Relationship between grip strength and bone mineral density in healthy Hong Kong adolescents

Multivariable reference centiles for maximum grip strength in childhood to young adults

OBJECTIVES

Maximum grip strength (mGS) is a useful predictor of health-related outcomes in children and adults. The aim of the study was to generate sex- and age-adjusted reference centiles for mGS for children, adolescents and young adults, while adjusting for body height and body mass index (BMI).

METHODS

A retrospective analysis of longitudinal data from children and young adults participating in the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study (single center, open cohort study) from 2004 to 2022 was conducted. To generate sex-, age-, height- and BMI-adjusted reference centiles, a new algorithm combining multiple linear regression and the LMS method was conducted.

RESULTS

Overall, 3325 measurements of mGS of 465 females and 511 males were eligible. The mean age at measurement of females was 12.6 ± 3.9 years, mean age of males was 12.4 ± 4.7 years. The median of number of repeated measurements per individual was 3 (range 1-8). The mGS was significantly (p < 0.001) correlated to body height and BMI (r = 0.303-0.432). Additional reference centiles for the change of z-scores of mGS were generated for children and young adults from 8 to 20 years.

CONCLUSIONS

We proposed to evaluate mGS in children, adolescents and young adults with the presented reference centiles adjusted to sex, age, height and BMI. The method presented may also be applicable to other biological variables that depend more than just on sex and age. For the first time, also reference centiles to assess the change of mGS in repeated measurements were presented.

Role of muscle mass in the association between handgrip strength and blood pressure in children and adolescents

Studies have reported conflicting results on the association between handgrip strength (HGS) and blood pressure during childhood and adolescence. High multicollinearity involving somatic components that influence both HGS and blood pressure might be an important source of bias. This study sought to investigate the independent effects of HGS and muscle mass on blood pressure levels in children and adolescents. Muscle mass and fat mass (Multifrequency Electrical Bioimpedance) and systolic (SBP) and diastolic (DBP) blood pressure (Automatic oscillometric device) were assessed in 833 volunteers aged 6-18 years, of both sexes. Handgrip strength-for-age quartiles were calculated and participants were assigned to groups by HGS quartiles. Analysis of covariance was conducted to address the linear association between HGS and SBP adjusted for height, muscle mass, and fat mass. To test for linear trend, contrast analysis was conducted. Partial eta-squared was used to confirm or rule out a small significant effect of the independent variables on SBP. The effect size of HGS on SBP was not significant in both sexes. In girls, 1.7% of the between-groups variance in SBP was accounted for by muscle mass (P = 0.016). In boys, 2.3% and 1.8% of the between-groups variance in SBP was accounted for by muscle mass (P = 0.001) and height (P = 0.005), respectively. In conclusion, children with a more advanced physical maturity for their age, that is, who are taller, stronger, and have greater fat-free mass, may be nearly reaching the physiological parameters of adulthood, and consequently have higher systolic blood pressure.

Comparison of finger flexion strength and muscular recovery of male lead sport climbers across climbing classes

BACKGROUND/OBJECTIVE

The purpose of this study was to compare finger flexor strength (FS), finger flexor muscle recovery (FR), and forearm circumference (FC) across three different climbing classes in male lead sport climbers.

METHODS

A total of 37 male lead sport climbers were classified into low (LC), intermediate (IC), and advanced classes (AC) categories according to the International Rock Climbing Research Association (IRCRA) Scale. All participants measured FS three times for both open grip (OG) and crimp grip (CG). Following FS measurement, the FR was observed immediately after the all-out training. The FC was measured twice using an inelastic tape.

RESULTS

The FS differed significantly across climbing classes for both grip styles and hands, regardless of dominant hand, with the higher classes showing greater FS (all, p ≤ 0.001). FR was significantly higher in AC compared to IC and LC at 5 min (all, p ≤ 0.001), 10 min (all, p ≤ 0.005) and 15 min (all, p ≤ 0.005). The FC showed significant differences with climbing classes for both forearms.

CONCLUSION

Climbing classes are associated with differences in FS, with higher class corresponding to greater FS. Similarly, climbing classes are linked to FR and FC, with higher classes being associated with faster recovery and larger FC.

Hand grip strength, vitamin D status, and diets as predictors of bone health in 6-12 years old school children

BACKGROUND

Vitamin D and calcium-rich foods, exposure to sunlight, and physical activities (PA) play a pivotal role in promoting the production of sufficient vitamin D and improving grip strength needed for better bone health among school children.

PURPOSE

This study aimed to determine the effects of hand grip muscle strength (HGS), vitamin D in addition to diets, and PA on bone health status among 6-12 years old schoolchildren.

METHODS

This study was based on a cross-sectional observational design, which was descriptive in nature. A diverse sample of 560 elementary school children aged 6-12 years old were invited to participate in this descriptive cross-sectional study. The Dual-Energy X-Ray Absorptiometry (DXA), QUS technique, and ACTi graph GT1M accelerometer were used respectively as a valid tools to identify BMD, BMC, and other parameters of bone health like c-BUA values and bone stiffness (SI), and physical activity (PA) of all individuals participated in this study. In addition, a hydraulic dynamometer was used to measure hand grip strength among the participants. Moreover, an immunoassay technique was used to measure the serum levels of vitamin 25(OH)D level, and bone metabolism markers; NTX, DPD, Ca, and sBAP in all participants. Bone loss (osteoporosis) was cross-sectionally predicted in 19.64% of the total population, most of whom were girls (14.3% vs. 5.4% for boys; P = 0.01). Compared to boys, the incidence of osteoporosis was higher and significantly correlated in girls with lower HGS, deficient vitamin D, inadequate vitamin D and Ca intake, greater adiposity, poor PA, and lower sun exposure. Also, in girls, lower vitamin 25(OH)D levels, and poor HGS were shown to be significantly associated with lower values of BMD, BMC, SI, and higher values of bone resorption markers; NTX, DPD, and sBAP and lower serum Ca than do in boys. The findings suggested that deficient vitamin D, lower HGS, adiposity, PA, and sun exposure as related risk factors to the pravelence of bone loss among school children, particularly in girls. In addition, these parameters might be considered diagnostic non-invasive predictors of bone health for clinical use in epidemiological contexts; however, more studies are required.

