Effects of backpack loads and positions on the variability of gait spatiotemporal parameters in young adults

Abstract Introduction: People carry backpacks of different weight in different positions every day. The effects of backpack wearing under different loads and positions were assessed according to the gait's spatiotemporal parameters and their variability in young adults. Methods Twenty-one subjects performed trials of 4 min in the conditions: control condition with no backpack; bilateral back load consisting of 10% body weight (BW); bilateral back load of 20% BW (B20); unilateral load of 10% BW; unilateral load with 20% BW (U20); bilateral frontal load with 10% BW; bilateral frontal load with 20% BW. Results Step length (SL) and step frequency (SF) show that frontal conditions differed from others as seen in B20. Gait cycle phases showed an increase in the B20 condition for double stance phase and stance phase, swing phase presented reduction in the B20 condition. There were significant main effects in position for SL, SF, and walk ratio, in load only for stride width. The highest variability of spatiotemporal parameters occurred in the U20 condition. All load conditions with 20% BW showed a greater variability when compared to the 10% BW counterpart. Conclusion We concluded that young adults can cope with up to a 15% BW load under a bilateral back position, but in the frontal position not even a 10% BW load was proven to be a safe limit. 20% BW loads should be avoided in any position. These recommendations may assure increased gait stability, decreased trunk forward lean and decreased muscle activation and fatigue reducing back pain occurrence.

Analysis of the kinematic variation of human gait under different walking conditions using computer visión / Análisis de la variación cinemática de la marcha humana bajo diversas condiciones de caminado usando visión por computadora

ABSTRACT: This paper presents the analysis of human gait of three young adults under several walking conditions similar to those in real life. The aim is to evaluate how the human gait varies when different walking conditions are considered. In order to evaluate the human gait variations under different walking conditions, first a 3D computer visión system to reconstruct human gaits is developed and presented. Then, a set of kinematic gait parameters is defined in order to analyse the different gait patterns. Finally, several experiments are conducted with three normal Young adults walking under different real-life conditions, such as ascending a slope walk, no arm-swing walk, carrying a front load walk, carrying a lateral load walk, fast walk and high-heel shoes walk. The results has shown that the human gait pattern vary according to the walking conditions, being the most common variation a slower walk with shorter steps than the normal walk. Since the aim of the paper is to identify and evaluate human gait variations under different walking conditions, only three subjects were considered in the study. However, in order to provide more precise and standard results the number of subjects must be increased considering different age, height, sex, weight, and health conditions of the participants. Human walking patterns are very important for medical diagnosis and orthopedics, pathological and aging evaluation, medical rehabilitation, and design of rehabilitation systems, human prosthesis and humanoid robots. However, most of the research work in the literature has been primarily focused on the analysis of gait patterns under normal walking conditions. This fact has led to a limited knowledge of the human gait patterns since real-life walking conditions are diverse, e.g. walking carrying a load. This paper presents the analysis of human gait of three young adults under walking conditions similar to those in real life. Human gait patterns vary with the walking conditions, which must be considered during the analysis, evaluation and diagnosis of gait performance, or during the design process of prostheses or rehabilitation systems.

RESUMEN: En este artículo se presenta el análisis del patrón de caminado de tres adultos jóvenes bajo diversas condiciones de caminado tal como se presentan en la vida real. El objetivo es determinar la variación del patrón de caminado cuando se tienen diferentes condiciones de caminado. Con el propósito de evaluar la variación del patrón de caminado bajo diversas condiciones de caminado, primero se desarrolla y presenta un sistema de visión por computadora para la reconstrucción 3D de las trayectorias del caminado humano. Posteriormente se define un conjunto de parámetros cinemáticos de caminado para analizar los diferentes patrones de caminado. Finalmente se realiza una serie de experimentos con tres adultos jóvenes a los cuales se les pidió caminar bajo diferentes condiciones como en la vida real, tales como caminar subiendo una pendiente, caminar sin braceo, caminar sosteniendo una carga la frente, caminar sosteniendo una carga lateral, caminar rápido y caminar con zapato de tacón alto. Los resultados han demostrado que el patrón de caminado humano varía de acuerdo a las condiciones del caminado, siendo una de las variaciones más comunes un caminado más lento con pasos más cortos que el caminado normal. Debido a que el objetivo del trabajo es identificar y evaluar variaciones del patrón de caminado bajo diversas condiciones, solamente se consideraron tres sujetos de estudio. Sin embargo, para proporcionar resultados más precisos y normalizados el tamaño de la muestra debe incrementarse considerando diferentes edades, estaturas, sexo, peso, y condiciones de salud de los participantes. Los patrones del caminado humano son muy importantes para el diagnóstico médico y ortopédico, las evaluaciones patológicas y de envejecimiento, la rehabilitación médica, y el diseño de sistemas de rehabilitación, prótesis humanas y robots humanoides. Sin embargo, la mayoría de los trabajos de investigación reportados en la literatura se han enfocado principalmente en el análisis del patrón de caminado humano bajo condiciones normales de caminado. Estos estudios del caminado humano han dado lugar a un conocimiento limitado debido a que las condiciones del caminado en la vida real son diversas, por ejemplo caminar con una carga. Este trabajo presenta el análisis del patrón de caminado de tres adultos jóvenes bajo diversas condiciones de caminado similares a la vida real. El patrón de caminado humano varía de acuerdo a las condiciones de caminado, lo cual debe ser considerado durante en análisis, evaluación y diagnóstico del desempeño de caminado, o durante el proceso de diseño de prótesis o sistemas de rehabilitación.

