Children with autism display altered ankle strategies when changing speed during over-ground gait.

BACKGROUND: Examining gait mechanics when altering speed has been used in various clinical populations to understand the pervasiveness of neurological impairments. Few studies have examined whether different gait mechanics exist when altering speed in children with Autism Spectrum Disorder, although autism may present as a movement disorder due to abnormalities in the central nervous system. Most autism gait-related research has used preferred walking speed, while different speeds may yield discernible patterns that can be used for future interventions. The purpose of this study was to examine kinematic strategies used by children with autism in preferred, fast, and slow walking speeds. METHODS: Three-dimensional kinematic data were obtained on 14 children (aged 8-17 years) during preferred, fast, and slow walking. Hip, knee, and ankle angular joint positions were examined at loading response, pre-swing, and terminal swing sub-phases due to their importance on forward propulsion and weight transfer. Repeated measures analyses of variance (α = 0.05) were used to test for statistical differences and effect sizes were interpreted with Cohen's d. FINDINGS: Although significant differences were observed for each joint and sub-phase, the left and right ankle joints during pre-swing displayed the most consistent differences among conditions (p < 0.001, and p < 0.001), respectively. Additionally, the left ankle displayed a moderate effect size (η2 = 0.71) and the right ankle displayed a large effect size (η2 = 0.80). INTERPRETATIONS: These findings reveal that the ankle joint, during pre-swing, is the primary kinematic strategy used by children with autism when altering gait speed, whereas previous evidence suggests that the hip joint was the primary strategy.

Weighted Vest Loads Do Not Elicit Changes in Spatial-Temporal Gait Parameters in Children and Adolescents With Autism.

Weighted vests have been used primarily as behavioral interventions for children and adolescents with autism. Contemporary research has begun to examine weighted vest effects on movement. Previous research in children with neurotypical development revealed 15% body mass loads modified spatial-temporal gait characteristics; however, a value applicable to children and adolescents with autism has not been established. The purpose of this study was to establish an appropriate mass value by examining spatial-temporal gait parameters in children and adolescents with autism with various loads in a weighted vest. Nine children and adolescents with autism, aged 8-17, walked without a weighted vest, with 5%, 10%, 15%, and 20% body mass while spatial-temporal data were captured. Repeated-measures analysis of variance (α = .05) were conducted among conditions for each variable, with a Holm-Bonferroni method correction. Analysis revealed significant decreases in right step length, but no differences in stride width, left step length, double-limb support time, or stride velocity were observed. Due to insignificant findings, an appropriate mass value could not be determined for weighted vests for children with autism. However, unchanged spatial-temporal gait parameters with increasing loads could be clinically relevant as weighted vest loads of 10% are typically used for behavioral interventions.

Children With Autism Exhibit More Individualized Responses to Live Animation Biofeedback Than Do Typically Developing Children.

Children with autism have displayed imbalances in responding to feedback and feedforward learning information and they have shown difficulty imitating movements. Previous research has focused on motor learning and coordination problems for these children, but little is known about their motoric responses to visual live animation feedback. Thus, we compared motor output responses to live animation biofeedback training in both 15 children with autism and 15 age- and sex-matched typically developing children (age range: 8-17 years). We collected kinematic data via Inertial Measurement Unit devices while participants performed a series of body weight squats at a pre-test, during live animation biofeedback training, and at post-test. Dependent t-tests (α = 0.05), were used to test for statistical significance between pre- and post-test values within groups, and repeated measures analyses of variance (α = 0.05) were used to test for differences among the training blocks, within each group. The Model Statistic technique (α = 0.05) was used to test for pre- and post-test differences on a single-subject level for every participant. Grouped data revealed little to no significant findings in the children with autism, as these participants showed highly individualized responses. However, typically developing children, when grouped, exhibited significant differences in their left hip position (p = 0.03) and ascent velocity (p = 0.004). Single-subject analyses showed more individualistic live animation responses of children with autism than typically developing children on every variable of interest except descent velocity. Thus, to teach children with autism new movements in optimal fashion, it is particularly important to understand their individualistic motor learning characteristics.

Lesser magnitudes of lower extremity variability during terminal swing characterizes walking patterns in children with autism.

BACKGROUND: Anecdotally, children with Autism Spectrum Disorder have highly variable lower extremity walking patterns, yet, this has not been sufficiently quantified. As such, the purpose of this study was to examine walking pattern variability by way of lower extremity coordination and spatio-temporal characteristics in children with autism compared with individuals with typical development during over-ground walking. METHODS: Bilateral continuous relative phase variability was computed for the thigh-leg, leg-foot, and thigh-foot segment couples for 11 children with autism and 9 children with typical development at each gait sub-phase. Furthermore, left and right stride lengths and stride width were computed and compared. The Model Statistic was utilized to test for statistical differences in variability between each child with autism to an aggregate group with typical development. Effect sizes were computed to determine the meaningfulness between responses for children with autism and typical development. Coefficient of variation and effect sizes were computed for stride lengths and stride width. FINDINGS: Analysis revealed that children with autism exhibited differences in variability in each gait sub-phase. Notably, all but two children with autism exhibited lesser variability in all segment couples during terminal swing. Differences in stride lengths were relatively minimal, however, greater coefficient of variation magnitudes in stride width were observed in children with autism. INTERPRETATION: This finding reveals that children with autism may have limited or a preferred movement strategy when preparing the foot for ground contact. The findings from this study suggest variability may be an identifiable characteristic during movement in children with autism.