title: Influence of dual-task on sit-to-stand-to-sit postural control in Parkinson's disease.
abstract: Postural control deficits are the most disabling aspects of Parkinson's disease (PD), resulting in decreased mobility and functional independence. The aim of this study was to assess the postural control stability, revealed by variables based on the centre of pressure (CoP), in individuals with PD while performing a sit-to-stand-to-sit sequence under single- and dual-task conditions. An observational, analytical and cross-sectional study was performed. The sample consisted of 9 individuals with PD and 9 healthy controls. A force platform was used to measure the CoP displacement and velocity during the sit-to-stand-to-sit sequence. The results were statistically analysed. Individuals with PD required greater durations for the sit-to-stand-to-sit sequence than the controls (p < 0.05). The anteroposterior and mediolateral CoP displacement were higher in the individuals with PD (p < 0.05). However, only the anteroposterior CoP velocity in the stand-to-sit phase (p = 0.006) was lower in the same individuals. Comparing the single- and dual-task conditions in both groups, the duration, the anteroposterior CoP displacement and velocity were higher in the dual-task condition (p < 0.05). The individuals with PD presented reduced postural control stability during the sit-to-stand-to-sit sequence, especially when under the dual-task condition. These individuals have deficits not only in motor performance, but also in cognitive performance when performing the sit-to-stand-to-sit sequence in their daily life tasks. Moreover, both deficits tend to be intensified when two tasks are performed simultaneously.
authors.affiliation: Escola Superior da Tecnologia de Saúde do Instituto Politécnico do Porto, Área Científica de Terapia Ocupacional, Centro de Estudo do Movimento e da Atividade Humana, Portugal; Faculdade de Engenharia, Universidade do Porto, Portugal. Electronic address: amf@estsp.ipp.pt.
authors.forename: Ângela
authors.initials: Â
authors.lastname: Fernandes
authors.affiliation: Escola Superior da Tecnologia de Saúde do Instituto Politécnico do Porto, Área Científica de Fisioterapia, Centro de Estudo do Movimento e da Atividade Humana, Portugal. Electronic address: asp@estsp.ipp.pt.
authors.forename: Andreia S P
authors.initials: AS
authors.lastname: Sousa
authors.affiliation: Escola Superior de Tecnologia da Saúde do Instituto Politécnico do Porto, Área Cientifica de Terapia Ocupacional, Portugal. Electronic address: joana.couras@gmail.com.
authors.forename: Joana
authors.initials: J
authors.lastname: Couras
authors.affiliation: Escola Superior da Tecnologia de Saúde do Instituto Politécnico do Porto, Área Científica de Terapia Ocupacional, Laboratório de Reabilitação Psicossocial, Centro de Estudo do Movimento e da Atividade Humana, Portugal. Electronic address: nrocha@eu.ipp.pt.
authors.forename: Nuno
authors.initials: N
authors.lastname: Rocha
authors.affiliation: Instituto de Ciência e Inovação em Engenharia Mecânica e Engenharia Industrial, Departamento de Engenharia Mecânica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal. Electronic address: tavares@fe.up.pt.
authors.forename: João Manuel R S
authors.initials: JM
authors.lastname: Tavares
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000503:physiopathology* / Q000523:psychology*; D004856:Postural Balance; D011187:Posture; D011312:Pressure; D013995:Time
keywords: Dual-task; Parkinson's; Postural control; Sit-to-stand-to-sit