Sex Differences in Gross Motor Competence in Italian Children Aged 3–11 Years: A Large-Scale Cross-Sectional Study

Background/Objectives: In recent years, there has been a significant increase in studies examining motor learning during preschool age and the early years of primary school. This study aimed to investigate sex differences in gross motor competence among Italian children aged 3–11 years. Methods: A convenience sample of 8500 children (mean age = 8.37 years, SD = 1.98; 50% female) was included in this cross-sectional study. Gross motor skills were assessed using the Italian version of the Test of Gross Motor Development–3, which evaluates locomotion and ball control skills. A Linear Mixed Model was applied to examine the interaction between sex and age, with school included as a random intercept and BMI as a covariate. Results: The results revealed a consistent trend of boys achieving significantly higher total scores for global motor competence (p < 0.001) across all age groups, except at age 11. Boys also demonstrated superior performance in ball control skills (p < 0.005) at all ages. In contrast, no significant differences were observed for locomotion skills overall. However, girls outperform boys in locomotor skills at ages 6, 7, and 8 (p < 0.001), with this trend disappearing by age 9. Conclusions: These findings highlight important sex-related differences in gross motor development during childhood, influenced by both biological and environmental factors. The results underscore the need for targeted interventions in educational settings to provide equitable opportunities for motor skill development, particularly for girls. Enhancing the quality of physical education and addressing gender disparities can support the acquisition of essential motor skills and promote lifelong physical activity.