A regularized functional method to determine the hip joint center of rotation in subjects with limited range of motion

The symmetrical center of rotation estimation (SCoRE) is probably one of the most used functional method for estimating the hip join center (HJC). However, it requires of complex multi-plane movements to find accurate estimations of HJC. Thus, using SCoRE for people with limited hip range of motion will lead to poor HJC estimation. In this work, we propose an anisotropic regularized version of the SCoRE formulation (RSCoRE), which is able to estimate the HJC location by using only standard gait trials, avoiding the need of recording complex multi-plane movements. RSCoRE is evaluated in both accuracy and repeatability of the estimation as compared to functional and predictive methods on a self-recorded cohort of fifteen young healthy adults with no hip joint pathologies or other disorders that could affect their gait. Given that, no medical images were available for this study, to quantify the global error of HJC the SCoRE residual was used. RSCoRE presents a global error of about 12 mm, similarly to the best performance of SCoRE. The comparison of the coordinate's errors at each coordinate indicates that HJC estimations from SCoRE with complex multi-plane movements and RSCoRE are not statistical significantly different. Finally, we show that the repeatability of RSCoRE is similar to the rest of the tested methods, yielding to repeatability values between 0.72 and 0.79. In conclusion, not only the RSCoRE yields similar estimation performance than SCoRE, but it also avoids the need of complex multi-plane movements to be performed by the subject of analysis. For this reason, RSCoRE has the potential to be a valuable approach for estimating the HJC location in people with limited hip ROM.Fil: Ravera, Emiliano Pablo. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina. Universidad Nacional de Entre Ríos. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática; ArgentinaFil: Peterson, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; Argentin

Effects of walking speed and age on the muscle forces of unimpaired gait subjects

Clinical gait analysis provides great contributions to the understanding of gait disorders and also provides a mean for a more comprehensive treatment plan. However, direct measures of muscle forces are difficult to obtain in clinical settings because it generally requires invasive techniques. Techniques of musculoskeletal modeling have been used for several decades to improve the benefits of clinical gait analysis, but many of the previous studies were focused on analyzing separately the muscle forces distribution of children or adult subjects with only one condition of walking speed. For these reason, the present study aims to enhance the current literature by describing the age and speed gait effects on muscle forces during walking. We used a musculoskeletal model with 23 degrees of freedom and 92 musculotendon actuators to represent 76 muscles in the lower extremities and torso. The computed muscle control algorithm was used to estimate the muscle forces from the kinematics and to adjust the model obtained in the residual reduction algorithm. We find that hamstrings has an important peak in the mid-stance phase in the adult group but this peak disappears in the children group with the same walking speed condition. Furthermore, the rectus femoris presents an increase in the muscle force during the pre- and mid-swing in concordance with the increment in the walking speed of subjects. This behavior could be associated with the role that the rectus femoris has in the acceleration of the knee joint. Finally, we show that the soleus is the muscle that perform the major force throughout the gait cycle regardless of age and walking speed.Fil: Fliger, Carlos G.. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Crespo, Marcos J.. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Braidot, Ariel A.. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Ravera, Emiliano Pablo. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Electromyography as an Important Parameter for a Proper Assessment of Dynamic Muscles Strength in Gait Analysis

Normal gait is a functional movement involving the most efficient energy transfer. Cerebral Palsy describes a group of developmental disorders of movement and posture causing activity restriction or disability. It represents one of the most common cause of physical disability in children. Gait analysis provides great contributions to the understanding of gait disorders originating from musculoskeletal abnormalities. In these patients provides a mean for a more comprehensive treatment plan. At this point, the potential and necessity of using correct biomechanical models that consistently study the abnormalities become clear. Reinforcing and correcting a simple gait analysis and eliminating the unknowns when selecting the appropriate treatment are crucial in clinical settings. In this paper a musculoskeletal thigh model with a simple rescaling method using subject-specific anthropometric data is presented. The thigh model estimates muscle forces of the six muscles through the walking based in static optimization without including electromyography data as input. We used the model proposed for identify the muscles strength involved in normal and pathological gait. The forces obtaining for normal subjects achieved high concordance with their electromyography data and outcomes to other musculoskeletal model recently presented. In other hand, in patients with cerebral palsy with crouch gait the outcomes of our musculoskeletal model don't show a correct concordance with their electromyography data. For this reason we get on the conclusion that take electromyography data became important in modeling a pathological gait as crouch gait.Fil: Ravera, Emiliano Pablo. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Catalfamo Formento, Paola Andrea Lucia. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Crespo, Marcos Jose. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Braidot, Ariel Andrés Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentin

Modelo músculo-esquelético del miembro inferior: Un enfoque teórico en busca de la aplicabilidad clínica

