PROJECT SUMMARY / ABSTRACT Cerebral palsy (CP), the most common cause of childhood disability, results from a non-progressive disturbance to the developing brain and leads to impairments which negatively impact mobility and function. Individuals with CP demonstrate abnormal reactions to anticipated (proactive) and unanticipated (reactive) balance challenges, placing them at increased risk of falls. Adults with CP are 3.64x more likely to fall than their typically developing peers, and the incidence of falls in children with CP is similarly increased. Balance control is worsened with the addition of a secondary (dual) cognitive task. This causes cognitive-motor interference, which results when motor and cognitive tasks are competing for the same resources and leads to degradation in performance of one or both tasks. These cognitive-motor tasks mimic daily life situations such as walking and talking with friends, and the difficulty that children with CP experience in these situations leads to declines in participation and function. Previous work has investigated this cognitive-motor dual task paradigm; however, all studies have utilized proactive balance challenges, with the primary motor tasks of balance or straight path ambulation. Evaluation of a more functional proactive balance task, such as obstacle negotiation, is needed in the context of a cognitive-motor dual task situation. Additionally, previous studies have shown that children with CP fall more and have decreased stability during single task reactive balance challenges; however, this single task condition requires the addition of a secondary task to become functionally relevant and mimic daily life scenarios. Our specific aims will address these mechanistic and participatory gaps in the literature by investigating: (1) proactive balance control through negotiation of an overground obstacle in single and dual task conditions, in children with CP compared to TDC; (2) reactive balance control through stance slip-like treadmill induced perturbations in single and dual task, in children with CP compared to TDC; and (3) the correlation between balance control and participation in mobility-related habits of daily life in children with CP utilizing the LIFE-H, linking the biomechanical and mechanistic laboratory findings (Aims 1 +2) to participation and quality of life (Aim 3) for children with CP. We hypothesize that children with CP will demonstrate decreased stability and greater falls in both single and dual task conditions when compared to TDC, and that both groups will experience these declines in performance, when compared to themselves, in dual task conditions. The results from this study will be integral in establishing the mechanisms underlying balance control during functional proactive and reactive balance challenges, and how this stability correlates with overall mobility-based participation for children with CP. This will provide valuable insights for developing effective clinica...