cardiovascular responses to isometric contraction in young and elderly individuals
TRANSCRIPT
- - I
CARDIOVASCULAR RESPONSES TO ISOMETRIC CONTRACTION IN YOUNG AND ELDERLY INDIVIDUALS -
A QUASI-EXPERIMENTAL STUDY
BY
Mr. RAVISH .S. TAORI
Dissertation submitted to Rajiv Gandhi University of Health Sciences,
Bangalore, Karnataka
In partial fulfilment of the requirement of the degree of
MASTER OF PHYSIOTHERAPY (MPT)
In
PHYSIOTHERAPY IN CARDIO-RESPIRATORY DISORDERS
AND
INTENSIVE CARE
Under the guidance of
Mr. K. RAJMOHAN, M.P.T. (CARDIO RESPIRATORY)
Department of Cardio Respiratory Physiotherapy
KRUPANIDHI COLLEGE OF PHYSIOTHERAPY
BANGALORE
2010
- - II
Rajiv Gandhi University of Health Sciences Bangalore, Karnataka
DECLARATION BY THE CANDIDATE
I hereby declare that this thesis entitled
“CARDIOVASCULAR RESPONSES TO ISOMETRIC
CONTRACTION IN YOUNG AND ELDERLY INDIVIDUALS -
A QUASI-EXPERIMENTAL STUDY”
is a bonafide and genuine research work carried out under the guidance of
Mr. K. RAJMOHAN MPT, Associate Professor Krupanidhi College of
Physiotherapy, Bangalore.
Date: Signature of the candidate
Place: Bangalore Mr. RAVISH .S. TAORI
- - III
CERTIFICATE BY THE GUIDE
THIS IS TO CERTIFY THAT THE DISSERTATION ENTITLED
“CARDIOVASCULAR RESPONSES TO ISOMETRIC
CONTRACTION IN YOUNG AND ELDERLY INDIVIDUALS -
A QUASI-EXPERIMENTAL STUDY”
IS A BONAFIDE RESEARCH WORK DONE BY Mr. RAVISH .S. TAORI
IN PARTIAL FULFILMENT OF THE REQUIREMENT OF THE
DEGREE OF MASTER OF PHYSIOTHERAPY
Mr. K. RAJMOHAN
ASSOCIATE PROFESSOR
H.O.D.Department of Cardiopulmonary
Place: Bangalore Krupanidhi College of Physiotherapy
Date: Bangalore-560037
- - IV
ENDORSEMENT BY PRINCIPAL/HOD OF THE INSTITUTION
THIS IS TO CERTIFY THAT THE DISSERTATION ENTITLED
“CARDIOVASCULAR RESPONSES TO ISOMETRIC
CONTRACTION IN YOUNG AND ELDERLY INDIVIDUALS -
A QUASI-EXPERIMENTAL STUDY”
a bonafide research work done by Mr. RAVISH .S. TAORI
under the guidance of MR. K. RAJMOHAN, ASSOCIATE
PROFESSOR, KRUPANIDHI COLLEGE OF PHYSIOTHERAPY,
BANGALORE.
Seal & Signature of H.O.D. Seal & Signature of PRINCIPAL
Mr. K. RAJMOHAN Mr. Masih Muhammad Khan.
Date: Date:
Place: Bangalore Place: Bangalore
- - V
COPYRIGHT
DECLARATION BY THE CANDIDATE
I hereby declare that the Rajiv Gandhi University of Health
Sciences, Bangalore, Karnataka shall have the rights to preserve, use and
disseminate this dissertation/thesis in print or electronic format for
academic/research purposes.
Date: (Signature of the Candidate)
Place: Mr. RAVISH .S. TAORI
© Rajiv Gandhi University of Health Sciences, Karnataka.
- - VI
ACKNOWLEDGEMENT
My knowledge has been enriched throughout the process of this study. I would
like to acknowledge all those well wishers who have guided me at every juncture and
have offered me their help and support whenever needed to help me complete my
project.
I would like to express my heartfelt wishes to my parents who have ever been
so instrumental in building the confidence in me and for their blessings and support
all throughout.
With due respect, I would like to thank Prof. Suresh Nagpal, Chairman and
Mr. Masih Muhammad Khan, Principal, Krupanidhi College of Physiotherapy for
giving me the freedom to access and make use of the facilities of the college and their
valuable guidance in course of this project.
I would like to take the honour to thank my guide Mr. K. Rajmohan,MPT,
Associate professor, HOD, Department of Cardiopulmonary, Krupanidhi college of
Physiotherapy, Bangalore, for his constant support and guidance throughout this
journey. His interest in the project from day one has been a great source of
inspiration and his continued encouragement all through the process has been a great
pillar of strength to help me complete my project.
I am grateful to all my lecturers for their support and encouragement
all throughout.
I express my heartfelt thanks to all my subjects who have been ever so
patient with me till completion of this study.
- - VII
I would also like to thank Prof. Gangaboriah, Dept of Bio-Statistics, KIMS
College for helping me with the necessary statistical analyses and calculations.
Finally, I thank God for completion of this study and for his presence
and guidance at every step in life.
Date: Signature of the candidate
Place: Bangalore. Mr. RAVISH .S. TAORI
- - VIII
LIST OF ABBREVIATION USED
BP : BLOOD PRESSURE
CVS : CARDIOVASCULAR SYSTEM
DBP : DIASTOLIC BLOOD PRESSURE
HR : HEART RATE
MVC : MAXIMUM VOLUNTARY CONTRACTION
SBP : SYSTOLIC BLOOD PRESSURE
WHO : WORLD HEALTH ORGANIZATION
- - IX
ABSTRACT
Background and objectives: Activities that produce static or isometric muscular
contractions are common in many aspects of everyday life. Cardiac aging alters many
of the acute response to exercise stress, but the extent to which submaximal isometric
exercise or training can alter or improve the effects of aging in humans is unclear.
Thus, objective of this study was to examine the cardiovascular responses to isometric
contraction in young and elderly individuals. Method: 40 male subjects with age
group 20-30years and 60-70years satisfying the inclusion criteria were selected and
divided into two groups namely young and elderly group respectively. Resting HR
and BP were recorded followed by HR and BP responses to isometric exercise in both
the groups were assessed. Isometric contraction was held till 60seconds using the
hand held dynamometer at 40% of the maximal voluntary contraction (MVC). Pre and
post HR and BP were compared. Results: The older subjects had a lower heart rate
and a higher blood pressure response than their younger counterparts. Interpretation
and conclusion: The result indicates that increasing age is associated with an altered
heart rate and blood pressure response to isometric exercise.
Key words: Isometric contraction, cardiovascular aging
- - X
TABLE OF CONTENTS
Serial No.
Title
Page no.
1
2
3
4
5
6
7
8
9
10
INTRODUCTION
OBJECTIVES
REVIEW OF LITERATURE
METHODOLOGY
RESULTS
DISCUSSIONS
CONCLUSION
SUMMARY
BIBLIOGRAPHY
ANNEXURES
1
9
11
20
28
35
39
40
41
46
- - XI
LIST OF TABLES
Serial No.
Title
Page no.
