Atividade do córtex pré-frontal na modulação do andar de idosos

• Autor(a) principal: Belli, Vinicius de [UNESP]
• Data de Publicação: 2019
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/234630
• topic: Cortical activity; Locomotion; Gait speed; Aging; Atividade cortical; Locomoção; Velocidade do andar; fNIRS; Envelhecimento

Aging leads to loss of gait automaticity, hence older people need to recruit cognitive areas during walking. In greater demanding situations, such as fast walking speed, older people further increase prefrontal cortex activity to maintain task performance. Although previous studies have shown the role of the prefrontal cortex during fast walking, studies have analysed walking in a treadmill. Therefore, the aim of this study was to compare the prefrontal activity during overground walking at preferred and fast speed in older people. Twenty-five older people walked a 26.8m long circuit under two experimental conditions: preferred and fast walk speed. Each experimental condition were composed by five trials of 60s (30s of rest and 30s of data acquisition during walking).. A carpet with sensors pressure was used to record the spatiotemporal parameters of gait. A mobile functional near-infrared spectroscopy (fNIRS) system, with 8 channels, was placed over forehead of participants to record prefrontal cortex activity. Oxygenated hemoglobin (HbO₂) concentration was used as a hemodynamic activity marker of the prefrontal cortex. The HbO₂ analysis during walking was divided into two periods: baseline (10 last seconds of the rest period) and experimental task (5 to 25 s of the data acquisition during walking). T-tests were used to compare HbO₂ and gait variables between gait condition (p≤0.05). Analysis indicated longer step length (p>0.001), higher step velocity (p>0.001) and shorter step duration (p>0.001) and swing phase (p>0.001) during fast walking compared to preferred walking speed. In addition, older people presented higher HbO₂ concentration in the prefrontal cortex (p=0.024) during fast walking compared to preferred walking speed. In conclusion, older people increased the prefrontal cortex activity during overground walking, and in a greater demanding situation, such as fast walking speed, older people needed to increase cortical activity even more, possibly to maintain their task performance (33.48% increase).