Static and Dynamic Handgrip Endurance in Young Adults

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Indian Journal of Physiotherapy and Occupational Therapy. October-December 2017, Vol. 11, No. 4 116
Static and Dynamic Handgrip Endurance in Young Adults
Gaurang Baxi
1
, Shamika R Tigdi
2
, Tushar J Palekar
3
, Soumik Basu
4
, Kedar Sule
4
1
Associate Professor,
1Associate Professor,
1
2
Post-Graduate Resident,
2Post-Graduate Resident,
2
3
Principal,
4
Assistant Professor,
4Assistant Professor,
4
Dr. D. Y. Patil College of Physiotherapy, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, India
ABSTRACT
Background:
Many professions involve manual gripping tasks requiring dynamic movements, concentric
and eccentric muscle contractions, and static tasks like application of continuous, steady, isometric force for
sustained period of time. These repetitive manual activities make an individual prone to various work related
musculoskeletal disorders. This study assess the static and dynamic handgrip endurance, by performing
sustained muscle contraction.
Methods and Materials:
This observational study was conducted at Dr. D. Y. Patil College of Physiotherapy,
Dr. D. Y. Patil Vidyapeeth, Pune. 500 healthy volunteers in the age group of 18-25 years were included.
Static endurance during sustained isometric contraction and dynamic endurance over a number of rhythmic
repetitive contractions were assessed using a dynamometer, at 60% of Maximal Voluntary Contraction.
Findings:
Data was analysed to examine the role of hand dominance and gender on MVC, Static hand
grip endurance and Dynamic hand grip endurance. Significant difference in static and dynamic handgrip
endurance of both the genders was seen (p < 0.001).
Conclusion:
This study provides preliminary data on static and dynamic handgrip endurance in healthy
young adults. While the strength of maximal voluntary contraction was more in males, females had higher
static as well as dynamic endurance compared to males.
Keywords:
Handgrip Endurance, handgrip strength, Maximum Voluntary Contraction (MVC), Work-related
musculoskeletal disorders (WRMDs).
Corresponding author:
Shamika R Tigdi
Dr. D. Y. Patil College of Physiotherapy,
Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune- 411018,
India. Email: shamikatigdi@gmail.com,
Mobile No.: 9987461351
STATIC AND DYNAMIC HANDGRIP
ENDURANCE IN YOUNG ADULTS
Background: The human hand is the most active and
interactive part of the upper extremity. The high degree
of development of human hand, like prehensile grasp
and opposing thumb allow various unique functional
and creative capabilities, majorly contributing to the
dominance of human species.1 The important functions
of the hand as a creative tool are an extension of
intellect, a means of nonverbal communication and a
leading sensory tactile organ.
The term “Hand Dexterity” refers to the functional
ability of the hand.2 Hand function and manual dexterity
determine the quality of performance in daily living
skills, work-related functions, and recreational activities.
All these include extremely fine, sensitive movements,
as well as tasks requiring considerable force.1 Reaction
time, aiming, hand and arm stability are few of the
unique abilities of human hand.2
Hand grip strength is a widely explored component
of hand function.3 Handgrip fits into the International
Classification of Functioning, Disability and Health
(ICF) domain of ‘body function and structure’.
Measuring hand function is one of the most fundamental
for any evaluation.4 Handgrip strength is an indicator
of the efficacy of various treatment strategies for
the hand.5 It also provides an objective index of the
functional integrity of the upper extremity,3 and an
important indicator of parameters like nutritional status
DOI Number: 10.5958/0973-5674.2017.00131.9

