Musculoskeletal fitness: relative handgrip strength and vertical jump power from 10 to 18 years old.

Background: There is an increasing consensus on the relevance of musculoskeletal fitness for health throughout the life cycle, requiring evaluation approaches and description of results capable of characterizing different age groups and body sizes. This study aimed to describe the musculoskeletal fitness of young Portuguese people aged 10-18 through handgrip strength (HGS) and vertical jump power (VJP) and investigate differences between the sexes. Methods: The sample included 736 participants (359 girls recruited from schools. HGS (kg) was assessed using a handheld dynamometer, and VJP (W) was assessed using a force platform; both measurements were standardized for body mass. Results: Higher HGS and VJP were observed in boys than in girls from 13 years old (13 years: p ≤ 0.05; 14-18 years: p ≤ 0.001), with no significant differences before this age. The percentile distributions of HGS and VJP are described for each sex using the lambda, mu, sigma (LMS) method. The pattern of development of these variables as a function of age is presented. Conclusions: Handgrip strength and vertical jump power show differences between the sexes from 13 years of age and similar trajectories to populations in other countries in the same age group.

Risk phenotype for sarcopenia in older adults from Amazonas, Brazil; a cross-sectional study.

BACKGROUND: There are several markers for the suspicion, identification, and confirmation of sarcopenia. OBJECTIVES: To analyse the importance of several markers for assessing sarcopenia by classifying phenotypes based on five domains: symptomatology, muscle function, muscle mass, physical performance, and physical function. METHODS: A cross-sectional study analysing 312 older adults (72.6±7.8 yrs) was conducted in Novo Aripuanã, Amazonas, Brazil. Symptoms of sarcopenia were determined with the SARC-Calf; muscle function was assessed using the 30-Chair Stand test (CST), 30-CST power, and handgrip strength (HGS) with and without normalisation for body mass/height; the skeletal muscle mass index (SMMI) was estimated from anthropometry; physical performance was determined through the 4-m gait speed (GS) and 6-min walking test (6MWT); and physical function was determined with the Composite Physical Function Scale (CPF). RESULTS: Cluster analysis revealed two phenotypes (at risk vs not at risk for sarcopenia) and the contribution of each marker (ranged from 0 to 1). In men, the contribution of each marker was: 1 for SARC-Calf, 0.18 for SMMI, 0.09 for 30-CST power and 0.06 for HGS; in women: 1 for SARC-Calf, 0.25 for 30-CST power, 0.22 for SMMI, 0.06 for GS, 0.04 for HGS, and 0.03 for CPF. Considering the cutoff values proposed by Rikli and Jones (2013) for physical function and Cruz-Jentoft et al. (2019) for the other domains, the risk profile for sarcopenia was characterized by: high SARC-Calf in both sexes (men:51.8 vs 3.6%, p<0.001; women:71.2 vs 1.1%, p<0.001), low SMMI (men:73.2 vs 44.6%, p<0.002; women:44.1 vs 23.6%, p = 0.002); in women, low GS (38.7 vs 12.4%, p<0.001) and low CPF (29.7 vs 15.7%, p = 0.020), and no differences in HGS between groups in both sexes. CONCLUSIONS: SARC-Calf, SMMI, and 30-CST were more relevant markers for sarcopenia risk in older adults of both sexes, GS and CPF played also an important role in women.

Learning needs in healthy and active aging according to key stakeholders: a multinational survey.

Healthy and active aging and age-friendly society frameworks attempt to address the well-documented challenges and opportunities of population aging. To meet the needs of an increasingly older society, there is a demand for professionals with appropriate age-related knowledge and skills. To this end, a master's in active aging is in development. This study reports on the consultation with prospective students, employers, older people and academics on the knowledge areas to be included in the course. An anonymous online survey gathered data from stakeholders in Ireland, Slovenia, Austria, Portugal, Finland, and Greece. Participants ranked the importance of 14 broad knowledge areas and linked topics. The influence of participant characteristics on decisions was examined using multivariate regression modeling. Across all stakeholder groups (total sample N = 757), health promotion was most often deemed very important (80%), followed by psychology (73%), and social inclusion and engagement (71%). Potential students from healthcare backgrounds were more interested than others in aging physiology, social aspects, and the physical environment. More western-located European countries overall showed more enthusiasm for the topics presented, additional to regional variations between topics. This learning needs analysis provides multi-stakeholder insights into priorities regarding learning in healthy and active aging and age-friendly society.

