title: Standing balance in individuals with Parkinson's disease during single and dual-task conditions.
abstract: This study aimed to examine the differences in standing balance between individuals with Parkinson's disease (PD) and subjects without PD (control group), under single and dual-task conditions. A cross-sectional study was designed using a non-probabilistic sample of 110 individuals (50 participants with PD and 60 controls) aged 50 years old and over. The individuals with PD were in the early or middle stages of the disease (characterized by Hoehn and Yahr as stages 1-3). The standing balance was assessed by measuring the centre of pressure (CoP) displacement in single-task (eyes-open/eyes-closed) and dual-task (while performing two different verbal fluency tasks). No significant differences were found between the groups regarding sociodemographic variables. In general, the standing balance of the individuals with PD was worse than the controls, as the CoP displacement across tasks was significantly higher for the individuals with PD (p<0.01), both in anteroposterior and mediolateral directions. Moreover, there were significant differences in the CoP displacement based parameters between the conditions, mainly between the eyes-open condition and the remaining conditions. However, there was no significant interaction found between group and condition, which suggests that changes in the CoP displacement between tasks were not influenced by having PD. In conclusion, this study shows that, although individuals with PD had a worse overall standing balance than individuals without the disease, the impact of performing an additional task on the CoP displacement is similar for both groups.
authors.affiliation: Escola Superior da Tecnologia de Saúde do Instituto Politécnico do Porto, Rua Valente Perfeito, 322, 4400-330 Vila Nova de Gaia, Portugal; Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal; Centro de Estudos de Movimento e Actividade Humana, Escola Superior da Tecnologia de Saúde do Instituto Politécnico do Porto, Rua Valente Perfeito, 322, 4400-330 Vila Nova de Gaia, Portugal.
authors.forename: Ângela
authors.initials: Â
authors.lastname: Fernandes
authors.affiliation: Escola Superior da Tecnologia de Saúde do Instituto Politécnico do Porto, Rua Valente Perfeito, 322, 4400-330 Vila Nova de Gaia, Portugal; Unidade de Investigação e Formação sobre Adultos e Idosos, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Tiago
authors.initials: T
authors.lastname: Coelho
authors.affiliation: Escola Superior da Tecnologia de Saúde do Instituto Politécnico do Porto, Rua Valente Perfeito, 322, 4400-330 Vila Nova de Gaia, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Vitória
authors.affiliation: Centro Hospitalar Entre Douro e Vouga, EPE - Hospital S. Sebastião, Rua Doutor Cândido Pinho, 4520-211 Santa Maria da Feira, Portugal.
authors.forename: Augusto
authors.initials: A
authors.lastname: Ferreira
authors.affiliation: Centro de Estudos de Movimento e Actividade Humana, Escola Superior da Tecnologia de Saúde do Instituto Politécnico do Porto, Rua Valente Perfeito, 322, 4400-330 Vila Nova de Gaia, Portugal.
authors.forename: Rubim
authors.initials: R
authors.lastname: Santos
authors.affiliation: Escola Superior da Tecnologia de Saúde do Instituto Politécnico do Porto, Rua Valente Perfeito, 322, 4400-330 Vila Nova de Gaia, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Rocha
authors.affiliation: Unidade de Investigação e Formação sobre Adultos e Idosos, Centro de Investigação em Tecnologias e Sistemas de Informação em Saúde, Faculdade de Medicina, Universidade do Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
authors.forename: Lia
authors.initials: L
authors.lastname: Fernandes
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; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*; D013647:Task Performance and Analysis
keywords: Centre of pressure; Dual-task; Parkinson's disease; Single-task; Standing balance