Introduction: Electronic devices have been used by increasingly younger people, leading researchers to investigate the impact of these technologies on the health of developing children. Objective: To investigate the impact of smartphone use on the postural control of Brazilian children 6 to 9 years old.Methods: This cross-sectional study was conducted with 278 children from public schools in Goiânia (Goiás, Brazil). The children were assessed in an orthostatic posture with the computerized baropodometry system in three conditions: eyes open, eyes closed, and using a free smartphone application. Results: The children were 8.36 years old on average, 82% of them were well-nourished, and had a daily mean screen time of 2 hours. The postural control analyses revealed that the children made greater postural adjustments with their eyes closed than with them open. When using the smartphone application, the postural adjustments were similar to those with eyes closed. In the stabilometry, the postural displacements made by the children behaved similarly to the static assessment only in total feet surface area. Conclusion: Smartphone use and absence of visual stimulus in the orthostatic position caused postural instability in children 6 to 9 years old. These findings can contribute to understanding the impact of technologies on children’s development of balance in daily tasks.

This study aimed to analyze the intra-and inter-rater reliability in the assessment and classification of the longitudinal plantar arch of children from 6 to 10 years old in the eyes-open (EO) testing condition. Methods: A total of two-hundred and seventy-eight Brazilian children (556 feet), boys and girls, from 6 to 10 years of age participated in the study. The children's feet were examined on a baropodometric platform, and the Staheli index was used for calculating the plantar arch index. Footprint analyses were performed at two different times, with an interval of 7 to 10 days, by three physical therapists in a single testing condition, resulting in 3,336 footprints. To determine the reliability of the continuous measurements, the Intraclass Correlation Coefficients (ICC) with 95% confidence intervals (CIs), Standard error of the mean (SEM), absolute value and percentage, and the Minimum Detectable Change (MDC) were calculated. To determine the reliability of the longitudinal arch classification, inter-rater reliability was evaluated by Weighted Fleiss Kappa Coefficient and the test-retest reliability was estimated by Weighted Cohen Kappa Coefficient. Results: Regarding inter-rater reliability, we observed values of ICC ranging from 0.79 to 0.96; thus, the results were classified as substantial to excellent reliability), being the lowest ICC values occur for line B, mainly in the first assessments. SEM ranges from 0.08 to 0.21 (percentage: 3.74 to 28.7), being the best, the lowest SEM values occur for Plantar Arch Index assessments and the MDC varies between 0.22 and 0.59. Regarding intra-rater reliability, the results indicated excellent reliability: values of ICC range from 0.92 to 0.99, being the lowest ICC values also occurs for line B analysis. SEM ranges from 0.03 to 0.20 (percentage: 2.32 to 26.6), being the lowest SEM values occur for Plantar Arch Index assessments and MDC varies between 0.09 and 0.54. Analyzing the interrater reliability for the longitudinal arch classifications, we observed values of Weighted Fleiss Kappa Coefficient ranging from 0.83 to 0.87, expressing almost perfect agreement among the raters before and after evaluations. The testretest reliability of the longitudinal arch classification resulted in values of Weighted Cohen Kappa Coefficient ranging from 0.80 to 0.996, expressing substantial to almost perfect agreement intra-rater. Conclusion: The study showed high reliability in the clinical assessment of the longitudinal plantar arch index of children from 6 to 10 years of age indicating that the Staheli method is applicable to pressure platform assessments with intra-and inter-rate reliability.