Introduction: This study aimed to investigate postural control strategy development during unipedal standing via stabilogram diffusion analysis (SDA).

Methods: Twenty-six healthy children aged 5-10 years and 14 young adults participated in the experiment. The child cohort was divided into two groups by age: 5-7 (n = 13) and 8-10 (n = 13) years. The main outcomes were center of body's mass (COM) (COM_area, COM height, and nCOM_area) and SDA (Δt_c, Δr²_c, Drs, Drl, Hs, and Hl) parameters. Furthermore, the coefficients of determination of each regression line were calculated (R²_Drs, R²_Drl, R²_Hs, and R²_Hl). For each analysis, the range of the long-term region was performed for maximum durations of 0.5 and 8 s.

Results: The median value of R²_Drl in all groups were 0.81-0.96 and 0.41-0.63 for the 0.5 and 8 s durations, respectively. The nCOM_area was significantly larger in the 5-7 years age group than in the adult group (p < 0.01). In addition, the Drs was significantly higher in the 5-7 years age group than in the adult group (p = 0.04). In contrast, the Hs was significantly smaller in the 5-7 years age group than in the adult group (p = 0.01).

Discussion: A maximum long-term region duration of 0.5 s may be better when evaluating the postural control strategy during unipedal standing. Furthermore, our study suggests that younger children, aged 5-7 years, mainly use open-loop postural control during unipedal standing.