Abstract Background: Previous studies discussed the repeatability and variability in plantar pressure measurement, but a few considered different age groups. Here we determine within and between-days repeatability and variability of plantar pressure measurement during gait in participants from different age groups. Method: Plantar pressure was recorded in children, young adults and older adults walking at preferred speed in four non-consecutive days within one week. Data from 10 steps from each foot in each day were analyzed considering the different regions of the foot. Mean and peak plantar pressure and data variability were compared between the steps, foot regions and days. Results: To describe mean and peak pressure during gait in children and adults a single measurement can be enough, but elderly will requires more attention especially concerning peak values. Variability in mean pressure did not differ between age groups, but peak pressure variability differed across foot regions and age groups. Conclusion: One single observation can be used to describe plantar pressure during gait in children and adults. When the interest concerns older people, it might be pertinent to consider more than one day of assessment, especially when looking at peak pressure.

RESUMOIntrodução:A repetibilidade e a variabilidade da pressão plantar em avaliações da marcha são componentes importantes na avaliação clínica do idoso. Contudo, pouco é conhecido sobre a consistência dos padrões de pressão plantar em idosos.Objetivo:Analisar a variabilidade e repetibilidade da pressão plantar durante da marcha de idosos, considerando valores médios, picos e assimetrias.Métodos:A pressão plantar foi avaliada em quatro diferentes dias em 10 idosos (cinco mulheres), com idade média ± desvio-padrão de 73 ± 6 anos, durante o andar descalço em velocidade preferida. Os dados de pressão plantar foram comparados entre as pisadas em cada dia e entre os diferentes dias de avaliação.Resultados:Dados de pressão média e pico foram similares entre os diferentes dias de avaliação. Os índices de assimetria observados foram similares entre os diferentes dias avaliados.Conclusão:A pressão plantar (média e pico) apresentou um padrão consistente nos idosos. Contudo, os índices de assimetria observados sugerem que idosos estejam sistematicamente expostos a cargas assimétricas durante a locomoção. Essa observação requer futuras investigações, especialmente em relação ao impacto dessas assimetrias na origem de doenças articulares.

ABSTRACTIntroduction:Repeatability and variability of the plantar pressure during walking are important components in the clinical assessment of the elderly. However, there is a lack of information on the uniformity of plantar pressure patterns in the elderly.Objective:To analyze the repeatability and variability in plantar pressure considering mean, peak and asymmetries during aged gait.Methods:Plantar pressure was monitored in four different days for ten elderly subjects (5 female), with mean ± standard-deviation age of 73 ± 6 years, walking barefoot at preferred speed. Data were compared between steps for each day and between different days.Results:Mean and peak plantar pressure values were similar between the different days of evaluation. Asymmetry indexes were similar between the different days evaluated.Conclusion:Plantar pressure presented a consistent pattern in the elderly. However, the asymmetry indexes observed suggest that the elderly are exposed to repetitive asymmetric loading during locomotion. Such result requires further investigation, especially concerning the role of these asymmetries for development of articular injuries.