Children with Low Handgrip Strength: A Narrative Review of Possible Exercise Strategies to Improve Its Development

BACKGROUND

Handgrip strength (HGS) is a predictor of health in both children and adults. Evidence suggests that without a possible strategy, children with low HGS may become adults with low HGS. However, little is known about what strategies are effective for children with low HGS to achieve a higher baseline level in adulthood. This narrative review aimed to investigate whether physical exercise interventions could improve HGS in children.

METHODS

The relevant databases/search engine was searched using keywords related to the main topics discussed throughout this review.

RESULTS

Our findings suggest that it may not be possible to improve HGS over that observed from normal development with physical education or traditional resistance-training programs. However, if the training program includes exercises that directly stimulate the forearm/hand muscle groups to grip, it may be possible to obtain changes in HGS that exceed the changes due to normal developmental growth.

CONCLUSION

Although there are associations between HGS and markers of health, no research could be identified that examined whether increasing HGS would lead to an improvement in health. If an increase in HGS really does represent an improvement in long-term health, then gripping exercise may need to be included into physical activity programs during the growth/development phase.

Is Subjective Age Associated with Physical Fitness in Community-Dwelling Older Adults?

Although subjective age has been associated with a range of health-related outcomes, there has been little systematic study on the relationship between the subjective age and physical fitness in a given population. The purpose of this study was to determine the prospective association between subjective age and physical fitness in community-dwelling older adults. A sample of 276 older people who lived in the community was studied. Subjective age was measured by a face-to-face interview. Grip strength, balancing on one leg with eyes open, the 30 s chair stand test, 4 m habitual walk, and 6 min walk test were measured to reflect physical fitness. Results indicated that the felt younger older adults had a higher level of physical fitness compared to their felt older and felt the same counterparts. Multiple linear regression analysis indicated that all the measured physical fitness items were significantly associated with subjective age in older men. All of the measured physical fitness items except for the 4 m habitual walk were remarkably related to subjective age in older women. The findings suggest that subjective age is closely associated with physical fitness in community-dwelling older adults. Much attention should be paid to the promotion of physical fitness to improve the subjective age of older adults.

Trust in Healthcare during COVID-19 in Europe: vulnerable groups trust the least

Aim

We examined predictors of trust in the healthcare system during the COVID-19 pandemic in 27 European countries.

Subjects and methods

We used population-based data drawn from the Living, working and COVID-19 survey (N = 21,884, 52% female, ages 18 to 92 years) covering 27 European countries dated June and July 2020. Multilevel linear regression, linear regression, and regression-tree analyses were conducted.

Results

We found that most participants tended to trust the healthcare system, although a substantial part could still be classified as distrusting (approx. 21%). Multiple variables, including being middle-aged or of older age, being female, lower levels of education, unemployment, worse general health status, having income difficulties, having unmet needs for healthcare, no healthcare contact during the COVID-19 pandemic, higher mental distress, and loneliness, were significantly associated with lower levels of trust. Among these variables mental distress, income difficulties, and unmet needs for healthcare emerged as especially important and, across European regions and countries, consistent predictors for lower trust in the healthcare system during the COVID-19 pandemic.

Conclusions

Medically vulnerable subgroups, such as individuals with unmet healthcare needs, higher levels of mental distress, and older age, as well as people living in socially and economically vulnerable situations, such as higher levels of loneliness and financial difficulties, were the least trusting of the healthcare system during the COVID-19 pandemic. As these vulnerable subgroups are also at highest risk for contracting COVID-19 and experiencing negative COVID-19-related outcomes, more targeted prevention and intervention efforts should be implemented in these groups.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-022-01705-3.

Relationship Between Muscle Strength, Body Composition and Bone Mineral Density in Adolescents

Adolescence is an important period for the acquisition of bone mass, which can be enhanced by several factors. This study aimed examine the relationships of handgrip strength, free-fat mass, and fat mass with bone mineral density in adolescents. 118 adolescents (60 girls), aged 10 to 14 years, participated in the study. Information on sex, age, handgrip strength, free-fat mass, fat mass and bone mineral density were collected. Multiple linear regression analyses were conducted to examine possible relationships between bone mineral density and handgrip strength, free-fat mass and fat mass. There was a relation between handgrip strength and free-fat mass with bone mineral density in both sexes. Fat mass was correlated with bone mineral density only in girls (r= 0.314, p< 0.014). The final models, adjusted for sexual maturation, included free-fat mass (girls - β= 0.419, p< 0.001; boys - β= 0.455; p< 0.001) and handgrip strength (girls - β= 0.358, p< 0.05; boys - β= 0.325; p< 0.05) and these variables together explained 51.8% and 62.9% of the variation of bone mineral density, in girls and boys, respectively. Handgrip strength and free-fat mass were positively associated with bone mineral density. A sex-specific difference indicated that higher levels of free-fat mass are of paramount importance for both sexes.

Muscle-bone axis in children with chronic kidney disease: current knowledge and future perspectives

Bone and muscle tissue are developed hand-in-hand during childhood and adolescence and interact through mechanical loads and biochemical pathways forming the musculoskeletal system. Chronic kidney disease (CKD) is widely considered as both a bone and muscle-weakening disease, eventually leading to frailty phenotype, with detrimental effects on overall morbidity. CKD also interferes in the biomechanical communication between two tissues. Pathogenetic mechanisms including systemic inflammation, anorexia, physical inactivity, vitamin D deficiency and secondary hyperparathyroidism, metabolic acidosis, impaired growth hormone/insulin growth factor 1 axis, insulin resistance, and activation of renin-angiotensin system are incriminated for longitudinal uncoordinated loss of bone mineral content, bone strength, muscle mass, and muscle strength, leading to mechanical impairment of the functional muscle-bone unit. At the same time, CKD may also interfere in the biochemical crosstalk between the two organs, through inhibiting or stimulating the expression of certain osteokines and myokines. This review focuses on presenting current knowledge, according to in vitro, in vivo, and clinical studies, concerning the pathogenetic pathways involved in the muscle-bone axis, and suggests approaches aimed at preventing bone loss and muscle wasting in the pediatric population. Novel therapeutic targets for preserving musculoskeletal health in the context of CKD are also discussed.

