The goal of this clinical trial is to evaluate whether Neurodevelopmental Treatment (NDT) can improve balance, mobility, walking capacity, and functional independence in preschool children with Down syndrome.

The main questions it aims to answer are:

• Does an 8-week Neurodevelopmental Treatment program improve balance performance in children with Down syndrome?
• Does Neurodevelopmental Treatment improve mobility, walking capacity, functional independence, and gross motor function in children with Down syndrome?
• Are baseline balance performance and age of independent standing associated with treatment-related balance improvements?

All participants will receive individualized Neurodevelopmental Treatment based on the Bobath concept twice weekly for 8 weeks.

Participants will:

• Undergo baseline assessments of balance, mobility, walking capacity, functional independence, and gross motor function
• Participate in individualized Neurodevelopmental Treatment sessions twice weekly for 8 weeks
• Complete the same outcome assessments following the intervention period

The findings may help improve understanding of rehabilitation outcomes and factors associated with treatment responsiveness in children with Down syndrome.

Down syndrome (DS) is one of the most common genetic conditions associated with intellectual disability and is frequently accompanied by motor impairments, including hypotonia, ligamentous laxity, delayed motor development, impaired balance, and reduced functional mobility. These impairments may negatively affect participation in daily activities and functional independence during childhood.

Neurodevelopmental Treatment (NDT), also known as the Bobath concept, is widely used in pediatric rehabilitation to facilitate postural control, movement quality, sensory-motor integration, and functional performance. Although NDT is commonly applied in clinical practice, evidence regarding its effects on balance, mobility, walking capacity, and functional independence in children with Down syndrome remains limited.

This pilot study was designed to investigate changes in motor and functional outcomes following an individualized 8-week NDT program in preschool children with Down syndrome. In addition to evaluating intervention-related changes, the study explored whether baseline balance performance and age of independent standing were associated with treatment responsiveness. Understanding factors that may influence rehabilitation outcomes could support more individualized treatment planning and improve clinical decision-making in pediatric rehabilitation.

The findings of this study are expected to provide preliminary evidence regarding the potential role of NDT in improving functional outcomes in children with Down syndrome and to inform the design of future controlled rehabilitation trials.

Inclusion Criteria:

Diagnosis of Down syndrome Age between 3 and 6 years Gross Motor Function Classification System (GMFCS) Level I or II Ability to walk independently without assistive devices Ability to cooperate with assessment and treatment procedures Parent or legal guardian willing to provide informed consent

Exclusion Criteria:

Severe visual impairment Diagnosis of autism spectrum disorder Significant cooperation difficulties preventing participation in assessments or treatment Failure to regularly attend the physiotherapy program Lower-extremity surgery within the previous 6 months Any medical condition that would prevent safe participation in the intervention program

De-identified individual participant data underlying the results reported in the publication, including demographic characteristics, outcome measure scores, and derived variables used in the analyses, will be made available to qualified researchers upon reasonable request.

Data will be available beginning 6 months after publication of the primary study results and will remain available for 5 years following publication.

Access will be granted to researchers whose proposed use of the data has been approved by the study investigators. Requests should include a methodologically sound research proposal. De-identified participant-level data, the study protocol, and statistical analysis plan will be provided for non-commercial scientific research purposes. Data will be shared through direct contact with the corresponding author and subject to a data-sharing agreement.