Martin Vigorimeter assesses muscle fatigability in older adults better than the Jamar Dynamometer

The relationship between self-perceived fatigue, muscle endurance, and circulating markers of inflammation in participants of the Copenhagen aging and Midlife Biobank (CAMB)

BACKGROUND

Fatigue, low muscle endurance, muscle weakness and low-grade inflammation are strongly related to frailty at higher age. When signs of self-perceived fatigue and low muscle endurance are interrelated with low-grade inflammation at midlife, they might be used as early markers for frailty. This study investigated whether the interrelationships among self-perceived fatigue, muscle endurance and inflammation can be observed at midlife.

METHODS

A total of 965 participants of the Copenhagen Aging and Midlife Biobank (aged 52 ± 4 years, 536 males, 426 females) were assessed for self-perceived fatigue (20-item multidimensional fatigue inventory), muscle endurance (grip work), circulating markers of inflammation (hsCRP, IL-6, IL-10, TNF-alpha and IFN-γ), daily physical activity (PAS-2), body composition (%body fat assessed by bio-impedance) and self-reported health status. Participants were categorised (correcting for age and gender) according to high fatigue and/or low muscle endurance, differences in inflammatory profile between fatigue categories were assessed by ANCOVA (corrected for PAS-2, %body fat and presence of inflammatory conditions).

RESULTS

Overall, muscle endurance, fatigue and inflammatory markers were significantly interrelated. Higher levels of hsCRP (p < 0.001), IL-6 (p < 0.001), IL-10 (p = 0.035) and TNF-alpha (p = 0.028) were observed in participants presenting both low muscle endurance and high fatigue. IFN-γ was highest in those with high fatigue but normal muscle endurance (p = 0.015).

CONCLUSIONS

Middle-aged participants with higher fatigue in combination with low muscle endurance show higher levels of inflammation, independently from physical activity, body fat and inflammatory pathology. The underlying mechanisms should be identified and future studies should also investigate whether these individuals show early signs of reduced physiological reserve capacity, which in later life come to full expression by means of frailty.

Grip strength cut-points from the Swiss DO-HEALTH population

BACKGROUND

While grip strength (GS) is commonly assessed using a Dynamometer, the Martin Vigorimeter was proposed as an alternative method especially in older adults. However, its reference values for Swiss older adults are missing. We therefore aimed to derive sex- and age-specific GS cut-points for the dominant and non-dominant hand (DH; NDH) using the Martin Vigorimeter. Additionally, we aimed to identify clinically relevant weakness and assess convergent validity with key markers of physical function and sarcopenia in generally healthy Swiss older adults.

METHODS

This cross-sectional analysis includes baseline data from Swiss participants enrolled in DO-HEALTH, a 3-year randomized controlled trial in community-dwelling adults age 70 + . For both DH and NDH, 4 different definitions of weakness to derive GS cut-points by sex and age category (≤ 75 vs. > 75 years) were used: i) GS below the median of the 1st quintile, ii) GS below the upper limit of the 1st quintile, iii) GS below 2-standard deviation (SD) of the sex- and age-specific mean in DO-HEALTH Swiss healthy agers (i.e. individuals without major chronic diseases, disabilities, cognitive impairment or mental health issues) and iv) GS below 2.5-SD of the sex- and age-specific mean in DO-HEALTH Swiss healthy agers. To assess the proposed cut-points' convergent validity, we assessed their association with gait speed, time to complete the 5 Times Sit-To-Stand (5TSTS) test, and present sarcopenia.

RESULTS

In total, 976 participants had available GS at the DH (mean age 75.2, 62% women). According to the 4 weakness definitions, GS cut-points at the DH ranged from 29-42 and 25-39 kPa in younger and older women respectively, and from 51-69 and 31-50 kPa in younger and older men respectively. Overall, weakness prevalence ranged from 2.0% to 19.3%. Definitions of weakness using the median and the upper limit of the 1st GS quintile were most consistently associated with markers of physical performance. Weak participants were more likely to have lower gait speed, longer time to complete the 5TSTS, and sarcopenia, compared to participants without weakness.