Handgrip strength is positively associated with bone mineral density in middle and aged adults: results from NHANES 2013-2014

Few studies have examined the association between handgrip strength and BMD in specific subgroups. Therefore, we examined the associations of handgrip strength with BMD aged ≥ 40 years and found that handgrip strength is associated with BMD which is independent of BMI, physical activity, and other potential confounders.

PURPOSE

Previous studies have revealed that handgrip strength is a measure of muscular fitness and is associated with fracture and bone mineral density (BMD) in adolescents and adults, with conflicting results. In addition, few studies have examined the association between handgrip strength in predefined subgroups such as sex, age, and physical activity in a whole population.

METHODS

We examined the associations of handgrip strength with BMD in 2720 adults (1359 men and 1361 women) aged ≥ 40 years (mean age, 58.6 ± 11.8 years) from the National Health and Nutrition Examination Survey (NHANES) 2013-2014. NHANES collects data via household interviews and direct standardized physical examinations conducted in specially equipped mobile examination centers. The date of final data collection was 2014 and the present data analysis was conducted in January to February 2020.

RESULTS

Handgrip strength was significantly associated with total femur (r = 0.482, P < 0.001) and femoral neck BMD (r = 0.427, P < 0.001) among all participants, respectively. After adjustment for age, sex, race, body mass index (BMI), physical activity, smoking, history of diabetes, history of hypertension, and history of high cholesterol, each unit (1 SD) of BMI-adjusted handgrip strength was positively associated with 0.026 g/cm² increase in total femur BMD (P < 0.001) and 0.027 g/cm² increase in femoral neck BMD (P < 0.001). There was a significant increasing trend in total femur and femoral BMD as handgrip strength increased from the lowest quartile to the highest quartile (P for trend < 0.001). For subgroup analysis, there were no significant interaction effects of handgrip strength with BMD between predefined subgroups (all P > 0.05).

CONCLUSIONS

High level of handgrip strength is associated with increased BMD. The association is independent of BMI, physical activity, and other potential confounders.

Association between handgrip strength and bone mineral density of Brazilian children and adolescents stratified by sex: a cross-sectional study

Background

To examine the association of handgrip strength (HGS) and bone mineral density (BMD) of Brazilian children and adolescents.

Methods

The sample included 243 children and adolescents aged from 4 to 15 years (9.3 ± 2.2 years), 171 males and 72 females. The following measurements were performed: weight, height, trunk length, and years to the peak height velocity (PHV). The percentage lean soft tissue (PLST), percentage fat mass (PFM), and BMD were obtained using Dual Energy X-ray Absorptiometry (DXA) and HGS using a dynamometer.

Results

In girls, HGS was positively associated with higher BMD, even after the adjustments, by arms [β = 0.006; p < 0.001], legs [β = 0.014; p < 0.001], pelvis [β = 0.019; p < 0.001], trunk [β = 0.013; p < 0.001], spine [β = 0.013; p = 0.008], and total body [β = 0.009; p < 0.001]. The same occurred in the boys, even after the adjustments a positive relationship was observed, whereas higher HGS was related to greater BMD in arms [β = 0.006; p < 0.001], legs [β = 0.017; p < 0.001], pelvis [β = 0.014; p < 0.001], trunk [β = 0.009; p < 0.001], spine [β = 0.008; p < 0.001], and total body [β = 0.007; p < 0.001].

Conclusion

HGS was positively associated to BMD in boys and girls, regardless of age, PHV, PLST, and PFM.

Osteoporosis Detection by Physical Function Tests in Resident Health Exams: A Japanese Cohort Survey Randomly Sampled from a Basic Resident Registry

Osteoporosis may increase fracture risk and reduce healthy quality of life in older adults. This study aimed to identify an assessment method using physical performance tests to screen for osteoporosis in community dwelling individuals. A total of 168 women aged 50–89 years without diagnosed osteoporosis were randomly selected from the resident registry of a cooperating town for the evaluation of physical characteristics, muscle strength, and several physical performance tests. The most effective combinations of evaluation items to detect osteoporosis (i.e., T-score ≤ −2.5 at the spine or hip) were selected by multivariate analysis and cutoff values were determined by likelihood ratio matrices. Thirty-six women (21.4%) were classified as having osteoporosis. By analyzing combinations of two-step test (TST) score and body mass index (BMI), osteoporosis could be reliably suspected in individuals with TST ≤ 1.30 and BMI ≤ 23.4, TST ≤ 1.32 and BMI ≤ 22.4, TST ≤ 1.34 and BMI ≤ 21.6, or TST < 1.24 and any BMI. Setting cut-off values for TST in combination with BMI represents an easy and possibly effective screening tool for osteoporosis detection in resident health exams.

Activity-Inactivity Patterns, Screen Time, and Physical Activity: The Association with Overweight, Central Obesity and Muscle Strength in Polish Teenagers. Report from the ABC of Healthy Eating Study

Today, the time spent actively is increasingly being replaced by screen-based media, although in some teenagers, a high level of physical activity (PA) and longer time spent in front of a screen (screen time, ST) may coexist as a mixed behavioral pattern. This study aimed to examine the association of the pattern created as activity (low/high ST with high PA) and inactivity patterns (low/high ST with low PA) with overweight, central obesity, and muscle strength in Polish teenagers taking into consideration socioeconomic and demographic factors. Cross-sectional data were collected from elementary school children (n = 1567), aged 11–13 years. Height, weight, waist circumference, and handgrip strength were measured. Body mass index (BMI) was calculated as the overweight measure, and the waist-to-height ratio (WHtR) was calculated as the central obesity measure. Data on ST, PA, socioeconomic status, demographics, and nutrition knowledge were collected by a questionnaire. Activity–inactivity patterns were defined by an a priori approach. Multivariate logistic regression modelling was applied. The most active pattern (lowST-highPA) was found in 17% of the total sample. Teenagers with the most inactive pattern (highST-lowPA) had over four times higher chance of general overweight. No association between WHtR ≥0.5 and highST-highPA pattern was found. Higher muscle strength (>1 SD) was associated only with high physical activity. Urban residence or lower socioeconomic status increased adherence to the most inactive pattern. From a public health perspective, implementing interventions promoting active patterns in 11–13-year-old teenagers is important for obesity prevention and enhanced physical fitness, especially in girls, teenagers living in urban areas, and from families with lower socio-economic status.

