Secular Trends in Gross Motor Coordination: A Study of Peruvian Children Living at High Altitude

PURPOSE

To (1) describe secular trends in gross motor coordination (GMC) scores by sex and age; (2) investigate GMC trends adjusted for concomitant secular trends in height, weight, and overall physical fitness; and (3) examine trends in children's frequencies within different GMC categories.

METHOD

The sample comprises 1562 Peruvian children (690 in 2009 and 872 in 2019), aged 6-11 years, from Junín (a high-altitude region). GMC was assessed with the KörperkoordinationsTest für Kinder. Physical fitness was assessed with handgrip strength, standing long jump, and shuttle-run test. Height and weight were measured with standardized protocols. Analysis of variance, covariance, and logistic regression were used.

RESULTS

A negative secular trend in GMC (based on raw scores) for boys and girls aged 6-8 years was observed. However, a positive trend was observed at 11 years of age but only in boys. Finally, there were no significant changes in the likelihood of children having below-normal GMC from 2009 to 2019.

CONCLUSIONS

Secular trends in GMC were negative in Peruvian children, especially at 6-8 years of age. Further, body size and physical fitness trends did not affect the negative secular trend. A high prevalence of children had below-normal GMC in both 2009 and 2019.

Differences and Relationship between Body Composition and Motor Coordination in Children Aged 6-7 Years

BACKGROUND

The primary goal of this study was to investigate the relationship between body composition and motor coordination performance, and the secondary goal was to determine sex differences in body composition and motor coordination of preschool children.

METHODS

Forty-eight children (23 boys and 25 girls) underwent assessments for body composition and motor coordination using the Köperkoordinationstest für Kinder (KTK).

RESULTS

Linear regression analysis revealed significant associations between body composition and motor coordination in boys (p < 0.05) but not in girls. In boys, Body height (p = 0.01), Total muscle mass (p = 0.03), Total fat (p = 0.03), and Total water (p = 0.02) show statistically significant influence on single-leg jumps. Similar results were obtained for lateral jumps where there was a statistically significant influence of Body height (p = 0.01), Total muscle mass (p = 0.03), and Total water (p = 0.02). Interestingly, predictive variables showed no statistically significant influence on KTK overall score in boys (p = 0.42) nor in girls (p = 0.90).

CONCLUSIONS

The predictive system of morphological variables demonstrated significance only among boys in this age group and sample. Girls outperformed boys due to early maturation, resulting in better average KTK scores.

Visuomotor tracking strategies in children: associations with neurodevelopmental symptoms

Children with neurodevelopmental disorders (NDDs) often display motor problems that may impact their daily lives. Studying specific motor characteristics related to spatiotemporal control may inform us about the mechanisms underlying their challenges. Fifty-eight children with varying neurodevelopmental symptoms load (median age: 5.6 years, range: 2.7-12.5 years) performed an interactive tablet-based tracking task. By investigating digit touch errors relative to the target's movement direction, we found that a load of neurodevelopmental symptoms was associated with reduced performance in the tracking of abrupt alternating directions (zigzag) and overshooting the target. In contrast, reduced performance in children without neurodevelopmental symptoms was associated with lagging behind the target. Neurodevelopmental symptom load was also associated with reduced flexibility in correcting for lateral deviations in smooth tracking (spiral). Our findings suggest that neurodevelopmental symptoms are associated with difficulties in motor regulation related to inhibitory control and reduced flexibility, impacting motor control in NDDs.

Poor Motor Competence Affects Functional Capacities and Healthcare in Children and Adolescents with Obesity

BACKGROUND

From a young age, children learn different motor skills known as fundamental motor skills. The acquisition of these skills is crucial for the future development of context-tailored actions that could improve adherence to physical activity (PA) practice. Motor competence and function deficits have been associated with pediatric obesity. We reviewed the literature data regarding motor competence in pediatrics and impaired motor performance in children and adolescents with obesity.

METHODS

We assessed the abstracts of the available literature (n = 110) and reviewed the full texts of potentially relevant articles (n = 65) that were analyzed to provide a critical discussion.

RESULTS

Children and adolescents with obesity show impaired motor performance, executive functions, postural control, and motor coordination. Children's age represents a crucial point in the development of motor skills. Early interventions are crucial to preventing declines in motor proficiency and impacting children's PA and overall fitness levels.

CONCLUSIONS

To involve children, the PA protocol must be fun and tailored in consideration of several aspects, such as clinical picture, level of physical fitness, and motor skills. A supervised adapted exercise program is useful to personalized PA programs from an early pediatric age.

Gender differences and climate zones in overweight and obesity prevalence in European elementary school children from 2000 to 2020: a systematic review and meta-analysis

Introduction

After 2000, there are more obese than underweight people in the world. We face a rapid increase in average global warming of 1.5°C, reported as a syndemic problem of three interconnected epidemics: obesity, global warming, and undernutrition. We aimed to analyze the impact and association between global warming and obesity in children and differences by gender across Europe after 2000.