Body composition and musculoskeletal fitness: A cluster analysis for the identification of risk phenotypes for pediatric sarcopenia.

BACKGROUND AND AIM: Sarcopenia is primarily a disease in older people characterized by reduced muscle mass and strength. Nevertheless, sarcopenia may, at least partially, have pediatric origins. The study aimed to identify risk phenotypes for sarcopenia in healthy young people using clustering analysis procedures based on body composition and musculoskeletal fitness. METHODS: We conducted a cluster cross-sectional analysis of data from 529 youth aged 10-18 yr. Body composition was assessed using whole-body dual-energy x-ray absorptiometry (DXA), determining: lean body mass index (LBMI, kg/m2), fat body mass index (FBMI, kg/m2), abdominal FBMI (kg/m2), and lean body mass/fat body mass ratio (LBM/FBM); body mass index was also calculated (BMI, kg/m2). Musculoskeletal fitness was assessed using handgrip strength (kg) and vertical jump power (W) tests. Results were presented as absolute values and adjusted by body mass. Plank endurance (s) was also assessed. All variables were sex and age in years standardized (Z-score). LBMI or LBM/FBM ratio ≤ -1 SD were used to identify participants at risk for sarcopenia. Maturity was estimated as the years of distance from the peak height velocity (PHV) age. RESULTS: Using the Z-score means for body composition and musculoskeletal fitness and having LBMI or LBM/FBM ratio as the categorical variables (at risk vs. not at risk), the cluster analyses indicated three homogeneous groups (phenotypes, P): P1, risk body composition and unfit; P2, non-risk body composition and non-fit, and P3, non-risk body composition and fit. With the LBMI as a categorical variable, the ANOVA models showed that the body composition and absolute values of musculoskeletal fitness were in P1 < P2 < P3 and the estimated PHV age of P1 > P3 in both sexes (p < 0.001). Having the LBM/FBM as a categorical variable, higher values of BMI, FBMI, and abdominal FBMI, and lower values of handgrip strength and vertical jump power both adjusted for body mass and plank endurance were observed in P1 than in P2 and/or P3 and the P2 than in the P3 in boys and girls (p < 0.001). CONCLUSIONS: Two risk phenotypes for sarcopenia were identified in apparently healthy young people: I. a low LBMI phenotype with low BMI and II. a low LBM to FBM phenotype with high BMI and FBMI. In both risk phenotypes I and II, musculoskeletal fitness was low. For screening, we suggest using absolute measures of handgrip strength and vertical jump power in phenotype I and body mass adjusted measures of these markers, as well as the plank endurance time in phenotype II.

Musculoskeletal Fitness for Identifying Low Physical Function in Older Women.

AIMS: This cross-sectional study aimed to analyze the relevance of musculoskeletal fitness for identifying low physical functioning in community-dwelling older women. METHODS: Sixty-six older women (73.62 ± 8.23 yrs old) performed a musculoskeletal fitness assessment of the upper and lower limbs. A handheld dynamometer was used to evaluate upper-limb muscle strength through a handgrip (HG) test. Lower-limb power and force were assessed from a two-leg countermovement vertical jump (VJ) on a ground reaction force platform. Physical functioning was assessed subjectively using the Composite Physical Function (CPF) questionnaire and objectively by daily step count measured by accelerometry and gait speed/agility assessed by the 8-Foot Up-and-Go (TUG) test. Logistic regressions and ROC curves were carried out to define odds ratios and ideal cutoff values for discriminatory variables. RESULTS: VJ power showed the ability to identify low physical functioning when evaluated through the CPF (14 W/kg, 1011 W), gait speed/agility (15 W/kg, 800 W), or daily accumulated steps (17 W/kg). Considering that VJ power was normalized for body mass, the increase of 1 W/kg corresponds to a decrease of 21%, 19%, or 16% in the chance of low physical functioning when expressed by these variables, respectively. HG strength and VJ force did not show a capacity to identify low physical functioning. CONCLUSIONS: The results suggest that VJ power is the only marker of low physical functioning when considering the three benchmarks: perception of physical ability, capacity for mobility, and daily mobility.