Normative Values for Muscular Fitness for Chinese Children and Adolescents Aged 7–18 Years

The primary aim of this study was to establish sex and age-specific muscular fitness (MF) norms for Chinese children and adolescents aged 7–18 years old. The secondary aim was to compare their MF values with those of children and adolescents in other countries and regions. The MF of 93,755 participants from China was evaluated by handgrip strength (upper limbs strength), sit-ups (trunk strength) and a standing broad jump (lower limbs strength), with a total of 90,424, 90,281 and 90,663 data values, respectively. The Lambda-Mu-Sigma (LMS) method was used to calculate smooth curves and table data. The MF of Chinese boys was higher than that of girls in all age groups. After the age of 11, the growth rate of boys accelerated while that of girls slowed down. Age-related changes were larger for boys than for girls. In the international comparison, all the MF indicators of Chinese children and adolescents were lower than those of their Japanese peers but were higher than those of their European peers, with the exception of handgrip strength. The results of this study can be used to evaluate, monitor and apply interventions that improve MF. They can also be used to compare trends across countries and regions.

Association between grip strength and bone mineral density in general US population of NHANES 2013-2014

Association between strength of nonadjacent muscles and bone mineral density is unclear. We used data from the National Health and Nutrition Examination Survey to convince the effect of grip strength on femoral neck and lumbar spine mineral density in the general US population. This research can broaden the area of muscle-bone interaction.

INTRODUCTION

Grip test measures the maximum isotonic strength of hand and forearm and is often used as an indicator of general muscle strength. Muscle has been shown to exert positive effects on bone health, and studies are needed to test whether grip strength can be associated with bone mineral density of nonadjacent bones. The aim of this study is to assess whether grip strength is an independent predictor for bone mineral density (BMD) of femoral neck and total lumbar spine in the general US population.

METHODS

We used the data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014, and 1850 participants aged from 40 to 80 years old were included in the analysis. Grip strength was recorded as the largest reading of three efforts of one's dominant hand using a handgrip dynamometer. Femoral neck and lumbar spine BMDs were measured through Dual-energy X-ray absorptiometry (DXA) scan. Univariate and multivariate linear regression analyses were done to examine the association between grip strength and BMDs.

RESULTS

After adjusting for age, ethnicity, body mass index (BMI), use of female hormones, smoking habit, drinking habit, family history of osteoporosis, use of calcium and vitamin D supplements, physical activity, serum calcium, and phosphorus levels, grip strength is associated with increased femoral neck and total lumbar spine BMDs in men (P < 0.001, P = 0.005), premenopausal women (P = 0.040, P = 0.014), and postmenopausal women (P = 0.016, P = 0.012).

CONCLUSIONS

Our results suggest that (1) grip strength can be associated with BMD of nonadjacent bones, and (2) grip strength of dominant hand can be an indicator of BMD in the general US population across genders and menopausal status.

Occupational Activities: Factors That Tip the Balance From Bone Accrual to Bone Loss

Bone adaptation to persistent overloading can be counteracted by superimposed inflammatory and loading-induced damage that can tip the balance from bone accrual to loss.

Supplemental digital content is available in the text.

It is commonly assumed that beneficial adaptations in bone occur with vigorous exercise, yet any adaptive re/modeling in bone undergoing persistent overloading can be counteracted by superimposed inflammatory, compressive, and tensile loading–induced damage responses above thresholds of tissue fatigue failure and repair. This leads to a tenuous balance between achieving bone accrual and loss.

Change in grip strength in trans people and its association with lean body mass and bone density

OBJECTIVE

Gender-affirming hormonal treatment (HT) in trans people changes physical appearance. Muscle mass and strength are important aspects of physical appearance, but few data exist on the effect of HT on grip strength and muscle mass. This study aimed to investigate the change in grip strength in trans people during the first year of HT and to study the possible determinants of this change and the associations between changes in grip strength, lean body mass and bone mineral density (BMD).

DESIGN AND METHODS

A multicenter, prospective study was performed, including 249 transwomen and 278 transmen. Grip strength, lean body mass and BMD were measured at baseline and after 1 year.

RESULTS

After 1 year of HT, grip strength decreased with -1.8 kg (95% CI -2.6; -1.0) in transwomen and increased with +6.1 kg (95% CI +5.5; +6.7) in transmen. No differences in grip strength change was found between age groups, BMI groups, hormonal administration routes or hormone concentrations. In transmen, increase in grip strength was associated with increase in lean body mass (per kg increase in grip strength: +0.010 kg, 95% CI +0.003; +0.017), while this was not found in transwomen (per kg increase in grip strength: +0.004 kg, 95% CI -0.000; +0.009). Change in grip strength was not associated with change in BMD in transwomen and transmen.

CONCLUSIONS

After 1 year of HT, grip strength decreased in transwomen, and increased in transmen. In transmen only, change in grip strength was associated with change in lean body mass.

A School-Based Screening Tool for Adolescents With Low Motor Coordination Abilities

This study sought to select the most relevant test items from the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition (BOTMP-2) and from a selection of health-related fitness tests for identifying school teenagers with poor motor coordination. The 241 participants in this study (144 boys, 97 girls aged 13-14 years old) were tested on the short form of the BOTMP-2 and on the following additional fitness tests: (a) seated medicine ball test, (b) broad jump, (c) handgrip strength, (d) alternate hand ball wall toss, (e) 10 × 5-meter agility shuttle run, and (f) Chester step test. We performed a factor analysis of participant scores on these various tasks and BOTMP-2 test items to reduce them to the least number of meaningful and useful items. Four factors explained 45% of the data variance: gross motor skills and power (including broad jump, hand ball toss, shuttle run, and sit-ups tests); fine motor skills (including copying star, following the maze and paper folding); core strength and balance (including push-ups, hopping, and balance beam); and general body strength (including medicine ball throw and handgrip). We conclude that an efficient school-based battery of test items to screen 13-14 year old adolescents for fitness and coordination should assess these four factors and might especially rely upon the broad jump, copying a star shape, hopping handgrip strength, aerobic fitness, and wall ball toss.

Low muscle mass and strength in pediatrics patients: Why should we care?