Methods

We searched PubMed, MEDLINE, Google Scholar, ScienceDirect, and Embase databases. The considered population were children aged 6-14. Only cross-sectional studies that defined obesity by the IOTF cutoffs and the subjects' place of residence, used to determine precise climate zones, were included. We assessed the prevalence of obesity and overweight using a random-effects and the Mantel-Haenszel fixed-effect method when heterogeneity was greater/lower than 50%. We did a subgroup analysis for prevalence across gender, obesity, and overweight, two decades, regions, countries, and the Köppen-Geiger climate zones. Random effects of the meta-regression were used to study the global warming impact and differences in trends across European countries by gender for both conditions separately.

Results

We identified 114 studies that included 985,971 children from 39 European countries. A significant difference between genders was in favor of obese girls 4.78 (95% CI: 3.85-5.93) versus boys 5.76% (95% CI: 5.11-6.48, p = 0.03), respectively, but not for overweight children. Most of the obese girls were in South Europe 7.51% (95% CI: 6.61-8.51) versus East Europe 2.86% (95% CI: 23-3.12), versus boys in South Europe 8.66% (95% CI: 7.68-9.74) and North Europe 3.49% (95% CI: 2.90-4.19), respectively. The "cold" Köppen-Geiger climate zone, with lowest temperatures, has the largest trend rise between two decades of 2.8% and 1.53% for obese girls and boys, and 5.31% and 1.81% for overweight girls and boys, respectively, followed by the smallest number of obese girls 3.28% (95% CI: 2.17-4.92) and boys 3.58% (95% CI: 2.39-5.33), versus the zone with the highest temperatures "hot" for girls 7.02% (95% CI: 6.30-7.82) and for boys 8.23% (95% CI: 7.55-8.96), respectively. The meta-regression proved global warming has a significant impact on the distribution of obesity and overweight across climate zones, R2 = 0.52 and R2 = 0.22. No significant gender differences, or significant interaction, was noted.

Conclusion

Our meta-analysis provides a comprehensive overview of the association between and impact of global warming on obesity. This impact increases obesity among children in Europe throughout all climate zones, and emphasizes an urgent call for further preventive methods in schools, since obesity differences continue their trend of disappearing into the future.Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021282127, identifier: CRD42021282127.

Motor Coordination in Primary School Students: The Role of Age, Sex, and Physical Activity Participation in Turkey

Motor coordination (MC) is an essential skill underpinning precise and controlled movements, contributing significantly to daily functioning and overall performance. The developmental trajectory of MC in children is intricately shaped by a spectrum of factors encompassing age, gender, and physical activity engagement. Delving into the complex interrelation of these variables holds the potential to unravel nuanced developmental trends and offer targeted avenues for interventions aimed at augmenting motor proficiency in the pediatric population. This study aimed to assess the differences in MC of primary school students based on sex, age, and physical activity participation (PAP). A total of 848 students from public primary schools, aged between 6-9 years, including 412 boys and 436 girls. The MC was measured using Körperkoordinationstest für Kinder (KTK3+) test battery, which included Jumping sideways (JS), Balancing backward (BB), Moving sideways (MS), and Eye-Hand Coordination (EHC). One-way multivariate analysis of variance (MANOVA) was used to determine the binary and triple interactions of sex, age, and PAP variables on the MC parameters of the participants. The study revealed that boys aged 6-9 had higher scores than girls on eye-hand coordination (EHC) (p < 0.02). No significant gender-related differences in balancing backward (BB), jumping sideways (JS), and moving sideways (MS) were found. When the subtests of KTK3+ were compared by age, a significant difference was observed between the groups in all subtests (p < 0.05). With respect to PAP, students with PAP had a significant advantage in all subtests of the KTK3+ (p < 0.05). The double co-effects or triple co-effects of age, sex, and PAP parameters do not influence the KTK parameters. This study presents evidence supporting sex differences in the motor skills of children within this age range and highlights the potential impact of age and physical activity on motor development.

How Do Health, Biological, Behavioral, and Cognitive Variables Interact over Time in Children of Both Sexes? A Complex Systems Approach

The present study examined gender differences in health, physical activity, physical fitness, real and perceived motor competence, and executive function indicators in three time points, and analyzed the dynamic and non-linear association between health, biological, behavioral, and cognitive variables in children followed over time. A total of 67 children (aged between six and 10 years) were followed during two years and split into two cohorts (six to eight years old: C1; eight to 10 years old: C2). Data regarding health, physical activity, real and perceived motor competence, physical fitness, and executive function indicators were obtained according to their respective protocols. Comparison tests and network analysis were estimated. Significant gender differences were found in both cohorts. The emerged networks indicated different topologies in both cohorts. No clusters were observed between the variables in C1, and there was a greater number of interactions at eight years of age. Sparse networks were observed in children aged eight and 10 years in C2, and greater connectivity was observed at nine years of age between health, physical fitness, motor competence, and physical activity indicators. This study showed that there are non-linear dynamic relationships between health, biological, behavioral, and cognitive variables over time during child development.