1
2
3
4
5
6
MEAN OF PRE AND POST SYSTOLIC BLOOD
PRESSURE IN YOUNG AND ELDERLY
INDIVIDUALS
TO COMPARE THE SYSTOLIC BLOOD
PRESSURE BETWEEN YOUNG AND
ELDERLY SUBJECTS
MEAN OF PRE AND POST DIASTOLIC
BLOOD PRESSURE IN YOUNG AND
ELDERLY INDIVIDUALS
TO COMPARE THE DIASTOLIC BLOOD
PRESSURE BETWEEN YOUNG AND
ELDERLY SUBJECTS
MEAN OF PRE AND POST HEART RATE IN
YOUNG AND ELDERLY INDIVIDUALS
TO COMPARE THE HEART RATE BETWEEN
YOUNG AND ELDERLY SUBJECTS
29
29
31
31
33
33
- - XII
LIST OF ILLUSTRATIONS
Serial No.
Title
Page no.
1
2
3
4
5
6
7
8
9
CARDIOVASCULAR SYSTEM
HEART RATE MONITOR
SPHYGMOMANOMETER AND
STETHOSCOPE
MANUAL HAND HELD DYNAMOMETER
SUBJECT PERFORMING ISOMETRIC
CONTRACTION
SUBJECT PERFORMING ISOMETRIC
CONTRACTION
GRAPH REPRESENTING PRE AND POST SBP
OF YOUNG AND ELDERLY INDIVIDUALS
GRAPH REPRESENTING PRE AND POST DBP
OF YOUNG AND ELDERLY INDIVIDUALS
GRAPH REPRESENTING PRE AND POST HR
OF YOUNG AND ELDERLY INDIVIDUALS
1
23
24
25
27
27
30
32
34
- - 1
INTRODUCTION The cardiovascular system is continuous vascular circuits that consists of a
pump, a high pressure distribution circuit, exchange vessels and a low-pressure
collection and return circuit.01 It consist of a heart, arteries, capillaries and veins. The
cardiovascular system serves to integrate the body as a unit and provides the muscles
with a continuous stream of nutrients and oxygen so that high-energy output can be
maintained for a considerable time period. Conversely, by-products of metabolism are
rapidly removed from the site of energy release.
FIG.1: CARDIOVASCULAR SYSTEM
- - 2
With modernization and changes in lifestyle, cardiovascular system is more severally
affected. Cardiovascular disease is the world's leading killer, accounting for 16.7
million or 29.2 per cent of total global deaths in 2003. In India in the past five
decades, rates of coronary disease among urban populations have risen from 4 per
cent to 11 per cent. The World Health Organization (who) estimates that 60 per cent
of the world's cardiac patients will be Indian by 2010.02 The American Heart
Association (AHA) considers ischemic (coronary) heart diseases, hypertensive
diseases, rheumatic fever/rheumatic heart diseases and cerebrovascular diseases
(stroke) to be major cardiovascular diseases. The WHO estimates that by 2020
cardiovascular diseases will account for up to 40% of all deaths worldwide.03 Looking
forward to this upcoming problem, cardiac rehabilitation has gain its importance.
The WHO has defined cardiac rehabilitation as the sum of activity
required to ensure cardiac patients the best possible physical, mental and social
condition so that they may by there own efforts regain as normal as possible a place in
the community and lead an active life.04 Cardiac rehabilitation is a medically
supervised exercise and counselling program designed to help overcome some of the
physical complications of heart disease, limit the risk of developing additional heart
trouble, help a person return to an active social or work schedule, and improve the
psychological well-being. It has four main components: Medical evaluation,
supervised exercise, lifestyle education and psychosocial support. Exercise does
remain a key component of rehabilitation. With onset of exercise, blood is directed
away from less essential areas of the body and redirected to the working muscles.
This is accomplished by a complex set of acute changes within cardiovascular system
that are controlled by cardiovascular centre in brain.05 Various chemical, neural, and
- - 3
hormonal adjustments takes place prior to and during exercise. At the onset of
exercise, cardiovascular changes are initiated from nerve centres above the medullary
region. These adjustments significantly increase the rate and pumping strength of the
heart, as well as predictable alterations in regional blood flow that are proportional to
exercise severity.01 Exercise that employs the larger muscle mass and greater relative
strain elicits the greater response.06
In the 1950s isometrics were popularised as an effective and efficient
means of developing strength. Hislop and Perrine (1967) described isometric exercise
as muscular contractions against a load which is fixed or immovable or is simply too
much to overcome. Isometric exercise can increase blood pressure and heart rate to
levels that would be dangerous for anyone with undiagnosed cardiac problems (Nagle,
Seals and Hanson 1988, White and Carrington 1993 and Baum et al. 1995). Because
of the characteristic cardiovascular responses, isometrics and other resistance
exercises are generally not recommended for some patient populations, i.e.,
individuals with hypertension, patients with heart failure, etc. However, over the last
decade, the value of resistance exercise training for maintaining normal
cardiovascular functioning in older adults and some patient groups has been
recognized. 07 Isometric exercise produces a characteristic pressor increase in blood
pressure, which may be important in maintaining perfusion of muscle during
sustained contraction. This response is mediated by combined central and peripheral
afferent input to medullary cardiovascular centres. In normal individuals the increase
in blood pressure is mediated by a rise in cardiac output with little or no change in
systemic vascular resistance.08
- - 4
The central cardiac and hemodynamic responses to resistance exercise
are different than those seen with endurance exercise. As opposed to the volume
overload imposed on the heart by endurance exercise, resistance (i.e., dynamic or
static) exercise imposes a pressure overload. Accordingly, this form of exercise is
characterized by a disproportional increase in heart rate (HR) and blood pressure (BP)
for a given metabolic rate (i.e., VO2). 06 The cardiovascular response to static
exercises are well established and includes increase in blood pressure and heart rate.09-
11 During isometric, peak systolic and diastolic blood pressures mirror the
hypertensive state and may pose a risk to individuals who have existing hypertension.
Regular training can blunt hypertensive response.01
With aging there are changes in the cardiovascular system, which result in
alterations in cardiovascular physiology. The changes with age occur in everyone but
not necessarily at the same rate, therefore accounting for the difference seen in some
people between chronologic age and physiologic age. The changes in the
cardiovascular system associated with aging are a decrease in elasticity and an
increase in stiffness of the arterial system. This results in increased afterload on the
left ventricle, an increase in systolic blood pressure, and left ventricular hypertrophy,
as well as other changes in the left ventricular wall that prolong relaxation of the left
ventricle in diastole. There is a dropout of atrial pacemaker cells resulting in a
decrease in intrinsic heart rate. 12-13. The age-associated decline in cardiovascular
performance is more apparent during stress than at rest. The hallmarks of
cardiovascular aging are reduced maximal heart rate, ejection fraction, and, in most
studies, reduced maximal cardiac output with exercise, 14-20increased blood pressure
during exercise21, and an increase in isometric endurance22 The status of physical
- - 5
conditioning of the individual can radically affect the measurements of cardiovascular
function in the elderly and changes in physical activity can profoundly change
cardiovascular function.06
- - 6
NEED FOR STUDY:
Due to the large isometric component involved in daily tasks, it is important to
understand the cardiovascular responses to isometric exercises. This understanding
has implications for aging populations and for cardiac rehabilitation programs where
isometric exercises have often been discouraged due to potentially hazardous effects
on the cardiovascular system However, over the last decade, the value of resistance
exercise training for maintaining normal cardiovascular functioning in older adults
and some patient groups has been recognized. But controversies are still there.
