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Abstract

BACKROUND AND OBJECTIVE:

Grip and knee strength are commonly measured but controversy exists as to whether either is a proxy for the other. The purpose of this meta-analysis was to summarize the correlation between the 2 variables.

METHODS:

Relevant literature was sought using PubMed, Google, and a hand search. Information on populations, measurements, and correlations were extracted. Correlational data were subjected to meta-analysis.

RESULTS:

Results from 17 studies were consolidated. The summary correlation between grip and knee extension strength was 0.64 with 95% CI of 0.57 to 0.71. Data were highly heterogeneous but did not show publication bias.

CONCLUSION:

The correlation between the grip and knee extension strength is good. However, it is not good enough to justify using either as a proxy for the other.

Keywords

Muscle strength measurement clinimetrics

Table 1
Basic data relevant to the methods and findings of 17 studies addressing the relationship between grip and knee extension strength of adults

Study	Population	Grip measurement	Knee extension measurement*	Correlations**
Alonso et al. (2018)	Brazilian women (mean 67.4y) sans overt impairments or limitations ( $n=$ 110)	Jamar dynamometer Mean force of test trials of each side	Biodex IKD (60 ${}^{\circ}$ /s) Maximum peak torque of test trials of each side normalized against body weight	Dominant side: $r=$ 0.43
Nondominant side: $r=$ 0.35
Alqahtani et al. (2017)	Americans (mean 87.0y) living in residential care communities ( $n=$ 29)	Jamar dynamometer Mean force of test trials of dominant side	Measurement
Specialties uni-axial fixed load cell
Mean force of test trials of dominant side	Dominant side: $r_{s}$ $=$ 0.56
Bohannon (2012)	Americans (mean 80.2y) receiving home-care therapy ( $n=$ 34)	Jamar dynamometer
Force of test trial of each side	MicroFET2 HHD
Force of test trial of each side	Right side: $r=$ 0.58
Left side: $r=$ 0.68
Bohannon (2015)	American (mean 79.1y) patients receiving home-care therapy ( $n=$ 44)	Jamar dynamometer
Force of test trial of each side	MicroFET HHD
Force of test trial of each side	Right side: $r=$ 0.54
Left side: $r=$ 0.44
Bohannon et al. (2012)	Americans (mean 48.8y) living in community ( $n=$ 164)	Jamar dynamometer
Best force of test trials of each side	Biodex IKD (0 ${}^{\circ}$ /s)
Best peak torque of test trials of each side	Right side: $r=$ 0.81
Left side: $r=$ 0.78
Chan et al. (2014)	Dutch (median 83.3y) patients seen in general practice ( $n=$ 764)	Jamar dynamometer
Best force of test trials of dominant side	MicroFET2 HHD
Best force of test trials of dominant side	Dominant side:
Felicio et al. (2014)	Brazilian women (mean 71.1y) living in community ( $n=$ 221)	Jamar dynamometer
Mean force of test trials of dominant side	Biodex IKD (60 ${}^{\circ}$ /s, 180 ${}^{\circ}$ /s) Peak torque of dominant side (absolute and normalized)	Dominant side (60 ${}^{\circ}$ /s): $r=$ 0.26
Dominant side (60 ${}^{\circ}$ /s, normalized): $r=$ 0.12
Dominant side (180 ${}^{\circ}$ /s): $r=$ 0.15
Dominant side (60 ${}^{\circ}$ /s, normalized): $r=$ 0.03
Ito et al. (2020)	Japanese (mean 76.8y) belonging to senior club ( $n=$ 75)	“Smedley type”
Best force of test trials of both sides	Takei Scientific Instruments fixed load cell
Peak force of best test trial of both sides	Best side: $r=$ 0.77
Martien et al. (2015)	Belgians (mean 72.6y) from 3 settings ( $n=$ 947)	Jamar dynamometer
Best force of test trials of dominant side normalized against body weight	Kern dynamometer stabilized by belt
Peak force of best test trial of right side normalized against body weight	Right side: $r=$ 0.67
Ostolin et al. (2021)	Brazilians (mean 44.0y) participating in a cohort study ( $n=$ 780)	Saehan dynamometer
Best force of test trials of dominant side	Biodex IKD (60 ${}^{\circ}$ /s and isometric 60 ${}^{\circ}$
Best peak torques of test trials of dominant side	Dominant side (60 ${}^{\circ}$ /s): $r=$ 0.71
Dominant side (60 ${}^{\circ}$ ): $r=$ 0.70
Pijnappels et al. (2008)	Dutch (mean 71y), fit and sans system problems ( $n=$ 17)	Takei dynamometer
Best force of test trials of both sides summed	Cybex Norm IKD or custom-built dynamometer (0 ${}^{\circ}$ /s)
Best peak torque of trials of both sides summed and normalized against body weight	Both sides: $r=$ 0.71
Porto et al. (2019)	Brazilians (mean 68.8y) living in community ( $n=$ 150)	Jamar dynamometer
Mean force of test trials of dominant side	Biodex IKD (0 ${}^{\circ}$ /s)
Mean peak torque of test trials of dominant side	Dominant side: $r=$ 0.62

