title: Relationship between early motor milestones and severity of restricted and repetitive behaviors in children and adolescents with autism spectrum disorder.
abstract: This study explored the relationships between the later age of achievement of early motor milestones, current motor atypicalities (toe walking), and the severity of restricted and repetitive behaviors (RRBs) in individuals with autism spectrum disorder (ASD). Parents of 147 children and adolescents with ASD (Mage= 8.09 years, SD = 4.28; 119 males) completed an early developmental milestones questionnaire and the Social Responsiveness Scale as a measure of Insistence on Sameness (IS) and Repetitive Mannerisms (RM). Two hierarchical regression analyses were conducted to test whether RM and IS behaviors were predicted by early motor milestones, or current toe walking. The final model predicting RM accounted for 15% of the variance (F = 3.02, p = .009), with toe walking as a unique and independent predictor of RM scores (t = 3.568, p = .001). The final model predicting IS accounted for 19.1% of variance in IS scores (F = 4.045, p = .001), with chronological age (CA) (t = 2.92, p = .004), age when first standing (t = 2.09, p = .038), and toe walking (t = 2.53, p = .013) as unique independent predictors. Toe walking (t = 2.4, p = .018) and age when first sitting (t = 2.08, p = .04) predicted the severity of RRBs on the Autism Diagnostic Observation Schedule (F = 2.334, p = .036). Our study replicates previous findings on the relationship between concurrent motor impairments and RRBs, and provides the first evidence for the association between RRBs and age of attainment of early motor milestones. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1163-1168. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
authors.affiliation: School of Psychology and Public Health, Olga Tennison Autism Research Centre, La Trobe University, Victoria, 3086, Australia.|Cooperative Research Centre for Living with Autism (Autism CRC), Long Pocket, Brisbane, Queensland, Australia.
authors.forename: Mirko
authors.initials: M
authors.lastname: Uljarević
authors.affiliation: School of Psychology and Public Health, Olga Tennison Autism Research Centre, La Trobe University, Victoria, 3086, Australia.
authors.forename: Darren
authors.initials: D
authors.lastname: Hedley
authors.affiliation: Cooperative Research Centre for Living with Autism (Autism CRC), Long Pocket, Brisbane, Queensland, Australia.|Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Gail A
authors.identifier: http://orcid.org/0000-0003-3351-5919
authors.initials: GA
authors.lastname: Alvares
authors.affiliation: Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Kandice J
authors.initials: KJ
authors.lastname: Varcin
authors.affiliation: Cooperative Research Centre for Living with Autism (Autism CRC), Long Pocket, Brisbane, Queensland, Australia.|Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Andrew J O
authors.initials: AJO
authors.lastname: Whitehouse
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000067877:Autism Spectrum Disorder / Q000150:complications* / Q000503:physiopathology*; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D012720:Severity of Illness Index; D019956:Stereotypic Movement Disorder / Q000150:complications* / Q000503:physiopathology*
keywords: atypical gait; autism; motor milestones; repetitive behavior