Several researchers have described the relationship between intensity
of isometric contraction and cardiovascular responses, but previous studies on the
relationship of age to isometric contraction and cardiovascular responses are few.23
Therefore, the purpose of this study is to determine the comparative effects of
isometric contraction in young and elderly normal individuals.
- - 7
STATEMENT OF THE STUDY
In the present study an endeavour was made to know effects of isometric contraction
in young and elderly normal individuals. Thus the problem for the present study is
stated as – WEATHER ISOMETRIC EXERSISE CAN BE INCLUDED IN
ELDERLY NORMAL INDIVIDUALS FITNESS AND CARDIAC
REHABILITATION PROGRAMME.
- - 8
OPERATIONAL DEFINITIONS
For the purpose of this study the key terms are defined as follows:
• Isometric contraction: These are muscular contractions against a load which
is fixed or immovable or is simply too much to overcome. Thus there is no
visible change in joint angle.
• Blood pressure (BP): It is the lateral pressure exerted by blood on the vessels
walls while flowing through it. Systolic blood pressure (SBP) is the
maximum pressure during systole. Diastolic blood pressure (DBP) is the
minimum pressure during diastole.
• Heart rate (HR): Heart rate is the number of times per minute that the heart
contracts - the number of heart beats per minute (bpm).
- - 9
OBJECTIVES
• To study heart rate and blood pressure responses, to isometric
contraction in young normal individuals.
• To study heart rate and blood pressure responses, to isometric
contraction in elderly normal individuals.
.
• To compare the heart rate and blood pressure responses, to isometric
contraction in young and elderly normal individuals.
- - 10
HYPOTHESIS
NULL HYPOTHESIS:
• There is no significant difference in heart rate response to isometric
contraction in young and elderly normal individuals.
• There is no significant difference in blood pressure response to
isometric contraction in young and elderly normal individuals.
EXPERIMENTAL HYPOTHESIS:
• There is significant difference in heart rate response to isometric
contraction in young and elderly normal individuals.
• There is significant difference in blood pressure response to isometric
contraction in young and elderly normal individuals.
- - 11
REVIEW OF LITERATURE
Daniel W. Jones; Lawrence J. Appel ; Sheldon G. Sheps; Edward J. Roccella,;
Claude Lenfant (2003) 24 said for more than 100 years, clinicians and researchers
have used the mercury sphygmomanometer, a simple, gravity-based instrument, for
blood pressure measurement. Because of its accuracy and reliability, the mercury
sphygmomanometer is generally regarded as the gold standard against which all other
devices for blood pressure measurement should be compared.
Virgil Mathiowetz (2002)25 compared the Jamar and Rolyan hydraulic
dynamometers to determine their concurrent validity with known weights as well as
their inter-instrument reliability and concurrent validity for measuring grip strength in
a clinical setting. Results showed that the Jamar and Rolyan dynamometers have
acceptable concurrent validity with known weights (that is, correlation coefficients
were r ≥0.9994), excellent inter-instrument reliability (that is, intraclass correlation
coefficients ranged from 0.90 to 0.97) and strong concurrent validity (that is, no
significant differences between dynamometers' scores). Data indicate that Jamar and
Rolyan dynamometers measure grip strength equivalently and can be used
interchangeably.
. Gervasoni JP, Bovet P, Rwebogora A, Mkamba M, Paccaud F (2001) 26 assessed
systematic difference in blood pressure (BP) readings measured with a mercury
sphygmomanometer (MS) and electronic sphygmomanometers and found that BP
readings were systematically lower with electronic sphygmomanometers than with a
mercury sphygmomanometer and differences tended to vary according to arm size and
- - 12
BP. These findings have important relevance as automatic devices are useincreasingly
often and considering that currently available data and recommendations on BP are
mainly based on readings with mercury sphygmomanometer.
Goodie, Jeffrey L.; Larkin, Kevin T.; Schauss, Scott (2000) 27 examined the
validity of the Polar monitor for measuring heart rate. The Polar heart rate monitor
provides an ambulatory, inexpensive method of continuously measuring heart rate.
Heart rates were measured simultaneously using the Polar monitor and
electrocardiography (ECG) during a hand grip exercise . The correspondence between
observed mean heart rates from the Polar monitor and ECG suggest that the Polar
monitor provides a valid measure of heart rate during stationary laboratory tasks.
Boutcher S. H.;Stocker D.(1999)28 did study to compare the cardiovascular response
of young and older males during light handgrip isometric exercise. Blood pressure,
heart rate, rate pressure product, as well as pre-ejection period (derived from
impedance cardiography) were obtained for 15 young [mean (SE) age: 21 (0.7) years]
and 15 older males [59 (0.8) years] during and after light handgrip exercise. The
parasympathetic influence on the heart was also assessed through a time-series
analysis of heart period variability (HPVts). Both during and when recovering from
the handgrip exercise, the older subjects exhibited a significantly higher absolute
systolic and diastolic blood pressure, and rate pressure product, and a lower HRVts
than the young subjects. Relative to baseline, the change in pre-ejection period was
lower for the young subjects during the handgrip tasks. These results indicate that
although the sympathetic influence on both the myocardium and the vasculature was
- - 13
less pronounced in the older males, the aging cardiovasculature was under greater
hemodynamic stress both during rest and during exposure to light isometric challenge.
Smolander J, Aminoff T, Korhonen I, Tervo M, Shen N, Korhonen O,
Louhevaara V (1998) 29 did a study to examine the isometric endurance response and
the heart rate and blood pressure responses to isometric exercise in two muscle groups
in ten young (age 23-29 years) and seven older (age 54-59 years) physically active
men with similar estimated forearm and thigh muscle masses. Isometric contractions
were held until fatigue using the finger flexor muscles (handgrip) and with the
quadriceps muscle (one-legged knee extension) at 20%, 40%, and 60% of the
maximal voluntary contraction (MVC). Heart rate and arterial pressure were related to
the individual's contraction times. The isometric endurance response was longer with
handgrip than with one-legged knee extension, but no significant difference was
observed between the age groups. The isometric endurance response averaged 542
(SEM 57), 153 (SEM 14), and 59 (SEM 5) s for the handgrip, and 276 (SEM 35), 94
(SEM 10) and 48 (SEM 5) s for the knee extension at the three MVC levels,
respectively. Heart rate and blood pressure became higher during one-legged knee
extension than during handgrip, and with increasing level of contraction. The older
subjects had a lower heart rate and a higher blood pressure response than their
younger counterparts, and the differences were more apparent at a higher force level.
The results would indicate that increasing age is associated with an altered heart rate
and blood pressure response to isometric exercise although it does not affect isometric
endurance.
- - 14
R. Laukkanen and P. Virtanen. (1998) 30 Lightweight telemetric heart rate monitors
equipped with conventional electrodes have been proved to be accurate and valid
tools for heart rate monitoring and registering in field measurements. Polar Heart Rate
Monitors and their measurement accuracy compared to Holter ECG devices at rest
and during exercise.
John R. Stratton; Wayne C. Levy; Manuel D. Cerqueira; Robert S. Schwartz;
Itamar B. Abrass (1994) 31 conclude that there is an age-associated decline in heart
rate, ejection fraction, and cardiac output responses to exercise in healthy men.
