Purpose
A quantitative and objective measure of isometric muscular strength of the hand and forearm.
Cost
Not FreeDiagnosis/Conditions
- Stroke Recovery
Primary Image
Hand-held Dynamometer / Grip Strength
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Populations
Key Descriptions
- This instrument is scored using force production in kilograms (0-90) or pounds (0-200).
- Standardized procedure for positioning of instrument when using normative data is the following:
1) Subject is seated with back, pelvis, and knees as close to 90 degrees as possible.
2) Shoulder is adducted and neutrally rotated, elbow flexed at 90 degrees, forearm neutral, wrist held between 0-15 degrees of ulnar deviation.
3) The arm is not supported by examiner or armrest and the dynamometer is presented vertically and in line with the forearm (Horowitz, 1997). - Maximum grip is the mean of three trials.
Number of Items
1
Equipment Required
- Requires purchase of a handheld dynamometer
Time to Administer
5 minutes
5 minutes or less
Required Training
Reading an Article/ManualInstrument Reviewers
Initially reviewed by Michele Lamb, OTR in 11/2013
Updated with normative data for healthy children and adolescents in 5/2025
ICF Domain
Body StructureBody Function
Considerations
- There is a wide range of instruments that test grip strengths, most studies use the Jamar dynamometer
- Must follow the standardized testing protocol and testing position for reliability and normative data. Changes in body position from protocol will result in altered grip strengths (Richards et al., 1996)
- The positioning of the handle will affect result in measurement discrepancies, instrument should be set at the second position on hydraulic instruments (Innes, 1999)
- Maximal grip is the mean of three trials, studies have shown that the mean of three trials is the most accurate measure of hand strength (Mathiowetz, V., Weber, K. et al., 1984)
- It is recommended that a 3 second or less grip contraction is sufficient to register maximum reading (Innes, 1999)
- 60 second rest periods between trials may prevent fatigue although studies have shown measurements taken at shorter durations result in minimal differences (Innes, 1999)
- Instrument calibration is required annually or more frequently if used on a daily basis (Roberts et al., 2011)
- Use the same test instrument for pre and post-testing for accurate results
- Coefficient of variation (CV), a statistical stability of measures, is based on three trials of maximum grip strength at a single setting. Acceptable CV for the Jamar dynamometer are 10% male and 12% female (Innes, 1999)
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Stroke
back to PopulationsStandard Error of Measurement (SEM)
Chronic Stroke:
(Bertrand, et al, 2007; n = 17; mean age 53.7(13.0); paresis of the arm as a result of a unilateral stroke that occurred > one year earlier; three trials with time intervals between two sessions as well as the time of day not fixed; participants were not involved in a rehabilitation program)
Session/Trial
Paretic SEM
Non-paretic SEM
1,1
28.78 (20%)
22.27 (8%)
1,3
26.15 (18%)
17.10 (6%)
2,1
20.35 (14%)
16.07 (6%)
2,3
18.49 (13%)
12.23 (4%)
- SEM = 0.10 (19%) session 1
- SEM = 0.07 (13%) session 2
(Boissy et al, 1999; n=15; mean age = 47 (14) years; single CVA with upper limb paresis > one year ; three measurement sessions held one week apart at approximately the same time of day; Lafayette modified prehensile dynamometer)
- SEM = 33 (non-affected handgrip force)
- SEM = 25 (affected handgrip force)
- SEM = 16 (Left handgrip force control)
- SEM = 66 (Right handgrip force control)
Reported acceptable SEMs (mean SEM = 14% of mean MVGF)
Minimally Clinically Important Difference (MCID)
Stroke:
(Lang et al, 2008; n = 52; mean age 64 (14); independent prior to hemiparesis, Jamar grip dynamometer, Acute Stroke)
- 5.0 and 6.2 (kg) for the affected dominant and non-dominant sides
Test/Retest Reliability
Stroke:
(Bertland et al, 2007, Chronic Stroke)
- Excellent test-retest reliability (ICC 0.80 to 0.89)
Interrater/Intrarater Reliability
Stroke:
(Boissey et al, 1999, Chronic Stroke)
- Excellent intrarater reliability (ICC > 0.086-0.95)
