Hand grip strength in the adult Malaysian population.

Abstract

To measure the hand grip strength of Malaysians aged 18 to 65 years.
Between January and April 2003, 412 subjects (200 women and 212 men) were recruited from staff, students, and visitors of the University of Malaya Medical Centre. Socioeconomic, general health, and lifestyle data were collected from each subject using a standard questionnaire. Weight and height were measured prior to testing. Standardised positioning and instructions based on several hand grip protocols were used. Data were collected using the LIDO kinetic work set.
93% of the subjects were right-hand dominant and 7% were left-hand dominant. Hand grip strength was significantly correlated with hand dominance, gender, occupation, height, and weight, but not body mass index. No significant differences in grip strength were noted with regard to race or level of income. Men were stronger than women in all age-groups, with a ratio of 1.75:1. In both right- and left-hand dominant groups, the dominant hand was consistently stronger than the non-dominant side, with a ratio of 1.12:1 in the right-hand dominant group and 1.05:1 in the left-hand dominant group. The strongest hand grip strength in the right-hand dominant group occurred in the age-group of 25 to 34 years; in the left-hand dominant group it was in the age-group of 18 to 24 years. In western populations, the mean grip strength can be as much as 1.5 times greater than in the Malaysian population.
Data derived from western populations cannot be applied to a comparable Malaysian population. Gender, hand dominance, age, occupation, weight, and height must be considered when establishing normal values for grip strength.

Full text

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Hand grip strength in the adult Malaysian
population
T Kamarul, TS Ahmad
University of Malaya Medical Centre, Kuala Lumpur, Malaysia
WYC Loh
Department of Orthopaedic Surgery, Southport District General Hospital, Town Lane, Kew, Southport, Merseyside, United
Kingdom
noted with regard to race or level of income. Men were
stronger than women in all age-groups, with a ratio of
1.75:1. In both right- and left-hand dominant groups,
the dominant hand was consistently stronger than the
non-dominant side, with a ratio of 1.12:1 in the right-
hand dominant group and 1.05:1 in the left-hand
dominant group. The strongest hand grip strength in
the right-hand dominant group occurred in the age
group of 25 to 34 years; in the left-hand dominant
group it was in the age-group of 18 to 24 years. In
comparison to the western population, the mean grip
strength can be as much as 1.5 times stronger than our
Malaysian population.
Conclusion. Data derived from a western population
cannot be applied to a comparable Malaysian
population. Sex, hand dominance, age, occupation,
weight, and height must be considered when
establishing the normal value of grip strength.
Key words: hand strength; kinetics
Address correspondence and reprint requests to: Dr Tunku Kamarul Zaman, Department of Orthopaedic Surgery, University of
Malaya Medical Centre, Pantai Valley, 59100, Kuala Lumpur, Malaysia. E-mail: tkzrea@um.edu.my
ABSTRACT
Purpose. To measure the hand grip strength of
Malaysians aged 18 to 65 years.
Methods. Between January and A pril 2003, 412
subjects (200 women and 212 men) were recruited from
staff, students, and visitors of the University of Malaya
Medical Centre. Socioeconomic, general health, and
lifestyle data were collected from each subject using a
standard questionnaire. Weight and height were
measured prior to testing. Standardised positioning
and instructions based on several hand grip protocols
were used. Data were collected using the LIDO kinetic
work set.
Results. 93% of the subjects were right-hand dominant
and 7% were left-hand dominant. Hand grip strength
was significantly correlated with hand dominance, sex,
occupation, height, and weight, but not body mass
index. No significant differences in grip strength were
Journal of Orthopaedic Surgery 2006;14(2):122-7

