Effects of flooring and Hemi body on Ground Reaction Forces and Coefficient of Friction in stroke gait

The aim of this study was to investigate the possible effects of flooring and affected hemi body on the ground reaction forces and on the required coefficient of friction (RCOF) in stroke barefoot gait. Twenty-four volunteers participated in this study, being 12 stroke patients and 12 age-matched healthy subjects as control group. The participant was oriented to walk barefoot, on its own preferred speed, over two force plates on the following flooring: 1) homogeneous vinyl (HOV); 2) carpet; 3) heterogeneous vinyl (HTV); 4) mixed (the first half part of the pathway were covered by HOV and the second by HTV). All the four surfaces presented safe coefficient of friction (ranging from 0.44-0.55) and they are widely used in residences and public facilities. The flooring effect was found on RCOF during the toe off for the affected and unaffected side. Moreover, differences among hemi bodies for RCOF in heel contact and toe off phases were also observed. The control group presented higher RCOF than the stroke unaffected and affected side, and the unaffected showed higher friction than the affected side. In conclusion, the gait of stroke patient was altered due to the four flooring tested in the toe off phase

Visual restriction and anterior-posterior body oscillations in Parkinson’s disease

Sem visão poucos ajustes antecipatórios e/ou compensatórios ocorrem na doença de Parkinson e as evidências destes ajustes são menores quando a evolução da doença e as oscilações corporais são consideradas. Objetivo: O objetivo deste estudo foi evidenciar os efeitos da restrição visual sobre os ângulos das oscilações corporais ântero-posteriores na postura ereta de parkinsonianos considerando os estágios inicias de evolução da doença. Método: Dez idosos com Doença de Parkinson até o estágio 2 de Hoehn & Yahr (HY) ficaram de pé parados por 30 segundos para medir os ângulos das oscilações corporais com e sem visão. Resultados: ANOVA two-way com medidas repetidas revelou efeito principal de visão (F(1,7) = 8,931; p < 0,02). Conclusão: Os ângulos das oscilações corporais ântero-posteriores sem visão foram maiores do que com visão, estes não diferiram entre si quanto aos estágios de HY e as condições de visão interferiram no controle da postura independente do estágio de evolução da Doença de Parkinson.With their vision restricted, sufferers of Parkinson’s disease (PD) make few anticipatory and/or compensatory adjustments in their posture and the evidence of these adjustments is even less when the disease progresses and body oscillations are considered. Objective: The aim of this study was to demonstrate the effects of visual restriction on the anterior-posterior body oscillation angles in parkinsonian stance considering the early stages of this disease. Method: Ten elderly PD patients with Hoehn & Yahr (HY) stage 2 remained standing still for 30 seconds to measure the body oscillation angles with and without restricted vision. Results: Two-way ANOVA analyses with repeated measurements revealed the main effect of vision (F(1,7) = 8.931, p < 0.02). Conclusion: The angles of the anterior-posterior body oscillations without visibility were greater than with visibility. They did not differ in correlation with the HY stages and visibility conditions interfered with the postural control regardless of the PD evolution stage

