Effects of displacement and trajectory length on the variability pattern of reaching movements

dc.contributor.authorJaric, S.
dc.contributor.authorFerreira, SMS
dc.contributor.authorTortoza, C.
dc.contributor.authorMarconi, N. F.
dc.contributor.authorAlmeida, G. L.
dc.contributor.institutionNatl Inst Working Life
dc.contributor.institutionUniversidade Estadual de Campinas (UNICAMP)
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-20T15:29:34Z
dc.date.available2014-05-20T15:29:34Z
dc.date.issued1999-12-01
dc.description.abstractThe design of the present study enabled the authors to distinguish between the possible effects of movement displacement and trajectory length on the pattern of final positions of planar reaching movements. With their eyes closed, 9 subjects performed series of fast and accurate movements from different initial positions to the same target. For some series, the movements were unconstrained and were therefore performed along an approximately straight vertical line. For other series, an obstacle was positioned so that trajectory length was increased because of an increase in movement curvature. Ellipses of variability obtained by means of principal component analysis applied to the scatter of movement final positions enabled the authors to assess the pattern of movement variable errors. The results showed that the orientation of the ellipses was not affected by movement displacement or by trajectory length, whereas variable errors increased with move ment displacement. An increase in trajectory length as a consequence of increased curvature caused no change in variable error. From the perspective of current motor control theory, that finding was quite unexpected. Further studies are required so that one can distinguish among the possible effects of various kinematics, kinetics, and other variables that could affect the pattern of variable errors of reaching movements.en
dc.description.affiliationNatl Inst Working Life, Dept Musculoskeletal Res, S-90713 Umea, Sweden
dc.description.affiliationUniv Estadual Campinas, BR-13081970 Campinas, SP, Brazil
dc.description.affiliationUniv Estadual Paulista, Rio Clara, SP, Brazil
dc.description.affiliationUnespUniv Estadual Paulista, Rio Clara, SP, Brazil
dc.format.extent303-308
dc.identifierhttp://dx.doi.org/10.1080/00222899909600996
dc.identifier.citationJournal of Motor Behavior. Washington: Heldref Publications, v. 31, n. 4, p. 303-308, 1999.
dc.identifier.doi10.1080/00222899909600996
dc.identifier.issn0022-2895
dc.identifier.urihttp://hdl.handle.net/11449/39127
dc.identifier.wosWOS:000083842500001
dc.language.isoeng
dc.publisherHeldref Publications
dc.relation.ispartofJournal of Motor Behavior
dc.relation.ispartofjcr1.513
dc.relation.ispartofsjr0,617
dc.rights.accessRightsAcesso restrito
dc.sourceWeb of Science
dc.subjectdisplacementpt
dc.subjecterrorpt
dc.subjecthumanpt
dc.subjectreaching movementspt
dc.subjecttrajectory lengthpt
dc.titleEffects of displacement and trajectory length on the variability pattern of reaching movementsen
dc.typeArtigo
dcterms.rightsHolderHeldref Publications

Arquivos

Licença do Pacote
Agora exibindo 1 - 1 de 1
Nenhuma Miniatura disponível
Nome:
license.txt
Tamanho:
1.71 KB
Formato:
Item-specific license agreed upon to submission
Descrição:

Coleções