Validity and Reliability of Functional Range Testing Using Movement Analysis Software in Paediatric Population With Autism Spectrum Disorder.

Introduction. Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder and can be seen from an early age, although diagnosis remains complicated in milder cases. The therapies received are directed at the main characteristics that define this disorder, related to difficulties in the areas of language and cognition, as well as in the social sphere. In this way, physiotherapy is relegated to a secondary role, although, regarding gross motor development, alterations in coordination have been described. Therefore, this study aims to establish the convergent and criterion validity, as well as the inter-observer and test-retest reliability of the measurement of the Functional Reach Test (FRT) using movement analysis software in the assessment of Postural Control (PC), in relation to the conventional method of recording the test, in paediatric population with ASD aged 3 and 12 years. Methods and Analysis. The research presented is a cross-sectional observational study of validity and reliability. The sample size will be 60 participants aged 3-12 years, divided into two groups. First group: 30 typically developing (TD) screened by inclusion criteria 1) TD, and exclusion criteria 1) pharmacological treatment that affects the child's motor function. TD children will be recruited at the University Complutense of Madrid (UCM) and associated centres. Second group: 30 ASD children screened by inclusion criteria 1) diagnosis of ASD, 2) traits of ASD under medical and/or psychological criteria, 3) ability to stand independently, and exclusion criteria 1) motor score on the Bayley Child Development Scale – III below item J, corresponding to item 39 “sits with control”, 2) concomitant diagnosis of neurological, cardiorespiratory or orthopaedic disease limiting the performance of the FRT test, 3) pharmacological treatment that has an impact on the child’s motor function and 4) difficulties in understanding and carrying out simple activities through verbal instructions and/or imitation. ASD children will be recruited at ADEMPA. The socio-demographic and clinical characteristics will be collected, as well as the limits of stability, which were evaluated using the FRT. These data will be recorded both by manual and video measurement, for subsequent analysis using Kinovea® software. The Test will be recorded in a standardized setting, with body markers placed on key anatomical points to track joint angles and movement trajectories. TD participants will perform the test in one session, while the ASD group will complete three sessions over 10 days to assess test-retest reliability. Inter-observer reliability will be also calculated based on two independent raters. Statistical analysis of the results will be performed using programme Jamovi Software 2.3 (2022) for R. Ethics and dissemination. The present study has been granted ethical approval by the Clinical Research Ethics Committee of the Hospital Universitario Clínico San Carlos (Madrid, Spain) with the reference number 25/294-IC_P_CE (O)_Tesis and under the indications of the Declaration of Helsinki.