Author Description

There is a consensus that individuals with Autism Spectrum Disorder (ASD) fall short of the recommended 60-minute daily moderate-to-vigorous physical activity (MVPA), and some experience motor delays and abnormalities. Yet ASD interventions focusing on addressing these challenges are insufficient in the existing literature. Research evidence supports the effectiveness of neurotypical (NT) sibling involvement in ASD intervention, therefore, using NT siblings as intervention agents to promote PA and motor skills in their sister/brother with ASD may be a viable option. The three studies within this dissertation were conducted during the COVID-19 pandemic when free and unstructured physical activity (PA) was suggested to be achieved by playing with siblings. This dissertation's first investigation was a qualitative study investigating the perceptions of NT siblings and caregivers on prospective sibling-guided motor intervention in children with ASD. The principal investigator also gathered information that ball games, in-person format, once or twice per week frequency, weekend days, and 30-minute session duration were most preferred. Prior to designing and implementing the PA intervention, a cross-sectional study was conducted with 18 parent-ASD-NT triads (54 participants) to understand PA, parental perceived motor competence, and PA-related family dynamics in children with ASD during COVID-19. The findings from the PA questionnaire revealed that children with ASD spent a significantly greater amount of time in sedentary behaviors (mean = 2379.06 mins; SD = 1480.10) during an entire week than in leisure time activities (mean = 316.88 mins; SD = 301.48) and sports activities (mean = 183.00 mins; SD = 153.94). Also, parents perceived their children's competence on most skills listed in the parental proxy of the Pictorial Scale of Perceived Movement Skill Competence (PMSC-parent) as not too good or sort of good. In addition, it was indicated that NT siblings' self-efficacy