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119 Indian Journal of Physiotherapy and Occupational Therapy, October-December 2017, Vol. 11, No. 4
and bone mineral content.5 Grip strength has also been
shown to predict the general body strength, body cell
mass depletion, postoperative complications, premature
mortality, early onset of disability and functional
decline.6
Since many years, instruments like strain gages,
sphygmomanometers and dynamometers have been used
to assess the grip strength.4 The Jamar dynamometer was
first introduced in 1954 by Bechtol. It has an indwelling
sealed hydraulic system with adjustable hand placing
over five handle positions which record handgrip force
in pounds per square inch.7 Measurements are sensitive,
and are delivered on a continuous scale. The strength
measurement of contralateral hand is used as the
reference value.8
Most of the activities of daily living (ADLs)
require exertion of a sustained effort over a period of
time.9 Hence it is important to consider measurement
of handgrip endurance as an important component
of assessment of physical performance, in addition
to handgrip strength. Endurance is the ability of a
muscle group to perform repeated contractions over a
time period, sufficient to cause muscular fatigue or to
maintain a specific percentage of maximum voluntary
contraction for a prolonged time. An exercise induced
reduction in the maximal force capacity of the muscle
is Muscle Fatigue.10 It is characterised by a decrease
in muscle force production capacity and shortening
velocity, and a prolonged or extended relaxation of
motor units between recruitment.10
Many professions necessitate lifting and holding
heavy loads with a proportionately static grip or
repetitive or forceful gripping movements.11 A varied
range of tasks, from relatively dynamic movements
involving concentric and eccentric contractions, to
relatively static tasks mainly producing an isometric
contraction, comprise the manual activities involving
grip at work place.11 Manual activities under poor
ergonomic conditions can predispose an individual to
work related musculoskeletal disorders (WRMDs).
Handgrip strength evaluation helps identify
individuals at risk of WRMDs involving hands and
forearms, efficacy of treatment and assesing pseudo
injuries.11 However, hand grip strength is not a
true measure of hand function, since it is measured
isometrically, while most daily activities require
dynamic gripping. Also many ADLs require sustained
effort exerted over a period of time.10 Therefore, muscle
endurance remains an important aspect of performance,
and has to be considered when assessing musculoskeletal
function.
Normative values of handgrip strength are available.
However, normative values for handgrip endurance are
not available. Thus, this study was conducted to find
the static handgrip endurance and dynamic handgrip
endurance in young adults, in the age group of 18-25
years.
MATERIALS AND METHOD
This study was conducted at Dr. D. Y. Patil College
of Physiotherapy, Dr. D. Y. Patil Vidyapeeth, Pune.
Approval from the ethical committee of the institute was
taken prior to subject enrolment. Informed consent was
taken from volunteers fulfilling the inclusion criteria of
age group 18-25 years.
Procedure:
Peak grip strength was measured on each hand using
Jamar Dynamometer, with the subject seated upright
with feet fully resting on the floor, hips as far back in
chair as possible, and the hips and knees positioned at
90o approximately. The elbow was on the armrest at
approximately 90° and the shoulder of gripping arm
was maintained in adduction; the elbow was flexed
comfortably between about 90° and 120°. The wrist was
position between 0o and 30o of extension, and between 0o
and 15o ulnar deviation.
The dynamometer was held with index finger at
the top of the grip, while keeping all fingers on the grip
band. The second dynamometer handle position was
used and the subject was instructed to produce a smooth
gripping force, without sudden wrenching or jerking
movements. Subjects were instructed to exhale during
the grip exertion and the grip was held for 3 seconds. A
rest period of 15 seconds was allowed between the grip
repetitions. The grip strength score was recorded from
the dynamometer. Three repetitions were taken, the
maximum reading was noted as the peak grip strength.
Dominant hand was tested first and, same procedure
was repeated on the other hand, each hand was tested
alternately. After the assessment of the Maximal
Voluntary Contraction over three trials for each hand,
static and dynamic endurance testing was done.

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119 Indian Journal of Physiotherapy and Occupational Therapy, October-December 2017, Vol. 11, No. 4
verbally motivated to repeat the contractions of set
intensity as many times as possible.
DATA ANALYSIS
Average of three readings for each volunteer was
calculated for all variables. Descriptive and Inferential
statistical analysis was done using statistical software
‘Epi info’. The data was analysed for normal distribution
and nonparametric test (Kruskal Wallis) was applied
because of uneven distribution of data.
Graph No. 1: Gender Distribution of Data.
Interpretation: 500 healthy volunteer subjects
were included, majority were women.
A) Static hand grip endurance test:
Subjects were seated in initial position. They were
asked to grip the handheld dynamometer at 60% of their
maximum voluntary contraction (MVC). The duration
for which they maintained the grip strength was noted in
seconds. Subjects were verbally encouraged to maintain
the contraction at the set target for as long as possible.
The test was terminated when the subjects failed to
maintain the 60% MVC for two consecutive times. Two
recordings were obtained with a gap of five minutes
between each effort.
B) Dynamic hand grip endurance test:
After static hand grip endurance test, the subjects
performed the dynamic hand grip endurance test.
Subjects were instructed to give repetitive contractions
at 60% of their maximal voluntary contraction (MVC)
on the beat of the metronome set at 70 beeps per minute
until fatigue set in and they were no longer able to
produce the same intensity of contraction (target force
was missed three consecutive times). The metronome
was introduced to set uniformity in the rhythm of
contraction. Subjects were given visual feedback to view
the target force they were supposed to generate during
this experiment with the help of a mirror. Subjects were
Table No. 1: Gender wise distribution of maximum voluntary contraction in dominant and non-dominant
hand.
Maximum voluntary contraction in Dominant hand
Gender
Range
Mean
SD
P Value
Male
45.00-140.00
85.61
16.85
>0.001
Female
20.00-85.00
50.65
10.79
Maximum voluntary contraction in Non Dominant Hand
Gender
Range
Mean
SD
P Value
Male
40.00-140.00
82.35
17.83
>0.001
Female
20.00-80.00
48.32
10.18
Interpretation: The Maximum Voluntary Contraction strength was significantly more (p >0.001) in males than
in females.

