Grip strength measurement in older adults in Taiwan: a comparison of three testing positions

Effect of work experience and upper-limb muscle activity on grip strength of manual workers

Objectives. The current study correlated grip strength (GS) measurements with upper-limb muscle activity (UMA) for three different experience levels of manual workers (beginner, intermediate and advanced). Methods. A total of 182 male and female manual workers were chosen, and GS was assessed in some contexts using a digital handgrip dynamometer. Results. The GS values change significantly depending on the amount of experience of the workers. The difference in GS for different UMA demonstrates that continuous exposure to hand tools in different conditions of the hands (twisting, bending, etc.) significantly impacts manual arm strength. Conclusions. These findings suggest that repetitive use of hand tools in various manual operations (cutting, digging, pruning, spading, etc.) causes GS to vary significantly. In addition, beginner experience-level individuals exhibited much lower GS values in the dominant hand, whereas advanced experience-level workers had the greatest strength. Thus, for generating higher forces, professionals (advanced and intermediate levels) choose to execute safer activity (i.e., more neutral positions) than beginners.

Narrative Review of Sex Differences in Muscle Strength, Endurance, Activation, Size, Fiber Type, and Strength Training Participation Rates, Preferences, Motivations, Injuries, and Neuromuscular Adaptations

ABSTRACT

Nuzzo, JL. Narrative review of sex differences in muscle strength, endurance, activation, size, fiber type, and strength training participation rates, preferences, motivations, injuries, and neuromuscular adaptations. J Strength Cond Res 37(2): 494-536, 2023-Biological sex and its relation with exercise participation and sports performance continue to be discussed. Here, the purpose was to inform such discussions by summarizing the literature on sex differences in numerous strength training-related variables and outcomes-muscle strength and endurance, muscle mass and size, muscle fiber type, muscle twitch forces, and voluntary activation; strength training participation rates, motivations, preferences, and practices; and injuries and changes in muscle size and strength with strength training. Male subjects become notably stronger than female subjects around age 15 years. In adults, sex differences in strength are more pronounced in upper-body than lower-body muscles and in concentric than eccentric contractions. Greater male than female strength is not because of higher voluntary activation but to greater muscle mass and type II fiber areas. Men participate in strength training more frequently than women. Men are motivated more by challenge, competition, social recognition, and a desire to increase muscle size and strength. Men also have greater preference for competitive, high-intensity, and upper-body exercise. Women are motivated more by improved attractiveness, muscle "toning," and body mass management. Women have greater preference for supervised and lower-body exercise. Intrasexual competition, mate selection, and the drive for muscularity are likely fundamental causes of exercise behaviors in men and women. Men and women increase muscle size and strength after weeks of strength training, but women experience greater relative strength improvements depending on age and muscle group. Men exhibit higher strength training injury rates. No sex difference exists in strength loss and muscle soreness after muscle-damaging exercise.

Lack of significant seasonal association between serum 25(OH)D concentration, muscle mass and strength in postmenopausal women from the D-FINES longitudinal study

The aim of the present study was to assess the seasonal relationship between serum 25(OH)D concentration, lean mass and muscle strength. This was a secondary data analysis of a subgroup of 102 postmenopausal women participating in the 2006-2007 D-FINES (Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England) study. The cohort was assessed as two age subgroups: <65 years (n=80) and ≥65 years (n=22). Outcome measures included lean mass (DXA), muscle strength (handgrip dynamometry) and serum 25(OH)D concentration (enzymeimmunoassay). Derived outcomes included appendicular skeletal muscle mass (ASM) and relative appendicular skeletal muscle index (RASM). Sarcopenia status was assessed using the European Working Group on Sarcopenia in Older People 2018 criteria. Non-parametric partial correlation using BMI as a covariate was used to evaluate the study aims. There were no statistically significant associations between total lean mass, ASM or RASM and 25(OH)D in any group at any season. There was a trend for handgrip strength to be positively associated with serum 25(OH)D concentration. There was a trend showing a higher prevalence of sarcopenia in women ≥65 years. Sarcopenia status appeared transient for five women. In conclusion, the present study found no significant association between vitamin D status and functional indicators of musculoskeletal health, which were additionally not affected by season.