Although the stroke volume responses of the young and old are similar, the old tend to
augment stroke volume during exercise more through cardiac dilatation, with an
increase in end-diastolic volume (+8%) but without much change in ejection fraction
(+3 ejection fraction units), whereas the young rely more on an increase in the
ejection fraction (+11 ejection fraction units) with no cardiac dilatation (-10%).
Despite the significant cardiovascular changes that occur in the response to a single
bout of exercise with aging, adaptations to chronic exercise training were not different
with aging and included improvements in maximal workload and increases in ejection
fraction, stroke volume index, and cardiac index at peak exercise.
Taylor and colleagues (1991) 32 did a study on 14 younger (26 ±1.0 years) and 14
older (66 ±1.0 years) healthy males perform a 30% maximal voluntary contraction
(MVC) isometric handgrip exercise to the point of exhaustion (inability to maintain
target force). MVC for the younger (402 ± 20 N) and older (392 ± 20 N) subjects was
similar, as was time to exhaustion (315 ± 27 seconds in younger vs. 339 ± 17 seconds
in older men). During the sustained trial, electromyography activity and ratings of
- - 15
perceived exertion were similar between groups, indicating comparable voluntary
efforts. HR rose above baseline within the first 20% of the exercise duration and
continued to increase (p < 0.05) throughout the handgrip in both groups. However, at
every point during the exercise, the absolute level of HR was lower and the magnitude
of the increase from control was less (p <0.05) in the older subjects. Taylor et al. also
reported no differences in BP responses between younger and older men while they
were executing isometric handgrip exercises to the point of fatigue.
S.C. Gandevia and S.F.Hobbs (1990) 33 concluded in there study that Blood pressure
and heart rate increased progressively during isometric contraction of 33 and 50%
maximal voluntary strength (for 120 and 75 s respectively).
Van Loan et al. (1989) 34 compared 24 younger (23.7 ±3.8 years) and 24 older (57.8
± 5.6 years) males performing small muscle (finger flexor) and large muscle (leg
extensor) isometric muscle contractions (45-second duration) at 4 different intensities
(15, 30, 45, and 60% MVC). Results indicated that higher HR responses were found
during leg extension exercises at each increase in % MVC workload and in the
younger subjects (with both muscle groups) at all exercise levels. Van Loan et al. (51)
found a significant but modest increase in BP (10 mm Hg for SBP and 7 mm Hg for
DBP) between the younger and older subjects.
Sagiv M, Hanson P, Goldhammer E, Ben-Sira D, Rudoy J (1988) 35 Studied
echocardiographically cardiovascular responses in 10 young (23 +/- 3 years) and 10
elderly (67 +/- 4 years) men, during upright isometric handgrip and deadlift. During
handgrip and deadlift both groups showed significant increases in systolic and
- - 16
diastolic blood pressure. Those responses were significantly greater in both groups
during deadlift. Heart rate was significantly higher in both groups during deadlift than
resting and handgrip values. Oxygen uptake increased progressively and significantly
across conditions, and was significantly higher for the younger subjects. Ejection
fraction remained unchanged during handgrip in both groups. During deadlift it
remained unchanged in the elderly while it increased significantly in the younger.
Both groups increased significantly heart volumes from rest to handgrip. During
deadlift end systolic volume was significantly lower from resting and handgrip values
only in the young group. These data indicate a similar cardiovascular response to
acute pressure overload in both groups.
Seals DR, Hurley BF, Hagberg JM, Schultz J, Linder BJ, Natter L, Ehsani AA.
(1985) 36 did a study to determine whether regular exercise improves left ventricular
(LV) contractile function in persons 60 years and older, systolic time intervals (STIs)
were measured in 10 healthy men and women (mean age 62 +/- 1 year [+/- standard
deviation]) before and after 6 months of intense endurance training. STIs, systolic and
diastolic blood pressure (BP) and heart rate (HR) were determined at rest and in
response to isometric handgrip exercise. Systolic BP, diastolic BP and HR increased
acutely from rest in response to handgrip (p less than 0.002). After training, systolic
and diastolic BP were reduced at rest (p less than 0.002) and, along with HR, were
lower in response to handgrip (p less than 0.002). However, training did not alter STIs
at rest or during handgrip. These findings indicate that healthy persons in their 60s
have a normal LV response to isometric exercise. Prolonged, intense endurance
training does not alter LV contractile function at rest or in response to isometric
exercise. However, training can significantly reduce BP at rest, and markedly lower
- - 17
the HR-systolic BP product attained during acute isometric stress, even in
normotensive older subjects.
Camus G, Thys H, Pigeon G, Dreezen E(1982) 37 measured Blood pressure and
heart rate during static contraction of forearm muscles holding a tension of 30%
maximal voluntary strength for 5 mn. Eleven young men and eleven elderly male
subjects were used. Maximal voluntary strength is reduced by 19% in elderly subjects.
Relative mean cardio-vascular responses were unaffected by age.
J. S. Petrofsky and A. R. Lind (1975) 38 assessed the maximal handgrip strength, the
duration of a fatiguing handgrip contraction at a tension of 40% of maximal strength
and the heart rate and blood pressure during that contraction of 100 men aged from 22
to 62 yr. The subjects of this study were all men employed in a machine shop for a
large aircraft corporation. The homogeneity of their occupations may well explain
why, unlike previous reports, we found no change in muscular strength or muscular
endurance with age. However, although heart rate increased during the contraction in
all subjects, the increase in heart rate was greater in younger men. In contrast, while
both systolic and diastolic blood pressures increased during the contraction in all
subjects, the largest increase in systolic blood pressure was attained by the men in the
older decades; there was no difference due to age in the diastolic blood pressures.
Jerrold S. Petrofsky and Alexander R. Lind (1975) 39 did a study where
relationship of sex, age, and body fat content were assessed on the maximal voluntary
strength (MCV), The endurance of a sustained contraction held at. 40% of the
subject's maximal strength and the associated changes in blood pressure and hears
- - 18
rate. Heart rate, which always increased during exercise, attained its highest
magnitude during exercise in the subjects who had the highest resting heart rates.
However, older subjects displayed a smaller increase in exercising heart rates than
younger subjects. The blood pressure at the end of the 40%MVC was directly related
to the resting blood pressure. However, aging increased the resting systolic blood
pressure; this aging effect was further exaggerated during the exercise.
J. S. Petrofsky and A. R. Lind. (1975) 40 has done a study to find out relationship of
sex, age, and body fat content on the maximal voluntary strength (MVC), the
endurance of a sustained contraction held at 40% of the subject's maximal strength,
and the associated changes in blood pressure and heart rate. Isometric handgrip
strength was, as expected, greater in men than in women; however, in both sexes, age
was inversely related to isometric strength, particularly in women. Body fat content,
however, was directly related to strength. In contrast, in both male and female
subjects aging was directly related to isometric endurance while body fat content was
now inversely related to isometric endurance. The increase in heart rate throughout a
fatiguing contraction at 40% MVC was strikingly similar in men and women. Heart
rate, which always increased during exercise, attained its highest magnitude during
exercise in the subjects who had the highest resting heart rates. However, older
subjects displayed a smaller increase in exercising heart rates than younger subjects.