Variation and Predictors of Gross Motor Coordination Development in Azorean Children: A Quantile Regression Approach

We investigated the development of gross motor coordination (GMC) as well as its predictors in school-aged Azorean children. The sample included 181 children (90 girls), followed consecutively for 4 years from 6 to 9 years of age. GMC was assessed with the Körperkoordinationstest für Kinder, and predictors included body mass index, standing long jump, 50-yard dash, and shuttle run. The changes in GMC and the effects of predictors were analyzed with mean-modeling as well as quantile regression. In the latter, we considered the following three quantiles (Q): Q20, Q50, and Q80 as markers of low, median, and high GMC levels, respectively. All analyses were conducted using R software and alpha was set at 5%. The GMC changes were curvilinear in both models, but the quantile approach showed a more encompassing picture of the changes across the three quantiles in both boys and girls with different rates of change. Further, the predictors had different effect sizes across the quantiles in both sexes, but in the mean-model their effects were constant. In conclusion, quantile regression provides more detailed information and permits a more thorough understanding of changes in GMC over time and the influence of putative predictors.

Effects of Equine-Assistant Activity on Gross Motor Coordination in Children Aged 8 to 10 Years

Generally, adequate motor coordination (MC) ability is one among the critical factors for the overall development of children. In this paper, we have thoroughly analyzed the effects of equine-assistant activity (EAA) training on MC in children. For this purpose, MC test, specifically for children, was used to the Körperkoordinationstest für Kinder (KTK), and a total of 100 children, particularly those in 8 to 10 age, were equally separated into equine-assistant activity group (EAAG) and control group (CG), respectively. The EAAG group has attended a 14-week EAA training program, while the CG joined in physical education activity once per week. The experimental results have indicated that four indices of KTK test (i.e., backward walk [WB], height jump [HH], jumping sideways [JS] and moving sideways [MS], and motor quotient [MQ] score) showed significant differences ( ^∗ P < 0.05) after a 14-week EAA training. Furthermore, the indices of physical fitness test, standing long jump (SLJ), and sit and reach (SAR) showed significant differences ( ^∗ P < 0.05), but the handgrip (HG) increased slightly without significant difference (P > 0.05) after a 14-week EAA training. In conclusion, there were improvements in MC, lower limb strength, and flexibility by EAAG for those who participated in a 14-week EAA training, and this study has demonstrated the effectiveness of the KTK assessment of MC in children 8 to 10 years.

DEVELOPMENT OF BALANCE IN CHILDREN PARTICIPATING IN DIFFERENT RECREATIONAL PHYSICAL ACTIVITIES

Balance, an important motor coordination ability, underlies the performance of variousmotor skills and allows for participation in common childhood activities. Research indicatesthat sport participation could support balance development in children. To confirm the aboveeffect, this study investigated whether participation in different recreational physicalactivities could induce differences in children’s balance ability. Specifically, 138 children, 5-11 years old (Mage=8.4±1.3), classified into four groups according to the activity they tookpart in (basketball, track and field, rhythmic gymnastics, contemporary dance), were assessedby the balance subset of the KörperKoordinationstest für Kinder. Pearson correlations wereapplied to detect associations of balance scores with age, height, body mass index (BMI) andshowed significant correlations for BMI (p< .001). The analyses of covariance (covariate:BMI) that were computed on children’s balance scores showed statistically significant effectsof group (p< .001). Sidak post hoc tests indicated that children participating in rhythmicgymnastics surpassed all three other groups; whereas those taking part in basketball had thelowest scores in almost every balance item. It seems that the type of physical activity a childparticipates in could be a significant contributor to the development of his/her balance.Physical activities encompassing the execution of various balance tasks, such as rhythmicgymnastics, seem to offer children greater opportunities to make improvements in this areacompared to children engaging in activities of low balancing requirements. This findinghighlights the potential that is available to coaches: they can contribute to children’s balancedevelopment by implementing sport-specific programs that target this human ability.