Mediating effect of muscle power on the relationship of physical activity with physical fitness and physical function in older women.

OBJECTIVE: This study analyzed if the associations of physical activity with physical fitness and physical function in older women are mediated by muscle power. METHODS: Participants were 54 older women (age 73.5 ± 6.8 yrs). Moderate-to-vigorous intensity physical activity (min day-1) was measured by accelerometry. Lower limb muscle power (W/kg) was estimated from a single two-leg countermovement jump performed on a force platform. Physical fitness (lower body strength, agility/dynamic balance, and aerobic endurance) was objectively assessed through the Senior Fitness Test Battery, respectively: 30s chair stand (repetitions), 8-ft up-and-go (s), and 6-min walk test (m). Physical function was subjectively evaluated via the 12-item Composite Physical Function Scale Questionnaire (score). Mediation effects were estimated using bootstrapped 95% confidence intervals and were deemed significant if 0 was not included in the intervals. RESULTS: Mediation analysis controlling to age revealed an indirect effect of moderate-to-vigorous intensity physical activity through muscle power on all physical fitness components, specifically lower body strength (B = 0.048, 95% BootCI [0.013, 0.114]), agility/dynamic balance (B = -0.009, 95% BootCI [-0.024, -0.002]) and aerobic endurance (B = 0.656, 95% BootCI [0.142, 1.597]) and on physical function global score (B = 0.040 95% BootCI [0.009, 0.094]). CONCLUSIONS: These results suggest that physical activity of at least moderate intensity is relevant to daily functional competence, by promoting the maintenance or improvement of muscle power.

Postgraduate education in healthy and active ageing: learning needs, curriculum and expected outcomes: a scoping review protocol.

Background: As the European population ages, it becomes increasingly important to promote and facilitate healthy and active ageing and age-friendly societies. Professionals across a range of disciplines and sectors need knowledge and skills to support both. Objective: This scoping review aims to identify and map the literature on learning needs, learning outcomes and respective curricula in healthy and active ageing and age-friendly society concepts. Inclusion criteria: Studies focused on the teaching/learning process in healthy and active ageing and/or age-friendly society, of any design type, are eligible. Included studies may focus on undergraduate, postgraduate or continuing education and on any aspect of the educational process, such as needs analysis, content delivery, learner satisfaction/acceptability, or education outcome. Methods: This review will follow the Joanna Briggs Institute (JBI) methodology for conducting scoping reviews. Four electronic databases, PubMed, EBSCO (Academic Search Complete), Scopus and Applied Social Sciences Index and Abstracts (ASSIA), will be searched, limited to studies published from 1 st January 2000. Text language will be limited to English, German, Greek, Portuguese, Finnish, and Slovenian. Google Scholar and Research Gate will be searched for grey literature, limited to the first 50 results of each. Title and abstract screening, followed by full-text screening will be undertaken independently by at least two reviewers. The JBI extraction tool will be adapted for data extraction. Quality assessment will be conducted using a tool developed by Hawker and colleagues. A narrative synthesis will outline the data in relation to the aims and objectives outlined.

Adaptation of Proximal Femur to Mechanical Loading in Young Adults: Standard Vs Localized Regions Evaluated by DXA.