Table 1, continued
Study	Population	Grip measurement	Knee extension measurement*	Correlations**
Samuel and Rowe (2012)	Scotts (mean 73.2y) living in community ( $n=$ 82)	Jamar dynamometer
Mean of best forces of both sides	Custom dynamometer (0 ${}^{\circ}$ /s)
Mean peak torque @ 3 angles averaged for both sides	Both sides: $r=$ 0.78
Singhal et al. (2020)	East Indian (mean 72.5y) outpatients ( $n=$ 100)	Spring type dynamometer Best force of test trials of both sides	Quadriceps chair
Best 1 repetition maximum weight lifted on 2 sides	Best side: $r_{s}=$ 0.49
Strandkvist et al (2021)	Swedes (mean 75.5y) living in community ( $n=$ 45)	Biometrics dynamometer
Best force of test trials of each side	Biodex IKD (0 ${}^{\circ}$ /s)
Best torque of test trials of each side	Right side: $r=$ 0.82
Left side: $r=$ 0.76
Tieland et al (2015)	Dutch (mean 79.0y) considered frail or prefrail ( $n=$ 127)	Jamar dynamometer
Best force of test trials of both sides	Technogym machine 1 repetition maximum of bilateral knee extension	Both sides: $r_{s}=$ 0.67
Yeung et al (2018)	Europeans from 5 studies (mean 23.4 to 81.7y) mostly living in community ( $n=$ 478 men and 482 women)	Jamar and other dynamometers
Best force of test trials of both hands	Biodex IKD, other dynamometers and fixed load cells (0 ${}^{\circ}$ /s)
Best torques or forces of test trials of both sides	Men: $r=$ 0.67

*IKD $=$ isokinetic dynamometer, HHD $=$ hand-held dynamometer; **Underlined correlations were used in meta-analysis.

1. Introduction

The convenience of using the strength of a single muscle action to characterize overall muscle strength is compelling [1]. Hand-grip strength has often been advocated for such a purpose [2], as has knee extension strength [2]. The legitimacy of using either measure as an indicator of the strength of the other has been examined by analyzing the correlation between the 2 measures in multiple studies of adults. The conclusions drawn from the analyses are contradictory – with recommendations for [3] and against [4, 5] using grip strength as a proxy for overall strength. Based on the variability of the study samples, procedures, and findings, this integrative review and meta-analysis was undertaken to provide practitioners with summary evidence they might use to decide on whether grip and knee extension strength are informative of one another.

2. Methods

Inclusion of studies in the review required that they reported correlations between grip and knee extension strength in adults. Studies were excluded if they focused on children or exclusively on patients with pathology (eg, cancer). Studies were also excluded if they did not provide sufficient detail as to the exact grip and knee extension strength measures used or if they looked at leg press (a compound measure including but not limited to knee extension.) In cases where multiple relationships between grip strength and knee extension strength were reported, measurements of the right or dominant side and of isometric or the slowest isokinetic speeds for knee extension took priority in meta-analysis.

Relevant articles were identified through a computer search of PubMed (May 1, 2021) with the search string “(grip or hand) AND (knee extension) AND (strength) AND (association OR relationship OR correlation)”, a Google search (May 5, 0210) using the search string “(hand AND knee) And strength AND relationship” and by hand searches of reference lists and personal files. Key information regarding samples studied, grip and knee extension measurements, and correlations were extracted when available and recorded. When missing, authors were contacted for details.

Summary correlations were calculated using the random effects meta-analysis model of the MedCalc Software [6]. Heterogeneity and publication bias were determined using the same software.

3. Results

The PubMed search identified 335 potentially relevant articles. The Google search identified 4 additional articles. The hand search yielded 5 more articles. After examination of titles, abstracts, and full text, 17 unique articles were found to qualify for use in the review.