Effects of Overweight/Obesity on Motor Performance in Children: A Systematic Review

Childhood obesity is a serious public health problem. Childhood obesity and overweight are associated with the appearance of coordination deficit disorder and can cause impaired motor performance. We searched online databases for all related articles using comprehensive international databases from the Medline PubMed Institute, Web of Science, ScienceDirect, SCOPUS, and PsycINFO up to December 20, 2020. Overall, 33 studies were included in this systematic review. The present review demonstrated that children with higher percentage of body fat had lower levels of moderate to vigorous physical activity, as well as decreased levels of gross motor coordination, as shown by tests for neuromuscular performance. These results corroborate the hypothesis that overweight and obesity in children and adolescents are associated, not only with insufficient performance during gross motor coordination activities, but also with a greater risk to physical health.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42020182935].

Monitoring physical and motor traits in primary school: a local harmful situation for older children

BACKGROUND

Health-related testing in school environments may be led by PE lessons facilities, which represent an optimal context. Aiming to investigate the developmental trajectories of physical and motor traits during PE lessons, we recruited 381 children in grades 1, 2, 4 and 5 of primary school in Abruzzo, Italy.

METHODS

We included anthropometric indexes (Body Mass Index and Waist-to-Height Ratio) and fitness tests, i.e. 4×10 m Shuttle Run test (4×10 SR), handgrip strength test, and standing long jump test (LJ). We also included two fine motor skills (FMS) tests and collected data about sports participation.

RESULTS

Gender differences were found about sports participation (boys were more involved in open-skills sports) and motor skills, with girls outperforming boys in FMS and vice versa in fitness measures, even if with small evidence. There was an increment in all the tests with age, with the most robust evidence about handgrip strength and FMS. School clustering had a significant random effect on some fitness measures (4×10 SR and LJ). Despite high sports participation, an impairment in older children was detected, with a special alarm in older boys about metabolic risk.

CONCLUSIONS

The small-to-moderate correlations between parameters suggest that there are similarities in the developmental trajectories, but also that it should be assessed a wide range of motor skills and anthropometric indexes. In conclusion, we support the assessment of gender-and-context-related developmental trajectories in the school setting, by the mean of fitness measures, anthropometric indexes, and FMS, to be compared with local and general references, as evidence-based planning of PE interventions.

Association between body mass index, physical activity and motor competence in children: moderation analysis by different environmental contexts

BACKGROUND

Although the association between body mass index (BMI), physical activity (PA) and motor competence (MC) has been widely investigated, the influence of different environmental contexts is not well defined.

AIM

To analyse the relationship between BMI, PA and MC and the moderating role of the environmental context.

SUBJECTS AND METHODS

A cross-sectional study was performed with 668 children (318 boys) aged 5-7 years (north-eastern district - Brazil). MC (Körper koordination test fur Kinder; KTK), BMI and PA (parent reporting) were assessed. To classify three contexts of the environment a variable was created based on the presence of a sports court in school and/or environment for play or sports practice out of school. Multilevel mixed-effects linear regressions, interaction test and estimation of coefficients in moderation analysis were used.

RESULTS

BMI (β = -2.93; p < .01) and age (β = 19.02; p < .01) were associated, and PA was not associated (β = 0.07; p = .05) with MC. The strength of the association between BMI and MC changed based on the environmental contexts. The better the environment context the weaker the association between BMI and MC (β = -2.93, p < .01 to β = -2.38, p = .33 to β = 0.26, p = .94).

CONCLUSIONS

The association between BMI and MC is moderated by environmental contexts.

Change and Stability in Sibling Physical Fitness: The Portuguese Sibling Study

PURPOSE

This study aims to 1) describe mean changes in muscular and motor fitness components in sibships over 2 yr, 2) analyze individual tracking of fitness within sibships, 3) investigate sibling resemblance in fitness over time, and 4) examine the joint influence of biological, behavioral, and familial characteristics on fitness.

METHODS

The sample comprises 166 Portuguese biological sibling pairs (brother-brother, sister-sister, brother-sister) age 9-17 yr assessed at baseline and 2 yr later. Physical fitness components were measured with standardized tests. Percentage body fat and biological maturation were assessed, and physical activity, diet, screen time, and familial characteristics were obtained by questionnaires. Multilevel models were used to analyze the clustered longitudinal data.

RESULTS

Crude results showed that, on average, all sib-types increased their muscular and motor fitness components from baseline to follow-up (except sister-sister pairs in standing long jump and shuttle run). When adjusted for covariates, the mean changes were no longer significant. Individual tracking was moderate to high for the muscular component but low to moderate for the motor component. Consistency in sibling resemblance was higher in sister-sister pairs than in brother-brother and brother-sister pairs. More mature sibs were fitter in both components, whereas siblings with higher body fat percentage were less fit. Screen time, physical activity, and parental occupation were not associated with fitness components.

CONCLUSIONS

Biological characteristics were more strongly associated with fitness components than individual behaviors and familial characteristics. Furthermore, the muscular component tracked better than the motor component. Sister-sister pairs had greater resemblance in fitness over time compared with brother-brother or sister-brother pairs.

