This paper examines upper-body movement kinematics in individuals with high-functioning autism (HFA) and Asperger's disorder (AD). In general, the results indicate that HFA is more consistently associated with impaired motoric preparation/initiation than AD. The data further suggest that this quantitative difference in motor impairment is not necessarily underpinned by greater executive dysfunction vulnerability in autism relative to AD. Quantitative motoric dissociation between autism and AD may have down-stream effects on later stages of movement resulting in qualitative differences between these disorder groups, e.g. "motor clumsiness" in AD versus "abnormal posturing" in autism. It will be important for future research to map the developmental trajectory of motor abnormalities in these disorder groups.
KeywordsHigh-functioning autism; Asperger's disorder; Movement kinematics; Motor preparation kinematics; Motor preparation Autism is a pervasive developmental condition defined by impairments in communication, social reciprocity, and repetitive-stereotyped behavioral patterns (American Psychiatric Association, 1994). Although motor functioning deficits are widely reported in the literature (Berkeley, Zittel, Pitney, & Nichols, 2001;Beversdorf et al., 2001;Brasic & Barnett, 1997;Ghaziuddin, Butler, Tsai, & Ghaziuddin, 1994;Manjiviona & Prior, 1995;Miyahara et al., 1997;Rinehart et al., 2001a), there is debate about how to describe and define motor abnormalities in this population (e.g. clumsy movement versus poorly coordinated movement versus poorly planned movement), and debate about whether the nature of motor