Table 1 [3, 4, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22] shows some study details. Seven studies involved Europeans, 4 were focused on Americans, 4 sampled Brazilians, and 2 involved Asians. All involved community-dwelling adults (though some were under medical/rehabilitation care. The mean of the ages of participants ranged from 23.4 to 87.0 y. The sample size of individual studies ranged from 17 to 947. The total number of participants was 4634. Grip strength was usually tested with a Jamar dynamometer but with a diversity of protocols. Knee extension strength was most often tested with a Biodex isokinetic dynamometer or a MicroFET handheld dynamometer, however again with diverse protocols.

Figure 1.

Forrest plot showing correlations between grip and knee extension strength for adults in 17 studies.

Figure 2.

Funnel plot showing lack of significant publication bias in correlations between grip and knee extension strength for adults in 17 studies.

Correlations reported between grip and knee extension strength in individual studies ranged from 0.03 to 0.82, but for correlations included in the meta-analysis ranged from 0.26 to 0.82 (Fig. 1). The summary correlation for the meta-analysis was 0.64 with 95% confidence intervals of 0.57 to 0.70. Heterogeneity of the studies was high (I ${}^{2}$ $=$ 92.04%). Neither Egger’s test ( $p=$ 0.64) nor Begg’s test ( $p=$ 0.46) suggested publication bias. Neither did the funnel plot (Fig. 2).

4. Discussion

This meta-analysis addressed the controversy surrounding the legitimacy of using grip strength as a proxy for knee extension strength. The summary correlation, which should provide a better indicator than correlations from individual studies, suggests that grip strength does covary with knee extension strength. That is, individuals with greater grip strength can be expected to demonstrate greater knee extension strength as well. The magnitude of the summary correlation, which might be considered “quite good…particularly in certain types of epidemiologic or psychosocial data [23]”, explains less than 40% of the variance between grip and knee extension strength. Consequently, the findings of some individual studies notwithstanding [3, 11], the results of this meta-analysis do not justify using grip and knee extension strength interchangeably. Perhaps the strength tested should be determined by the information required, patient specifics, and the resources available. Regarding information required, rising from a chair is correlated strongly with knee extension strength [24] but weakly with grip strength [25]. As for patient specifics, an individual in the intensive care unit may be amenable to testing grip strength but not knee extension strength. Concerning availability, a hand grip dynamometer is portable, easily used, and relatively inexpensive. An isokinetic dynamometer is not.

This review had several limitations. First, as only one bibliographic index was used, some key articles may have been overlooked. However, given the yield of the Google and hand searches, the relevant literature has likely been found. Second, the meta-analysis was highly heterogeneous. This means that the variation across studies was not due to chance. To what it might be attributed is uncertain- though procedural differences might be a factor. Publication bias seems not to blame.

In conclusion, grip and knee extension strength both provide an indication of limb strength. However, the correlation between these two variables is too weak to consider either measurement as a replacement for the other.

Ethical considerations

This study, as a literature review, is exempt from Institutional Review Board approval.

Funding

None.

Footnotes

Acknowledgments

None.

Conflict of interest

None.

References

Bohannon

. Is it legitimate to characterize muscle strength using a limited number of measures? J Strength Cond Res. 2008; 22(1): 166-173.

Cruz-Jentoft

Baeyens

, BauerJM Boirie

Cederholm

Landi

, et al. Sarcopenia: European consensus on the definition and diagnosis. Age Ageing. 2010; 39(4): 412-423.

Strandkvist

Larsson

Pauelsen

Nyberg

Vikman

Lindberg

, et al. Hand grip strength is strongly associated with lower limb strength but only weakly with postural control in community-dwelling older adults. Arch Gerontol Geriatr. 2021; 94: 104345.

Yeung

SSY

Reijnierse

Trappenburg

Hogrel

McPhee

Piasecki

, et al. Handgrip strength cannot be assumed a proxy for overall muscle strength. J Am Med Dir Assoc. 2018; 19(8): 703-709.

Harris-Love

Benson

Leasure

Adams

McIntosh

. The influence of upper and lower extremity strength on performance – based sarcopenia assessment tests. J Funct Morphol Kinesiol. 2018; 3(4): 53.

MedCalc Software Manual, Ostend Belgium, 2017; 161-167.

Alonso

Ribeiro

Luna

NMS

Peterson

Bocalini

Serra

, et al. Association between handgrip strength, balance, and flexion/extension strength in older adults. PLos One. 2018; 13(6): e0198185.

Alquhtani

Ferchak

Hupert

Sejdic

Perera

Greenspan

, et al. Standing balance and strength measurements in older adults living in residential care communities. Aging Clin Exp Res. 2017; 29(5): 1021-1030.