Prevalence and Trends of Overweight and Obesity in European Children From 1999 to 2016: A Systematic Review and Meta-analysis

IMPORTANCE

Studies of trends in excess weight among European children throughout the last few decades have rendered mixed results. Additionally, some studies were outdated, were based on self-reported weight and height, or included only a few European countries.

OBJECTIVE

To assess prevalence trends in measured overweight and obesity among children across Europe from 1999 to 2016 using a systematic methodology.

DATA SOURCES

MEDLINE, Embase, CINAHL, and Web of Science were searched from their inception until May 2018. Moreover, searches were conducted on health institutions' websites to identify studies not published in scientific journals.

STUDY SELECTION

The inclusion criteria were: (1) studies reporting the population-based prevalence of excess weight (overweight plus obesity) or obesity according to body mass index cutoffs proposed by the International Obesity Task Force; (2) cross-sectional or follow-up studies; and (3) studies including populations aged 2 to 13 years.

DATA EXTRACTION AND SYNTHESIS

Literature review and data extraction followed established guidelines. The Mantel-Haenszel method was used to compute the pooled prevalence estimates and their 95% CI whenever there was no evidence of heterogeneity (I2 < 50%); otherwise, the DerSimonian and Laird random-effects method was used. Subgroup analyses by study year, country, or European region (Atlantic, Iberian, Central, and Mediterranean) were conducted. Prevalence estimates were calculated as an aggregate mean, weighted by the sample size and the number of individuals in each study.

RESULTS

A total of 103 studies (477 620 children aged 2 to 13 years) with data from 28 countries were included. The combined prevalence of overweight and obesity in the Iberian region tended to decrease from 30.3% (95% CI, 28.3%-32.3%) to 25.6% (95% CI, 19.7%-31.4%) but tended to increase in the Mediterranean region from 22.9% (95% CI, 17.9%-27.9%) to 25.0% (95% CI, 14.5%-35.5%). No substantial changes were observed in Atlantic Europe or Central Europe, where the overweight and obesity prevalence changed from 18.3% (95% CI, 14.0%-23.9%) to 19.3% (95% CI, 17.7%-20.9%) and from 15.8% (95% CI, 13.4%-18.5%) to 15.3% (95% CI, 11.6%-20.3%), respectively.

CONCLUSIONS AND RELEVANCE

The prevalence of childhood overweight and obesity is very high, but trends have stabilized in most European countries. There are substantial between-country differences in the current levels and trends of overweight and obesity. The rising prevalence in some Mediterranean countries is worrisome.

TRIAL REGISTRATION

PROSPERO identifier: CRD42017056924.

KTK MOTOR TEST: REVIEW OF THE MAIN INFLUENCING VARIABLES

OBJECTIVE

To analyze the scientific literature regarding the effects of external variables on KTK motor test scores and to verify which motor tests are associated with KTK.

DATA SOURCES

Four databases (PubMed, Science Direct, Scientific Electronic Library Online - SciELO - and Latin American and Caribbean Health Sciences Literature - LILACS) were used to search for studies in which the descriptors Körperkoordinationstest für Kinder and KTK were presented in the title, abstract and keywords. Inclusion criteria were: articles published in English or Portuguese from January 2006 to December 2016; free access to the article in full and texts available online; presenting the descriptor terms mentioned above in the title, abstract or keywords; containing sample with children and adolescents aged 4 to 16 years old; being indexed in a journal with a rating of B2 or higher (WebQualis; Qualis 2016) for the area of physical education. The following were excluded: studies in books, chapters of books, theses and dissertations; duplicate scientific articles; conference summaries; articles published in proceedings and abstracts of congresses.

DATA SYNTHESIS

After the three stages of selection (identification, screening and eligibility) and the criteria proposed at the PICOS scale, 29 studies were included in this review.

CONCLUSIONS

Body composition and the regular practice of physical activities were the variables that presented the greatest influence on KTK. It is important that health professionals working with the pediatric public encourage regular physical activity to improve body composition and, thus, to obtain better KTK scores. Additionally, the Movement Assessment Battery for Children (M-ABC) test had the highest positive correlation with the KTK test.

Normative values of the motor competence assessment (MCA) from 3 to 23 years of age

OBJECTIVES

Growing evidence of the importance of motor competence for developing a healthy lifestyle has been established in the last decade. Nonetheless, no single instrument or observation tool have been able to fully measure this construct, particularly because most were built for the diagnosis of children in risk for motor impairment; are limited to a few years of the developmental span; lack objectivity in the assessment protocols; or do not include the locomotor, stability, and manipulative components. This led to the difficulty of comparing researches, and longitudinally follow children into adulthood. Recently, a novel proposal to assess motor competence was presented - the Motor Competence Assessment (MCA) - and this study aims to present the MCA normative data from 3-to-23 years.