The blood pressure at the end of the 40% MVC was directly related to the resting
blood pressure. However, aging and body fat content both increased the resting
systolic blood pressure in men and women; this aging effect was further exaggerated
during the exercise.
- - 19
Mcdermott, D.J., W.J. Stekiel, J.J. Barboriak, L.C.Kloth, and J.J. Smith (1974)41
did comparative investigation of 10 younger (25.3 ± 1.3 years) and 12 middle-aged
(46.8 ±0.8 years) men who performed 5-minute static forearm contractions at 33%
MVC demonstrated a comparable (but not a significant) HR. HR increased linearly
from mean resting values of 58.3 ± 1.9 bpm in the older group and 57.3 ± 3.6 bpm in
the younger group to 89.6 ± 4.9 bpm and 95.7 ± 5.5 bpm, respectively, at the fifth
minute of the contraction. McDermott et al. measured BP by auscultation each
minute during 5 minutes of isometric handgrip contraction at 33% MVC, observing
progressive increases from control levels (younger 5 128/83 mm Hg; older 5 117/87
mm Hg) to a peak level of 191/142 mm Hg and 191/137 mm Hg in younger and older
subjects, respectively.
- - 20
METHODOLOGY
POPULATION OF THE STUDY
40 subjects which includes normal males.
RESEARCH DESIGN
Quasi-Experimental study
SOURCE OF DATA
Subjects from Krupanidhi group of colleges, Bangalore and old age homes,
Bangalore.
SAMPLING TECHNIQUE
Purposive Sampling.
SAMPLE SIZE
Total 40 subjects were studied, randomly divided as 20 each into two groups.
The study groups were namely
Group 1: 20 subjects with young age group 20-30 years
Group 2: 20 subjects with elderly age group 60-70 years
- - 21
STUDY DURATIION
One time study
SAMPLING CRITERIA:
Inclusion criteria
• Age group: 20-30 and 60-70 years.
• Subjects should be males.
• All subjects should be normotensive.
Exclusion criteria
• Subjects with chronic history of alcohol and smoking.
• Subjects with resting tachycardia (> 120 beats per min).
• Subjects with hypertension.
• Subjects with history of any other cardiovascular disorder
• Subjects with any peripheral vascular disease.
• Subjects should not be on any regular exercise program.
• Un-cooperative subjects.
- - 22
MATERIALS USED
• Hand held dynamometer
• Stop watch
• Chair
• Table
• Towel
Measurement tools:
• Mercury sphygmomanometer
• Stethoscope
• Heart rate monitor
DESCRIPTION OF TOOLS:
Heart rate monitor: A heart rate monitor is a device that allows a user to measure
their heart rate in real time. It usually consists of two elements: a chest strap
transmitter and a wrist receiver (which usually doubles as a watch).
The chest strap has electrodes in contact with the skin to monitor the electrical
voltages in the heart. When a heartbeat is detected a radio signal is transmitted,
which the receiver uses to determine the current heart rate. This signal can be a
simple radio pulse or a unique coded signal from the chest strap; the latter prevents
one user's receiver from using signals from other nearby transmitters (known as
cross-talk interference).
- - 23
There are a wide number of receiver designs, with all sorts of advanced features.
These include average heart rate over exercise period, time in a specific heart rate
zone, calories burned etc.
FIG.2: HEART RATE MONITOR: Chest strap transmitter and a
wrist receiver
Sphygmomanometer: A sphygmomanometer or blood pressure meter is a device
used to measure blood pressure comprising an inflatable cuff to restrict blood flow,
and a mercury or mechanical manometer to measure the pressure. Manual
sphygmomanometers are used in conjunction with a stethoscope. An arterial blood
pressure reading consists of two numbers, which typically may be recorded as x/y.
The x is the systolic pressure, and y is the diastolic pressure. Systole refers to the
contraction of the ventricles of the heart, when blood is forced from the heart into the
pulmonary and systemic arterial circulation, and diastole refers to the resting period.
- - 24
FIG.3: SPHYGMOMANOMETER AND STETHOSCOPE
Hand held dynamometer: Is an instrument for measuring the force of muscular
contraction. It measures the gross grip strength of the hand muscles. Also called
ergometer. The device features an adjustable handle with five positions to
accommodate any hand size. The indicator remains at the individual's maximum
reading until reset. The device registers up to 200 pounds.
- - 25
FIG.4: HAND HELD DYNAMOMETER
- - 26
PROCEDURE:
• Based on selection criteria, 40 subjects were selected from the population.
• The subjects were allocated into two groups with 20 subjects each, namely
experimental group one and experimental group two with purposive
sampling.
• Both the experimental group1 and group2, which received isometric exercise
for forearm
• A written consent has been cleared with subjects after receiving full details of
the protocol.
• Pre-test evaluation was done for heart rate and blood pressure and the results
were recorded.
• Isometric contraction was performed by a hand-held dynamometer in the
seated position with trunk supported, with the arm at approximately 30o of
abduction, with the elbow flexed 90 rested on the arm rest of the chair and
the wrist rested on rolled towel 8 cm in diameter. The forearm was in neutral
pronation/supination
• Subjects underwent several preliminary session during which they were
taught and carefully trained to perform maximum voluntary contraction
(MVC) of forearm. MVC was determined as the highest force developed by
the subject in previous 5-seconds maximal contraction trials.
• Subjects were instructed to breathe normally and avoid holding breath.
• Each subject gripped hand dynamometer at 40% (MVC) with the dominant
hand for 60 seconds.
• Post exercise Heart rate and blood pressure were taken and recorded.
- - 27
FIG.5 AND FIG.6: SUBJECTS PERFORMING ISOMETRIC
CONTRACTION.
- - 28
RESULTS AND DATA ANALYSIS
This chapter deals with the most important and crucial aspect of investigating
the data to answer the data through suitable statistical treatment. Analysis means a
critical examination of the assembled and grouped data for studying the
characteristics of the object under study and for determining the patterns of
relationships among the variables relating to it.
Samples of 40 individualscomprising of both young and elderly subjects were
selected. Subjects were made to perform the isometric exercise with hand held
dynamometer for period of 1 min. Heart rate and blood pressure were measured.
Emphasis has been given to the examination of data where various appropriate
analytical techniques have been used to synthesize the research data. The data were
put into suitable statistical techniques. Data collected during the study was analyzed
using appropriate statistical tests and results are given in terms of test material, figures
and tables in the subsequent pages.
The Statistical software namely SPSS 11.0, was used for the analysis of data
.
STATISTICAL ANALYSIS
The results obtained were analyzed statistically by using the following test:
• Paired‘t’ test- used for the comparison of pre and post values of heart rate and
blood pressure within the group.
• Unpaired‘t’ test used.
- - 29
TABLE 1: MEAN OF PRE AND POST SYSTOLIC BLOOD PRESSURE IN
YOUNG AND ELDERLY INDIVIDUALS
GROUP MEAN SD t-value p-value
YOUNG PRE SBP
POST SBP
121.40
127.10
5.80
6.34
10.40
p<0.01
ELDERLY PRE SBP
POST SBP
132.50
143.60
4.19
7.06
9.60 p<0.01
In the study it is observed that the Mean ± SD of PRE SBP of the young group during
Pre test is 121.40± 5.80 and during Post test is 127.10±6.34.In elderly subjects, mean
PRE SBP was 132.50±4.19 and in post test it was 143.60±7.06. The t-test shows that
there is high significant increase in SBP among young and elderly subject as p<0.01
for both the groups.