Effectiveness of Elastic Band Exercises on the Functional Fitness of Older Adults in Long-Term Care Facilities

BACKGROUND

Population aging has caused a rise in the institutionalization, disability, and mortality rates of older adults worldwide. Older adults are able to engage in muscle training. Elastic band exercises can safely and effectively improve the upper and lower muscle strength and balance of older adults.

PURPOSE

This study was developed to examine the effects of a 3-month elastic band exercise program on the activities of daily living (ADLs), hand muscle strength, balance, and lower limb muscle strength of older adults living in institutional settings.

METHODS

This was a randomized controlled trial. Sixty-one participants were randomly sampled from two long-term care facilities (LTCFs) in northern Taiwan (31 participants in the experimental group and 30 participants in the control group). Both groups underwent pretesting concurrently. The experimental group participated in 3 months of elastic band exercises, whereas the control group participated in the routine exercise program in their LTCFs. All of the participants were tested 1 and 3 months after the intervention.

RESULTS

The average ADL, hand muscle strength, balance, and lower limb muscle strength scores of participants in the experimental group had improved significantly more than those of the control group at posttest (all p s < .05).

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

Elastic band exercises positively affect ADLs, hand muscle strength, balance, and lower limb muscle strength in older adults living in LTCFs. Moreover, the high benefit-to-cost ratio of these exercises helps lower the threshold of health promotion. We recommend including elastic band exercises in routine activities and designing different elastic band exercises for older adults at different proficiency levels. Furthermore, an elastic band exercise network should be established to improve the policy and implementation aspects of elastic band activities, raise awareness among community-dwelling and institutionalized older adults, and promote elastic band exercises to LTCFs nationwide.

Physical fitness and frailty status of frail older adults in long-term care facilities after acupunch exercises: A cluster-randomized controlled trial

BACKGROUND

Frailty is a complex geriatric syndrome and serves as an indicator for functional degradation in older adults. Regular exercise intervention could reduce the level of frailty and improve general physical fitness. The aim of this study was to test the effects of the Vitality Acupunch (VA) exercise on the promotion of physical fitness and the improvement of frailty status among frail older adults in long-term care facilities.

METHOD

This study was a cluster-randomized controlled trial adopted a pretest-posttest design. Using convenience sampling, 81 frail adults older than 65 years of age from 10 long-term care facilities participated in this study. The older adults were cluster-randomized by facility into an intervention group (5 long-term care facilities, n = 40) and a control group (5 long-term care facilities, n = 41). The intervention group engaged in the VA exercise 3 times a week, each lasting 40 min, for 24 weeks. The control group maintained regular activities of daily living. The outcome measures for physical fitness were assessed before study began (pretest), at the 12th week (posttest 1), and at the 24th week (posttest 2) in the study.

RESULTS

After a 24-week intervention, the frail older adults who engaged in the VA exercise program showed significant improvements in handgrip strength, upper-limb muscle endurance, lung function, shoulder flexibility, forward flexion, shoulder joint flexion, and shoulder joint abduction (all p < .05) but not in lower-limb muscle endurance (p = .502) compared against their pretest data. The intervention group had significantly better physical fitness and positive changes in frailty status than the control group (all p < .001), except for the lower-limb muscle endurance (p = .557).

CONCLUSION

Regular engagement in the VA exercise program for 24 weeks significantly improved the physical fitness and frailty status of frail older adults in long-term care facilities.

The Effect of Posture on Maximum Grip Strength Measurements

INTRODUCTION/BACKGROUND

The purpose of this study was to compare the grip strength values obtained under 4 postures, and to identify the position providing the maximum grip strength value. We also explored the effects of different body positions on grip strength measurements and the significance of the selection of measurement position for guiding the screening and diagnosis of sarcopenia.