CONCLUSIONS

In generally healthy Swiss older adults, weakness defined by the median or the upper limit of the 1st GS quintile may serve as reference to identify clinically relevant weakness. Additional research is needed in less healthy populations in order to derive representative population-based cut-points.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01745263.

Comparison of Grip Strength Measurements by Widely Used Three Dynamometers in Outpatients Aged 60 Years and Over

Grip strength (GS) is widely used in various fields such as sports, rehabilitation, and geriatrics to assess muscle strength, and to diagnose sarcopenia and frailty in older adults. There is a potential for measurement differences among different dynamometers available, and studies comparing GS measurements by variable tools have conflicting results. The two most frequently used dynamometers are the Jamar hydraulic (Jamar) and spring-type hand grip dynamometers, and Jamar has not been compared to Jamar PLUS+ Digital (Jamar+) dynamometer in older adults. So, we aimed to assess GS measurements with the Jamar as the reference standard against Jamar+, and spring-type Takei T.KK. 5401 (Takei) digital dynamometers. One hundred and ten outpatients aged >60 years were included. Inter-instrumental reliability was determined. The differences between dynamometers were evaluated by Bland-Altman plots and measurement error. The measurements with Jamar+, and Takei dynamometers were reliable and valid regarding the Jamar dynamometer. Takei and Jamar+ dynamometers overestimated GS over the Jamar dynamometer. Though the differences in the measured values might be disregarded in clinical practice, individuals defined to have low GS varied by the use of different dynamometers. Grip strength better be measured by the same dynamometer in serial measurements of older individuals.

Comparison between Two Different Handgrip Systems and Protocols on Force Reduction in Handgrip Assessment

INTRODUCTION

Fatigue resistance (FR) can be assessed as the time during which grip strength (GS) drops to 50% of its maximum during a sustained maximal voluntary contraction. For the first time, we compared force-time characteristics during FR test between two different handgrip systems and investigated age- and clinical-related differences in order to verify if a briefer test protocol (i.e., until 75%) could be sufficiently informative.

METHODS

A cohort of young healthy controls (Y, <30 y, 24 ± 3 y, 54% women), middle-aged (MA, 30-65 y, 47 ± 11 y, 54% women), and older (OLD, >65 y, 77 ± 7 y, 50% women) community-dwelling persons, and hospitalized geriatric patients (HOSP, 84 ± 5 y, 50% women) performed the FR test. For this purpose, an adapted vigorimeter (original rubber bulb of the Martin Vigorimeter connected to a Unik 5000 pressure gauge) here defined as "pneumatic handgrip system" (Pneu) and Dynamometer G200 system (original Jamar Dynamometer handle with an in-build strength gauge) here defined as "hydraulic handgrip system" (Hydr) were used. Force-time curves were analysed from 100% to 75% and from 75% to 50% of the initial maximal GS during the FR test. The area under the curve (GW) was calculated by integrating the actual GS at each time interval (i.e., 1/5,000 s) and corrected for body weight (GW/body weight).

RESULTS

For both systems, we found fair associations between FR100-50 and FR100-75 (Pneu mean difference = 50.1 s [95% CI: 47.9-52.4], r2 = 0.48; Hydr mean difference = 28.4 s [95% CI: 27.0-29.7], r2 = 0.52, all p < 0.001) and also moderate associations between GW(100-50)/body weight and GW(100-75)/body weight (Pneu mean difference = 32.1 kPa*s/kg [95% CI: 30.6-33.6], r2 = 0.72; Hydr mean difference = 8.1 kg*s/kg [95% CI: 7.7-8.6], r2 = 0.68, all p < 0.001). Between MA and OLD, we found a significant age-related difference in the GW results in the first 25% strength decay for Pneu (10.2 ± 0.6 kPa*s/kg against 7.1 ± 1.2 kPa*s/kg, respectively).

CONCLUSION

The brief test protocol is valid. Differences within the first 25% strength decay in GW between OLD and HOSP were identified when using Pneu but not when using Hydr. Therefore, a brief FR test protocol using a continuous registration of the strength decay seems to be sufficiently informative in a clinical setting to appraise muscle fatigability, however, only when using a Pneu system.