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Vol. 14 No. 2, August 2006 Hand grip strength in Malaysian 123
INTRODUCTION
A reliable hand grip assessment is important when
assessing the results of various surgical treatments. A
baseline grip strength value for the normal population
is needed. There has been no study of the normal grip
strength in the adult Asian population. Most normative
data are based on the western literature and may not
apply to Asians.1–3
MATERIALS AND METHODS
Between January and April 2003, 412 volunteers were
recruited from the staff, medical students, and visitors
of the University Malaya Medical Centre. Subjects were
excluded if they had a history of upper-limb injury or
deformity, or related health conditions. Socioeconomic
background, general health, and lifestyle of the subjects
were assessed using a standard questionnaire. Weight
and height were measured prior to testing.
A LIDO kinetic work set was used; a grip device
attached to the rotatory arm of the work set was
calibrated for each subject. A dedicated technician
operated the machine to ensure consistent results. The
hand grip protocol was based on the School of
Kinesiology and Recreation of the Illinois State
University and the New York State University: the
subject was seated upright with shoulder in adduction;
the elbow was flexed at 90Ο. The wrist was in a neutral
position facing inwards. The device handle was
opened to fit onto the palm with the fingers in 90Ο
flexion at the proximal and distal interphalangeal joints
with the thumb in 90Ο abduction (Fig. 1).
Grip strength, or torque, was measured in Newton
meters (Nm). Subjects were instructed to grasp the
handle for 5 seconds and rest for 5 seconds, and
perform the action a total of 6 times. The contralateral
hand was then examined using the same protocol. Data
were recorded and analysed using LIDO kinetic work
set software. The mean value of the 3 most powerful
grips was recorded and used for comparison.
RESULTS
Out of the 412 recruited subjects (200 men, 212 women)
aged 18 to 65 years (mean, 34.3 years), 383 (93%) were
right-hand dominant and 29 (7%) were left-hand
dominant. None was ambidextrous. The highest mean
grip strength of both hands was recorded in right-hand
dominant subjects aged 25 to 34 years and left-hand
dominant subjects aged 18 to 24 years (Table 1). Among
men the highest mean grip strength was encountered
in those aged 25 to 34 years and in women in those
aged 18 to 24 years (Table 2). Men were stronger than
women in all age-groups, with a ratio of 1.75:1. The
dominant hand was consistently stronger than the non-
dominant hand, with a ratio of 1.12:1 in the right-hand
dominant group and 1.05:1 in the left-hand dominant
group (Table 3). The mean difference in grip strength
within individuals between each side was statistically
significant (p<0.01, paired t-test) in the right-hand
dominant group, but not in the left-hand dominant
group (p=0.159, Wilcoxon signed rank test).
There was a significant difference in the grip
strength of the left hand between different dominant
groups (p<0.05, independent t-test), but not the right
hand. Due to the skewed distribution of data and the
small number of subjects in the left-hand dominant
group, a non-parametric test (Mann-Whitney U test)
was performed. In comparing the grip strength of the
respective hand sides between the different hand
dominant groups, the p value for the left hand was
0.028 while the right hand was 0.642. It was only in
the right-hand dominant group that significant
differences were noted between the mean grip strength
of a particular (either left or right) hand side within
the different age groups (one-way ANOVA test), and
between the 2 hands in the respective sex groups
(paired t-test), with p<0.001 in all tests. There were no
Figure 1
grip testing is followed: the shoulder is adducted and the arm
flexed at 90Ο with the wrist in neutral position.
The left hand is being tested. A strict protocol of