METHODOLOGY

A total of 764 people (409 males and 355 females) participated in this study. Grip strength was measured in 4 positions: (1) standing with the elbow fully extended; (2) standing with arms raised; (3) sitting with the elbow flexed 90°; and (4) sitting with the elbow extended. Multiple linear regression model was used to compare the grip strength measurements obtained from these 4 positions by each hand when considering the influence of age, gender, body mass index, and other factors.

RESULTS

Both male and female grip strength values in the standing position with the elbow fully extended were significantly greater than those in other positions. In addition, the grip strength measured by standing posture was generally greater than measured by sitting posture. In contrast, grip strength values in the 2 sitting positions did not differ significantly. The grip strength of men was generally greater than that of women.

CONCLUSIONS

The findings reveal that grip strength measured while standing with the elbow fully extended is greater than that measured while sitting, which is the posture currently recommended in clinical practice. Clinicians and researchers should choose the appropriate and optimal postures to measure grip strength.

Potential benefits of environmental volunteering programs of the health of older adults: a pilot study

PURPOSE

To study the effects of participating in a 12-week environmental volunteering program on the physical performance of older adults across different age groups MATERIALS AND METHODS: We conducted a pretest-posttest pilot study with a single group. The intervention consisted of twice-weekly recycling activities and once-weekly rehabilitation exercise at community-based care centers. The recycling activities of the environmental volunteering program included sorting and handling paper products, plastics, and metals; disposing electronic products; and sorting clothes. The rehabilitation exercise program comprised a 90-min course for special needs and 30 min of health education. The evaluation tools were the handgrip strength, five-times-sit-to-stand test, sit-and-reach test, Timed Up and Go (TUG) test and usual and fast gait speeds.

RESULTS

In total, 45 participants completed the program. After the program, the participants showed significantly great improvements compared to baseline in all outcome measures. We further divided these participants into two age subgroups [65-75 years (n = 31) and >75 years (n = 14)]. The 65-75-year subgroup only showed significant improvements in handgrip strength, TUG and usual gait speed. However, the >75-year subgroup showed significant improvements in all outcome measures.

CONCLUSIONS

This innovative environmental volunteering program conducted in a local Taiwanese community can be a sustainable and feasible model to improve physical performance in the participants, the subgroup aged >75 years in particular. It also provides a potential avenue for researchers and policymakers to address environmental and aging-related issues.

Normative data and associated factors of hand grip strength among elderly individuals: The Yilan Study, Taiwan

Weak grip strength is associated with subsequent mortality in elderly populations. The normative data and associated factors of HGS in community-dwelling elderly Taiwanese populations require further evaluation. From February 2012 until the end of 2016, all residents of Yilan City, Taiwan aged 65 years or older were randomly selected for a population-based community health survey. A total of 2,470 older adults were enrolled in this study. The relationships between HGS and various anthropometric and sociodemographic correlates were examined. The results showed that HGS was higher in men than in women. The mean HGS exhibited a decreasing trend with advanced age in both men and women. HGS was significantly associated with height, weight, and exercise habits. The physical as well as the mental component summary measures of health-related quality of life (HRQoL) were positively associated with HGS. After HRQoL was integrated into the regression model, female sex, age, waist circumference, and diabetes mellitus were significantly negatively associated with HGS. In conclusion, HGS significantly decreased with advanced age. among community-dwelling Taiwanese elderly people, Various factors had different effects on HGS.

Association of gait speed and grip strength with risk of cardiovascular events in patients on haemodialysis: a prospective study

Background

Gait speed (GS) and handgrip strength (HGS), both factors associated with frailty and sarcopenia, are reportedly associated with CV events in the general population. However, little is known about the impact of these factors on the outcome of patients on dialysis. This study aimed to evaluate whether evaluation of GS and HGS could be associated the onset of fatal/non-fatal cardiovascular (CV) events in patients on haemodialysis (HD).

