The purpose of this study was to investigate the tracking of gross motor coordination (GMC) and to profile children at 6 years of age who consistently showed higher stability patterns in different levels of GMC. The participants were 245 children (123 boys and 122 girls) who were assessed longitudinally from 6 to 9 years of age. GMC was assessed using the Korperkoordinationtest fur Kinder (KTK) test battery. Anthropometry, physical activity, and health- and performance-related physical fitness were also measured. Cohen’s kappa (κ) was used to estimate tracking. Tracking was poor for all GMC tests (0.17 ≤ κ ≤ 0.38) and moderate for the GMC motor quotient (MQ) in both boys and girls (0.44 ≤ κ ≤ 0.45). Instability at the extremes was low in GMC tests and negligible for MQ. Children who consistently showed high GMC levels during the 4 years of follow-up were lighter, had lower body mass index and subcutaneous fat, and showed higher scores in physical fitness tests at 6 years of age than those who consistently had low GMC levels. In conclusion, GMC showed low-to-moderate tracking over time in childhood. However, children who consistently demonstrated high GMC levels over time had healthier profiles at 6 years of age.

This study aimed to provide height, body mass, BMI and waist circumference (WC) growth centile charts for school-children, aged 4–17 years, from central Peru, and to compare Peruvian data with North-American and Argentinean references. The sample consisted of 8753 children and adolescents (4130 boys and 4623 girls) aged 4 to 17 years, from four Peruvian cities: Barranco, La Merced, San Ramón and Junín. Height, body mass and WC were measured according to standardized techniques. Centile curves for height, body mass, BMI and WC were obtained separately for boys and girls using the LMS method. Student t-tests were used to compare mean values. Overall boys have higher median heights than girls, and the 50th percentile for body mass increases curvilinearly from 4 years of age onwards. In boys, the BMI and WC 50th percentiles increase linearly and in girls, the increase presents a curvilinear pattern. Peruvian children are shorter, lighter and have higher BMI than their counterparts in the U.S. and Argentina; in contrast, age and sex-specific WC values are lower. Height, body mass and WC of Peruvian children increased with age and variability was higher at older ages. The growth patterns for height, body mass, BMI and WC among Peruvian children were similar to those observed in North-American and Argentinean peers.

Children from developed and developing countries differ in their body size and shape due to marked differences across their life history caused by social, economic and cultural differences which are also linked to their motor performance (MP). We used allometric models to identify size/shape characteristics associated with MP tests between Brazilian and Peruvian schoolchildren. A total of 4,560 subjects, 2,385 girls and 2,175 boys aged 9–15 years were studied. Height and weight were measured; biological maturation was estimated with the maturity offset technique; MP measures included the 12 minute run (12MR), handgrip strength (HG), standing long jump (SLJ) and the shuttle run speed (SR) tests; physical activity (PA) was assessed using the Baecke questionnaire. A multiplicative allometric model was adopted to adjust for body size differences across countries. Reciprocal ponderal index (RPI) was found to be the most suitable body shape indicator associated with the 12MR, SLJ, HG and SR performance. A positive maturation offset parameter was also associated with a better performance in SLJ, HG and SR tests. Sex differences were found in all motor tests. Brazilian youth showed better scores in MP than their Peruvian peers, even when controlling for their body size differences The current study identified the key body size associated with four body mass-dependent MP tests. Biological maturation and PA were associated with strength and motor performance. Sex differences were found in all motor tests, as well as across countries favoring Brazilian children even when accounting for their body size/shape differences.