DESIGN AND METHODS

Two thousand and eighty-seven participants (1102 boys) between 3 and 23 years of age were evaluated in the MCA (standing long jump, 10 m shuttle run, throwing velocity, kicking velocity, lateral jumps, shifting platforms). Results for each test were introduced in the LMS Chartmaker 2.3. The best model for test and sex was used, resulting in normative curves and percentile values.

RESULTS

Final norms showed a good fit to the instrument developmental expectations, allowing to differentiate and classify performances along the age interval.

CONCLUSIONS

The MCA age- and sex- normative values allow to assess motor competence from childhood to early adulthood. Future directions will include obtaining a total MCA score and the normative scores for the MCA components (stability, locomotion, object control), and to expand the norms to adulthood and old age.

A mixed-longitudinal study of children's growth, motor development and cognition. Design, methods and baseline results on sex-differences

BACKGROUND

There is a renewed interest in longitudinal studies which link children's growth, motor and cognition development. This is important for both educational outcomes and identification of children who are at risk.

AIM

To identify cross-sectional sex-differences.

SUBJECTS AND METHODS

In total, 1166 Portuguese children, aged 4-11 years, were recruited into the Growth, Motor Development and Cognition Study (GMDC-Vouzela study). Measures included: anthropometry, gestational development, motor coordination, cognitive performance, laterality, physical fitness, metabolic syndrome risk, lifestyle characteristics and environmental exposures. Analysis of covariance was used to compare outcomes between boys and girls, adjusting for chronological age.

RESULTS

Most variables did not show significant differences between the sexes (p > 0.05). However, girls had more body fat mass than boys (p < 0.05) and boys were significantly heavier at birth (p < 0.05); furthermore, boys outperformed girls in a hopping high coordination test (p < 0.001) and were more physically fit (p < 0.05).

CONCLUSIONS

Baseline results from the GMDC-Vouzela study indicate the dynamic relationships between children's biological and environmental characteristics. They also highlight lifestyle traits that will most likely effect subsequent growth, motor and cognitive development.

How Consistent are Genetic Factors in Explaining Leisure-Time Physical Activity and Sport Participation? The Portuguese Healthy Families Study

This study investigates how consistent genetic factors are, as measured by heritability estimates (h2), in the leisure-time physical activity index (LTPAI) and sport participation index (SPI) from early (10-14 yrs) to late adolescence (15-19 yrs). The sample comprises 12,385 subjects from 3,378 Portuguese nuclear families. Height and weight were measured and body mass index (BMI) was calculated, and the LTPAI and SPI were estimated by questionnaire. Socioeconomic status (SES) was assessed by parental occupation. Analyses were done using S.A.G.E. software. Our results showed that h2 estimates for the LTPAI and SPI in the two age groups (10-14 yrs and 15-19 yrs) were stable: for the LTPAI, h2 = 0.297 and 0.322, respectively; and for the SPI, h2 = 0.413 and 0.428, respectively. Sibling correlations and environmental correlations are higher in the younger age group for both the LTPAI and the SPI. Spousal correlations are higher in the younger age group for the LTPAI and lower for the SPI than the older group. Parent-offspring correlations are similar in both age groups for the LTPAI and SPI. In conclusion, the influence of genetic factors on physical activity and sport participation remains stable across age in adolescence. However, variation in sibling correlations - in particular, environmental correlations - was observed. These findings suggest that shared/non-shared environmental factors express different degrees of importance across age. Future intervention programs aiming to promote change in behaviors need to consider these results to bring about positive changes in physical activity and sport participation behaviors within the family setting.

Modeling children's development in gross motor coordination reveals key modifiable determinants. An allometric approach

Children change their body size, shape, and gross motor coordination (GMC) as they grow. Further, GMC is expected to link to changes in children's body size, physical activity (PA), and physical fitness (PF). The objective was to model GMC changes in children followed longitudinally and to investigate associations between these changes and PA and PF levels. A total of 245 children (122 girls) were observed at 6 years of age and followed annually until 9 years. A sequence of allometric models was fitted, that is, 1. body mass, stature, and PA; 2. addition of four PF tests; 3. addition of four more PF tests. In Model 1, changes in GMC are nonlinear, and body mass (-0.60 ± 0.07, P < .001) and stature (2.91 ± 0.35, P < .001) parameter estimates were significant suggesting children with a more linear body size/shape showed higher GMC performances. Girls tend to outperform boys across time, and PA was not associated with GMC changes. Model 2 fitted the data better, and the PF tests (handgrip, standing long jump, 50-yard dash, and shuttle run) were significantly linked to GMC change. In Model 3, adding the remaining PF tests did not change the order of any factors importance. The greatest GMC changes were achieved by children whose body size/shape has an ectomorphic dominance across the years. Considering that leaner and physically fitter children tended to be more coordinated, physical education should also focus on PF development in components related to muscular strength, speed, agility, and aerobic capacity, along with nutritional education to reduce fat mass.