Methods

One-hundred-eighty-two patients with end-stage renal disease (ESRD) undergoing HD at four dialysis clinics in April 2015 provided written informed consent to participate in the study. We excluded patients who had physical disability, were unable to walk without help, or had recently experienced CV events. Usual GS over a 4-m walk and HGS were measured at baseline, and 173 patients (men, 124; women, 49) were divided into sex-specific quartiles according to GS and HGS and were followed-up for fatal/non-fatal CV events for a median of 2 years. We examined the association of GS and HGS with CV events and determined cut-off values using Cox regression analysis adjusted for age, sex, HD duration, history of CVD, and diabetes.

Results

During the follow-up period, 46 CV events occurred. Both physical performance factors were significantly associated with CV events. Low GS (< 0.82 m/s for men and 0.81 m/s for women) and weak HGS (< 29.0 kg for men and 19.7 kg for women) were associated with CV events. For low vs. high GS, the hazard ratio (HR) for CV events was 2.29 [95% confidence interval (CI): 1.20–4.33; P = 0.01], and for low vs. high HGS, the HR was 2.15 [95% CI: 1.00–5.04; P < 0.05]. These HRs remained significant after adjusting for confounding factors, such as sex, age, dialysis vintage, history of CV disease, and diabetes.

Conclusions

Slow GS and weak HGS in patients on HD were suggested to be independent predictors of fatal/non-fatal CV events.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1370-6) contains supplementary material, which is available to authorized users.

CORP: Measurement of upper and lower limb muscle strength and voluntary activation

Muscle strength, the maximal force-generating capacity of a muscle or group of muscles, is regularly assessed in physiological experiments and clinical trials. An understanding of the expected variation in strength and the factors that contribute to this variation is important when designing experiments, describing methodologies, interpreting results, and attempting to replicate methods of others and reproduce their findings. In this review (Cores of Reproducibility in Physiology), we report on the intra- and inter-rater reliability of tests of upper and lower limb muscle strength and voluntary activation in humans. Isometric, isokinetic, and isoinertial strength exhibit good intra-rater reliability in most samples (correlation coefficients ≥0.90). However, some tests of isoinertial strength exhibit systematic bias that is not resolved by familiarization. With the exception of grip strength, few attempts have been made to examine inter-rater reliability of tests of muscle strength. The acute factors most likely to affect muscle strength and serve as a source of its variation from trial-to-trial or day-to-day include attentional focus, breathing technique, remote muscle contractions, rest periods, temperature (core, muscle), time of day, visual feedback, body and limb posture, body stabilization, acute caffeine consumption, dehydration, pain, fatigue from preceding exercise, and static stretching >60 s. Voluntary activation, the nervous system’s ability to drive a muscle to create its maximal force, exhibits good intra-rater reliability when examined with twitch interpolation (correlation coefficients >0.80). However, inter-rater reliability has not been formally examined. The methodological factors most likely to influence voluntary activation are myograph compliance and sensitivity; stimulation location, intensity, and inadvertent stimulation of antagonists; joint angle (muscle length); and the resting twitch.

New Methods to Assess Forearm Torque and Lifting Strength: Reliability and Validity

PURPOSE

To determine the repeatability and validity of new methods designed to objectively measure forearm torque and lifting strength in a clinical setting.

METHODS

Twenty-eight healthy volunteers, 19 women and 9 men, were tested for lifting strength and forearm torque with the Kern and Baseline dynamometers. Two raters tested each participant on 3 occasions in the standing position. One of the raters also examined 15 subjects, 3 times, for forearm torque in the seated position and for lifting strength and forearm torque by the Work Simulator II, Baltimore Therapeutic Equipment (BTE II). Intraclass correlation coefficients (ICC) model 2,1 was used to calculate ICCs for intra- and interrater reliability. The same ICC model and Bland-Altman plots were used to analyze the validity and agreement between the new test methods and the BTE II equipment and for comparison between tests performed in the standing and seated positions.

