Reliability of Isometric Knee Extension Muscle Strength Measurement Using a Hand-held Dynamometer with a Belt: A Study of Test-retest Reliability in Healthy Elderly Subjects

Sarcopenia and muscle strength reduction are a frequent disorder in non-communicable chronic diseases. The aims of this study are: (a) to verify if the absolute and relative to body weight muscle strength of lower limb is affected by the presence of pathology; (b) to verify if the trends are different among knee and ankles joints. One-hundred and forty-five elderly were recruited (16 liver transplant recipients, 48 kidney transplant recipients, 52 elderly with obesity, 30 healthy elderly). Muscular strength of lower limb was evaluated. Evaluation protocol included maximal isometric knee extension, maximal isokinetic knee extension and flexion, maximal isokinetic ankle (both right and left) extension and flexion. A statistically significant interaction between measurement and group membership was found for absolute strength measure (F (4.23, 170.56) = 3.316, p = 0.011, partial η2 (η2p) = 0.076), and relative strength measure(F (4.44, 174.72) = 16.407, p < 0.01, partial η2 (η2p) = 0.294). Elderly patients living with kidney transplants showed the lower level of absolute muscular strength, while relative muscular strength is mainly lacking in the elderly with obesity. The strength profile of elderly subjects is affected by obesity, liver transplantation, and kidney transplantation.

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Reliability and Structural and Construct Validity of the Functional Strength Measurement in Children Aged 4 to 10 Years

Physical Therapy ◽

10.2522/ptj.20140018 ◽

2016 ◽

Vol 96 (6) ◽

pp. 888-897 ◽

Cited By ~ 13

Author(s):

Wendy F.M. Aertssen ◽

Gillian D. Ferguson ◽

Bouwien C.M. Smits-Engelsman

Keyword(s):

Factor Analysis ◽

Muscle Strength ◽

Construct Validity ◽

Exploratory Factor Analysis ◽

Convergent Validity ◽

Discriminant Validity ◽

Structural Validity ◽

Strength Measurement ◽

Retest Reliability ◽

Test Retest Reliability

Background Adequate muscle strength, power, and endurance are important in children's daily activities and sports. Various instruments have been developed for the assessment of muscle function; each measures different aspects. The Functional Strength Measurement (FSM) was developed to measure performance in activities in which strength is required. Objective The study objective was to establish the test-retest reliability and structural and construct validity of the FSM. Design A cross-sectional descriptive study was conducted. Methods The performance of 474 children with typical development on the FSM was examined. Test-retest reliability (n=47) was calculated with the intraclass correlation coefficient (2.1A) for agreement. Structural validity was examined with exploratory factor analysis, and internal consistency was established with the Cronbach alpha. Construct validity was determined by calculating correlations between FSM scores and scores obtained with a handheld dynamometer (HHD) (n=252) (convergent validity) and between FSM scores and scores on the Movement Assessment Battery for Children–2 (MABC-2) (n=77) (discriminant validity). Results The test-retest reliability of the FSM total score ranged from .91 to .94. The structural validity revealed one dimension, containing all 8 FSM items. The Cronbach alpha was .74. The convergent validity with the HHD ranged from .42 to .74. The discriminant validity with MABC-2 items revealed correlations that were generally lower than .39, and most of the correlations were not significant. Exploratory factor analysis of a combined data set (FSM, HHD, and MABC-2; n=77) revealed 2 factors: muscle strength/power and muscle endurance with an agility component. Limitations Discriminant validity was measured only in children aged 4 to 6 years. Conclusions The FSM, a norm-referenced test for measuring functional strength in children aged 4 to 10 years, has good test-retest reliability and good construct validity.

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A portable isometric knee extensor strength testing device: test-retest reliability and minimal detectable change scores of the Q-Force ӀӀ in healthy adults

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04848-8 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Johanneke Hartog ◽

Sandra Dijkstra ◽

Joke Fleer ◽

Pim van der Harst ◽

Massimo A. Mariani ◽

...

Keyword(s):

Muscle Strength ◽

Standardized Test ◽

Knee Extensor ◽

Knee Extension ◽

Minimal Detectable Change ◽

Clinical Settings ◽

Detectable Change ◽

Retest Reliability ◽

Knee Extensor Strength ◽

Test Retest Reliability

Abstract Background Although knee extensors are essential in daily activities (e.g. walking, climbing stairs), knee extensor strength is often not measured in clinical settings. Existing devices to test muscle strength are not always suitable to accurately measure the high forces of this muscle group. Therefore, a device to test muscle strength that is convenient, feasible, reliable, and valid in clinical settings is required. This study evaluated the reliability, responsiveness, and level of discomfort of the newly developed Q-Force ӀӀ (i.e. a portable device to measure isometric knee extensor strength) in healthy middle-aged and elderly adults. Methods Participants (n = 22) conducted two standardized test sessions on the Q-Force ӀӀ (five to ten days apart). Each session consisted of one familiarisation trial followed by three trials of peak isometric knee extension per each leg. Per trial, peak and mean knee extension force (N) and torque (Nm) were measured at 90° flexion. The level of discomfort was determined using a visual analog scale (VAS: 0-100). Intra Class Correlation (ICC, model: two-way mixed with absolute agreement), Standard Error of Measurement (SEM), and minimal detectable change (MDC) were determined. A repeated measures ANOVA was used to determine between-test variation. Results Excellent test-retest (ICC > 0.95) and inter-trial (ICC > 0.91) reliability for both legs were shown. No significant differences were found in peak and mean knee forces and torques between test and retest of both legs, indicating good test-retest reliability (P-value range: 0.360-0.538; F(1,21) range: 0.4-0.9). The SEM of the peak and mean forces and torques ranged from 28.0 to 30.4 N (6.0-6.8%) and from 9.2 to 10.4 Nm (6.4-7.7%), respectively. The MDC for these outcomes ranged respectively from 77.6 to 84.1 N (16.5-18.8%) and from 25.5 to 28.9 Nm (17.6-21.4%). The level of discomfort was low (median range: 7-10, IQR: 4-18). Conclusion The portable Q-Force ӀӀ is a comfortable, responsive, and relatively cheap device with excellent test-retest reliability. This device would be potentially suitable to measure isometric knee extensor strength in clinical settings.

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