Resemblance in physical activity levels: The Portuguese sibling study on growth, fitness, lifestyle, and health

OBJECTIVES

To investigate the relationships of biological, behavioral, familial, and environmental characteristics with siblings´ physical activity (PA) levels as well as the intrapair resemblance in PA.

METHODS

The sample comprises 834 (390 females) biological siblings [brother-brother (BB), sister-sister (SS), brother-sister (BS)] aged 9 to 20 years. Total PA index (TPAI) was estimated by questionnaire. Information on potential behavioral, familial, and environmental correlates was obtained by self-report; body mass index (BMI), biological maturation, and physical fitness were measured. Multilevel models were used to analyze siblings´ clustered data, and sibling resemblance was estimated with the intraclass correlation (ρ).

RESULTS

On average, younger sibs, those more physically fit, and those with more parental support had greater TPAI. Further, BB pairs had higher TPAI levels than SS or BS pairs, but also had greater within-pair variance. When adjusted for all covariates, SS pairs demonstrated greater resemblance in TPAI (ρ = 0.53, 95%CI = 0.38-0.68) than BS (ρ = 0.26, 95%CI = 0.14-0.43) or BB pairs (ρ = 0.18, 95%CI = 0.06-0.44).

CONCLUSIONS

Age, physical fitness, and parental support were the best predictors of TPAI levels. A moderate level of resemblance in TPAI was observed in SS pairs, while lower resemblance was found for BS and BB pairs. These findings may be due to differences in the roles of shared genetic factors, familial, and environmental characteristics across different sibling types.

A multilevel analysis of health-related physical fitness. The Portuguese sibling study on growth, fitness, lifestyle and health

This study investigates biological, behavioural and sociodemographic correlates of intra-pair similarities, and estimates sibling resemblance in health-related physical fitness (PF). The sample comprises 1101 biological siblings (525 females) aged 9–20 years. PF components and markers were: morphological [waist circumference (WC) and %body fat (%BF)], muscular [handgrip strength (GS) and standing long jump (SLJ)], motor [50-yard dash (50YD) and shuttle run (SR)], and cardiorespiratory (1-mile run). Biological maturation was assessed; physical activity (PA), TV viewing and socioeconomic status (SES) information was obtained. On average, older and more mature subjects are better performers in all PF components; PA was negatively associated with SR, while SES was negatively associated with SLJ and SR. A pattern was observed in the intraclass correlations (ρ) wherein same sex siblings demonstrate greater resemblance for most PF components (sister-sister: 0.35≤ ρ≤0.55; brother-brother: (0.25≤ρ≤0.60) than brother-sister pairs (BS) (0≤ρ≤0.15), except for %BF (ρBB>ρSS>ρBS), and the 1-mile run (ρSS>ρBS>ρBB). In conclusion, behavioural and sociodemographic correlates play different roles in siblings PF expression. Further, a significant familial PF resemblance was observed with different trends in different sibling types, probably due to variations in shared genetic factors and sociodemographic conditions.

Multilevel modelling of somatotype components: the Portuguese sibling study on growth, fitness, lifestyle and health

BACKGROUND

Somatotype is a complex trait influenced by different genetic and environmental factors as well as by other covariates whose effects are still unclear.

AIMS

To (1) estimate siblings' resemblance in their general somatotype; (2) identify sib-pair (brother-brother (BB), sister-sister (SS), brother-sister (BS)) similarities in individual somatotype components; (3) examine the degree to which between and within variances differ among sib-ships; and (4) investigate the effects of physical activity (PA) and family socioeconomic status (SES) on these relationships.

SUBJECTS AND METHODS

The sample comprises 1058 Portuguese siblings (538 females) aged 9-20 years. Somatotype was calculated using the Health-Carter method, while PA and SES information was obtained by questionnaire. Multi-level modelling was done in SuperMix software.

RESULTS

Older subjects showed the lowest values for endomorphy and mesomorphy, but the highest values for ectomorphy; and more physically active subjects showed the highest values for mesomorphy. In general, the familiality of somatotype was moderate (ρ = 0.35). Same-sex siblings had the strongest resemblance (endomorphy: ρ_SS > ρ_BB > ρ_BS; mesomorphy: ρ_BB = ρ_SS > ρ_BS; ectomorphy: ρ_BB > ρ_SS > ρ_BS). For the ectomorphy and mesomorphy components, BS pairs showed the highest between sib-ship variance, but the lowest within sib-ship variance; while for endomorphy BS showed the lowest between and within sib-ship variances.

CONCLUSIONS

These results highlight the significant familial effects on somatotype and the complexity of the role of familial resemblance in explaining variance in somatotypes.

