Normative data for handgrip strength in Iranian healthy children and adolescents aged 7-18 years: comparison with international norms

Toward a Robust Definition of Sport Sex

Elite individual sports in which success depends on power, speed, or endurance are conventionally divided into male and female events using traditional binary definitions of sex. Male puberty creates durable physical advantages due to the 20- to 30-fold increase in circulating testosterone producing a sustained uplift in men's muscle, bone, hemoglobin, and cardiorespiratory function resulting from male puberty and sustained during men's lives. These male physical advantages provide strong justification for a separate protected category of female events allowing women to achieve the fame and fortune from success they would be denied if competing against men. Recent wider social acceptance of transgender individuals, together with the less recognized involvement of intersex individuals, challenge and threaten to defeat the sex classifications for elite individual female events. This can create unfair advantages if seeking inclusion into elite female events of unmodified male-bodied athletes with female gender identity who have gained the physical advantages of male puberty. Based on reproductive physiology, this paper proposes a working definition of sport sex based primarily on an individual's experience of male puberty and can be applied to transgender and various XY intersex conditions. Consistent with the multidimensionality of biological sex (chromosomal, genetic, hormonal, anatomical sex), this definition may be viewed as a multistrand cable whose overall strength survives when any single strand weakens or fails, rather than as a unidimensional chain whose strength is only as good as its weakest link.

Secular trends and sociodemographic, biological, and behavioural factors associated with handgrip strength in adolescents in southern Brazil: An allometric approach

The purpose of this study was to analyse secular trend in handgrip strength (HGS) in adolescents using an allometric approach and identify the factors associated. The sample comprised 657 and 1004 adolescents (14 to 19 years) in 2007 and 2017/2018, respectively, of public schools in Florianópolis, Brazil. The dependent variable was HGS normalised to body mass and height. Covariance analysis was used to examine secular trends in HGS, and multiple linear regression was used to identify associated factors. The independent variables were sociodemographic, biological, and behavioural factors. Comparison of HGS between surveys indicated a negative secular trend in both sexes (p < 0.001). In boys, there was a positive association of HGS with age and FFM in both surveys. In 2017/18, there was a positive association with sexual maturation and a negative association with sitting time and fat percentage. In girls, FFM was positively associated with HGS in both surveys. In 2007, there were positive associations of HGS with age and vigorous physical activity, whereas, in 2017/18, negative associations were observed with economic level and sitting time. The findings of the present study show a decline in adolescent HGS. And behavioural changes appear to be contributing to declines in HGS.

Breaking paradigms: Long non-coding RNAs forming gene fusions with potential implications in cancer

Long non-coding RNAs (lncRNAs) are non-coding RNAs longer than 200 nucleotides with dynamic regulatory functions. They interact with a wide range of molecules such as DNA, RNA, and proteins to modulate diverse cellular functions through several mechanisms and, if deregulated, they can lead to cancer development and progression. Recently, it has been described that lncRNAs are susceptible to form gene fusions with mRNAs or other lncRNAs, breaking the paradigm of gene fusions consisting mainly of protein-coding genes. However, their biological significance in the tumor phenotype is still uncertain. Therefore, their recent identification opens a new line of research to study their biological role in tumorigenesis, and their potential as biomarkers with clinical relevance or as therapeutic targets. The present study aimed to review the lncRNA fusions identified so far and to know which of them have been associated with a potential function. We address the current challenges to deepen their study as well as the reasons why they represent a future therapeutic window in cancer.

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.

Association between arthritis and hand grip strength indices combined with anthropometry in an older Korean population

BACKGROUND

Hand grip strength (HGS) is related to arthritis and all-cause mortality. Many studies have examined the association between HGS and arthritis, but these studies did not consider relative HGS indices. The objectives of this study were to examine the association between arthritis and HGS indices in an older Korean population and to compare an absolute HGS index and a relative HGS indices.

METHODS

In a large-scale cross-sectional study, a total of 16,860 subjects older than 50 years from the Korea National Health and Nutrition Survey from 2014 to 2019 were included for statistical analysis. A binary logistic regression model was used to examine the association between arthritis and HGS indices in crude and covariate-adjusted models.

RESULTS

In the crude analysis, all anthropometric and HGS indices were associated with arthritis except for weight in men. In adjusted models 1 and 2, among the anthropometric indices, waist circumference (WC) and waist-to-height ratio (WHtR) were associated with arthritis in men but not in women. Absolute HGS and all relative HGS indices showed a negative association with arthritis among both men and women, and the magnitude of the association of arthritis with the absolute HGS index and the relative HGS indices was similar. However, the magnitude of the association between all HGS indices and arthritis was higher for men than for women except in the crude analysis.