Bohannon

. Are hand-grip and knee extension strength reflective of a common construct. Percept Motor Skills. 2012; 114(2): 514-518.

10.

Bohannon

. Association of grip and knee extension strength with walking speed of older women receiving home-care physical therapy. J Frailty Aging. 2015; 4(4): 181-183.

11.

Bohannon

Magasi

Bubela

Wang

Gershon

. Grip and knee extension strength reflect a common construct among older adults. Muscle Nerve. 2012; 46(10): 555-558.

12.

Chan

OYA

van Houwelingen

Gussekloo

Blom

den Elzen

WPJ

. Comparison of quadriceps strength and handgrip strength in their association with health outcomes in older adults in primary care. Age. 2014; 36(5): 9714.

13.

Felicio

Pereira

, Assumpção de Jesus-Moraleida

de Queiroz

da Silva

, et al. Poor correlation between handgrip strength and isokinetic performance of knee flexor and extensor muscles in community-dwelling elderly women. Geriatr Gerontol Int. 2014; 14(1): 185-189.

14.

Martien

Delecluse

Boen

Seghers

Pelssers

VanHoecke

, et al. Is knee extension strength a predictor of functional performance than handgrip strength among older adults in three different settings? Arch Geontol Geriatr. 2013; 60(2): 252-268.

15.

Ito

Aoki

Sato

Ishii

. Comparison pf quadriceps setting strength and knee extension strength tests to evaluate lower limb muscle strength based on health-related physical fitness values in elderly people. BMJ Open Sport Exerc Med. 2020; 6(1): e000753.

16.

Ostolin

TLVDP

de Barros Gonze

de Oliviera Viera

de Oliveira

Nascimento

, et al. Association between the handgrip strength and the isokinetic muscle function of the elbow and knee in asymptomatic adults. Sage Open Med. 2021; 9: 2050312121993294.

17.

Pijnappels

van den Berg

JCE

Reeves

van Dieën

. Identification of elderly fallers by muscle strength measures. Eur J Appl Physiol. 2008; 102(5): 585-592.

18.

Porto

Nakaishi

APM

Cangussu-Oliveira

Júior

RCF

Spilla

Abreu

DCC

. Relationship between grip strength and global muscle strength in community-dwelling older people. Arch Gerontol Geriatr. 2019; 82: 273-278.

19.

Rodacki

ALF

Moreira

Pitta

Wolf

Melo Filho

Rodacki

CLN

Pereira

. Is handgrip strength a useful measure to evaluate lower limb strength and functional performance in older women? Clin Intervent Aging. 2020; 15: 1045-1056.

20.

Samuel

Rowe

. An investigation of the association between grip strength and hip and knee joint moments in older adults. Arch Gerontol Geriatr. 2012; 54(2): 357-360.

21.

Singhal

Bansal

Dewangan

Upadhyay

Dwivedi

Chatterjee

, et al. Low one-repetition-maximum knee extension is significantly associated with poor grip strength, female sex, and various aging-related syndromes. Aging Med. 2020; 3(2): 125-131.

22.

Tieland

Verdijk

de Groot

LCPGM

van Loon

LJC

. Handgrip strength does not represent an appropriate measure to evaluate changes in muscle strength during an exercise intervention program in frail older people. Int J Sport Nutr Exerc Metab. 2015; 25(1). 27-36.

23.

Feinstein

. Clinical epidemiology. The Architecture of Clinical Research, Philadelphia, WB Saunders Company, 1985; 178.

24.

Eriksrud

Bohannon

. Relationship of knee extension force to independence in sit-to-stand performance in patients receiving acute rehabilitation. Phys Ther. 2003; 83: 544-551.

25.

Yee

Allen

Latib

Tay

Bakar

HMA

, et al. Performance on sit-to stand tests in relation to measures of functional fitness and sarcopenia diagnosis in community-dwelling older adults. Eur Rev Aging Phys Act. 2021; 18(1): 5.

Correlation of grip and knee extension strength in mature adults

Abstract

BACKROUND AND OBJECTIVE:

METHODS:

RESULTS:

CONCLUSION:

Keywords

Table 1 Basic data relevant to the methods and findings of 17 studies addressing the relationship between grip and knee extension strength of adults

2. Methods

3. Results

Ethical considerations

Funding

Footnotes

Acknowledgments

Conflict of interest

References

Table 1
Basic data relevant to the methods and findings of 17 studies addressing the relationship between grip and knee extension strength of adults