Influence of Auditory Noise and Weighted Vests on Stance Phase Kinetics in Children with Autism

Children with autism spectrum disorder (ASD) often demonstrate atypical sensory processing (i.e., hyper- and hypo-sensitivities to auditory stimuli). Such deficits may influence motor coordination while walking in everyday environments. Weighted vests are commonly used by clinicians as a sensory integration therapy technique intended to primarily remediate behavioral responses. Despite its potential to positively influence walking mechanics, weighted vests have only been examined to a limited extent. In addition, the influence of auditory noise during walking has been largely understudied during gait regardless of its association with atypical sensory processing. Understanding stance phase kinetics may help characterize heterogenous responses to sensory stimuli during gait in children with ASD. PURPOSE: This study used a single-subject analysis approach to examine the influence of auditory noise and the application of a weighted vest on stance phase ground reaction forces (GRF) along the vertical and anterior-posterior directions during walking. METHODS: Seven children (11.42 ± 2.81 yr, 1.52 ± 0.16 m, 46.81 ± 18.09 kg) with a clinical diagnosis of ASD completed overground walking trials under four experimental conditions, including both with and without auditory noise and with and without a weighted vest (5% body weight) while three-dimensional kinetic data were collected from an in-ground force platform. The model statistic technique (a = 0.05) and the coefficient of variation were used to determine statistically significant and meaningful differences, respectively, in stance phase duration, vertical GRF (vGRF), and anterior-posterior GRF (A-P GRF) characteristics. RESULTS: Stance phase durations (6 of 7 participants) and vertical impulses (5 of 7 participants) displayed the most consistent differences (p < 0.05) across participants, although the specific responses were unique to each individual. Moreover, the presence of auditory noise was most frequently associated with alterations in stance phase duration and vertical impulse, whereas the weighted vest more consistently altered normalized vGRF peak magnitudes and anterior-posterior propulsive peak force. Anterior-posterior braking kinetics remained unchanged across all participants. CONCLUSION: Auditory noise and the application of a weighted vest can independently alter gait kinetics in children with ASD, leading to individual level adaptations of stance phase mechanics. These findings highlight the heterogeneous qualities of ASD and support the application of single-subject analysis approaches to examine individual adaptations to sensory challenges and common clinical interventions in this population.