Setting: The research will take place in the homes of infants and their families in Pennsylvania, Delaware, Washington, and Virginia.
Sample: There will be approximately 140 infants with neuromotor disorders completing participation in this study, beginning at the age the age of 7 to 16 months, as well as their families and interventionists. Infants will have gross motor delays but be able to sit propped up for at least 3 seconds when they are recruited for participation.
Intervention: Sitting Together And Reaching To Play (START-Play) is an intervention for infants with motor dysfunction or delay in which physical therapists visit the child's home to target work on siting, reaching, and problem solving. The therapist visits the home twice weekly for 3 months. During these visits, therapists and families work together to provide intensive, individualized, daily activities to advance reaching and sitting through small increments of challenge and support for these skills, which then become the building blocks for motor-based problem solving. More specifically, the intervention focuses on self-initiated, goal-directed movements to build orientation and attention to objects, while learning basic relationships of cause and effect. Infants and families in the intervention group will receive this intervention in addition to their usual early intervention services.
Research Design and Methods: This study will use a randomized controlled trial in which infants and their families are randomly assigned to the intervention group (START-Play in addition to usual services) or control group (usual early intervention services), stratified by severity of neuromotor disorder. There will be six measurement sessions during the 12-week intervention period, following by assessments during 1-, 3-, and 9-month follow-up visits. The study aims to determine the efficacy of the intervention on sitting and reaching (proximal outcomes) and motor-based problem solving skills (longer-term proximal outcome), which is hypothesized to serve as mediators to the more distal outcomes of global cognitive development and readiness to learn. The investigators will also explore fidelity of implementation to identify conditions that support fidelity and outcomes, as well as identify other moderating factors related to the child (severity of disorder, health, age, cognitive skill at entry), family (socioeconomic status, home environment), or services (fidelity of implementation, other services provided to child) to explore change over time.
Control Condition: Infants and their families in the control condition will continue to receive their regular Part C early intervention services.
Key Measures: Primary outcome measures in the study include the Gross Motor Function Measure and an observational measure of toy contacts for sitting and reaching, and the Individual and Growth Development Indicators (Early Problem Solving Indicator) and Bayley Scales of Infant and Toddler Development -Third Edition for problem solving and global development. Secondary measures include additional measures of postural control and reaching, child and family characteristics, and fidelity of implementation (logs and checklist).
Data Analytic Strategy: The investigators will use linear mixed modeling (LMM) to determine the efficacy of the intervention on child outcomes. Parallel process growth modeling within a structural equation modeling framework will be used to examine whether improvements in sitting and reaching are mediators leading to improvements in problem solving, which is then a mediator leading to long-term global cognitive development. LMM will also be used to examine moderating variables, as well as secondary motor outcomes.
