Longitudinal Study of the Impact of Sensory-Motor Skills on Functional Independence and Adaptive Behaviors of Children with ASD

Background: In recent years, the sensory-motor domain has gained increased attention among autism researchers. However, very few studies are addressing the impact of these skills on the autonomy or functional independence of children with autism spectrum disorders (ASD).

Objectives: 1) To describe the developmental trajectory of children with autism spectrum disorders at preschool-age over a period of 24 months regarding 3 developmental domains i ) motor skills, ii) sensory processing skills, and iii) the functional independence in daily living skills. 2) To determine the contribution of sensory-motor skills on functional independence in daily living skills.

Methods: This is a clinical longitudinal study of 37 children diagnosed with autism spectrum disorders and aged 3 to 5 years 11 months at Time 1 and re-assessed 24 months later (Time 2). Children were tested with the Peabody Developmental Motor Scales-PDMS-2, the Sensory Profile, and the Vineland Adaptive Behavior Scales-VABS-2. 83% of the children from the sample were boys with an average IQ of 59, from Caucasian families (70%), speaking English (67%), and whose mother had university degrees (70%).

Results: Based on the sensory Profile results, sensory processing difficulties of children with ASD do not diminish over time since no significant differences were observed between scores at time 1 and time 2 ( p > .05). Therefore, sensory processing difficulties are still apparent at school entry. All children learned new motor skills based on the increase of raw scores. Nevertheless, standard scores indicate that ASD children had stable gross motor skills development in comparison to norms but increased their performance in fine motor and total motor skills. However, when comparing results of only children under the age of 72 months at T2, (n = 21) for which norms are available, results were stable for gross motor and total motor scores, but a significant increase in standard score was still observed in fine motor skills. ASD children also did acquire new adaptive behaviors (increase in raw scores), however, standard scores remained stable and low for socialization and daily living skills (between 1 and 2 standard deviation below the norms). Only the communication skills did get significantly better over time (t = 3.926 p = .0004). Predictors of functional independence at T1 were sensory processing skills and fine motor skills (Couture, 2008). At T2, the only significant predictor was total motor quotient; language, cognition and sensory processing skills were not significant predictors.

Conclusions: Sensory-motor difficulties do not disappear by the end of the preschool period. At around the age of 6 years old, children with ASD still present important sensory processing and gross motor difficulties that are associated to their poor adaptive functioning. Specific interventions focusing on sensory-motor skills could potentially lead to better daily living skills and integration in daycare or school.