Construct Validity
Stroke:
(Boissy et al, 1999, stroke >1 yr, Chronic Stroke)
- Adequate correlation with Fugi-Myer upper limb performance test (r = 0.84)
- Adequate correlation with TEMPA upper limb function test
- Adequate correlation with Box and Block affected upper limb score
- Adequate correlation with finger-to-nose affected limb score
Responsiveness
Stroke:
(Roberts et al, 2011)
- Recovery after a stroke estimate the differences in repeat measures of hand grip strength to be between 4.7 kg and 6.2 kg
Mixed Conditions
back to PopulationsNormative Data
Community dwelling older adults:
(Desrosiers et al, 1994; n = 360; mean age = 73.9 (8.0) years; community dwelling older adults, Quebec, Canada , comparison Jamar dynamometer (kg) and Martin Vigorimeter (kPa))
Mean (Standard Deviation)
Women
Jamar
Jamar
Martin
Martin
Age
Right Hand (kg)
Left Hand (kg)
Right Hand (kPa)
Left Hand (kPa)
60-69
25.3 (4.8)
23.6 (4.7)
53.7 (10.2)
52.4 (9.9)
70-79
23.7 (5.1)
22.0 (4.7)
52.3 (12.0)
50.1 (11.2)
80+
20.0 (4.3)
18.5 (4.4)
44.1 (9.4)
42.7 (10.9)
Men
60-69
45.6 (8.6)
43.6 (8.7)
89.4 (16.7)
88.1 (17.2)
70-79
42.4 (9.1)
40.5 (8.5)
83.0 (18.2)
79.6 (16.2)
80+
34.5 (7.2)
32.1 (7.0)
64.6 (14.5)
64.3 (14.7)
(Jansen et al, 2008; n = 224; mean age = 75.4 (6.8); good health with normal hand functions; Jamar dynamometer)
Men Norms in Pounds
Age
Hand
Mean
SD
65-69
R
91.5
15.5
L
88.2
14.4
70-74
R
84.2
17.2
L
81.4
18.4
75-79
R
81.9
9.94
L
77.3
10.2
80-84
R
70.6
14.6
L
63.1
16.2
85+
R
54.2
14.2
L
50.3
13.8
Women Norms in Pounds
Age
Hand
Mean
SD
65-69
R
54.9
10.1
L
51.5
9.5
70-74
R
52.5
9.5
L
48.3
10.5
75-79
R
48.2
10.3
L
43.6
10.7
80-84
R
44.5
11.1
L
41.0
9.3
85+
R
40.4
11.6
L
37.7
8.6
Test/Retest Reliability
Community Dwelling Older Adults:
(Bohannon et al, 2005; n = 21; mean age 75(5.9); 2 trials over a 12-week period; healthy community dwelling)
- Excellent test-retest reliability (ICC = 0.954 L, 0.912 R)
(Abizanda, et al., 2012, n=281; mean age = 74.3 (4.9) years, healthy older adults)
- Excellent test-retest reliability (ICC = 0.9874)
Mixed Conditions
back to PopulationsStandard Error of Measurement (SEM)
Healthy Adults and Patients with Primary Osteoarthritis of the hand (POAH):
(Ziv et al, 2008; n = 32 POAH; mean age 70.4 (10), n = 25 healthy adults; mean age 74.6 (8.4); measured twice within one week; Jamar dynamometer)
- SEM = 0.90 (kgf) right grip (healthy adults)
- SEM = 0.70 (kgf) left grip (healthy adults)
- SEM = 1.51 (kgf) right grip (POAH)
- SEM = 1.98 (kgf) left grip (POAH)
Healthy Basketball players:
(Vassilis, G., 2012; n = 90; three groups: prepubertal 9.8(0.7), adolescents 14.4 (0.6), and adults 26.1 (5.6); three maximal isometric contractions on each hand, two occasions, one day apart)
- SEM = 2.88% preferred hand (whole group)
- SEM = 2.41% non-preferred hand (whole group)
- SEM = 5.55% preferred hand (prepubertal)
- SEM = 4.13% non-preferred hand (prepubertal)
- SEM = 2.83% preferred hand (adolescents)
- SEM = 2.86% non-preferred hand (adolescents)
- SEM = 2.40% preferred hand (adults)
- SEM = 2.22% non-preferred hand (adults)
Normative Data
Healthy Adults:
(Massy-Westropp et al, 2011; 1366 mean and 1312 women, community based Australian population, healthy adults, Jamar hand dynamometer)
Men Hand Grip Strength in kilograms: Mean (SD)
Age
Right
Left
20-29
47 (9.5)
45 (8.8)
30-39
47 (9.7)
47 (9.8)
40-49
47 (9.5)
45 (9.3)
50-59
45 (8.4)
43 (8.3)
60-69
40 (8.3)
38 (8.0)
70+
33 (7.8)
32 (7.5)
Women Hand Grip Strength in kilograms: Mean (SD)
Age
Right
Left
20-29
30 (7)
28 (6.1)
30-39
31 (6.4)
29 (6)
40-49
29 (5.7)
28 (5.7)
50-59
28 (6.3)
26 (5.7)
60-69
24 (5.3)
23 (5)
70+
20 (5.8)
19 (5.5)
(Mathiowetz et al, 1985; 628 volunteers between the ages of 20 - 94, free from disease or injury that can affect UE strength; Jamar dynamometer in pounds)
Healthy Children and Adolescents: (Ploegmakers et al., 2013; n = 2,241 children and adolescents (1,112 boys and 1,129 girls); age range = 4 to 15 years; grip strength measured by Jamar hydraulic dynamometer; Netherlands sample)
Number of Participants and Grip Strength Values for the Dominant and Non-dominant Hands by Age and Gender
Boys
Age (yr)
n
Dominant (kg)
Non-dominant (kg)
4
