Modelling the dynamics of children's gross motor coordination.

This study modelled children's gross motor coordination, investigated sex-differences and identified the effects of fixed and dynamic correlates on motor coordination development. A total of 344 Portuguese children (170 girls), from 6 age cohorts (5 to 9 years of age), were followed consecutively for three years (age range 5 to 11 years) using a mixed-longitudinal cohort design. Birth weight, hand dominance and socioeconomic status (SES) were identified. Gross motor coordination, body mass index, physical fitness (PF) and physical activity (PA) were assessed annually. A sequence of multilevel hierarchical linear models were developed. Model 1 found that age, age2, sex, sex-by-age and sex-by-age2 were significant predictors (p < 0.05) of gross motor coordination. Boys outperformed girls from 6 years of age onwards. Model 2 found a cohort effect (p < 0.05). Model 3 found that right handers were more coordinated (p < 0.05). When the confounders of body mass index, PF and PA were added to the model (Model 4) it was found that boys and girls had parallel trajectories in their gross motor coordination development. In conclusion children with increasing body mass index were less coordinated, while those who were stronger and more agile had steeper trajectories of gross motor coordination with 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.

Mastering movement: A Cross-sectional investigation of motor competence in children and adolescents engaged in sports.

INTRODUCTION: Motor Competence (MC) is related to the development of healthy lifestyles in children and adolescents, and many studies have compared it with different variables, including sports participation. This investigation aimed to characterize the components and total scores of MC regarding different physical activity practices, such as physical education (PE) classes, futsal, volleyball, and ballet, and to compare MC regarding sports, sex, and age-groups. METHODS: Using a cross-sectional study, 398 Portuguese children and adolescents (398 participants: 200 boys and 198 girls; 12.649±3.46 years) were conveniently chosen between 2022 and 2023. Four groups of different sports were created: PE classes (n = 187), futsal (n = 80), volleyball (n = 101) and ballet (n = 30), and four different age groups: 7 to 9 years old (n = 117); 10 to 12 years old (n = 65), 13 to 15 years old (n = 96) and, 16 to 19 years old (n = 120). All participants reported to participate in at least two training sessions per week (1 hour each) for at least two years. MC was assessed with Motor Competence Assessment (MCA) comprising three components with six tests (two tests for each component). Participants' total MC was calculated as the average of the three components of the MCA. Data were analyzed by applying ANOVA one-way with LSD post-hoc. RESULTS: Differences were found in MC among groups, where futsal participants showed better scores in general. Sex comparison showed that boys have a higher MC when practicing futsal, especially compared to volleyball players. Age-group analysis showed that younger participants had better MC levels compared to older ones. CONCLUSION: The whole group showed the 50th percentile of MC, but volleyball adolescents showed results below this reference. MC is intrinsically linked to an individual's motor experiences and motivations rather than depending directly on the specific practice of the sport.

Correlates of the Physical Activity Decline during Childhood.

PURPOSE: This study aimed to describe longitudinal trends in children's moderate-to-vigorous physical activity (MVPA) and to investigate associations with individual, familial, and school characteristics. METHODS: A sample of 341 Portuguese children age 5-10 yr (173 girls) from six age cohorts was followed over 3 yr using a mixed-longitudinal design. Physical activity, body mass index (BMI), gross motor coordination, and musculoskeletal fitness were assessed annually. Information on socioeconomic status and school characteristics was collected and analyzed with mixed models. RESULTS: MVPA shows a similar declining trend in both sexes, but on average, boys exceeded the World Health Organization recommendations of 60 min·d -1 . The best model showed that boys spend, on average, more time in MVPA than girls. Children with lower BMI are less prone to the decline in MVPA, whereas higher levels of musculoskeletal fitness were associated with lower declines in MVPA. Of all school characteristics, only playground dimension was related to MVPA decreasing trajectories. CONCLUSIONS: MVPA systematically declines from 5 to 10 yr of age in both boys and girls, but boys remained more active than girls across the age range. The best predictors of MVPA decline are sex, BMI, musculoskeletal fitness, and school playground dimension.