Skeletal muscle plays major roles in metabolism and overall health across the lifecycle. Emerging evidence indicates that prenatal (maternal diet during pregnancy and genetic defects) and postnatal factors (physical activity, hormones, dietary protein, and obesity) influence muscle mass acquisition and strength early in life. As a consequence, low muscle mass and strength contributes to several adverse health outcomes during childhood. Specifically, studies demonstrated inverse associations of muscle mass and strength to single and clustered metabolic risk factors. The literature also consistently reports that low muscle mass and strength are associated with reduced bone parameters during growth, increasing the risk of osteoporosis in old age. Furthermore, muscle mass gains are associated with improved neurodevelopment in the first years of life. Given these negative implications of low muscle mass and strength on health, it is crucial to track muscle mass and strength development from childhood to adolescence. Several body composition techniques are currently available for estimation of muscle mass, all with unique advantages and disadvantages. The value of ultrasound as a technique to measure muscle mass is emerging in pediatric research with potential for translating the research findings to clinical settings. For the assessment of muscle strength, the handgrip strength test has been widely employed but without a standardized protocol. Although further research is needed to define normative data and cut points for the low muscle mass and strength phenotype, the use of such non-invasive medical monitoring is a promising strategy to identify early abnormalities and prevent low muscle mass in adulthood.

Association of Modifiable Risk Factors with Bone Mineral Density among People with Distal Radius Fracture: A Cross-Sectional Study

Purpose: This study determined the extent to which modifiable risk factors (balance, muscle strength, and physical activity [PA]) explained variability in bone mineral density (BMD) among people with a recent distal radius fracture (DRF). Method: This cross-sectional study included 190 patients, aged 50-80 years, with a DRF. Participants were assessed for balance, muscle strength, PA, fracture-specific pain, and disability. Areal BMD at the femoral neck (BMD-FN) and total hip (BMD-TH) was assessed. Correlation and multiple linear regression was used to determine the contribution of modifiable risk factors to BMD. Results: Balance, handgrip strength, knee extension strength, and plantar-flexion strength had significant bivariate associations with BMD-FN. There was a weak to moderate correlation (r = 0.25-0.40; p < 0.05) of balance and grip strength with BMD. Grip strength independently (p < 0.05) explained 17% and 12% of the variability in BMD-FN (n = 81) and BMD-TH (n = 82), respectively. Stratified by age, balance (R ² = 0.10; p = 0.04) and grip strength (R ² = 0.32; p = 0.003) were independent significant predictors of BMD-FN among women aged 50-64 years and 65-80 years, respectively. Conclusions: Grip strength of the unaffected hand is independently associated with BMD-FN and BMD-TH in people with recent DRF. It may act as a surrogate for general bone health, frailty, or overall muscle strength rather than as a direct target for intervention.

Bone mineral density, hand grip strength, smoking status and physical activity in Polish young men

The human skeleton undergoes constant changes encompassing the phases of growth, consolidation and involution of the bone tissue. The aim of the research was to assess the relationship between bone mineral density (BMD) and such factors as hand grip strength, somatic structure or attitudes to tobacco smoking in men with different levels of physical activity. The study included 172 males aged 20-30 years. Mineral density and forearm bone mass were measured using the dual-energy X-ray absorptiometry method. Physical activity levels were assessed with the use of the International Physical Activity Questionnaire. Hand grip strength was measured with Jamar hand dynamometer. Attitudes towards smoking were assessed using the Global Adult Tobacco Survey. The correlation between a high level of physical activity among men and higher BMD and bone mass both in the distal and proximal parts of the forearm was statistically significantly greater compared to individuals with an insufficient level of physical activity. A better state of BMD and higher bone mass in both forearm bones was noted among non-smoking men. A high level of physical activity was the most significant predictor of BMD in the distal part of the forearm. The regression analysis in the proximal part revealed that body mass and a high level of physical activity were the most important predictors of BMD. The lack of physical activity was associated with more frequent occurrence of low bone mass in men. Tobacco smoking may be one of the most important risk factors of poor bone mineralization in young men.

Hand grip strength and maximum peak expiratory flow: determinants of bone mineral density of adolescent students

Background

Maintaining and building healthy bones during the lifetime requires a complicated interaction between a number of physiological and lifestyle factors. Our goal of this study was to analyze the association between hand grip strength and the maximum peak expiratory flow with bone mineral density and content in adolescent students.

Methods

The research team studied 1427 adolescent students of both sexes (750 males and 677 females) between the ages of 11.0 and 18.9 years in the Maule Region of Talca (Chile). Weight, standing height, sitting height, hand grip strength (HGS), and maximum peak expiratory flow (PEF) were measured. Furthermore, bone mineral density (BMD) and total body bone mineral content (BMC) were determined by using the Dual-Energy X-Ray Absorptiometry (DXA). Hand grip strength and PEF were categorized in tertiles (lowest, middle, and highest). Linear regression was performed in steps to analyze the relationship between the variables. Differences between categories were determined through ANOVA.

Results

In males, the hand grip strength explained 18–19% of the BMD and 20–23% of the BMC. For the females, the percentage of variation occurred between 12 and 13% of the BMD and 17–18% of the BMC. The variation of PEF for the males was observed as 33% of the BMD and 36% of the BMC. For the females, both the BMD and BMC showed a variation of 19%. The HGS and PEF were divided into three categories (lowest, middle, and highest). In both cases, significant differences occurred in bone density health between the three categories.

Conclusions

In conclusion, the HGS and the PEF related positively to the bone density health of both sexes of adolescent students. The adolescents with poor values for hand grip strength and expiratory flow showed reduced values of BMD and BMC for the total body. Furthermore, the PEF had a greater influence on bone density health with respect to the HGS of the adolescents of both sexes.

