Development of temporal and spatial characteristics of anticipatory postural adjustments during gait initiation in children aged 3-10 years.

This study aimed to analyze the development of direction specificities of temporal and spatial control and the coordination pattern of anticipatory postural adjustment (APA) along the anteroposterior (AP) and mediolateral (ML) directions during gait initiation (GI) in children aged 3-10 years. This study included 72 healthy children aged 3-10 years and 14 young adults. The child population was divided into four groups by age: 3-4, 5-6, 7-8, and 9-10 years. The GI task included GI using the dominant limb. The peak center of feet pressure (COP) shifts during APAs (APA), initiation time of COP shifts (APA), and the COP vectors in the horizontal plane were calculated to evaluate the direction specificity of spatial, temporal, and coordination control, respectively. A difference in direction specificity development was found for the APA. The APA in the mediolateral axis, but not in the anteroposterior axis, was significantly higher in the 7-8 years age group than in other groups. Although APA was not found for direction specificity, a significant difference between the adult and children groups (5-6 years, 7-8 years, and 9-10 years) was observed in the direction of the COP vector. In conclusion, the developmental process of the spatial, temporal, and coordination control of APAs during GI varied with age. Furthermore, the spatial control and coordination pattern of APAs was found to be direction specific. All components of APAs, namely temporal and spatial control, coordination pattern, and direction specificities, should be analyzed to capture the developmental process of anticipatory postural control.