Validity and reliability of Eforto®, a system to (self-)monitor grip strength and muscle fatigability in older persons

INTRODUCTION

We developed Eforto®, an innovative system for (self-)monitoring of grip strength (GS) and muscle fatigability (Fatigue Resistance (FR = time until GS decreased to 50% of maximum during sustained contraction) and grip work (GW = area under the strength-time curve)). The Eforto® system consists of a rubber bulb that is wirelessly connected to a smartphone-based application, and a telemonitoring platform. The aim was to evaluate the validity and reliability of Eforto® to measure muscle fatigability.

METHODS

Community-dwelling older persons (n = 61), geriatric inpatients (n = 26) and hip fracture patients (n = 25) were evaluated for GS and muscle fatigability. In community dwellers fatigability was tested twice in the clinic (once with Eforto®, once with Martin Vigorimeter (MV), standard analog handgrip system) and for six consecutive days as a self-assessment at home with Eforto®. In hospitalized participants, fatigability was tested twice using Eforto®, once by a researcher and once by a health professional.

RESULTS

Criterion validity was supported by good to excellent correlations between Eforto® and MV for GS (r = 0.95) and muscle fatigability (FR r = 0.81 and GW r = 0.73), and no significant differences in measurements between both systems. Inter-rater and intra-rater reliability for GW were moderate to excellent (intra-class correlation: 0.59-0.94). The standard error of measurement for GW was small for geriatric inpatients and hip fracture patients (224.5 and 386.5 kPa*s) and higher for community-dwellers (661.5 kPa*s).

DISCUSSION/CONCLUSION

We established the criterion validity and reliability of Eforto® in older community-dwelling persons and hospitalized patients, supporting the implementation of Eforto® for (self-)monitoring of muscle fatigability.

Physical functioning associated with life-space mobility in later life among men and women

Background

Life-space mobility is defined as the ability to access different areas extending from the room where the person sleeps to places outside one’s hometown. Life-space mobility is vital to support performance of daily life activities and autonomous participation in social life. However, there is a dearth of research that investigates a wider range of physical functions and functioning in relation to life-space mobility rather than just single aspects. Thus, the purpose of the present study was to identify and describe several measures of physical functioning associated with life-space mobility among older men and women.

Methods

Data used in this study was derived from the OCTO 2 study, a population-based study of health, functioning and mobility among older persons (n = 312) in Sweden. Associations between Life-Space Assessment (LSA) total score and age, sex, Short Physical Performance Battery (SPPB), dizziness, lung function i.e. Peak Expiratory Flow (PEF), grip strength, self-rated vision and hearing were analysed through bivariate and multivariate regression models.

Results

The bivariate models showed that life-space mobility was significantly associated with sex, but also age, SPPB, PEF and grip strength in the total group as well as among men and women. In addition, hearing was significantly associated with life-space mobility among women. Those factors that were statistically significant in the bivariate models were further analysed in multivariable models for the total group, and for men and women separately. In these models, sex, grip strength and SPPB remained significantly associated with life-space mobility in the total group, as well as SPPB among both men and women.

Conclusion

Sex, physical function in terms of physical performance measured by SPPB (balance, gait speed and chair stand), and grip strength are associated with life-space mobility. Consequently, these factors need to be considered in assessments and interventions aiming to maintain mobility in old age.

The interrelationship between grip work, self-perceived fatigue and pre-frailty in community-dwelling octogenarians

INTRODUCTION

Low grip work and high feelings of self-perceived fatigue could be an early characteristic of decline in reserve capacity, which comes to full expression as physical frailty in a later stage. When grip work and self-perceived fatigue can be identified as characteristics differentiating between robustness and pre-frailty it might allow to identify pre-frailty earlier. Therefore, this study aimed to investigate whether the combination of grip work and self-perceived fatigue is related to pre-frailty in well-functioning older adults aged 80 and over.

METHODS

Four-hundred and five community-dwelling older adults aged 80 and over (214 robust and 191 pre-frail) were assessed for muscle endurance (grip Work corrected for body weight (GW_bw)), self-perceived fatigue (MFI-20) and frailty state (Fried Frailty Index, FFI). A Capacity to Perceived Vitality ratio (CPV) was calculated by dividing GW_bw by the MFI-20 scores. ANCOVA analysis (corrected for age and gender) was used to compare robust and pre-frail older adults, and binary logistic regressions were applied to analyze the relationship between CPV and pre-frailty status.