Comparación de dos Sistemas de Captura de Movimiento por medio de las Trayectorias Articulares de Marcha / Comparison of two Motion Capture Systems by means of joint Trajectories of human gait

Resumen: En la actualidad, los métodos más comunes para una adecuada captura del movimiento humano en tres dimensiones requieren de un entorno de laboratorio y la fijación de marcadores, accesorios o sensores a los segmentos corporales. Sin embargo, el alto costo de estos equipos es un factor limitante en diversos entornos de trabajo. Sistemas de captura de movimiento como Microsoft Kinect TMpresentan un enfoque alternativo a la tecnología de captura de movimiento. En este trabajo se comparan dos sistemas de captura de movimiento por medio de las trayectorias articulares y las medidas antropométricas de una persona en un ciclo de marcha normal. El primero de ellos, es un sistema comercial de precisión que utiliza marcadores (Vicon TM) y el segundo, es la cámara Microsoft KinectTM. Ambos sistemas se evaluaron con el propósito de comparar la diferencia geométrica y el error RMS entre las trayectorias articulares de la marcha humana obtenidas por cada uno de los sistemas. Los resultados muestran una varianza mayor en las medidas antropométricas y trayectorias articulares para el Kinect, aunque este sistema es de bajo costo y de fácil uso e instalación, no puede ser utilizado para un análisis preciso de la cinemática de la marcha humana.

Abstract: Currently, the most common methods for proper capture of human movement in three dimensions require a laboratory environment and setting markers, accessories or sensors to the body segments. However, the high cost of equipment is a limiting factor in diverse environments. Motion capture systems such as Microsoft KinectTM present an alternative approach to motion capture technology. In this paper, two motion capture systems are compared by means of joint trajectories and anthropometric Currently, the most common methods for proper capture of human movement in three dimension measurements of a person in a normal gait cycle. The first is accurate trading system that uses markers (ViconTM), and the second is Microsoft KinectTM camera. Both systems were evaluated in order to compare the geometric difference and the RMS error between the joint trajectories for Kinct, although this system is inexpressive and easy to use and install, cannot be used for precise kinematic analysis of human walking.

Efeitos de um programa de psicomotricidade no bem-estar e na marcha em idosos / Effects of a psychomotor program on welfare and gait in older adults

Introdução: Por causa do envelhecimento, o ser humano compromete algumas estruturas fisiológicas importantes para o desempenho da marcha Vale salientar que as modificações da marcha no idoso se processam em relação a fatores tanto fisiológicos como emocionais, interferindo no estilo de vida que o idoso apresenta. Objetivos: Investigar o efeito de um programa de atividades psicomotoras na marcha e no bem estar físico, mental e social dos idosos. Metodologia: Trata-se de um estudo de intervenção sem grupo controle, descritiva, com abordagem quanti-qualitativa realizada na Clínica-Escola da Universidade Federal da Paraíba, João Pessoa-PB. A população do estudo foi constituída por 15 idosos. Para a coleta de dados, utilizou-se um instrumento com dados sociodemográficos, dados clínicos, exame físico, Mini Exame de Estado Mental, e avaliação de desempenho funcional da marcha (POMA-BRASIL). Estas avaliações faziam parte da triagem dos participantes, sendo o MEEM e o POMA realizados em três momentos da pesquisa, a cada dois meses. O estudo foi realizado no período de agosto a dezembro de 2011. No que se refere às considerações éticas, o estudo esteve de acordo com as normas da resolução 196/96. Quanto ao procedimento de intervenção, foram realizadas atividades psicomotoras cuja finalidade foi promover um fortalecimento muscular a partir dos elementos psicomotores, favorecendo um melhor desempenho da marcha, sendo desenvolvidas na água e no solo. Após o término do programa psicomotor, foram identificadas as percepções dos idosos através da técnica de entrevista individual, cuja pergunta norteadora foi: Qual a percepção acerca dos efeitos do programa psicomotor na sua vida? . Os depoimentos foram gravados, o que contribuiu para que as falas fossem transcritas com maior exatidão e fidedignidade. Para a análise dos dados quantitativos, utilizou-se a estatística descritiva e o teste de Friedman; sob o ponto de vista qualitativo, a análise de conteúdo de Bardin.

