Postural sway in primary school children

The maintenance of balance while standing is strictly related to a correct sensory motor control system. In childhood, balance control should increase with age (1). Aim of the study was to investigate the postural sways of healthy primary school children. The postural sways of 337 boys (age 9.0 ± 1.5 yr, body mass 31.3 ± 9.1 kg, standing height 130.7 ± 9.5 cm, BMI 18.0 ± 3.4 kg/m2), and 355 girls (9.1 ± 1. 5 yr, 30.4 ± 8.2 kg, 130.9 ± 9.7 cm, 17.5 ± 3.1 kg/m2) in bipedal standing position were measured (2). 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 anthropometric and postural parameter were computed within sex, age, and visual conditions (open, closed eyes). Comparisons were performed by ANOVA. The age of boys and girls did not differ (p > 0.05). In both boys and girls, body mass, standing height, and BMI significantly increased with age (p < 0.001). Body weight (p = 0.02), and BMI (p = 0.003) were larger in boys than in girls. The age-related differences of body mass were larger in boys than in girls (sex × age interaction, p < 0.001). 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). In conclusion in children, the ability to maintain balance in standing position significantly improved with age (1). 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. References: 1) Steindl et al., Develop Med & Child Neurol, 2006, 48(6):477-42; 2) Turci et al., It J Anat Embryol, 2007, 112: S259.