RESULTS

Pre-frail older adults who scored negative on the exhaustion item of the FFI still showed significantly lower GW (p < 0.001), CPV ratios (p < 0.001) and higher self-perceived fatigue (p < 0.05) compared to the robust ones. The likelihood for pre-frailty related significantly to higher age, being men and lower CPV ratios. In women, every unit increase in CPV ratio decreased the likelihood for pre-frailty by 78% (OR 0.22; 95% CI: 0.11-0.44), for men this effect was less strong (34%, OR 0.66; 95% CI: 0.47-0.93).

CONCLUSIONS

Pre-frail community-dwelling persons aged 80 years and over without clinical signs of exhaustion on the FFI still experience significantly higher fatigue levels (lower Grip Work, higher self-perceived fatigue and lower CPV levels) compared to robust ones. CPV ratio could therefore be a good tool to identify subclinical fatigue in the context of physical (pre-)frailty.

Fatigue and the prediction of negative health outcomes: A systematic review with meta-analysis

INTRODUCTION

Fatigue is a common complaint among older adults. Evidence grows that fatigue is linked to several negative health outcomes. A general overview of fatigue and its relationship with negative health outcomes still lacks in the existing literature. This brings complications for healthcare professionals and researchers to identify fatigue-related health risks. Therefore, this study gives an overview of the prospective predictive value of the main negative health outcomes for fatigue in community-dwelling older adults.

METHODS

PubMed, Web of Knowledge and PsycINFO were systematically screened for prospective studies regarding the relationship between fatigue and negative health outcomes resulting in 4595 articles (last search 5th March 2020). Meta-analyses were conducted in RevMan using Odds ratios (ORs), Hazard ratios (HRs) and relative risk ratios (RR) that were extracted from the included studies. Subgroup-analyses were performed based on (1) gender (male/female), (2) length of follow-up and (3) fatigue level (low, medium and high).

RESULTS

In total, thirty articles were included for this systematic review and meta-analysis encompassing 152 711 participants (age range 40-98 years), providing information on the relationship between fatigue and health outcomes. The results showed that fatigue is related to an increased risk for the occurrence of all studied health outcomes (range OR 1.299-3.094; HR/RR 1.038-1.471); for example, mortality OR 2.14 [1.74-2.63]; HR/RR 1.44 [1.28-1.62]), the development of disabilities in basic activities of daily living (OR 3.22 [2.05-5.38]), or the occurrence of physical decline (OR 1.42 [1.29-1.57]).

CONCLUSION

Overall fatigue increases the risk for developing negative health outcomes. The analyses presented in this study show that fatigue related physical decline occurs earlier than hospitalization, diseases and mortality, suggesting the importance of early interventions.

Muscle fatigability measured with Pneumatic and Hydraulic handgrip systems are not interchangeable

BACKGROUND

Fatigue resistance (FR) was here defined as the time during which grip strength (GS) drops to 50% of its maximum during sustained contraction. Since different GS systems exist, we compared FR obtained with Pneumatic (Pneu) and Hydraulic (Hydr) handgrip systems. Hand pain induced by both systems was also investigated since this might influence FR-outcomes.

METHODS

618 young controls (Y: reference group), 426 middle-aged (MA) and 234 old community-dwelling adults (OLD), and 50 hospitalized patients (HOSP) participated. FR was recorded with Pneu and Hydr. Grip work corrected for body weight (area under the strength-time curve; GW_BW = 0.75 ∗ maximal GS ∗ FR / body weight) was calculated. We corrected for body weight since heavier or more obese participants will have to engage more strength and sustain the effort over time. Thereafter GW_BW was expressed as T-scores representing the deviation from the mean score of the sex-specific reference group. Experienced pain, its intensity and whether pain hindered participants to sustain the contraction were questioned.

RESULTS

Overall, although significant correlation between FR measured with both systems was found (r = 0.418, p < 0.001), FR measured by Pneu (55.7 ± 35.0 s) was higher compared to Hydr (34.2 ± 18.4 s). There was a proportional difference in FR measured with both systems (R² = 0.36, p < 0.001), highlighting the longer participants could sustain FR test, the higher the difference in FR measured with both systems. Overall, there was no difference in pain variables between both systems. Independent of sex and system, GW_BW deviated less from reference group in MA compared to OLD and HOSP. In OLD, GW_BW deviated less from reference group than HOSP, independent of sex and system.