RESULTS

Intra- and interrater reliability for forearm torque measurements with both the Baseline and the BTE II demonstrated ICCs between 0.88 and 0.96. The comparison between the Baseline and the BTE equipment yielded lower ICCs of 0.74 to 0.88 but they were still substantial and in good agreement. The ICCs for torques recorded in the standing and seated position were 0.89 to 0.96. Lifting strength, measured in 3 different positions of forearm rotation, yielded ICC values between 0.84 and 0.96 for both raters and with both the Kern and the BTE II instruments. Similarly, comparisons between the Kern and the BTE II methods showed ICC values between 0.91 and 0.95.

CONCLUSIONS

Both the Baseline and the Kern dynamometers demonstrated excellent intra- and interrater repeatability. Except for forearm torque test in direction of pronation, which had a slightly lower ICC of 0.74, our new methods were valid when the BTE II was used as the reference standard. Assessments in the standing or seated position for torque measurements made little difference. Thus, we found the quality of measurements performed with our new methods sufficient for future studies of forearm torque and lifting strength.

CLINICAL RELEVANCE

Simple, yet reliable, methods to quantify torque and lifting strength in a clinical setting have the potential to improve evaluations of wrist and forearm disorders as well as their treatments.

Hand-grip strength among older adults in Singapore: a comparison with international norms and associative factors

BACKGROUND

Hand-grip strength (HGS) serves as a proxy measure for muscle function and physical health. Studies have shown that low HGS is associated with common age-related disorders including frailty and sarcopenia. The aim of the present study was to establish the normative values of HGS among older adults in Singapore and to compare it with data from Western and other Asian countries. The study also aimed to explore the sociodemographic and anthropometric correlates of HGS.

METHODS

Data were collected from 2043 men and women aged 60 years and above who took part in the Well-being of the Singapore Elderly study in 2013. HGS was obtained using a Jamar Plus + digital hand dynamometer. Normative data were stratified by; 5-year age groups, sex and ethnicity. Relationships between the HGS with various sociodemographic and anthropometric correlates were examined using multiple linear regression analysis.

RESULTS

The mean HGS demonstrate a decreasing trend with increased age across all ethnic groups and sexes. HGS among Singapore older adults were relatively low compared to Western and other Asian countries. Males in the youngest age group (60-64) and of Chinese ethnicity attained greater HGS values than their counterparts. When the regression analysis was stratified for sex, significant associations were found between height, upper arm circumference with HGS in the males sample, and between height, weight, waist circumference and HGS in the females sample.

CONCLUSIONS

Older adults in Singapore have a relatively weak HGS compared to other countries. Greater height and weight, and smaller waist circumference are independently associated with greater HGS in females but not males. These results facilitate the interpretation of HGS conducting using Jamar digital-type dynamometers among the older adults in Singapore.

Global variation in grip strength: a systematic review and meta-analysis of normative data

BACKGROUND

weak grip strength is a key component of sarcopenia and is associated with subsequent disability and mortality. We have recently established life course normative data for grip strength in Great Britain, but it is unclear whether the cut points we derived for weak grip strength are suitable for use in other settings. Our objective was to investigate differences in grip strength by world region using our data as a reference standard.

METHODS

we searched MEDLINE and EMBASE for reporting age- and gender-stratified normative data for grip strength. We extracted each item of normative data and converted it on to a Z-score scale relative to our British centiles. We performed meta-regression to pool the Z-scores and compare them by world region.

FINDINGS

our search returned 806 abstracts. Sixty papers met inclusion criteria and reported on 63 different samples. Seven UN regions were represented, although most samples (n = 44) were based in developed regions. We extracted 726 normative data items relating to 96,537 grip strength observations. Normative data from developed regions were broadly similar to our British centiles, with a pooled Z-score 0.12 SDs (95% CI: 0.07, 0.17) above the corresponding British centiles. By comparison, normative data from developing regions were clearly lower, with a pooled Z-score of -0.85 SDs (95% CI: -0.94, -0.76).

INTERPRETATION

our findings support the use of our British grip strength centiles and their associated cut points in consensus definitions for sarcopenia and frailty across developed regions, but highlight the need for different cut points in developing regions.