ABSTRACT
Background Patients with chronic heart failure frequently report intolerance to exercise and present with changes in walk pattern, but information about heart transplant patients is lacking. Alterations of the gait pattern are related to interaction changes between the metabolism, neurological system and the mechanical demands of the locomotor task. The aim of this study was to investigate the electromyographic cost, coactivation and cost of transport of walking of chronic heart failure and heart transplant patients. Design This research was of an exploratory, cross-sectional design. Methods Twelve chronic heart failure patients, twelve healthy controls and five heart transplant patients participated in the study. Electromyographic data and oxygen uptake were collected simultaneously at five walking speeds. Results In the experimental groups, the electromyographic cost, percentage of coactivation in the leg and cost of transport were higher than in controls. The electromyographic cost was in line with the cost of transport. The minimum electromyographic cost matched with the self-selected walking speed in controls, while in chronic heart failure and heart transplant patients, it was reached at speeds higher than the self-selected walking speed. Conclusion The largest postural isometric activation and antagonist activation resulted in the highest metabolic demand. These findings are of great clinical relevance because they support the concept that interventions in order to improve the muscle performance in these patients can increase the self-selected walking speed and therefore the metabolic economy of walking.
Subject(s)
Electromyography , Heart Failure/diagnosis , Heart Transplantation/methods , Physical Endurance/physiology , Walking Speed/physiology , Adult , Analysis of Variance , Chronic Disease , Cross-Sectional Studies , Energy Metabolism/physiology , Exercise Test/methods , Female , Heart Failure/rehabilitation , Heart Failure/surgery , Heart Transplantation/rehabilitation , Humans , Male , Middle Aged , Oxygen Consumption/physiology , Reference Values , Walking/physiologyABSTRACT
RESUMO Introdução: A velocidade de progressão é, em geral, determinada em pesquisas na área da locomoção. Objetivo: Comparar as medidas de velocidade autosselecionada no solo, na esteira rolante e a velocidade ideal estimada pelo número de Froude em sujeitos amputados transfemorais. Método: Primeiramente foi determinada a velocidade no solo; em seguida, realizou-se o teste na esteira, e a velocidade ideal foi estimada a partir dos dados antropométricos. Todos os sujeitos utilizavam joelho hidráulico e pé em fibra de carbono. Para comparação entre as velocidades foi realizada ANOVA de duas vias. Resultados: A velocidade autosselecionada na esteira foi menor (22%) do que no solo. Tanto a velocidade autosselecionada na esteira como a do solo foram 44% e 22% menores do que a velocidade ideal estimada, respectivamente. Conclusão: As velocidades analisadas no presente estudo foram diferentes, provavelmente, devido à variação dos parâmetros cinemáticos.
ABSTRACT Introduction: The speed of progression is generally determined in researches in the field of locomotion. Objective: To compare the self-selected velocity measurements on the ground, on treadmill and the optimal speed estimated by the Froude number in subjects with transfemoral amputation. Methods: First, the ground speed was determined; then the treadmill test was performed, and the optimal speed was estimated from anthropometric data. All subjects had hydraulic knee and carbon fiber foot. To compare the speeds, we used the two-way ANOVA. Results: The self-selected speed in the treadmill was lower (22%) compared with the ground. Both the self-selected speed in treadmill as ground were 44% and 22% lower than the estimated optimum speed, respectively. Conclusion: The speeds analyzed in this study were different, probably due to the variation of the kinematic parameters.
RESUMEN Introducción: La velocidad de progresión es generalmente determinada en investigaciones en el ámbito de la locomoción. Objetivo: Comparar las mediciones de la velocidad autoseleccionada en el suelo, en la cinta caminadora y la velocidad ideal estimada por el número de Froude en sujetos con amputación transfemoral. Métodos: En primer lugar, se determinó la velocidad en el suelo; después, se realizó la prueba en la cinta caminadora, y la velocidad ideal fue estimada a partir de los datos antropométricos. Todos los sujetos tenían rodilla hidráulica y pie en fibra de carbono. Para comparar las velocidades, se utilizó el ANOVA de dos vías. Resultados: La velocidad autoseleccionada en la cinta caminadora fue menor (22%) que en el suelo. Tanto la velocidad autoseleccionada en la cinta caminadora como la del suelo fueron 44% y 22% menores a la velocidad ideal estimada, respectivamente. Conclusión: Las velocidades analizadas en el presente estudio fueron diferentes, probablemente debido a la variación de los parámetros cinemáticos.
