title: Motor strategies and motor programs during an arm tapping task in adults with Down Syndrome.
abstract: Slow movements and atypical patterns of muscle activation are well-known features of Down Syndrome (DS). Some studies attribute these features to a deficit in voluntary motor commands and preprogramming of actions, that lead subjects with DS to be more reliant on feedback control. In the present study, we evaluated the movement strategies of 13 adult subjects with DS and of 22 age-matched controls (N) during an arm tapping task. By means of quantitative motion analysis, our aim was to describe movement differences in DS respect to typical population and provide a means of interpreting such differences in terms of the underlying different control processes. The results highlighted distinct motor strategies for the tapping task in the two groups, with DS relying more on the trunk motion and N relying on the elbow motion to accomplish the task. Furthermore, DS corrected their wrist trajectory more than N subjects, giving shape to multi-peaked velocity profiles. Longer duration of the trials and a higher index of curvature were found in DS. The results suggest that subjects with DS rely more on feedback control, whereas they have problems with movement planning and feed-forward control. The different strategy operated by subjects with DS leads to a different task performance.
authors.affiliation: Bioengineering Department, Politecnico di Milano, p.zza Leonardo da Vinci 32, 20133, Milan, Italy. vimercati.sara@gmail.com
authors.forename: Sara Laura
authors.initials: SL
authors.lastname: Vimercati
authors.forename: Manuela
authors.initials: M
authors.lastname: Galli
authors.forename: Chiara
authors.initials: C
authors.lastname: Rigoldi
authors.forename: Andrea
authors.initials: A
authors.lastname: Ancillao
authors.forename: Giorgio
authors.initials: G
authors.lastname: Albertini
mesh_terms: D000328:Adult; D001132:Arm / Q000503:physiopathology*; D016022:Case-Control Studies; D004314:Down Syndrome / Q000473:pathology* / Q000503:physiopathology*; D004551:Elbow Joint / Q000294:innervation; D005246:Feedback; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D018709:Statistics, Nonparametric; D013997:Time Factors; D014955:Wrist Joint / Q000294:innervation; D055815:Young Adult