CONCLUSION

Participants were unable to sustain the contraction with Hydr as long as with Pneu. Hydr seems less able to identify subjects with higher levels of muscle endurance. Based on the GW_BM-scores we can conclude that either system can be used for assessing muscle fatigability, but Pneu may be more sensitive as differences can be detected more easily.

Measurement and Interpretation of Handgrip Strength for Research on Sarcopenia and Osteoporosis

Handgrip strength (HGS) is associated with several chronic diseases, cognitive decline, length of hospital-stay, and mortality. More importantly, HGS is one of the diagnostic criteria of sarcopenia and gaining attention because of its relevance to bone mineral density (BMD) and osteoporotic fractures. As the measurement of HGS is widely used in clinical practice as well as in research, its accurate measurement and interpretation are becoming more crucial. This review describes how to use different types of dynamometers accurately, the impact of body and arm positions and anthropometric parameters on HGS, the current reference values of HGS for sarcopenia research, and the updates on the relationship between HGS and BMD and osteoporotic fractures.

The operationalization of fatigue in frailty scales: a systematic review

PURPOSE

To identify the different fatigue items in existing frailty scales.

METHODS

PubMed, Web of Knowledge and PsycINFO were systematically screened for frailty scales. 133 articles were included, describing 158 frailty scales. Fatigue items were extracted and categorized in 4 fatigue constructs: "mood state related tiredness", "general feeling of tiredness", "activity based feeling of tiredness" and "resistance to physical tiredness".

RESULTS

120 fatigue items were identified, of which 100 belonged to the construct "general feeling of tiredness" and only 9 to the construct "resistance to physical tiredness". 49,4% of the frailty scales included at least 1 fatigue item, representing 15 ± 9,3% of all items in these scales. Fatigue items have a significantly higher weight in single domain (dominantly physical frailty scales) versus multi domain frailty scales (21 ± 3.2 versus 10.6 ± 9.8%, p=<0,05).

CONCLUSION

Fatigue is prominently represented in frailty scales, covering a great diversity in fatigue constructs and underlying pathophysiological mechanisms by which fatigue relates to frailty. Although fatigue items were more prevalent and had a higher weight in physical frailty scales, the operationalization of fatigue leaned more towards psychological constructs. This review can be used as a reference for choosing a suitable frailty scale depending on the type of fatigue of interest.

Grip Work Measurement with the Jamar Dynamometer: Validation of a Simple Equation for Clinical Use

OBJECTIVES

Previously, we developed and validated an easy test to measure muscle fatigability during sustained maximal handgrip contraction in older persons using a Martin Vigorimeter device. This study aimed at validating the equation to estimate grip work (GW) during sustained maximal handgrip contraction, by monitoring continuously the grip strength (GS) decay using a Jamar Dynamometer-like (JD) device.

DESIGN

Cross sectional, explorative study.

SETTING

Data collection took place at The National Research Centre for the Working Environment in Copenhagen, Denmark.

PARTICIPANTS

962 subjects, belonging to a subgroup of the Copenhagen Aging and Midlife Biobank, were enrolled.

METHODS

GS was recorded continuously during sustained maximal contraction until it dropped to 50% of its maximum and fatigue resistance (FR, time to fatigue) was noted. GW, area under the force-time curve, was compared to its estimate which was calculated as GWestimated=GSmax*0.75*FR.

RESULTS

Excellent correlation was found between GWestimated and GWmeasured (R²=0.98 p<0.001). The equation slightly overestimated GW by 6.04 kg*s (95% CI[-0.08, 12.15]) with a coefficient of variation method error of 6%.

CONCLUSION

GW estimation is a valid parameter reflecting muscle work output during a sustained maximal grip effort in healthy middle-aged community-dwelling persons when using a JD. GW estimation is a promising outcome parameter in comprehensive geriatric assessment and its validation for commonly used instruments in geriatric practice will increase its clinical implementation.