Analysis of unsupported gait in toddlers with autism. Esposito G, Venuti P, Apicella F, Muratori F. Department of Cognitive Science and Education, University of Trento, Italy. firstname.lastname@example.org AIMS: A number of studies have suggested the importance of motor development in autism. Motor development has been considered a possible bio-marker of autism since it does not depend on either social or linguistic development. In this study, using retrospective video analysis we investigated the first unsupported gait in toddlers with autism. METHODS: Fifty-five toddlers, belonging to three groups were recruited: toddlers with autistic disorder (AD, n=20, age 14.2mo, sd 1.4mo) and as comparison groups: typically developing toddlers (TD, n=20, age 12.9mo, sd 1.1mo) and toddlers with non-autistic developmental delays of mixed aetiology (DD, n=15, age 13.1mo, sd 0.8mo). The Walking Observation Scale (WOS) and the Positional Pattern for Symmetry during Walking (PPSW) were used to gather data on the first unsupported gait. The WOS includes 11 items that analyze gait through three axes: foot movements; arm movements; general movements while the PPSW analyses static and dynamical symmetry during gait. RESULTS: Our results have identified significant differences in gait patterns among the group of toddlers with AD as opposed to the control groups. Significant differences between AD and the two control groups were found for both WOS (p<.001) and PPSW (p<.001). CONCLUSION: The specificity of motor disturbances we have identified in autism (postural asymmetry) is consistent with previous findings that implicated cerebellar involvement in the motor symptoms of autism.