Introduction: Because of aging, the human undertakes some physiological structures important for gait performance is noteworthy that the changes of gait in the elderly are processed in relation to factors both physiological and emotional, interfering with the lifestyle that the elderly presents. Objective: to investigate the effect of a program of psychomotor activities in gait and physical well-being, mental and social of elderly,. Methodology: It is an intervention study, without group control, descriptive, with quantitative-qualitative approach, conducted in a Clinical School of the Federal University of Paraíba, João performance of gait (POMA-BRAZIL). These evaluations were part of the triage of participants, being PEEM and POMA, Pessoa-PB. The population of the study was composed by 15 elderly. For data collection was utilized an instrument with socio demographic data, clinical data and physical examination, the mini mental state examination and the evaluation of functional performed in three moments of the research, every two months. The study was conducted in the period from August to December 2011. Referring to ethical considerations, the study was in accordance to the rules of Resolution1196/96. Regarding the intervention procedure were carried out psychomotor activities whose purpose a muscle strengthening from the psychomotor elements, favoring a better gait performance, being developed in the water and soil. After finishing the psychomotor program were identified perceptions of elderly through the individual interview technique of which guiding question was: What is the perception about the effects of the psychomotor program in your life? Their statements were recorded, which contributed so that the speeches could be transcribed with higher accuracy and reliability. For quantitative data analysis was utilized descriptive statistics and Friedman s test, from the qualitative point of view, the content analysis of Bardin.

Application of Kohonen maps to kinetic analysis of human gait / Aplicação de mapas de Kohonen à análise cinética da marcha humana

In recent years the use of artificial neural networks for classification and analysis of kinematic and kinetic characteristics of human locomotion has greatly increased. This happens in an attempt to overcome the limitations of traditional dynamic analysis and to find new clinical indicators for interpreting quick and objectively the large amount of information obtained in a gait lab. One of the most widely used neural networks for human gait analysis is the self-organizing or Kohonen map, based on unsupervised learning without prior definition of the formed natural groups. Among the advantages of using this type of neural network is the data dimensionality reduction, with minimal loss of information content, and the grouping of them in function of their similarities. Taking into account this, in this work an application case of a Kohonen map for clustering of locomotion kinetic characteristics in normal and Parkinson's disease individuals is presented. The results indicate that the groups identified by the map are consistent with the classification carried out by experts in function of traditional gait dynamic analysis, showing the potential of this technique for distinguishing between a population of individuals with normal gait and with gait disorders of different etiology.

Nos últimos anos, tem aumentado significativamente o uso de redes neurais artificiais para a classificação e análise cinemática e cinética da marcha humana, em uma tentativa de superar as limitações da análise dinâmica tradicional e de encontrar novos indicadores clínicos para interpretar, de forma rápida e objetiva, a grande quantidade de informação obtida em laboratórios de marcha humana. Uma das redes neurais mais utilizadas para análise de marcha é o mapa de Kohonen ou mapa auto-organizado, baseado em aprendizado não supervisionado, sem uma definição prévia de grupos naturais que se formam. O uso deste tipo de rede neural tem mostrado benefícios significativos associados com a redução da dimensionalidade dos dados com mínima perda de conteúdo de informação e com o agrupamento de dados de acordo com suas semelhanças. Neste contexto, este trabalho apresenta um caso de aplicação de um mapa de Kohonen como classificador das características cinéticas da locomoção em indivíduos normais e com doença de Parkinson. Os resultados indicam que os grupos identificados no mapa são consistentes com a classificação feita por especialistas com base em análise dinâmica tradicional, que mostra o potencial desta técnica para diferenciar populações de indivíduos com marcha normal e de indivíduos com distúrbios da marcha de etiologia diferente.