DISCUSSION

Absolute and relative HGS indices had negative associations with arthritis, and the magnitude of the association between the absolute HGS index and arthritis and between the relative HGS indices and arthritis was similar in all models. To our knowledge, this is the first report of an association between arthritis and relative HGS indices, which was not observed in previous studies.

Assessment of handgrip strength in healthy african subjects: Establishing age and gender stratified reference values

Background

The handgrip strength assesses hand function in traumatic and non-traumatic upper extremity conditions. It is also a surrogate marker for other systemic diseases unrelated to the upper limb. Various reference values have been established in different world regions, with few studies in our population.

Aim

To determine the average handgrip strength by gender and age categories among healthy subjects in Nigeria.

Materials and Methods

It was a cross-sectional study assessing handgrip strength by age category (ten-year bin width), gender, and handedness in 210 healthy persons aged 10 to 79 in Nigeria. Its relationship with age, height, weight, mid-arm circumference, triceps skinfold thickness, and mid-arm muscle area was evaluated using multiple linear regression.

Results

The mean handgrip strength in the dominant and non-dominant hands was 31.09 kg and 28.45 kg, respectively, P < 0.001. Males have higher values than females in all age categories. The grip strength peaked in the 30-39-year age group in both genders and declined afterward. Age exhibited a nonlinear pattern but had an overall negative relationship, while height was positively related to grip strength in both genders. In contrast, mid-arm circumference and mid-arm muscle area predicted handgrip strength only in males. Triceps skinfold thickness was excluded from the model because of multicollinearity with the mid-arm muscle area, while weight did not predict grip strength in either gender.

Conclusion

The handgrip strength in this study is less than that in western literature. Hence, test interpretation should reference the values from this study.

Association of handgrip strength with anthropometry of a Brazilian healthy adolescent sample

The importance of dynamometric and anthropometric information for industry is known; however, few studies have investigated the relationship between anthropometry and handgrip strength (HGS) in adolescents. The aim of the present study was to investigate the association of anthropometric variables with the level of HGS production in adolescents. Participants were 541 adolescents aged 12-16 years from a public school in the city of Rio de Janeiro. The behavior of the following variables was examined: the ability to generate HGS, age, total body mass, height and hand dimensions (hand width, hand span, hand length). The results showed an increase in the ability to generate HGS in adolescence and a significant difference between the genders from 13 years old, where boys generated higher HGS values. Correlations between HGS and total body mass and the hand width stood out in both genders, indicating a greater association.

Reference Values of Absolute and Relative Handgrip Strength in Chilean Schoolchildren with Intellectual Disabilities

Handgrip strength is a simple measure of general muscle strength and is related to functionality in people with intellectual disabilities. The objective of this research was to describe the normative values of absolute and relative handgrip strength in children, adolescents and adults according to sex. The sample was made up of 264 schoolchildren (n = 168 men) belonging to five special education schools in Santiago of Chile. The results show higher levels of absolute handgrip strength in males compared to females. The maximum peak of the absolute manual handgrip is reached in females in adolescence with a decrease in adulthood. Relative handgrip strength levels are similar in boys and girls. In females, the relative handgrip strength is similar in childhood and adolescence. Relative handgrip strength declines in both sexes from adolescence to adulthood. The reference values of this study can be used by professionals in the areas of health and education as a guide for interpretation, monitoring and follow-up of Chilean schooled people with intellectual disabilities.

Handgrip strength and its correlation with anthropometric determinants and hand dimensions in children aged 6-12 years: A cross-sectional study

BACKGROUND

Handgrip strength is considered an important interpreter of general health, and hand functions in children. It is mainly influenced by anthropometric determinants and hand dimensions.

OBJECTIVE

To assess the handgrip strength and their association with anthropometric determinants, hand circumference, hand span, and hand length among school children in both the dominant and non-dominant hand.

METHODS

Anthropometric measurements, hand circumference, hand span, hand length, and grip strength measurements were obtained from 133 school children of both genders aged 6-12 years. A Jamar hand-held dynamometer was used to measure handgrip strength and the hand dimensions with a tape measure in cm.

RESULTS

Significant differences were found between the handgrip strength among boys and girls. The dominant hand was found to be sturdier than the non-dominant hand in both genders. We also found a significant correlation of anthropometric determinants and hand dimensions with handgrip strength. Age, BMI, hand circumference, hand span, and hand length had a strong correlation with grip strength (p < 0.01).

CONCLUSIONS

The study revealed the reference values and concluded its correlations with hand dimensions among school children aged 6-12 years and this information can serve as a manual for interpretation of handgrip strength measurements in children.