ACCRESCIMENTO CORPOREO E CAPACITÀ COORDINATIVE NEI BAMBINI DELLA SCUOLA PRIMARIA

BODY GROWTH AND COORDINATION SKILLS IN PRIMARY SCHOOL CHILDREN. A longitudinal investigation on body growth in primary school children was performed during a 2yr life span. Body sway and eye-hand coordination were also studied in cross-sectional investigations. On October 2009, weights and standing heights of 261 (116 girls; 145 boys), 261 (116; 145), and 253 (108; 145) respectively 6, 7, and 8yr-old primary school-children were measured in Voghera (Pavia, Italy). Body Mass Indices (BMI) were calculated. The measurements were repeated 1 and 2 years later. For each age group, descriptive statistics of each parameter were computed within age, sex and session of measurements. Comparisons were performed by ANOVA (F1, factor 1, sex; F2, factor 2, age; F1×F2 interaction). Statistical significance was set at 5% for all comparisons. Frequencies and percentages of school-children relatively under (<3rd percentile), and overweight (>97th percentile) were computed, while comparing BMI to reference data for Italian children (1, 2). On average, weight, height, and BMI were larger in boys than in girls. Differences between sexes were significant (F1, p<0.001) in 8yr-old group. Boys and girls significantly grew with age (F2, p<0.001 for all comparisons). In 6yr-old group, the effects of age on height increments were larger in boys than in girls (F1×F2 interaction, p=0.017). In the 6 and 8yr-old groups, overweight was more frequent in boys than in girls. In the 6yr-old group, underweight was more frequent in girls than in boys, and increased with age. In the 7 and 8yr-old groups, this distribution decreased with age in both boys and girls. School-based anthropometric investigations represent a useful approach to address children and their families to correct life habits. Further investigations on this matter should be extended to adolescents, and prolonged as much as possible. The postural sways of 337 boys and 355 girls in bipedal standing position were measured. All participants had normal or corrected to normal vision. On week-days, they performed a standardized 30sec postural test (PT) on a portable baropodometrical platform (Winpod, Medicapteurs, Toulouse, F). Length and area variations of the center of foot pressure (COP) position during time were measured. Latero-lateral (LLV) and antero-posterior (APV) velocities of COP were also assessed. PT was performed with open and closed eyes. Descriptive statistics of each postural parameter were computed within sex, age, and visual conditions (open, closed eyes). Comparisons were performed by ANOVA. In both sexes, body sways were larger with closed than with open eyes, and decreased with age (p<0.01, for all comparisons). In both visual conditions, boys swayed more than girls (p<0.01, for all comparisons). The age-related differences of body sways were similar in boys and in girls, either with open or with closed eyes (sex × age interaction, p > 0.05 for all comparisons). The ability to maintain balance in standing position significantly improved with age. Postural control should be particularly pursued to favor the learning of several motor skills. The sex related differences should be studied more in detail, investigating also the effects of physical and sport activities. The detection of balance impairments could contribute to the diagnostic evaluation of neuromotor disorders in children, and could allow the intervention of a proper rehabilitation program. Further investigations into this matter could be performed in children younger than those participating in the present study. The accuracy of underhand ball-throwing task was studied in 538 girls and 583 boys with normal or corrected-to-normal vision aged 6-10 yr. A standardized underhand ball-throwing test (UBT), consisting in 10 underhand tennis ball throws into the floor area delimited by a 40 cm radius wooden hoop lying on the floor 9 m apart the standing pupil, was performed and scored. Descriptive statistics of UBT scores were calculated within age and sex group. Correlation coefficients were calculated between UBT scores and anthropometric variables (body mass, standing height, BMI). The effects of age and sex on UBT scores were compared by ANOVA (factor 1, sex; factor 2, age; sex x age interaction). UBT scores significantly increased with age (p=0.003). Boys obtained larger UBT scores than girls of the same age (p=0.002). The age-related differences of UBT scores were similar in boys and girls (p>0.05). In both sexes, UBT scores were significantly related to body mass (p<0.05) and standing height (p<0.01). No relations between BMI and UBT scores were found (p>0.05).