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124 T Kamarul et al. Journal of Orthopaedic Surgery
significant differences noted in the left-hand dominant
group using these similar tests as well as non-
parametric tests (Kruskal Wallis test and Wilcoxon
signed rank test, p>0.05). This may have been due to
the small number of left-handed subjects (n=27) in our
study. However, there were significant differences
between different sexes in both hands in the left-hand
dominant group (Mann-Whitney U test, p<0.001).
143 (35%) of subjects were manual workers, 243
(57%) were office workers, and 35 (9%) were retired or
pensioners. There was significant difference in grip
strength between occupations (one-way ANOVA test,
p=0.005 in the right hand, p=0.015 in the left hand),
but not level of income. There was no significant
difference in grip strength between races: 220 (53%)
were Malay, 68 (17%) were Chinese, and 124 (30%)
were Indian (one-way ANOVA test, p=0.577 in the
right hand, p=0.541 in the left hand).
A multiple regression analysis was used to
compare left- and right-hand grip strength, taking into
account factors that may influence grip strength such
as sex, age, weight, height, body mass index (BMI),
race, and occupation. Only age, weight, height,
occupation and sex were correlated with grip strength
Table 3
Comparison of mean torque (grip strength) of right and left
hands between men and women
Mean torque (SD) [Nm]
Men Women Ratio
Right-hand dominant
group
Right hand
Left hand
Ratio
Left-hand dominant
group
Right hand
Left hand
Ratio
41.2 (12.0) 24.5 (7.7)
36.9 (11.1) 21.9 (7.2)
1.12
1.68
1.69
- 1.12
44.6 (9.0)2 24.2 (7.6)
45.9 (11.1) 25.8 (8.0)
0.97
1.84
1.78
- 0.94
Table 4
Correlation between mean grip strength and age, height,
weight and body mass index (BMI)
VariablesMean grip strength p value, Pearson
correlation test
<0.002
<0.008
<0.001
<0.001
<0.001
<0.001
<0.178
<0.122
AgeLeft hand
Right hand
Left hand
Right hand
Left hand
Right hand
Left hand
Right hand
Height
Weight
BMI
Table 1
Mean torque (grip strength) of the right and left hand in the different dominant groups
Mean torque (Nm)
35–44
n=67
31.8
35.0
n=4
41.0
37.4
Age-group (years)
Right-hand dominant group
Left hand
Right hand
Left-hand dominant group
Left hand
Right hand
18–24
n=138
29.3
32.7
n=9
41.3
39.5
25–34
n=88
33.0
36.7
n=5
32.7
30.5
45–54
n=63
26.5
29.7
n=9
28.7
29.0
55–65
n=29
23.4
27.5
n=0
-
-
Table 2
Mean torque (grip strength) of men and women
Mean torque (Nm)
35–44
n=43
39.0
43.0
n=29
22.2
23.5
Age-group (years)
Men
Left hand
Right hand
Women
Left hand
Right hand
18–24
n=66
38.2
42.0
n=81
23.4
25.9
25–34
n=57
39.5
43.1
n=35
22.3
25.5
45–54
n=31
34.1
38.5
n=41
21.2
23.0
55–65
n=15
28.5
33.8
n=14
17.9
20.7

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Vol. 14 No. 2, August 2006Hand grip strength in Malaysian 125
40
0
Mean left hand torque=10.58+0.31*weight
r2=0.11
Weight (kg)
Mean left hand torque (Nm)
6080
25
50
75
100
Linear regression with 95% mean
prediction interval and 95% individual
prediction interval
Figure 2
weight.
Scatterplots showing the distribution of mean grip strength (torque) of both hands in comparison to height and
100
120
40
0
Mean right hand torque=10.78+0.36*weight
r2=0.13
Weight (kg)
Mean right hand torque (Nm)
6080
25
50
75
100
100
120
140
0
Mean left hand torque=-80.55+0.68*height
r2=0.26
Height (cm)
Mean left hand torque (Nm)
160
25
50
75
100
180200 140
0
Mean right hand torque=-91.59+0.77*height
r2=0.29
Height (cm)
Mean right hand torque (Nm)
160
25
50
75
100
180 200
(p<0.01). Using Pearson correlation test, significant
correlations were noted between grip strength and (i)
age, (ii) weight, and (iii) height, but not BMI (Table 4).
The regression (r2) value of height and weight were
calculated and a linear model equation proved that
height and weight were predictors of grip strength
(Fig. 2): for right- and left-hand grip strength,
regression values for height were 0.29 and 0.26, and
for weight, 0.13 and 0.11, respectively (Fig. 2).
DISCUSSION
The hand grip strengths of Malaysian subjects were
significantly weaker than those reported for American
or European populations.1–4 Table 5 compares our
findings with those of a previous study.2 The
comparison matches only age, sex and different hand
sides. If other factors (e.g. height and weight) were
available, the differences in grip strength between the