124
5.7 (2)
5.3 (2)
5
102
7.5 (3)
6.8 (3)
6
123
10.2 (3)
9.4 (3)
7
104
13.0 (4)
12.0 (3)
8
113
15.9 (4)
14.6 (3)
9
116
18.2 (4)
16.8 (4)
10
109
19.6 (2)
18.1 (3)
11
113
22.0 (5)
20.6 (4)
12
96
24.7 (5)
22.9 (5)
13
66
28.2 (6)
25.8 (6)
14
46
36.0 (7)
33.5 (7)
Girls
Age (yr)
n
Dominant (kg)
Non-dominant (kg)
4
109
5.1 (2)
4.7 (2)
5
105
6.7 (2)
6.0 (2)
6
108
9.0 (3)
8.3 (3)
7
98
12.9 (3)
11.9 (3)
8
118
14.4 (3)
13.1 (3)
9
119
16.7 (3)
15.1 (3)
10
103
19.1 (4)
17.2 (4)
11
113
20.6 (4)
19.1 (4)
12
106
24.2 (5)
22.3 (4)
13
97
26.4 (5)
24.5 (4)
14
53
29.1 (5)
26.6 (5)
- Boys were significantly stronger than girls with the dominant hand at ages 4 (p = 0.02), 5 (p = 0.04), 6 (p = 0.003), 8 (p = 0.001), 9 (p = 0.001), and 14 (p = 0.001). For the non-dominant hand, boys were significantly stronger at ages 4 (p = 0.03), 6 (p = 0.02), 8 (p = 0.001), 9 (p = 0.001), 11 (p = 0.01), and 14 (p = 0.001). With the exception of the dominant hand at age 7, where the scores for both genders were equal, there was an overall trend for boys to score higher than girls with both hands in all age groups.
Test/Retest Reliability
Healthy Adults:
(Mathiowetz et al, 1984; n = 27; mean age 25; female OT students; two separate observations)
- Excellent test-retest reliability (ICC = 0.822 R, 0.915 L)
(Reddon et al., 1985, n = 12, 6 men (21 to 36 yr.), 6 women (20 to 31 yr.), tested weekly for 10 weeks)
- Excellent test-retest reliability (ICC = 0.81-0.99) for preferred and non-preferred hands in men
- Excellent test-retest reliability (ICC = 0.83-1.0) for preferred and non-preferred hands in women
Interrater/Intrarater Reliability
Healthy Adults:
(Lindstrom-Hazel et al., 2009, n = 73 convenience sample, three trials bilaterally, healthy students, facility, and staff members from Midwest University)
- Excellent interrater reliability (ICC = 0.996-0.998)
(Mathewetz, V., 2002; n = 60; 30 females 30-49 years old mean 38.4 and 30 males 20-50 mean age 37.8; free from any neuromuscular or orthopedic dysfunction; testing between Jamar and Rolyan dynamometers)
- Excellent inter-instrument reliability Male R hand (ICC = 0.97)
- Excellent inter-instrument reliability Male L hand (ICC = 0.90)
- Excellent inter-instrument reliability Female R hand (ICC = 0.90)
- Excellent inter-instrument reliability Female L hand (ICC = 0.93)
(Mathiowetz, et al, 1984,)
- Excellent interrater reliability (ICC = 0.996 R, 0.999 L)
(Peolsson, 2001; n = 32; mean age = 29; convenient sample healthy adults; three test leaders)
- Excellent intrarater reliability (ICC = 0.94 and 0.98)
- Excellent interater reliability (ICC = 0.98 for right and left handgrip strength)
Criterion Validity (Predictive/Concurrent)
Healthy Adults:
(Bellace et al, 2000; n = 62; ages of 18-50, randomized order of testing between Jamar and Dexter dynamometer; healthy adults)
- Excellent concurrent validity between dominant hand (ICC = 0.99) and nondominant hand (ICC = 0.98)
(Mathewetz, V., 2002, healthy adults)
- Excellent concurrent validity Rolyan dynamometer with known weights (0.9994 and 0.9997 before and after study)
- Excellent concurrent validity Jamar dynamometer with known weights (0.9998 and 0.9998 before and after study)
Responsiveness
Healthy Adults :
(Nitschke et al, 1999; n = 42; mean age 32.3 (7.3) healthy female subjects & 42.6 (11.8) nonspecific regional pain in upper arm female subjects; Jamar dynamometer)
- A change of more than 6 kg (13.2 lb) is necessary to detect a genuine change in grip strength 95% of the time.
(Reddon et al., 1985)
- Small change: effect size 0.01 for men’s non-preferred and women’s preferred hand and 0.13 for men’s preferred and 0.14 for women’s non-preferred hands over 10 week trial
Bibliography
Abizanda, P., Navarro, J. L., et al. (2012). "Validity and usefulness of hand-held dynamometry for measuring muscle strength in community-dwelling older persons." Arch Gerontol Geriatr 54(1): 21-27. Find it on PubMed
Bellace, J. V., Healy, D., et al. (2000). "Validity of the Dexter Evaluation System's Jamar dynamometer attachment for assessment of hand grip strength in a normal population." J Hand Ther 13(1): 46-51. Find it on PubMed
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