The Relationship of Physical Activity and Anthropometric and Physiological Characteristics to Bone Mineral Density in Postmenopausal Women

The aim of this study is to investigate the relationship of physical activity and anthropometric and physiological characteristics to bone mineral density (BMD) in postmenopausal women. Ninety-seven postmenopausal women with an average age of 50.71 ± 6.86 yr were selected to participate in this study. After completing consent forms and the questionnaire on physical activity, the amounts of calcium and 25-hydroxyvitamin D levels in participants' blood were measured by blood tests. The BMDs of the subjects in the lumbar spine (L2-L4) and hip were measured by dual-energy X-ray absorptiometry device and the results were recorded. Also, anthropometric characteristics including height, weight, body fat percentage, body mass index, waist-to-hip ratio (WHR), digit ratio (2D:4D), skeletal muscle mass index, hand and calf circumferences and physiological parameters, including handgrip strength, quadriceps isotonic extension strength and balance of the subjects, were measured. The results showed that the 2D:4D ratio and skeletal muscle mass index had a significantly positive relationship with BMD of the lumbar spine (p ≤ 0.05) and the hip (p ≤ 0.05). Also, there was a negative relationship between the BMD of lumbar spine and hip and WHR (p ≤ 0.05). Moreover, there was a positive relationship between the calf circumferences and lumbar spine BMD (p ≤ 0.05). Contrary to this, there was no significant relationship between the calf circumference and the hip BMD, and between hand circumference with lumbar spine and hip BMD (p > 0.05). Results of physiological indices showed a significant positive relationship between physical activity, handgrip strength, quadriceps isotonic extension strength, standing on 1 foot with the lumbar spine and hip BMD (p ≤ 0.05). But the relationship was not observed between BMD and the ability to squat down on the floor (p > 0.05). Based on these results, it seemed that we can use some physiological and anthropometric indices that are important determinants of BMD and risk of osteoporosis in postmenopausal women.

Normative Reference Values for Handgrip Strength in Colombian Schoolchildren: The FUPRECOL Study

Ramírez-Vélez, R, Morales, O, Peña-Ibagon, JC, Palacios-López, A, Prieto-Benavides, DH, Vivas, A, Correa-Bautista, JE, Lobelo, F, Alonso-Martínez, AM, and Izquierdo, M. Normative reference values for handgrip strength in Colombian schoolchildren: the FUPRECOL study. J Strength Cond Res 31(1): 217-226, 2017-The primary aim of this study was to generate normative handgrip (HG) strength data for 10 to 17.9 year olds. The secondary aim was to determine the relative proportion of Colombian children and adolescents that fall into established Health Benefit Zones (HBZ). This cross-sectional study enrolled 7,268 schoolchildren (boys n = 3,129 and girls n = 4,139, age 12.7 [2.4] years). Handgrip was measured using a hand dynamometer with an adjustable grip. Five HBZs (Needs Improvement, Fair, Good, Very Good, and Excellent) have been established that correspond to combined HG. Centile smoothed curves, percentile, and tables for the third, 10th, 25th, 50th, 75th, 90th, and 97th percentile were calculated using Cole's LMS method. Handgrip peaked in the sample at 22.2 (8.9) kg in boys and 18.5 (5.5) kg in girls. The increase in HG was greater for boys than for girls, but the peak HG was lower in girls than in boys. The HBZ data indicated that a higher overall percentage of boys than girls at each age group fell into the "Needs Improvement" zone, with differences particularly pronounced during adolescence. Our results provide, for the first time, sex- and age-specific HG reference standards for Colombian schoolchildren aged 9-17.9 years.

Relationship of sarcopenia and body composition with osteoporosis

The purpose of the study is to investigate the relationship between sarcopenia and body composition and osteoporosis in cohorts of three different races with a total of 17,891 subjects. Lean mass and grip strength were positively associated with bone mineral densities (BMDs). Subjects with sarcopenia were two times more likely to have osteoporosis compared with normal subjects.

INTRODUCTION

The relationship between sarcopenia and osteoporosis is not totally clear. First, the present study assessed this relationship by using two different definitions for sarcopenia. Second, we examined the associations of body composition (including muscle mass as a major and important component) and muscle strength on regional and whole-body BMDs.

METHODS

In total, 17,891 subjects of African American, Caucasian, and Chinese ethnicities were analyzed. Sarcopenia was defined by relative appendicular skeletal muscle mass (RASM) cut points and also by the definition of the European Working Group on Sarcopenia in Older People (low RASM plus low muscle function). Multiple regression analyses were conducted to examine the association of fat mass, lean mass (including muscle mass), and grip strength with regional and whole-body BMDs. Multivariate logistic regression analysis was performed to explore the association between sarcopenia and osteopenia/osteoporosis.

RESULTS

BMDs were positively associated with lean mass and negatively associated with fat mass, after controlling for potential confounders. Grip strength was significantly associated with higher BMDs. Each standard deviation (SD) increase in RASM resulted in a ~37 % reduction in risk of osteopenia/osteoporosis (odds ratio (OR) = 0.63; 95 % confidence interval (CI) = 0.59, 0.66). Subjects with sarcopenia defined by RASM were two times more likely to have osteopenia/osteoporosis compared with the normal subjects (OR = 2.04; 95 % CI = 1.61, 2.60). Similarly, subjects with sarcopenia (low muscle mass and low grip strength) were ~1.8 times more likely to have osteopenia/osteoporosis than normal subjects (OR = 1.87; 95 % CI = 1.09, 3.20).

CONCLUSIONS

High lean mass and muscle strength were positively associated with BMDs. Sarcopenia is associated with low BMD and osteoporosis.

Relationships between self-reported lifetime physical activity, estimates of current physical fitness, and aBMD in adult premenopausal women

Osteoporosis is common, and physical activity is important in its prevention and treatment. Of the categories of historical physical activity (PA) examined, we found that weight-bearing and very hard physical activity had the strongest relationships with areal bone mineral density (aBMD) throughout growth and into adulthood, while for measures of strength, only grip strength proved to be an independent predictor of aBMD.

PURPOSE/INTRODUCTION

To examine relationships between aBMD (total body, lumbar spine, proximal femur, tibial shaft, distal radius) and estimates of historical PA, current strength, and cardiovascular fitness in adult premenopausal women.

METHODS

One hundred fifty-two adult premenopausal women (40 ± 9.6 years) undertook aBMD (dual-energy X-ray absorptiometry (DXA)) and completed surveys to estimate historical physical activity representative of three decades (Kriska et al. [1]), while subsets underwent functional tests of isokinetic strength (hamstrings and quadriceps), grip strength (hand dynamometer), and maximum oxygen uptake (MaxV02; cycle ergometer). Historical PA was characterized by demand (metabolic equivalents, PA > 3 METS; PA > 7 METS) and type (weight-bearing; high impact).