Regions of the proximal femur with less adaptive protection by mechanical loading may be at increased risk of structural failure. Since the size and location of these regions diverge from those defined by the dual-energy X-ray absorptiometry manufacturers the purpose of this study was to compare areal bone mineral density (aBMD) of different regions of the proximal femur considering impact loads from physical activity (PA). The participants were 134 young adults divided into 2 groups according to the impact of PA performed in the last 12 mo: high-impact PA and low-impact PA. The aBMD of the proximal femur was assessed by dual-energy X-ray absorptiometry at the standard femoral neck, intertrochanter, and trochanter, and at specific locations of the superolateral femoral neck and intertrochanteric region. The bone-specific physical activity questionnaire was used to estimate the impact load of PA. Comparisons between groups were adjusted for body height and body lean mass. Interaction analysis between sex and PA groups were conducted with analysis of variance. Comparisons of aBMD between bone regions were analyzed separately for men and women with repeated measures analysis of variance. In the high-impact PA group, men benefit more than women at all bone regions, except the aBMD at intertrochanteric region. Analyses of repeated measures did not reveal any significant interaction effect between bone regions (standard vs specific) and PA groups (low vs high-impact). In conclusion, aBMD differences due to mechanical loading were more pronounced in men than in women; the magnitude of the aBMD differences as a result of different levels of PA was similar between standard and localized regions.

Mediating Effect of Muscle on the Relationship of Physical Activity and Bone.

PURPOSE: This study analyzed prospective associations between distinct trajectories of objectively measured physical activity (PA) and late adolescent bone parameters and explored the mediating effects of lean soft tissue, a surrogate of muscle mass to associations. METHODS: Physical activity was measured by accelerometry starting at age 5 yr and continuing at 8, 11, 13, 15, and 17 yr in approximately 524 participants from the Iowa Bone Development Study. Sex-specific group-based trajectory modeling was used to construct developmental trajectories of moderate- and vigorous-intensity PA (MVPA) from childhood to late adolescence. At age 17 yr, proximal femur bone mineral density (aBMD) was assessed by dual X-ray energy absorptiometry, and its distribution was calculated by aBMD ratios. Specific geometric measures of the proximal femur were assessed using hip structural analysis. RESULTS: A significant portion of the total effect of MVPA from age 5 to 17 yr on bone parameters at age 17 yr was explained by an increase in leg lean soft tissue in both sexes. For males and females, indirect effects were observed on the total and all regional proximal femur aBMD, and on the ratio between the inferomedial and superolateral neck aBMD. The effect on the ratio between the trochanter and the total proximal femur was specific to females, whereas the effect on the hip axis length was specific to males. Direct effects of MVPA on aBMD were identified only in males. CONCLUSIONS: Using robust mediation analysis, this is the first study addressing the indirect effect (through muscle) of PA across childhood and adolescence on proximal femur bone parameters. To improve bone health at the proximal femur, the results suggest PA interventions during growth that increase muscle mass, particularly in females.

Sexual dimorphism in bone-muscle relationship in young adults.

The purpose of this study was to analyse associations between lean soft tissue (LST), a surrogate of skeletal muscle mass and key fracture-related geometric characteristics of the proximal femur. Moreover, we examined the role that muscle played on the proximal femur geometry in response to physical activity (PA). Participants were 83 young adults. Leg LST (exposure) was assessed by dual energy X-ray absorptiometry (DXA). Proximal femur geometry was derived from a left hip DXA scan. Geometric variables (outcomes) included the femoral neck axis length (FNAL), the femoral neck width (FNW), the neck-shaft angle and FNW|FNAL (an index of robustness). PA was evaluated by accelerometry. Linear regression was used to analyse relationships. Additional exposure variables included body height and mass. In males, leg LST explained 17.4% of variation in FNAL (P < 0.001) and 15% in FNW (P = 0.015). In females, it explained 8.8% of the variance in FNAL (P = 0.020). Associations remained significant in males, but not in females, when vigorous PA was added to the models. These results suggest that public health approaches to promote PA may be particularly important in females since vigorous PA seems to convey advantages in femur geometry and consequently in bone strength.

Sex- and Maturity-Related Differences in Cortical Bone at the Distal Radius and Midshaft Tibia Evaluated by Quantitative Ultrasonography.

