as described by Hotelling (6) and Kelly (7). Phase
structure quotient for both arm and leg movements were determined
as follows:
PSQ = (duration of main phase/ duration of initiation phase
+ duration of linking phase + duration of preparation phase)
x 100%(1).
RESULTS
Based on the time-discrete findings 9 parameters were found to
be relevant to describe the changes in swimming movement of
the CAD-patients examined. These 9 parameters showed a frequency
of change of more than 5 (Table 1). All in all only one
patient demonstrated no significant changes over the increasing
load steps. On average 31 (±14) parameters changed.
Rev Port Cien Desp 6(Supl.2) 351-357
Table 1. Frequency and Characteristic of time-discrete kinematic
parameters during swimming.
Frequency
Parameter ≥ 5 Characteristic
Vertical path of hand in main phase of arm 8 1 x s; 1 x f ; 5 x d (^);
1 x d (v)
Vertical path of foot in main phase of leg 7 2 x s; 1 x d (^); 4 x d (v)
Resultant path of hand in main phase of arm 6 2 x s; 2 x d (^); 2 x d (v)
Horizontal path of hand in main phase of arm 6 2 x s; 3 x d (^); 1 x d (v)
Horizontal path of hand during arm stroke 5 1 x s; 3 x d (^); 1 x d (v)
Horizontal path of hip during leg stroke 5 2 x f; 1 x d (^); 2 x d (v)
Duration of propulsion-pause between main
phase of arm and main phase of leg 8 2 x s; 2 x d (^); 4 x d (v)
Duration of propulsion-pause between main
phase of leg and main phase of arm 7 2 x f; 5 x d (^)
Angle of attack of hip-shoulder-water surface 5 1 x f; 4 x d (^)
Legend: s-increasing, f-decreasing, d-discontinuous (^)=direction
From the time-continuous point of view individual time series
patterns were observed in arm and leg movements. Figure 2
shows examples of an arm-swimmer (left) and leg-swimmer
(right). It was also possible to distinguish so called “changeswimmers”
(4) with differing propulsion of the arms and legs.
Only one patient actually demonstrated an ideal velocity-timeregime
of the hip according to Costill et al. (3) or Schramm
(10). In total a marked divergent regime in horizontal hipvelocity
was observed in this population: 12 arm-swimmers, 4
leg-swimmers and 10 change-swimmers.
The calculated PSQ describes some problems of these patients to
react to increased load conditions. Six patients showed significant
changes of PSQ of the arms. The other 20 patients did not
change time-continuous characteristics with increasing loads.
The calculated PSQ-values of the legs changed significantly in 10
patients whereas 16 patients showed no adaptation during the
step-test. As an example figure 3 shows the inter-individual
adaptation of the development of PSQ of the arms and legs.
Figure 2. Breaststroke arm-swimmer (left) and leg-swimmer (right).
Figure 3. Two examples of the development of PSQ of the arm (PSQ A)
and leg (PSQ B). Significant differences between load steps (*p ≤ .05,
**p ≤ .01) are indicated.

As a result of factor analysis 4 factor-components of relevance
provide indications for organizing swim rehabilitation programs
with a special view to movement co-ordination. Table 2
gives on overview of the specific movement parameters of each
relevant factor-component. The variance of the factor-components
are: 30% for time-structure, 18% for velocity-regime,
10% posture of upper part of the body, 8% for angle of attack
of thigh. The verification of reliability of the factors showned
good internal consistencies (Cronbachs Alpha from .62 to .89).
All main items may be evaluated as strong to very strong
regarding selectivity and being greater than the limiting value
of .4 (.55-.99).
Table 2. Loading of main items of each factor-component .
Factor: time-structure Factor-load
duration of leg movement .93
duration of arm movement .92
movement frequency of the legs .92
movement frequency of the arms .92
duration of propulsion-pause between main
phase of the arms and main phase of the legs .87
duration of propulsion-pause between main
phase of the legs and main phase of the arms .78
Factor: velocity parameters Factor-load
mean velocity of the hip in main phase of the arms .92
maximum velocity of the hip during arm stroke .91
maximum velocity of the hip during leg stroke .90
maximum velocity of the foot during leg stroke .74
Factor: posture of upper part of the body Factor-load
angle of attack of hip-shoulder-water surface
during to start main phase of the legs .96
angle of attack of hip-shoulder-water surface
at the end of main phase of the arms .94
angle of attack of hip-shoulder-water surface
at the end of main phase of the legs .89
angle of attack of hip-shoulder-water surface
during to start main phase of the arms .88
Factor: angle of attack of thigh Factor-load
angle of attack of thigh at the end of main
phase of the legs .84
angle of attack of thigh during start of main
phase of the legs .81
angle of attack of thigh-water surface during start
of main phase of the legs .69
angle of attack of thigh-water surface at the end
of main phase of the legs .65
DISCUSSION
Based on kinematic analysis of time-discrete parameters during
breaststroke in patients with CAD the movement path of the
arms and legs and of the hip, the duration of pause between
the movements of the extremities and the angle of attack of
hip-shoulder-water surface are of crucial importance to forward
speed. These findings are supported by the findings of factor
analysis where comparable parameters were found to be of relevance.
Results indicated large individual variations in timecontinuous
characteristics. The PSQ as a good predictor for
load specific adaptations related to movement co-ordination.
When compared to the findings on healthy volunteer’s from
Blaser (1) or for elite swimmer by Witte (13) different values
were observed. The values in CAD-patients are usually larger
ADAPTED SWIMMING SPORTS AND REHABILITATION
with no differences between arms and legs. Therefore the
majority of CAD-patients are not able to react to increasing
loads adequately. Patients who were not able to change the
PSQ-values under increasing external loads might be increasing
their cardiac stress. The movement patterns of CAD-patients
react in diverse ways to increased loads. Based on these findings
the importance of movement analysis in swimming of
CAD-patients was underlined in order to guarantee an adapted
sport-specific rehabilitation program as an additional way to
control the load-stress situation and to develop movement
skills.
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