RESULTS

Significant positive independent predictors varied by decade and site, with weight-bearing exercise and PA > 3 METS significant for the tibial shaft (10-19 decade) and only PA > 7 METS significant for the final two decades (20-29 and 30-39 years; total body and total hip). A significant negative correlation between high impact activity and tibial shaft aBMD appeared for the final decade. For strength measures, only grip strength was an independent predictor (total body, total hip), while MaxV02 provided a significant independent prediction for the tibial shaft.

CONCLUSIONS

Past PA > 7 METS was positively associated with aBMD, and such activity should probably constitute a relatively high proportion of all weekly PA to positively affect aBMD. The findings warrant more detailed investigations in a prospective study, specifically also investigating the potentially negative effects of high impact PA on tibial aBMD.

Establishing Normative Reference Values for Handgrip Among Hungarian Youth

PURPOSE

The purpose of this study was to examine age- and sex-related variation in handgrip strength and to determine reference values for the Hungarian population.

METHOD

A sample of 1,086 Hungary youth (aged 11-18 years old; 654 boys and 432 girls) completed a handgrip strength assessment using a handheld dynamometer. Quantile regression was used to compute separate models for boys and girls and included a linear, cubic, and quadratic term for age to account for nonlinear patterns. These terms were tested for statistical significance using the Wald statistical test with p < .05. Age- and sex-specific centiles were generated and the 50th percentile was used to describe the overall patterns in handgrip strength.

RESULTS

The linear, cubic, and quadratic terms for age fitted the data well for boys (p < .05), while both linear and quadratic terms for age were statistically significant for girls (p < .05). The 50th percentile values resulted in 21.4 kg, 21.7 kg, 25.0 kg, 30.0 kg, 35.4 kg, 40.0 kg, 42.6 kg, and 42.0 kg for boys aged 11 to 18 years old, respectively. The same percentile resulted in 20.0 kg, 19.5 kg, 19.6 kg, 20.3 kg, 21.6 kg, 23.5 kg, 26.1 kg, and 29.2 kg for girls aged 11 to 18 years old, respectively.

CONCLUSIONS

Muscle strength as determined by handgrip has distinct age-related patterns in boys and girls. We have accounted for biological age differences and developed norm-referenced values that can be used to interpret handgrip assessment scores obtained from school-aged children in Hungary.

Grip strength ratio: a grip strength measurement that correlates well with DASH score in different hand/wrist conditions

BACKGROUND

Grip strength correlates with personal factors such as gender, age and nutritional status and has a good inter-rater reliability. It reflects fairly well how much people can use their hands.The Disabilities of the Arm, Shoulder and Hand (DASH) Outcome Measure 3 is a 30-item, self-report, questionnaire that reflects the patients' opinion on their disability due to upper-limb disorders. We assessed if grip strength and grip strength ratio correlate with DASH score.

METHODS

In 3 groups (20 healthy volunteers, 17 patients after distal radius fractures, 12 patients with different hand/wrist conditions) grip strength and DASH scores (items 1-21, 22-30 and total) were assessed. To exclude personal factors grip strengths in the injured or non-dominant hand and grip strength ratios (grip strength in the injured or non-dominant hand divided by grip strength in the non-injured or dominant hand) were assessed too. Results were analyzed groups using Pearson Correlation Coefficients and with a multivariate ANOVA.

RESULTS

Grip strength ratio was 0.97 in healthy volunteers, 0.52 in patients after distal radius fracture and 0.74 in patients with various other hand/wrist disorders.Significant correlations were found between the grip strength ratio and DASH as well as DASH subsections in all groups and between DASH scores and grip strength in some. The correlations between the ratio of the grip strength (GSR) and DASH were much stronger than the correlation between grip strength and DASH. This emphasizes the value of the GSR. Age showed no correlation with grip strength ratio using a multivariate ANOVA.

CONCLUSION

Grip strength ratio correlates well with the DASH score in different hand and wrist conditions. It is a valuable tool to assess patients that speak a different language and have problems with the non-dominant hand and probably easier to follow over time than the DASH score, which is time consuming to fill in and process.

Efficacy of home-based virtual cycling training on bone mineral density in ambulatory children with cerebral palsy

The 12-week home-based virtual cycling training (hVCT) improved lower limb muscle strength and areal bone mineral density (aBMD) than the control program in children with cerebral palsy (CP). A muscle strengthening program, rather than general physical activity, is more specific in enhancing aBMD for these children. A novel hVCT is an effective and efficient strategy that enhances lower limb bone density in these children.

INTRODUCTION

This is the first study to assess the efficacy of a novel hVCT program on bone density for children with spastic CP using a well-designed randomized controlled trial.

METHODS

Twenty-seven ambulatory children with spastic CP, aged 6-12 years, were randomly assigned to the hVCT group (n=13) or control group (n=14). Outcome measures-motor function [Gross Motor Function Measure-66 (GMFM-66)], muscle strength (curl up scores and isokinetic torque of knee extensor and flexor muscle) and aBMD of the lumbar and distal femur-were administered before and immediately after the 12-week intervention.

RESULTS

Analysis of covariance results show that the hVCT group had greater distal femur aBMD and isokinetic torques of knee extensor and flexor muscles than the control group at posttreatment (p<0.05). However, curl up scores, GMFM-66, and lumbar aBMD at posttreatment did not differ between the two groups.

CONCLUSIONS

Analytical findings suggest that the muscle strengthening program is more specific in enhancing bone density for children with CP than general physical activity. Thus, the proposed 12-week hVCT protocol is an effective and efficient strategy for improving lower limb aBMD in these children.

Relationships of muscle strength and bone mineral density in ambulatory children with cerebral palsy

SUMMARY

This work explores the relationships of muscle strength and areal bone mineral density (aBMD) in ambulatory children with cerebral palsy (CP). The knee extensor strength, but not motor function, was related to aBMD. Thus, muscle strength, especially antigravity muscle strength, was more associated with aBMD in these children than motor function.

INTRODUCTION

Muscle strength is related to bone density in normal children. However, no studies have examined these relationships in ambulatory children with CP. This work explores the relationships of muscle strength and aBMD in ambulatory children with CP.