Coeficiente de atrito requerido na marcha normal e patológica : atrito e marcha

Orientador: Ricardo Machado Leite de BarrosTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação FísicaResumo: O objetivo principal desta tese foi analisar o coeficiente de atrito requerido (RCOF) na marcha de idosos, pacientes com acidente vascular cerebral (AVC) e com doença de Parkinson (DP). Esta tese contém seis capítulos. No Primeiro Capítulo a revisão de literatura sobre Tribologia (o estudo do atrito) e RCOF na marcha é apresentada. Atrito é a resistência ao movimento durante o deslizar ou girar que acontece quando um corpo sólido se move tangencialmente sobre outro corpo com o qual esta em contato. Na marcha, o RCOF é o atrito requerido entre o sapato e o chão para realizar vários tipos de atividades. O Segundo Capítulo discute a metodologia para calcular o RCOF baseada nas forças de reação do solo (FRS). Para calcular o RCOF os dados de FRS durante a marcha são adquiridos. Para isso, o participante é instruído a andar descalço em sua velocidade preferida ao longo de uma passarela, sob a qual duas plataformas de força estão embutidas no chão da sala de coleta de dados. Após coletados, os dados de GRF são normalizados pelo peso corporal do sujeito e em função da percentagem da fase de suporte. Em seguida, o RCOF é calculado como a razão entre as componentes horizontais de FRS (resultante das FRS lateral e antero-posterior) e a FRS vertical. Com esta metodologia foram realizados os estudos apresentados nos Terceito, Quarto, Quinto e Sexto Capítulos desta tese. No Terceiro e no Quarto Capítulos são apresentadas investigações os efeitos de diferentes superfícies no RCOF durante a marcha normal e patológica. Para isso, o participante foi orientado a caminhar sobre as seguintes superfícies: 1) piso vinílico (HOV); 2) carpete; 3) revestimento vinílico (HTV); 4) mista (a primeira parte da passarela foi coberta por HOV e a segunda por HTV). Todas as quatro superfícies apresentavam coeficiente de atrito estático seguro (que varia 0,44-0,55) e são amplamente utilizadas em residências e instalações públicas. Os principais resultados destes estudos foram: na marcha descalça indivíduos saudáveis apresentaram diferenças no RCOF entre os tipos de superfície nas fases de contato inicial e apoio terminal. Além disso, o RCOF na marcha dos pacientes com AVC foi alterada na fase apoio terminal devido as quatro superfícies testadas. No Quinto e no Sexto Capítulos, a análise da curva do RCOF em pacientes com AVC e DP foi apresentada, respectivamente. O RCOF dos pacientes com AVC e DP apresentaram padrões diferentes aos do grupo controle. Em pacientes com AVC o contato inicial, a fase de rolamento e o apoio terminal são as fases mais críticas para a incidência de quedas. Os pacientes com DP apresentaram valores RCOF mais baixos durante o contato inicial e a fase de apoio terminal em comparação com o grupo controle. Estas análises representam a primeira tentativa de explorar as características da curva RCOF durante a análise da marcha; além disso, esta variável também pode ser utilizada na predição da queda dos pacientes com AVC e DPAbstract: The main goal of this thesis was to analyze the required coefficient of friction (RCOF) on elderly, stroke and parkinsonian gait. This thesis is presented in six chapters. In the First Chapter the literature review of Tribology (the study of friction) and the RCOF during the gait are presented. Friction is the resistance to motion during sliding or rolling that is experienced when a solid body moves tangentially over another with which it is in contact. During the gait, the RCOF is the friction required at the shoe and floor interface to support different types of human activities. The Second Chapter discusses the methodology to calculate the RCOF based on the ground reaction forces (GRF). To calculate the RCOF the GRF data during the participant¿s gait analysis is acquired. For this the participant is ask to walk barefoot, at his or her selected speed, along a pathway, beneath which two force platforms embedded in the data collection room floor. After this the GRF data is normalized by the subject¿s body weight and it is expressed as a function of the percentage of the support phase. Then, the instantaneous RCOF is calculated as the ratio between the shear of the horizontal GRF components (resultant of lateral and anterior posterior GRF) and the vertical GRF. With this methodology the studies presented in the Third, Fourth, Fifth and Sixth chapters were design. The Third and the Fourth chapters the studies about the effects of flooring in RCOF during normal and pathological gait were discussed. For this, the participant was oriented to walk on the following flooring: 1) homogeneous vinyl (HOV); 2) carpet; 3) heterogeneous vinyl (HTV); 4) mixed (the first half part of the pathway were covered by HOV and the second by HTV). All the four surfaces presented safe static coefficient of friction (ranging from 0.44-0.55) and they are widely used in residences and public facilities. The main results of these studies were: in healthy subjects¿ barefoot gait, there were differences in the RCOF among the flooring types in the heel contact and toe-off phases. Moreover, the RCOF of stroke patients was altered on the toe off phase due to the four flooring tested. In the fifth and sixth chapters, studies about the instantaneous RCOF curve analysis in patients with Stroke and PD were presented respectively. The RCOF of patients with stroke and PD exhibited patterns that were different than those of the healthy subjects. In patients with stroke the initial contact, the mid stance and the terminal stance seem to be critical phases for the incidence of slips. The patients with PD performed lower RCOF values during the loading response and terminal stance phases in comparison with the control group. These analyses represent the first attempt to explore the RCOF curve parameters during the gait analysis; moreover, its might be used in the prediction of the real fall propensity of patients with stroke and PDDoutoradoBiodinamica do Movimento e EsporteDoutora em Educação Físic

Effects Of Flooring On Required Coefficient Of Friction: Elderly Adult Vs. Middle-aged Adult Barefoot Gait

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The aim of this study was to investigate the effect of flooring on barefoot gait according to age and gender. Two groups of healthy subjects were analyzed: the elderly adult group (EA; 10 healthy subjects) and the middle-aged group (MA; 10 healthy subjects). Each participant was asked to walk at his or her preferred speed over two force plates on the following surfaces: 1) homogeneous vinyl (HOV), 2) carpet, 3) heterogeneous vinyl (HTV) and 4) mixed (in which the first half of the pathway was covered by HOV and the second by HTV). Two force plates (Kistler 9286BA) embedded in the data collection room floor measured the ground reaction forces and friction. The required coefficient of friction (RCOF) was analyzed. For the statistical analysis, a linear mixed-effects model for repeated measures was performed. During barefoot gait, there were differences in the RCOF among the flooring types during the heel contact and toe-off phases. Due to better plantar proprioception during barefoot gait, the EA and MA subjects were able to distinguish differences among the flooring types. Moreover, when the EA were compared with the MA subjects, differences could be observed in the RCOF during the toe-off phase, and gender differences in the RCOF could also be observed during the heel contact phase in barefoot gait. (C) 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.50147152Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CAPES [process: BEX 11241/13-6]CNPq [473729/2008-3, 304975/2009-5, 140731/2011-3