Relationship between Body Composition and Gross Motor Coordination in Six-Year-Old Boys and Girls

The aim of this study was to investigate the association between morphological characteristics (body composition and anthropometric data) and gross motor coordination in preschool children (42 boys and 40 girls, aged 6.22 ± 0.43 years, height: 1.22 ± 0.48 m, body mass index: 20.22 ± 2.34 kg/m², muscle mass: 11.50 ± 2.08 kg, and fat mass: 5.43 ± 4.02 kg). Motor coordination was determined by the obstacle course backward test (OCB), while body composition was measured using the bioelectrical impedance (BIA) method. Sex differences in the OCB test and body morphology were determined by an independent t-test. Multiple linear regression was used to examine whether morphological characteristics could predict OCB scores. Boys were significantly taller, with greater muscle mass, protein mass, and total body water compared to girls (t = 2.01–3.73, p < 0.05). Inversely, mineral mass was greater in girls than in boys (t = 2.98, p = 0.01). No significant sex differences were observed in the results obtained for the OCB test (t = 0.74, p = 0.46). All morphological variables showed trivial-to-weak (r = 0.01–0.15) associations with the OCB results, without reaching statistical significance (p ≤ 0.16). The model of predictor variables did not have a statistically significant effect on the OCB scores in boys and girls (R² = 0.09, p = 0.91 and R² = 0.012, p = 0.92, respectively). These results indicate that sex dimorphism in body composition is present at an early age before puberty, while morphological characteristics have a negligible influence on motor coordination in 6-year-old children.