TABLE 2: TO COMPARE THE SYSTOLIC BLOOD PRESSURE BETWEEN
YOUNG AND ELDERLY SUBJECTS
GROUP MEAN SD t-value p-value
Diff. SBP YOUNG
ELDERLY
5.70
11.10
2.452
5.17
4.221 p<0.01
The result shows that the mean change in SBP among young was 5.7±2.4 that of
elderly was 11.1±5.1 this difference is significantly higher in elderly compare to
young subjects as p< 0.01.
- - 30
GRAPH 1: TO COMPARE THE SYSTOLIC BLOOD PRESSURE BETWEEN
YOUNG AND ELDERLY SUBJECTS
- - 31
TABLE 3: MEAN OF PRE AND POST DIASTOLIC BLOOD PRESSURE IN
YOUNG AND ELDERLY INDIVIDUALS
GROUP MEAN SD t-value p-value
YOUNG PRE DBP
POST DBP
77.50
79.80
4.39
4.15
6.33 p<0.01
ELDERLY PRE DBP
POST DBP
83.90
89.40
3.81
4.40
7.76 p<0.01
In the study it is observed that the Mean ± SD of PRE DBP of the young group during
Pre test is 77.50± 4.39 and during Post test is 79.80±4.15.In elderly subjects, mean
PRE DBP was 83.9±3.8, and in post test it was 89.4±4.40. The t-test shows that there
is high significant increase in DBP among young and elderly subject as p<0.01 for
both the groups.
TABLE 4: TO COMPARE THE DISTOLIC BLOOD PRESSURE BETWEEN
YOUNG AND ELDERLY SUBJECTS
GROUP MEAN SD t-value p-value
Diff. DBP YOUNG
ELDERLY
2.30
5.50
1.62
3.17
4.017 P<0.01
The result shows that the mean change in DBP among young was 2.3±1.6 that of
elderly was 5.5±3.1 this difference is significantly higher in elderly compare to young
subjects as p< 0.01.
- - 32
GRAPH 2: TO COMPARE THE DIASTOLIC BLOOD PRESSURE
BETWEEN YOUNG AND ELDERLY SUBJECTS.
- - 33
TABLE 5: MEAN OF PRE AND POST HEART RATE IN YOUNG AND
ELDERLY INDIVIDUALS
GROUP MEAN SD t-value p-value
YOUNG PRE HR
POST HR
75.50
85.25
5.32
7.19
15.04 p<0.01
ELDERLY PRE HR
POST HR
74.65
82.55
4.38
5.02
28.21 p<0.01
In the study it is observed that the Mean ± SD of PRE HR of the young group during
Pre test is 75.5±5.3 and during Post-test is 85.2±7.1. In elderly subjects, mean PRE
HR was 74.6±4.3, and in post test it was 82.5±5. The t-test shows that there is high
significant increase in HR among young and elderly subject as p<0.01 for both the
groups
TABLE 6: TO COMPARE HEART RATE BETWEEN YOUNG AND
ELDERLY SUBJECTS
GROUP MEAN SD t-value p-value
Diff. HR YOUNG
ELDERLY
9.75
7.90
2.90
1.25
2.619 .013
The result shows that the mean change in HR among young was 9.7±2.9 that of
elderly was 7.9±1.2 this difference is significantly higher in young compare to elderly
subjects as p< 0.01
- - 34
GRAPH 3: TO COMPARE THE HEART RATE BETWEEN YOUNG AND
ELDERLY SUBJECTS.
- - 35
DISCUSSION:
Over the last decade, the value of isometric exercise training for maintaining normal
cardiovascular functioning in older adults and some patient groups has been
recognized. But a cardiovascular response to isometric contraction in young and
elderly individuals is still debating.
It has been found that compared to dynamic exercise, isometric contractions
elicit marked increases in both systolic and diastolic blood pressures, while the rise in
heart rate is less pronounced (Lind et al. 1966). When comparing young and older
individuals, some studies have found comparable responses in heart rate to isometric
exercise (McDermott et al. 1974; Sagiv et al. 1988), whereas others have observed a
lower heart rate in the aged persons (Petrofsky and Lind 1975; Taylor et al. 1991,
1995). In contrast, it has been shown that the older persons exhibit either a similar
(McDermott et al.1974; Sagiv et al. 1988; Taylor et al. 1991) or a greater (Petrofsky
and Lind 1975) blood pressure response to isometric contractions. These differences
in readings may have arisen from variation in subject population, in experimental
protocol (fatiguing vs. non fatiguing contractions), or in the muscle group tested.
Comparisons of younger and older age groups may also have been confounded by
age-related changes in physical activity and reductions in skeletal muscle mass and
muscle strength (Evans 1995).
The present study examined the heart rate and blood pressure responses
to 40% MVC in two age groups of healthy men. The major findings of this study
suggest age-related differences exist in cardiovascular responses to isometric
contraction.
- - 36
Results within the group comparison showed significant increase in heart rate
and blood pressure after 60 seconds of 40% MVC. Among young subjects mean pre
SBP was 121.4±5.8, and in post test it was 127.1±6.3, in elderly subjects mean pre
SBP was 132.5±4.1, and in post test it was 143.6±7.0, Further there is high significant
increase in SBP among young and elderly subject as p<0.01 for both the groups.
Where as mean pre DBP among young subjects was 77.5±4.3, and in post test it was
79.8±4.1, in elderly subjects mean pre DBP was 83.9±3.8, and in post test it was
89.4±4.4, Further there is high significant increase in DBP among young and elderly
subject as p<0.01 for both the groups. Mean pre HR among young subjects was
75.5±5.3, and in post test it was 85.2±7.1, and in elderly subjects mean pre HR was
74.6±4.3, and in post test it was 82.5±5, Further there is high significant increase in
HR among young and elderly subject as p<0.01 for both the groups
However inter group comparison indicate mean change in SBP
among young was 5.7±2.4 that of elderly was 11.1±5.1 this difference is significantly
higher in elderly compare to young subjects as p< o.o1. Mean change in DBP among
young was 2.3±1.6 that of elderly was 5.5±3.1 this difference is significantly higher in
elderly compare to young subjects as p< o.o1. Mean change in HR among young was
9.7±2.9 that of elderly was 7.9±1.2 this difference is significantly higher in young
compare to elderly subjects as p< o.o1.
Thus, significant difference in heart rate and blood pressure response to
isometric contraction in young and elderly normal individuals exist. The older
subjects had a lower heart rate and a higher blood pressure response than their
younger counterparts. These results are concordant with studies done by Petrofsky
and Lind 1975; Taylor et al. 1991, 1995.
- - 37
Findings from the study & supporting review suggest that acute
cardiovascular responses to isometric contraction are not similar in healthy young and
elderly individuals. Study opposes the inclusion of isometric exercise as part of an
overall fitness program designed for healthy elderly individuals. Since the fastest
growing segment of the population consists of elderly individuals i.e. those over 60
years of age. Exercise professionals are encouraged to reach out to these members of
society with exercise programs that may improve bodily function and quality of life.
Attention has must paid to the influence of inherent factors such as aging, which
might modify cardiovascular responses to isometric exercise, while exercise
prescription.
- - 38
LIMITATIONS:
1. This is an experimental study and relies on self reported information.
2. The study did not make use of confounding variables such as muscle mass, muscle
strength and environmental factors.
3. Some subjects tend to do valsalva manoeuvre, which further increases pressor
response.
SUGGESTION:
1. The subject’s functional limitations can be made as a part of the study.
2. Number of subjects can be increased.
3. Study can be extended for longer duration and for multi session.
4. Intensity of isometric contraction can be varied.
5. Further study can be performed on different muscle groups and different position.
- - 39
CONCLUSION
The result indicates that increasing age is associated with an altered heart rate and
blood pressure response to isometric exercise. There was an increase in heart rate and
blood pressure with isometric exercise in both young and elderly group but the older
subjects had a lower heart rate and a higher blood pressure response than their
younger counterparts.
- - 40
SUMMARY
The purpose of this study was to compare the acute cardiovascular responses to
isometric contraction in healthy young and elderly individuals. 40 male subjects with
age group 20-30years and 60-70years satisfying the inclusion criteria were selected
and divided into two groups namely young and elderly group respectively. Resting
HR and BP were recorded followed by HR and BP responses to isometric exercise in
both the groups were assessed. Isometric contraction was held till 60seconds using the
hand held dynamometer at 40% of the maximal voluntary contraction (MVC). Pre and
post HR and BP were compared. After appropriate statistical analysis result shows
that there is age associated alteration in heart rate and blood pressure response to
isometric exercise.
The older subjects had a lower heart rate and a higher blood pressure response than
their younger counterparts. Thus study opposes the inclusion of isometric exercise as
part of an overall fitness program designed for healthy elderly individuals.
- - 41
BIBLIOGRAPHY:
01. William D. Mc.Ardle,Frank I.Katch, Victor L.Katch .Exersise Physiology
energy,nutrition,and human performance.-3rd edition p292.
02. Cardiovascular disease in India and the impact of lifestyle and food habits: Dr.
Rajesh Pande(senior consultant and head of department of Critical Care
Medicine Fortis Hospital, Noida).
03. Hillegass and Sandowsky. Essentials of cardiopulmonary physical therapy. - 2nd
Edition.
04. Fredric J. Pashkow and William A. Dafoe. Clinical cardiac rehabilation.- 2nd
Edition p6.
05. Stanley P. Brown, Wayne C. Miller, Jane M. Eason. Exercise physiology:basis
of human movement in health and disease-edition 2005 p193.
06. Seals, D.R., et al: Increased cardiovascular response to static contraction of
larger muscle group. J. Appl. Physiol., 54; 434, 1983..
07. Stanley P. Brown, Wayne C. Miller, Jane M. Eason. Exercise physiology:basis
of human movement in health and disease-edition 2005.
08. Hanson P, Nagle F. Isometric exercises: cardiovascular responses in normal and
cardiac populations Cardiol Clin 1987 May; 5(2): 157-70.
09. J.H. Mitchell, F. C. Payne, B. Saltin and B. Schibye. The role of muscle mass in
the cardiovascular response to static contractions. J. Physiol. 1980; 309; 45-54.
10. Mitchell JH, Wildenthal K: Static (isometric) exercise and the heart: Physiological
and clinical considerations. Annu Rev Med 25:369-381, 1974.
11. Nutter DO, Schlant RC, Hurst JW: Isometric exercise and the cardiovascular
system. Mod Concepts Cardiovasc Dis 41:11-15, 1972.
- - 42
12. Peter V. Vaitkevicius, MD; Jerome L. Fleg, MD; James H. Engel; Frances C.
O'Connor, MPH;Jeanette G. Wright; Loretta E. Lakatta, BSN; Frank C.P. Yin,
MD, PhD; Edward G. Lakatta, MD. Effects of Age and Aerobic Capacit on
Arterial Stiffness in Healthy Adults. Circulation 1993;88;1456-1462
13. Lakatta E, Mitchell J, Pomerance A. Human aging changes in structure and
function. JAm Coll Cardiol. 1987; 10:42A-47A.
14. Hossack KF, Bruce RA. Maximal cardiac function in sedentary normal men and
women: comparison of age-related changes. JAppl Physiol. 1982; 53:799-804.
15. Raven PB, Mitchell JH. Effect of aging on the cardiovascular response to dynamic
and static exercise. In: Weisfeldt M, ed. The Aging Heart. New York, NY: Raven
Press; 1980:269-296.
16. Julius S, Amery A, Whetlock LS, Conway J. Influence of age on the
hemodynamic response to exercise. Circulation. 1967; 36:222-229.
17. Port S, Cobb FR, Coleman RE, Jones RH. Effect of age on the response of the left
ventricular ejection fraction to exercise. NEngl J Med. 1980;303:1133-1137.
18. Rodeheffer RJ, Gerstenblith G, Becker LC, Fleg JL, Weisfeldt ML, Lakatta EG.
Exercise cardiac output is maintained with advancing age in healthy human
subjects: cardiac dilatation and increased stroke volume compensate for a
diminished heart rate. Circulation. 1984; 69:203-213.
19. Higginbotham MB, Morris KG, Williams RS, Coleman RE, Cobb FR.
Physiologic basis for the age-related decline in aerobic work capacity. Am J
CardioL 1986; 57:1374-1379.
20. Schulman SP, Lakatta EG, Fleg JL, Lakatta L, Becker LC, Gerstenblith G. Age-
related decline in left ventricular filling at rest and exercise. Am J Physiol. 1992;
263:H1932-H1938.
- - 43
21. Petrofsky JS, Lind AR. Aging, isometric strength and endurance and the
cardiovascular responses to static effort. J Appl Physiol. 1975; 38:91-95.
22. Petrofsky JS, Laymon M. The effect of aging in spinal cord injured individuals on
the blood pressure and heart rate responses during fatiguing isometric exercise.
Eur J Appl Physiol. 2002; 86:479-486.
23. Petrofsky JS, Lind AR. Aging, isometric strength and endurance and the
cardiovascular responses to static effort. J Appl Physiol. 1975; 38:91-95
24. Daniel W. Jones,; Lawrence J. Appel, ; Sheldon G. Sheps,; Edward J. Roccella,;
Claude Lenfant Measuring Blood Pressure Accurately :
JAMA. 2003;289:1027-1030.
25. Virgil Mathiowetz. Comparison of Rolyan and Jamar dynamometers for
measuring grip strength. .Copyright © 2002 Whurr Publishers Ltd.
26. Gervasoni JP, Bovet P, Rwebogora A, Mkamba M, Paccaud F. Systematic bias
between blood pressure readings measured with mercury and automatica
sphygmomanometers. Forum Med Suisse, Suppl2, 103S, 2001.
27. Goodie, Jeffrey L.; Larkin, Kevin T.; Schauss, Scott. Validation of Polar heart
rate monitor for assessing heart rate during physical and mental stress. Journal
of Psychophysiology. Vol 14(3), 2000, 159-164
28. Boutcher S.H.; Stocker D Cardiovascular responses to light isometric and aerobic
exercise in 21- and 59-year-old males. European journal of applied physiology
and occupational physiology 1999 , vol. 80, no3, pp. 220-226 .
29. Smolander J, Aminoff T, Korhonen I, Tervo M, Shen N. Heart rate and blood
pressure responses to isometric exercise in young and older men. Eur J Appl
Physiol Occup Physiol. 1998 Apr; 77(5):439-44.