Effects of different physical education programmes on children's skill- and health-related outcomes: a pilot randomised controlled trial

Aim of this study was to evaluate the effectiveness of two different 5-month physical education (PE) interventions conducted by a specialist PE teacher on primary school children's skill- and health-related outcomes. About 230 children were randomly assigned to one of three intervention groups: experimental_1 group, experimental_2 group or control group (school curriculum given by the generalist teacher). Pre- and post-intervention tests assessed pupils' fitness (pacer, curl-up, push-up, trunk lift, sit and reach tests) and gross motor coordination (shifting platforms, balance beam, jumping laterally, hopping on one leg over an obstacle tests). Both experimental groups significantly improved some fitness and coordinative tests after the intervention period when compared with control group. However, no differential changes on coordinative development were observed between the 2 experimental groups. Results of this study demonstrated that children benefitted from a well-structured PE intervention conducted and supervised by a specialist PE teacher improving their motor skills and fitness.

Do Girls with Excess Adiposity Perform Poorer Motor Skills than Leaner Peers?

The main aim of this study was to analyze the joint association of body fat percentage and physical activity levels on motor coordination scores in girls with different adiposity status. Sixty-eight school-aged children between 12 and 14 years participated in the study. Skinfold thickness was measured and the Körperkoordinationstest für Kinder test was administered. Participants completed a self-reporting questionnaire on physical activity. Children's adiposity status was attributed in according to age-specific cutoff points of a Brazilian database. Analysis of Variance was used to compare motor coordination scores among groups with different status of adiposity and physical activity. Girls with appropriate body fat percentage performed higher motor coordination scores than girls with excess adiposity, regardless of their physical activity levels (p < 0.05). Additionally, within groups with the same adiposity status, no differences were found in motor coordination scores (p > 0.05). Adiposity status was predominant over physical activity status when joint associations of body fat percentage and physical activity levels on motor coordination scores were analyzed in girls. In addition to metabolic and cardiovascular issues, the acquisition and/or maintenance of appropriate body fat levels in female students should be focused in physical education classes due to its association with motor skills performance.

Developmental and physical-fitness associations with gross motor coordination problems in Peruvian children

The aims of this cross-sectional study were to examine the developmental characteristics (biological maturation and body size) associated with gross motor coordination problems in 5193 Peruvian children (2787 girls) aged 6-14 years from different geographical locations, and to investigate how the probability that children suffer with gross motor coordination problems varies with physical fitness. Children with gross motor coordination problems were more likely to have lower flexibility and explosive strength levels, having adjusted for age, sex, maturation and study site. Older children were more likely to suffer from gross motor coordination problems, as were those with greater body mass index. However, more mature children were less likely to have gross motor coordination problems, although children who live at sea level or at high altitude were more likely to suffer from gross motor coordination problems than children living in the jungle. Our results provide evidence that children and adolescents with lower physical fitness are more likely to have gross motor coordination difficulties. The identification of youths with gross motor coordination problems and providing them with effective intervention programs is an important priority in order to overcome such developmental problems, and help to improve their general health status.

Skeletal Maturation, Body Size, and Motor Coordination in Youth 11-14 Years

PURPOSE

The objective of this study is to estimate the relative contribution of biological maturation to variance in the motor coordination (MC) among youth and to explore gender differences in the associations.

METHODS

Skeletal maturation (Tanner-Whitehouse 3), stature, body mass, and MC (Körperkoordinationstest für Kinder) were assessed in 613 youths, 284 boys and 329 girls 11-14 yr of age. Standardized residuals of skeletal age on chronological age were used as the estimate of skeletal maturity status independent of chronological age. Hierarchical multiple regression analyses were used to analyse associations between skeletal maturity status and MC.

RESULTS

Skeletal maturity status by itself, i.e., standardized residuals of skeletal age on chronological age (step 3) explained a maximum of 8.1% of the variance in MC in boys (ΔR3 in the range of 0.0%-8.1%) and 2.8% of the variance in girls (ΔR3 in the range of 0.0%-2.8%), after controlling for stature, body mass and interactions of the standardized residuals of skeletal age on chronological age with stature and body mass. Corresponding percentages for the interactions of the standardized residuals of skeletal age and stature and body mass, after adjusting for stature and body mass (step 2) were 8.7% in boys (ΔR2 in the range of 0.3%-8.7%) and 7.1% in girls (ΔR2 in the range of 0.1%-7.1%). Chow tests suggested structural changes in β-coefficients in the four MC tests among boys and girls, 12-13 yr.

CONCLUSION

The percentage of variance in the four MC tests explained by skeletal maturation was relatively small, but the relationships differed between boys and girls. By inference, other factors, e.g., neuromuscular maturation, specific instruction and practice, sport participation, and others may influence MC at these ages.