Boys usually have higher values of bone mineral density measured by dual-energy X-ray absorptiometry than girls, but contradictorily also have a greater incidence of fractures during growth. The purpose of this study was to investigate sex- and maturity-related differences in bone speed of sound (SoS) at the radius and tibia in a sample of 625 healthy children aged 10-14 y and to analyze the contributions of physical activity (PA) to possible dissimilarities. Radial and tibial SoS was evaluated by quantitative ultrasound, maturity was estimated as the years of distance from the peak height velocity age, and PA was assessed by accelerometry. Comparisons between sexes and maturity groups (low: below average [<-2.5 y], high: average or above [≥-2.5 y]) were made by two-sample t-tests with unequal variances. Girls in the high-maturity group had higher SoS at the radius and tibia compared with girls in the low-maturity group (p < 0.001). There were no SoS differences at the radius or tibia between the high- and low-maturity groups in boys. Within high-maturity children, girls had higher SoS than boys at the radius and tibia (p < 0.001). There were no differences at the radius and tibia between girls and boys with low maturity. The results were not modified after controlling for PA. Regardless of PA, the results provide insight into sex- and maturity-related differences in bone SoS at the distal radius and midshaft tibia from maturity less than 2.5 y from the peak height velocity age, with boys having lower SoS.

Measurement properties of radial and tibial speed of sound for screening bone fragility in 10- to 12-year-old boys and girls.

The objective of this study was to analyze measurement properties of the radial and tibial speed of sound (SoS) evaluated by quantitative ultrasound (QUS) for screening bone fragility. Bone fragility was defined as low whole body less head bone mineral density (WBLH BMD) measured by DXA (first tertile, 95% CI -1.1 to -0.9) and as past fractures evaluated by questionnaire. The sample included 319 nonobese boys and girls, ages 10-12 yr. All bone variables were standardized. The results revealed concordance coefficient correlations between WBLH BMD and radial and tibial SoS of 0.129 and 0.038, respectively. The regression lines between DXA and QUS variables were different from the identity lines. Cross-classification analysis by Kappa statistic showed that only 34% and 36% of the 113 participants categorized in the first tertile of WBLH BMD were also categorized in the first tertile of tibial and radial SoS, correspondingly. Logistic regression with gender and maturity adjustments demonstrates that radial SoS was the single significant variable in predicting OR for identifying participants with past fractures. In conclusion, the radial QUS revealed itself to be a valuable tool for screening bone fragility in youth of 10-12 yr, despite the absence of agreement with DXA WBLH BMD.

Ward's area location, physical activity, and body composition in 8- and 9-year-old boys and girls.

Bone strength is the result of its material composition and structural design, particularly bone mass distribution. The purpose of this study was to analyze femoral neck bone mass distribution by Ward's area location and its relationship with physical activity (PA) and body composition in children 8 and 9 years of age. The proximal femur shape was defined by geometric morphometric analysis in 88 participants (48 boys and 40 girls). Using dual-energy X-ray absorptiometry (DXA) images, 18 landmarks were digitized to define the proximal femur shape and to identify Ward's area position. Body weight, lean and fat mass, and bone mineral were assessed by DXA, PA by accelerometry, and bone age by the Tanner-Whitehouse III method. Warps analysis with Thin-Plate Spline software showed that the first axis explained 63% of proximal femur shape variation in boys and 58% in girls. Most of this variation was associated with differences in Ward's area location, from the central zone to the superior aspect of the femoral neck in both genders. Regression analysis demonstrated that body composition explained 4% to 7% of the proximal femur shape variation in girls. In boys, body composition variables explained a similar amount of variance, but moderate plus vigorous PA (MVPA) also accounted for 6% of proximal femur shape variation. In conclusion, proximal femur shape variation in children ages 8 and 9 was due mainly to differences in Ward's area position determined, in part, by body composition in both genders and by MVPA in boys. These variables were positively associated with a central Ward's area and thus with a more balanced femoral neck bone mass distribution.