Functional upper-extremity movements in autism: A narrative literature review

Many autistic individuals exhibit clinically-significant motor difficulties. Previous reviews focused on overall motor ability or coordination, but with little attention paid to quantifying differences in upper extremity skills, which are critical to many activities of daily living. Our objective was to identify and evaluate the published literature on upper extremity motor skills of autistic people.

We conducted a literature search in PubMed, Scopus, and PsycInfo for empirical research articles reporting functional upper extremity movement performance in autism. We included articles reporting results of primary data collection from autistic people published before July 10, 2024. Articles were identified and data were extracted and evaluated using EndNote and Microsoft Excel by a team of three authors.

Our search strategy yielded 1181 unique articles. After screening these articles, the final sample included 43 empirical research articles focused on functional upper extremity movements, including pointing (n = 13), reaching to grasp (n = 18), and handwriting (n = 12) in autism. Across these skills, autistic people exhibited slower, more variable movements than their non-autistic counterparts.

Upper extremity movement differences in autism are likely the result of differences in motor planning and increased online monitoring of movement execution. Limitations and potential bias exist in the racial, ethnic, age, and gender diversity of available data, and in the variability of methods used to assess performance. However, the current body of literature suggests significant differences between autistic and non-autistic upper extremity movements. Slower, more variable upper extremity movements likely affect many functional difficulties experienced in autistic people's daily lives.