How Trunk Control Links Autism Severity to Functional Exercise Capacity in Children With ASD

The goal of this observational study is to learn if trunk control (the ability to balance and stabilize the upper body while sitting or moving) links autism severity to functional exercise capacity in children aged 4-12 years with Autism Spectrum Disorder (ASD). The main questions it aims to answer are: 1. Does trunk control explain why children with more severe ASD have lower functional exercise capacity? 2. Do trunk control and functional exercise capacity differ across ASD severity levels (Level 1, 2, and 3)? Participants will complete two assessments in a single 30-40 minute session during their routine clinic visit: 1. A trunk control test, where a trained physiotherapist observes seated balance and movement. 2. A 6-Minute Walk Test (6MWT), where the child moves along a flat hospital corridor for 6 minutes and the total distance covered is recorded as a measure of functional exercise capacity. No treatment or intervention is involved. All assessments are safe, non-invasive, and conducted at a tertiary care children's hospital in Pakistan.

Inclusion Criteria: * Children aged 4-12 years (inclusive) at the time of assessment * Confirmed diagnosis of ASD according to DSM-5 criteria, documented in the hospital record by a licensed clinical psychologist or developmental paediatrician * Classified at DSM-5 severity Level 1, 2, or 3 in the existing clinical file * Currently attending physiotherapy or developmental rehabilitation outpatient services at the hospital * Able to attempt the Six-Minute Walk Test (6MWT) with or without verbal prompting * Written informed consent from parent or legal guardian; verbal assent from child where developmentally appropriate (aged 7 years and above) Exclusion Criteria: * Co-existing neurological condition independently affecting gait (e.g., cerebral palsy, uncontrolled epilepsy) * Orthopaedic condition precluding walking or safe execution of the Trunk Impairment Scale * Acute illness, fever, or significant behavioural crisis at the time of the scheduled assessment session * Current enrolment in a structured physiotherapy or physical activity intervention programme * Caregiver refusal of consent or participant non-cooperation with either assessment tool at the time of the visit