El análisis biomecánico, es una herramienta habitual de análisis clínico en sujetos con alteraciones motrices. Sin embargo, la distribución de las fuerzas musculares individuales durante el ciclo de marcha no está completamente representada. Un modelo músculo-esquelético representa mediante un conjunto de parámetros numéricos la interacción del sistema óseo-artro-múscular aportando estrategias más efectivas en el análisis y posterior abordaje terapéutico. El sistema locomotor humano es redundante y utiliza óptimos criterios de selección muscular para desarrollar un movimiento. Esto lleva a la utilización de métodos matemáticos de optimización que utilizan principios fisiológicos para explicar el mecanismo y significado funcional de las fuerzas musculares. En este trabajo se desarrolló un modelo musculo-esquelético del miembro inferior en el plano sagital constituido por once músculos y se lo analizó sobre cinco sujetos sin alteraciones de la marcha. El tejido muscular es representado mediante la utilización de un modelo de Hill. Para la resolución del problema de optimización se utilizó el algoritmo SQP. Se compararon los resultados obtenidos con modelos ya existentes. Se logró reflejar los lineamientos a seguir en el desarrollo de un modelo aplicable al ambiente clínico, ayudando a predecir el comportamiento funcional de los músculos y sus posibles modificaciones ante una patología.Biomechanical analysis is a common tool in clinician settings for the analysis of subjects with motor abnormalities. However, the individual muscle forces behavior through of the gait cycle is not fully represented on the gait analysis. Musculoskeletal models represent a set of numerical parameters showing the interaction of the system bone-joint-muscles, providing more effective strategies in the analysis and subsequent therapeutic approach. The human musculoskeletal system is redundant and uses optimal selection criteria for developing a muscular movement. This leads to the use of mathematical optimization methods that utilize physiological mechanism to explain the principles and functional significance of muscle forces.A musculoskeletal model of the lower limb was developed in this paper. The model represents the sagittal plane of movement and it consists of eleven muscles.In this work were analyzed five subjects without abnormal gait. Muscle tissue was represented by a Hill-Type model. To solve the static optimization problem the SQP algorithm was used. Our estimationsof the muscles force were compared with other musculoskeletal model, developed by other researcher groups. Through this work was possible to reflect the guidelines to follow in the developing a musculoskeletal model applicable in the clinical setting, helping to predict the functional behavior of muscles and the possible modifications from a pathological gait.Fil: Buyatti, Francisco. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería. Cátedra de Biomecanica; ArgentinaFil: Cano, Matías. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería. Cátedra de Biomecanica; ArgentinaFil: Braidot, Ariel Andrés Antonio. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería. Cátedra de Biomecanica; ArgentinaFil: Crespo, Marcos Jose. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Ravera, Emiliano Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Bioingeniería. Cátedra de Biomecanica; Argentin

Mejorar la enseñanza y el aprendizaje de la Matemática en Bioingeniería: Un desafío asumido desde la investigación-acción

En este trabajo se exponen las inquietudes y necesidades que, advertidas por un grupo de docentes de la Facultad de Ingeniería de la Universidad Nacional de Entre Ríos (FIUNER), originaron un proyecto de Investigación Educativa de carácter interdisciplinario. Se describen también las dificultades y algunos resultados alcanzados en la realización del mismo. Se aborda la problemática del aprendizaje y la enseñanza de la Matemática en una rama de la Ingeniería intrínsecamente interdisciplinaria: la Bioingeniería.The purpose of this work is to present the queries and needs perceived by a group of teachers at the Faculty of Engineering belonging to the National University of Entre Ríos (FI-UNER) which laid the foundations for an interdisciplinary educational research project. The difficulties encountered and some preliminary results are also described. The project addresses the problem of teaching and learning mathematics in an intrinsically interdisciplinary branch of engineering, i.e. bioengineering.Fil: Añino, María Magdalena. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Matemática E Informatica; ArgentinaFil: Perassi, Marisol Liliana. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Merino, Gabriela Alejandra. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Matemática E Informatica; ArgentinaFil: Ravera, Emiliano Pablo. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Matemática E Informatica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Entre Ríos. Universidad Nacional de Entre Ríos. Centro de Investigaciones y Transferencia de Entre Ríos; ArgentinaFil: Pita, Gustavo de Dios. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Matemática E Informatica; ArgentinaFil: Miyara, Alberto José. Universidad Nacional de Entre Rios. Facultad de Ingeniería. Departamento de Matemática E Informatica; ArgentinaFil: Waigandt, Diana Monica. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentin

Efecto de las estimaciones de los centros articulares en el análisis clínico de la marcha mediante enfoques predictivos y funcionales

Se reclutaron veinte adultos jóvenes sanos (10 hombres, 10 mujeres) sin patologías de la articulación de la cadera u otros trastornos que pudieran afectar la marcha. Todos los participantes dieron su consentimiento informado por escrito antes de participar. El protocolo de estudio fue aprobado por el Comité de Ética del Centro de Investigaciones Técnicas (Santa Fe, Argentina) del Consejo Nacional de Investigaciones Científicas y Técnicas. Los participantes estaban equipados con 8 marcadores para rastrear la posición de la pelvis y el muslo en su extremidad dominante. Se utilizó un sistema de captura de movimiento óptico Flex 13 OptiTrak (NaturalPoint, Corvallis, Oregón, EE. UU.) con 8 cámaras que funcionan a 120 Hz para adquirir las trayectorias de los marcadores. Cada participante fue evaluado por el mismo evaluador, quien realizó la colocación de los marcadores y recopiló los datos de captura de movimiento. Las pruebas se realizaron en dos sesiones separadas por una semana. Para cada sesión de prueba, a los participantes se les pidió que realizaran seis pruebas de cada tarea de movimiento funcional estándar (Cross, Arc, Star y StarArc como se describe en Camomilla et al. (2006)), comenzando con una prueba de calibración estática de pie, y seis pruebas de marcha a velocidad de marcha auto-seleccionada.Fil: Ravera, Emiliano Pablo. Universidad Nacional de Entre Ríos. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática; Argentin