- - 44
30. R. Laukkanen and P. Virtanen . Heart Rate Monitors - state of the art. Journal of
Sports Sciences 16:S3-S7, 1998.
31. Stratton JR, Levy WC, Cerqueira MD, Schwartz RS, Abrass IB. Cardiovascular
responses to exercise. Effects of aging and exercise training in healthy men.
Circulation 1994 Apr; 89(4):1648-55.
32. Taylor, J.A., G.A. Hand, D.G. Johnson, and D.R. Seals. Sympathoadrenal-
circulatory regulation during sustained isometric exercise in young and older
men. Am. J. Physiol. 261:R1061–1069.1991.
33 S.C.Gandevia and S.F.Hobbs, cardiovascular responses to static exercisein man:
central and reflex contribution. Journal of Physiology (1990), 430, pp. 105-117
34 Van Loan, M.D., B.H. Massey, R.A. Boileau, T.G. Lohman, J.E. Misner, and
P.L. Best. Age as a factor in the hemodynamic responses to isometric exercise.
J. Sports Med. Phys. Fitness 29:262–268. 1989.
35 Sagiv M, Hanson P, Goldhammer E, Ben-Sira D, Rudoy J. Left ventricular and
hemodynamic responses during upright isometric exercise in normal young and
elderly men. Gerontology, 1988; 34(4): 165-70.
36. Seals DR, Hurley BF, Hagberg JM, Schultz J, Linder BJ, Natter L, Ehsani AA.
Effects of training on systolic time intervals at rest and during isometric exercise
in men and women 61 to 64 years old. Am J Cardiol. 1985;55(6):797-800.
37. Camus G, Thys H, Pigeon G, Dreezen E Cardiovascular changes induced by
isometric exercise in aged subjects C R Seances Soc Biol Fil. 1982;176(5):740-3
38. Petrofsky JS, Lind AR. Aging, isometric strength and endurance and the
cardiovascular responses to static effort. J Appl Physiol. 1975; 38:91-95.
- - 45
39. Jerrold S. Petrofsky and Alexander R Lind. Isometric Strength, Endurance, and
the Blood Pressure and Heart Rate Responses during Isometric Exercise in
Healthy Men and Women, with Special Reference to Age and Body Fat
Content. Pflfigers Arch.1975; 360, 49--61
40. Petrofsky JS, Lind AR. Isometric strength, endurance, and the blood pressure and
heart rate responses during isometric exercise in healthy men and women, with
special reference to age and body fat content. Pflugers Arch.: 1975; 360(1): 49-
61.
41. Mcdermott, D.J., W.J. Stekiel, J.J. Barboriak, L.C.Kloth, and J.J. Smith. Effect of
age on hemodynamic and metabolic response to static exercise. J. Appl. Physiol.
37:923–926. 1974.
- - 46
ANNEXURE-1
CONSENT FORM
TITLE:
“CARDIOVASCULAR RESPONSES TO ISOMETRIC CONTRACTION IN
YOUNG AND ELDERLY INDIVIDUALS ”
INVESTIGATOR:
Mr. RAVISH TAORI
PURPOSE OF THE STUDY:
I …………………………………………………. have been informed that this study
will help clinicians, therapists to design exercise programs, that will help in the
rehabilitation of the elderly and cardiac population
PROCEDURE:
I understand that I’ll be given isometrics exercise of forearm using the hand held
dynamometer, under the direct supervision of the physiotherapist. I am aware that I
have to follow therapist’s instructions as has been told to me.
RISK AND DISCOMFORT:
I understand that there is some potential risks associated with this procedure, and
understand that Mr. RAVISH TAORI will accompany me during this procedure.
- - 47
CONFIDENTIALITY:
I understand that the medical information produced by this study will be confidential.
If the data are used for publication in the medical literature or for teaching purpose, no
names will be used and other literatures such as photographs and audio or videotapes
will be used only with permission.
REQUEST FOR MORE INFORMATION:
I understand that I may ask any question about the study at any time.
Mr. RAVISH TAORI available to answer my question. Copy of this concern form
will be given to me to keep for my careful reading.
REFUSAL OR WITHDRAWAL OF PARTICIPATION:
I understand that my participation is voluntary and I may withdraw consent and
discontinue participation at any time. I also understand that he may terminate my
participation in the study at anytime after he has explained the reasons for doing so.
INJURY STATEMENT:
I understand that the exercise, which I am going to perform under the guidance of my
therapist, may cause discomfort. In such case medical attention will be provided, but
no compensation will be provided. I understand my agreement to participate in this
study and I am not waiving any of my legal rights.
- - 48
I confirm that Mr. RAVISH TAORI has explained me the purpose of the study, the
study procedure and the possible risk that I may experience. I have read and I have
understood this concern to participate as a subject in this study.
……………. …………………
SUBJECT DATE
……………………………. …………………
WITNESS TO SIGNATURE DATE
I have explained to Mr.………………………………………….. the purpose of the
research, the required and the possible risks and benefits, to the best of my ability.
…………………… …………………….
INVESTIGATOR DATE
- - 49
ANNEXURE 2
PROFORMA FOR DATA COLLECTION TO BE ANALYSED NAME: AGE: GROUP:
CARDIOVASCULAR
RESPONSE
HEART RATE
BLOOD PRESSURE
PRE TEST
POST TEST
- - 50
ANNEXURE-3
MASTER CHART FOR GROUP 1 (YOUNG)
Sr.No. BLOOD PRESSURE HEART RATE
PRE TEST POST TEST PRE TEST POST TEST
1. 130/80 134/80 82 91
2. 118/76 130/80 76 89
3. 120/80 124/80 74 83
4. 120/82 126/84 64 72
5. 118/70 126/74 80 94
6. 126/86 130/86 77 85
7. 120/74 124/76 71 77
8. 118/72 122/74 70 81
9. 110/70 110/70 65 69
10. 124/78 132/80 80 92
11. 112/74 120/80 78 84
12. 122/78 128/80 75 83
13. 122/80 130/84 69 78
14. 130/80 136/82 74 86
15. 114/76 120/78 78 90
16. 126/84 130/86 83 92
17 122/76 126/78 78 87
18 118/74 124/78 81 97
19 130/82 136/84 78 89
20 128/78 134/82 77 86
- - 51
ANNEXURE-4
MASTER CHART FOR GROUP 2 (ELDER)
Sr.No. BLOOD PRESSURE HEART RATE
PRE TEST POST TEST PRE TEST POST TEST
1. 126/80 134/84 77 84
2. 128/86 136/90 75 83
3. 136/80 142/86 78 87
4. 130/78 136/82 71 79
5. 138/80 146/84 75 81
6. 130/82 138/86 69 74
7. 136/86 144/88 70 80
8. 130/84 138/90 70 78
9. 128/78 138/82 74 81
10. 128/78 148/92 77 85
11. 132/90 146/90 71 80
12. 138/86 142/94 72 79
13. 128/86 136/90 66 72
14. 136/88 152/96 80 88
15. 138/86 148/92 76 85
16. 134/90 152/96 81 90
17 128/86 140/90 72 80
18 138/84 162/96 81 90
19 132/84 144/88 78 87
20 136/86 150/92 80 88