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

Background: 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.

Research Question: 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?

Methods: 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.

Results: There was a weak correlation between age and postural sway (|r| < 0.10, p >  0.68), but a moderate-to-strong correlation between age and single-stepping thresholds (r > 0.68, p < 0.001). A weak correlation was found between postural sway and single-stepping thresholds (|r| < 0.20, p >  0.39).

Significance: 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.