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126 T Kamarul et al.Journal of Orthopaedic Surgery
2 studies might not have appeared so striking. There
were no data available for comparison from previous
studies that described important subjects’ parameters
such as height and weight. Categorical comparison of
different factors (e.g. occupation) that could also
influence grip strength was also not performed in
previous studies.
In this study, grip strength correlated with height
and weight (r2, 0.11–0.29; Fig. 2). Thus height and
weight, not just age, must be considered when
determining a normal grip strength value. Grip
strength has been reported to correlate with sex and
age5 and hand dominance.1 Weight and height proved
to be better predictors for grip strength than age. It is
therefore important to account other factors, not age
alone, to predict grip strength. Only one previous study
correlated weight and height with grip strength, but
details of the relationship between these factors and
grip strength was not reported.6
Grip strength of the right-hand dominant group
increased with age in subjects aged 18 to 34 years,
and decreased steadily thereafter. In the left-
hand dominant group, the peak strength occurred
in age-groups 18 to 24 years and 35 to 44 years.
A curvilinear relationship could not be established
due to the small number of subjects in the left-
hand dominant group. Nevertheless, the overall
data supported such a relationship of hand strength
with age, peaking somewhere between the age of
25 and 50 years and decreasing thereafter. This trend
was also described by Mathiowetz et al.2 Assumption
of a linear regression7 to predict adult hand
strength scores for normative data, based on a linear
inverse relationship was not well supported by our
study.
Compared to data from Mathiowetz et al.,2 the
overall grip strength of their western population is up
to 1.5 times more than in our Malaysian subjects (Table
5). This suggests that grip strength norms from the
western population may not accurately represent the
local population and local reference values are needed.
A limitation of our study was that we recruited
subjects from a single university, which may not be
representative of the whole country. Nonetheless, it is
a tertiary university for medical referral and education
and the subjects originated from different parts of the
nation. Another limitation was the small number of
left-hand dominant subjects (n=27), resulting in
skewed distribution of data. We therefore incorporated
the data of the left-hand dominant group into the
Table 5
Comparison of hand grip strength between our study and Mathiowetz et al.2 study
Grip strength of our study (pounds)
Men
SE
12.3
12.3
12.8
12.6
14.9
15.4
14.6
14.0
13.5
13.9
14.3
13.9
16.5
14.6
16.1
14.0
10.5
10.4
Women
SE
1.4
1.4
2.4
2.1
3.0
3.0
3.5
3.0
3.8
3.7
2.6
2.5
3.0
2.8
4.4
4.0
3.7
5.7
Age-group (years)
20–24
Hand
R
L
R
L
R
L
R
L
R
L
R
L
R
L
R
L
R
L
Mean
69.2
63.0
70.9
66.3
72.2
64.7
70.1
62.3
71.8
65.1
64.3
58.6
64.7
56.1
50.2
45.9
43.1
36.9
SD
18.5
18.9
17.1
15.6
21.4
23.4
21.4
18.8
17.2
18.9
17.0
15.7
22.7
16.0
22.1
14.5
18.2
18.0
Low
33.3
17.9
29.2
25.1
30.0
29.5
35.2
23.1
36.9
32.8
41.0
32.5
23.4
31.7
24.5
23.4
40.6
23.5
High
115.9
101.3
126.7
198.3
110.1
118.7
108.8
195.8
107.9
112.3
103.8
182.3
191.1
181.0
100.2
168.3
173.9
157.4
Mean
43.2
39.1
37.7
33.0
45.3
40.0
40.0
35.9
37.1
37.1
39.2
36.9
36.9
32.7
34.9
32.0
31.5
23.0
SD
12.0
11.9
11.1
19.5
13.3
13.5
12.7
10.9
14.3
13.9
12.1
11.5
12.8
12.0
15.3
14.0
16.4
19.9
Low
21.5
21.8
18.7
18.2
23.1
11.6
15.1
16.8
13.5
18.5
19.8
20.1
16.2
13.8
15.7
10.5
24.2
11.9
High
83.1
76.5
60.0
54.9
65.3
63.3
62.2
52.3
67.5
55.9
64.7
62.5
54.8
54.2
61.4
58.4
36.3
30.8
25–29
30–34
35–39
40–44
45–49
50–54
55–59
60–65
Overall
Our study R
L
R
L
168.4
161.8
104.3
193.1
19.6
18.2
28.3
27.6
1.3
1.3
1.6
1.6
23
18
32
27
127
119
176
160
41.0
37.1
62.8
53.9
12.7
12.1
17.0
15.7
0.9
0.3
1.0
0.9
14
19
25
23
183
176
137
115
Mathiowetz et al.2
study