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121 Indian Journal of Physiotherapy and Occupational Therapy, October-December 2017, Vol. 11, No. 4
Table No. 2: Gender wise distribution of static endurance in dominant and non-dominant hand.
Static Endurance In Dominant Hand
Gender
Range
Mean
SD
P Value
Male
8.40-115.02
38.66
20.24
>0.001
Female
5.90-121.73
45.05
20.81
Static Endurance In Non Dominant Hand
Gender
Range
Mean
SD
P Value
Male
7.18-118.53
38.11
20.43
>0.001
Female
7.84-135.00
44.68
21.41
Interpretation: Female subjects had greater static endurance compared to male subjects (p > 0.001). A
significant difference is seen between both genders in the time for which they could sustain the forces at 60% of
MVC. Marked inter-subject variability is observed in endurance time for both the genders.
Table No. 3: Gender wise distribution of Dynamic Endurance In dominant and non-dominant hands
Dynamic Endurance In Dominant Hand
Gender
Range
Mean
SD
P Value
Male
11.00-148.50
48.63
24.34
>0.001
Female
8.50-178.00
59.95
25.02
Dynamic Endurance In Non Dominant Hand
Gender
Range
Mean
SD
P Value
Male
8.00-122.00
45.07
22.21
>0.001
Female
10.50-176.50
55.03
23.50
Interpretation: Dynamic endurance is lower in male subjects than in females, this difference is statistically
significant (p > 0.001) for both dominant and non-dominant hands for both the genders.
DISCUSSION
Grip strength is one of the important fitness
components tested in assessment of hand function, and
is an important component of hand rehabilitation. It is
a marker of physiological functioning and the integrity
of anatomical structures of forearm and hand.13 Since
muscle force generated by hand in gripping activities
is essential for continual performance of ADL and
occupational tasks, reduced handgrip strength may limit
an individual’s ability to perform most of work-related
and daily activities.4
This study evaluates the static and dynamic handgrip
endurance in the age group of 18 to 25 years. Owing to
difference in muscle mass, male subjects produced
greater average grip force which has been documented
repeatedly in previous studies as well.14
The static and dynamic endurance tests were
conducted at a submaximal strength of 60% MVC.
A significant difference in both static and dynamic
endurance of males and females was seen, with females
having greater static as well as dynamic endurance than
males. This is consistent with previous researches, in
which men were found to be more fatigable than women
during both sustained and intermittent contractions.
Also when working at submaximal levels, females
have a greater muscular endurance than males. This
difference can be attributed to difference in muscle
fibre composition in both genders. Women have high
proportion of type 1 muscle fibres as compared to men.14
Difference are seen in dynamic contractions, type 2
fibres having the ability to produce higher force.14
It has been advocated that women have better ability
to adapt themselves to performance of endurance activity
than men because of higher potentiality for oxidation of
fat. It has also been seen that the rate of depletion of

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121 Indian Journal of Physiotherapy and Occupational Therapy, October-December 2017, Vol. 11, No. 4
glycogen is much lower in muscles of women, compared
to men during endurance activity. Consequently, females
are more capable of performing better than males at
workloads equal to 80% of maximum oxygen uptake.14
Studies have documented that force which can be
sustained is less than the peak force, and grip force
was found to decrease as the time duration of the test
progressed. This is in consistence with the findings
of this study. This can be because when submaximal
constant load is applied for a prolonged period of time,
static gripping produces an obstruction in blood flow
affecting the recruitment and fatigue of the fast twitch
fibres.14
Static and dynamic endurance measurements
persist to be irrelative, indicating that the contingent
contributions of physiological sources of fatigue differ
between the two respective tasks. This can be because
of accumulation of K+ in the t-tubules of muscle fibres,
interfering with propagation of action potential deep
into the muscle, caused by high frequency stimulation,
resulting in decreased strength of contraction.9 In
repetitive dynamic gripping, fibres have more time
between contractions to clear K+, contributing to less
fatigue than prolonged static holds. Hence, individuals
vary in resistance to different sources of fatigue due to
differences in muscle fibre histology and biochemistry,
as well as due to difference in motivation and
tolerance.11
Also, it was seen that dominant hand produced
relatively greater force than the non-dominant hand,
but onset of fatigue did not vary significantly. The
use of dominant hand in ADLs is extensive, this may
have trained the muscle fibres relatively towards
characteristics of fast-twitch fibres, resulting in greater
peak force strength.11
The number of left handed individuals in the
present study was notably low, therefore it was not
feasible to assess and compare the trends between
right-handed and left-handed individuals. There have
been inconsistent findings regarding handedness in grip
strength previously, and different degrees of handedness
do prevail. In literature, relatively few studies have
evaluated handedness and gender separately. These
findings need to be analysed in large numbers, to
postulate definite evidence of distinctness in endurance
between genders, age, muscle groups and handedness.11
More studies on larger samples, and on
different age groups are required to further substantiate
the findings obtained in this study. The effects of BMI
and body composition can also be explored.
CONCLUSION
The present study provides preliminary data on
static and dynamic handgrip endurance in healthy young
adults in the age group of 18 - 25 years. It was seen that
strength of maximal voluntary contraction was more in
male subjects as compared to females, whereas females
have higher static as well as dynamic endurance than
males.
Conflict of Interest: Nil.
Source of Funding: Nil.
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