Prolonged visual-motor dual-task effects on dynamic stability in children with ADHD subtypes

Abstract Research on dynamic stability in children with Attention-Deficit/Hyperactivity Disorder (ADHD) has predominantly relied on short-term laboratory paradigms, limiting understanding of how prolonged task demands affect gait stability. This study investigated the effects of prolonged visual-motor dual-task walking on gait stability across ADHD subtypes. Fifty-seven children (7–10 years) participated: 19 with the combined subtype (ADHD-C), 17 with the predominantly inattentive (ADHD-I), and 21 typically developing peers. Participants walked on a treadmill at self-selected speeds for three minutes under four visual conditions (no target, fixation, saccade, and smooth pursuit). Group-by-visual condition effects on Margin of Stability (MOS) and its coefficient of variation (CV) were analyzed via mixed-model ANOVA (α = 0.05). Typically developing children exhibited larger MOS and lower CV than both ADHD groups across most conditions. However, children with ADHD-C achieved stability levels comparable to typically developing children during fixation, whereas children with ADHD-I remained less stable across conditions. Smooth pursuit was associated with the lowest stability in both ADHD subtypes. Saccades and fixation conditions were associated with greater stability consistency, with saccades showing the lowest variability. Distinct patterns of stability were observed across ADHD subtypes and visual-task conditions. Prolonged visual-motor dual-task walking revealed subtype-specific patterns of gait stability in children with ADHD. These findings suggest that visual-task demands may differentially influence gait stability across ADHD subtypes and highlight the importance of considering visual-attentional demands when examining locomotor control in this population.