Three-dimensional kinematic analysis of upper and lower limb motion during gait of post-stroke patients

The aim of this study was to analyze the alterations of arm and leg movements of patients during stroke gait. Joint angles of upper and lower limbs and spatiotemporal variables were evaluated in two groups: hemiparetic group (HG, 14 hemiparetic men, 53 ± 10 years) and control group (CG, 7 able-bodied men, 50 ± 4 years). The statistical analysis was based on the following comparisons (P ≤ 0.05): 1) right versus left sides of CG; 2) affected (AF) versus unaffected (UF) sides of HG; 3) CG versus both the affected and unaffected sides of HG, and 4) an intracycle comparison of the kinematic continuous angular variables between HG and CG. This study showed that the affected upper limb motion in stroke gait was characterized by a decreased range of motion of the glenohumeral (HG: 6.3 ± 4.5, CG: 20.1 ± 8.2) and elbow joints (AF: 8.4 ± 4.4, UF: 15.6 ± 7.6) on the sagittal plane and elbow joint flexion throughout the cycle (AF: 68.2 ± 0.4, CG: 46.8 ± 2.7). The glenohumeral joint presented a higher abduction angle (AF: 14.2 ± 1.6, CG: 11.5 ± 4.0) and a lower external rotation throughout the cycle (AF: 4.6 ± 1.2, CG: 22.0 ± 3.0). The lower limbs showed typical alterations of the stroke gait patterns. Thus, the changes in upper and lower limb motion of stroke gait were identified. The description of upper limb motion in stroke gait is new and complements gait analysis.

Um movimento, dois olhares: a mudança de paradigma na análise do controle motor e seu efeito na abordagem da marcha humana / One movement, two perspectives: a paradigm change in the motor control

A análise de dados na ciência depende da bagagem cultural e experiência do pesquisador. Estudos sobre a marcha tem como base uma das principais teorias de controle motor: programa motor generalizado e teoria dos sistemas dinâmicos. O objetivo deste estudo foi analisar estas teorias e verificar como os estudos a partir destas correntes teóricas abordam o movimento humano denominado marcha. Foram selecionados artigos completos a partir dos unitermos: motor program, generalized motor program, dynamic system theory, gait. O programa motor generalizado analisa a semelhança dos dados para encontrar um padrão no movimento. Os sistemas dinâmicos visam analisar coordenação e variabilidade para verificar estabilidade ou emergência no movimento. Com isso os estudos a partir das duas teorias enfocam fatores diferentes para a análise e interpretação dos dados. Para a marcha a teoria do programa motor generalizado analisa a semelhança de dados de eletromiografia e cinemetria com o intuito de encontrar o padrão de movimento constante e segundo este padrão o programa motor abstrato para este movimento. A teoria dos sistemas dinâmicos visa analisar a coordenação inter e intra-membros e a variabilidade durante a tarefa para verificar a estabilidade do movimento ou a emergência de outro padrão. Pode ser caracterizado que estas duas teorias apesar de tratarem do mesmo tema, o fazem com objetivos diferentes, levando a constatação de uma divergência na abordagem e análise dos dados dependendo da teoria de base do pesquisador.

Data analysis, in any science field, depends on the investigator’s cultural luggage and experience. Among the studies regarding the motor control, two theories are currently in vogue: the generalized motor program and the dynamic systems theory. The aim of this study was to create a general view of both theories and verify how each theory explains the human movement named “gait”. To achieve this aim, full articles were selected through the following key words: motor program, generalized motor program, dynamic system theory, gait. The generalized motor program analyses data similarity in order to find a movement pattern. Dynamic systems theory verifies coordination and variability with the intention of explaining stability or emergence of a movement. Thereby, studies related to these two different theories focus on different factors when carrying out the data analysis and interpretation. Regarding the human gait, the generalized motor program theory analyses the similarities between the electromyographic and kinematic data in order to find a constant movement pattern and the abstract motor program of this movement. The dynamic systems theory aims to analyze intra-limb and inter-limb coordination and the variability during the task execution in order to verify the movement stability or the emergence of another pattern. By this means, despite the fact that both theories approach the same theme, different objectives can be characterized depending on the theory that is being used. This fact leads to a data approach divergence that is dependent upon the investigator’s theoretical background.