Process control as a source of integrator problems for a differential equations course in bioengineering

Bioengineering is a multidisciplinary program. With its foundations in basic science, Bioengineering applies different technological principles in order to solve problems in the health area. Mathematics, thanks to its methodological and conceptual insights, is an invaluable tool not only in the education of future bioengineers, but also in their professional activities. However, Mathematics courses represent an obstacle to many engineering students. Enhancing the teaching of Mathematics in this context is a need and a challenge for teachers. In this work, problem-solving activities that were carried out in a Differential Equations course are described. They aimed at fostering both the development of the students learning strategies, and the linking of mathematical concepts and methods to other areas. We focused on the possibility of bridging the gap between Differential Equations and Process Control through integrative problem-solving activities that articulate both perspectives and modes of thought.. © 2003-2012 IEEE.Fil: Merino, Gabriela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos; ArgentinaFil: Añino, Maria Magdalena. Universidad Nacional de Entre Ríos; ArgentinaFil: Ravera, Emiliano Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos; Argentin

Estimation of muscle forces in gait using a simulation of the electromyographic activity and numerical optimization

Clinical gait analysis provides great contributions to the understanding of gait patterns. However, a complete distribution of muscle forces throughout the gait cycle is a current challenge for many researchers. Two techniques are often used to estimate muscle forces: inverse dynamics with static optimization and computer muscle control that uses forward dynamics to minimize tracking. The first method often involves limitations due to changing muscle dynamics and possible signal artefacts that depend on day-to-day variation in the position of electromyographic (EMG) electrodes. Nevertheless, in clinical gait analysis, the method of inverse dynamics is a fundamental and commonly used computational procedure to calculate the force and torque reactions at various body joints. Our aim was to develop a generic musculoskeletal model that could be able to be applied in the clinical setting. The musculoskeletal model of the lower limb presents a simulation for the EMG data to address the common limitations of these techniques. This model presents a new point of view from the inverse dynamics used on clinical gait analysis, including the EMG information, and shows a similar performance to another model available in the OpenSim software. The main problem of these methods to achieve a correct muscle coordination is the lack of complete EMG data for all muscles modelled. We present a technique that simulates the EMG activity and presents a good correlation with the muscle forces throughout the gait cycle. Also, this method showed great similarities whit the real EMG data recorded from the subjects doing the same movement.Fil: Ravera, Emiliano Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Entre Ríos. Universidad Nacional de Entre Ríos. Centro de Investigaciones y Transferencia de Entre Ríos; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Departamento de Física Química. Laboratorio de Biomecánica Computacional; ArgentinaFil: Crespo, Marcos Jose. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Braidot, Ariel Andrés Antonio. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Departamento de Física Química. Laboratorio de Biomecánica Computacional; Argentin

Assessment of the energy-related cost function over a range of walking speeds

Cost funtions are needed for calculation of muscle forces in musculoskeletal models. The behavior of the energy-related cost function, proposed by Praagman et al. (J Biomech 39(4):758?765, 2006. https://doi.org/10.1016/j.jbiomech.2004.11.034) (CFP), can be used as an optimization criteria in musculoskeletal models for studying gait. In particular, in this work, its performance is compared against two empirical phenomenological models at different walking speed conditions. Also, the sensitivity of the CFP function to model parameters, such as muscle mass, maximal isometric muscle force, optimal muscle fiber length and maximum muscle velocity of the contractile element, was analyzed. The obtained results showed that CFP presents different behavior (in terms of the normalized root-mean-squared deviation (NRMSD) and the coefficient of multiple correlation (CMC)) for different muscles. Also, it provided estimates with median of NRMSD between 0.176 and 0.299 and median of CMC between 0.703 and 0.865 both metrics for slow, free and fast walking speed, which could be considered as acceptable results. Furthermore, the results indicated that CFP is insensitive to changes in muscle mass and relatively sensitive to maximal isometric muscle force. However, CFP presented a noisy behavior on estimations of muscle energy rate for some muscle as compared to phenomenological models. Finally, estimations by CFP during gait are within the values obtained by the empirical phenomenological models.Fil: Ravera, Emiliano Pablo. Universidad Nacional de Entre Ríos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Crespo, Marcos Jose. Laboratorio de Análisis de Marcha y Movimiento; ArgentinaFil: Catalfamo Formento, Paola Andrea Lucia. Universidad Nacional de Entre Ríos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin