The cross-sectional relationships between age, standing static balance, and standing dynamic balance reactions in typically developing children

•Age is related to balance reactions, but not standing sway in children 5–12 years.•Weak correlations between balance reaction and sway measures were observed.•Results suggest that static and dynamic balance are distinct skills in children. Static balance performance is a common metric for evaluating the development of postural control in children. Less is known about the potentially independent development of dynamic balance performance. How does age relate to static (i.e. postural sway) and dynamic (i.e. stepping thresholds) standing balance performance, and what is the relationship between postural sway and stepping thresholds? Twenty-six typically developing children (12 males, 14 females; 5–12 years of age) were recruited for this cross-sectional study. Static balance performance was quantified as the total path length during a postural sway assessment using a force platform with conditions of eyes open and eyes closed. Dynamic balance performance was quantified using a single-stepping threshold assessment, whereby participants attempted to prevent a step in response to treadmill-induced perturbations in the anterior and posterior directions. Relationships between age and body-size scaled measures of static and dynamic balance performance were assessed using Spearman rank correlations. There was a weak correlation between age and postural sway (|rs| < 0.10, p > 0.68), but a moderate-to-strong correlation between age and single-stepping thresholds (rs > 0.68, p < 0.001). A weak correlation was found between postural sway and single-stepping thresholds (|rs| < 0.20, p > 0.39). Dynamic, but not static standing balance performance, may improve with typical development between the ages of 5 and 12 years. Static and dynamic balance should be considered as unique constructs when assessed in children.