METHODS

Forty-eight ambulatory children with spastic CP, aged 5-15 years, were classified into two groups based on Gross Motor Function Classification System levels: I (n = 28) and II (n = 20). Another 31 normal development (ND) children were recruited as the comparison group for the aBMD. Children with CP underwent assessments of growth, lumbar and distal femur aBMD, Gross Motor Function Measure-66 (GMFM-66), and muscle strength of knee extensor and flexor by isokinetic dynamometer.

RESULTS

The distal femur aBMD, but not lumbar aBMD, was lower in children with CP than in ND children (p < 0.05). Children with level I had greater knee flexor strength and GMFM-66 scores than those with level II (p < 0.001). However, the knee extensor strength and distal femur and lumbar aBMD did not differ between two groups. Regression analysis revealed the weight and knee extensor strength, but not GMFM-66 scores, were related positively to the distal femur and lumbar aBMD (adjusted r (2) = 0.56-0.65, p < 0.001).

CONCLUSIONS

These results suggest the muscle strength, especially antigravity muscle strength, were more associated with the bone density of ambulatory children with CP than motor function. The data may allow clinicians for early identifying the ambulatory CP children of potential low bone density.

Risk factors for fractures among Japanese-American men: The Honolulu Heart Program and Honolulu-Asia Aging Study

Baseline risk factors were associated with fractures that developed after 29-31 years among Japanese-American men. Hip fracture risk increased with increasing BMI (28% increase for 1 U increase), physical activity (7% increase for 1 U increase), and was decreased with increasing arm girth (27% decrease for 1 U increase).

PURPOSE

The objective of this study was to identify risk factors among Japanese-American men aged 45-68 years at baseline that were associated with prevalence and incidence of fractures at advanced age.

METHODS

We used baseline information from Honolulu Heart Program (HHP) and Honolulu-Asia Aging Study (HAAS). The HHP was a prospective study with primary focus on risk factors for cardiovascular disease. A cohort of 8,006 men of Japanese ancestry aged 45-68 years residing on Oahu was recruited in 1965 and followed for 31 years. The HAAS started in 1991 in conjunction with the HHP with a focus on age-related health conditions. Self-reported hip, spine, and forearm fracture prevalence was ascertained in 1991-1993 among 3,845 men aged 71-93 years. Incidence was obtained during the period (1994-1999) among 2,737 men aged 74-98 years. Poisson regression models were used to determine multi-variable adjusted prevalence and incidence ratios for fracture.

RESULTS

Incident hip fracture was directly associated with baseline body mass index (BMI) and physical activity, and inversely associated with left upper arm girth. Incident spine fracture was directly associated with baseline age. Prevalent hip fracture was directly associated with baseline pack-years of smoking. Prevalent spine fracture was inversely associated with baseline education, and directly associated with standing height and use of medication for diabetes. Prevalent forearm fracture was inversely associated with baseline age, and directly associated with education.

CONCLUSIONS

Results indicated that multiple baseline demographic lifestyle and anthropometric characteristics predict fracture risk at advanced age. In addition, associations varied by fracture location.

Anthropometric and fitness variables associated with bone mineral density and broadband ultrasound attenuation in ambulatory children with cerebral palsy

We investigated anthropometric and fitness variables associated with areal bone mineral densities and broadband ultrasound attenuation in ambulatory children with cerebral palsy. Thirty-four children with cerebral palsy, aged 4-12 years, and 33 normal development children were collected. There were significant differences in femoral bone densities and calcaneus broadband ultrasound attenuation, but not in lumbar bone densities, between cerebral palsy and normal groups. Regression analysis revealed that different anthropometric and fitness variables were linked to bone densities of different skeletal regions in children with cerebral palsy (adjusted r(2) = .41-.67). Growth variables were mainly related to femoral and lumbar bone densities, while muscular endurance was mainly related to femoral and calcaneus bone densities. These findings suggest multiple complex variables can contribute to bone density variations among different skeleton areas in these children. These data can allow clinicians to identifying early these children at risk for low bone density.

Hand grip strength: outcome predictor and marker of nutritional status

BACKGROUND & AIMS

Among all muscle function tests, measurement of hand grip strength has gained attention as a simple, non-invasive marker of muscle strength of upper extremities, well suitable for clinical use. This review outlines the prognostic relevance of grip strength in various clinical and epidemiologic settings and investigates its suitability as marker of nutritional status in cross-sectional as well as intervention studies.

METHODS

Studies investigating grip strength as prognostic marker or nutritional parameter in cross-sectional or intervention studies were summarized.

RESULTS AND CONCLUSIONS

Numerous clinical and epidemiological studies have shown the predictive potential of hand grip strength regarding short and long-term mortality and morbidity. In patients, impaired grip strength is an indicator of increased postoperative complications, increased length of hospitalization, higher rehospitalisation rate and decreased physical status. In elderly in particular, loss of grip strength implies loss of independence. Epidemiological studies have moreover demonstrated that low grip strength in healthy adults predicts increased risk of functional limitations and disability in higher age as well as all-cause mortality. As muscle function reacts early to nutritional deprivation, hand grip strength has also become a popular marker of nutritional status and is increasingly being employed as outcome variable in nutritional intervention studies.

Handgrip strength in English schoolchildren

AIMS

The aims of this study were to evaluate patterns of handgrip (HG) strength in relation to gender and age in English schoolchildren and to compare this with existing data and produce reference data for this population.

METHODS

The HG of 7147 English schoolchildren (3773 boys and 3374 girls) aged 10-15.9 years was measured using a portable Takei handgrip dynamometer (Takei Scientific Instruments Co. Ltd, Tokyo, Japan). Centile data were produced using the Generalized Additive Models for Location, Scale and Shape. Z-scores were generated using existing data for European children. Age and gender interactions were analysed using analysis of covariance.

RESULTS

In boys and girls, significant increases in HG were found between every age-group (p < 0.001). Boys were significantly stronger than girls at every age (p < 0.001) and the boys' age-related increase was significantly greater than the girls' (p < 0.001).

CONCLUSION

This study provides reference data for handgrip strength in English schoolchildren. Handgrip strength in English children is broadly similar to existing European data, after adjusting for mass and stature. These data could be used for clinical or athletic screening of low and high strength in this population.