Influencia de la postura del pie sobre la rigidez de la columna medial durante la marcha

Esta tesis se presenta como un compendio de publicaciones, y en ella se abordan diferentes estudios de caracterización de la dinámica de las articulaciones de la columna medial del pie (tobillo y articulaciones mediotarsiana y metatarsofalángica) con diferente índice postural. En primer lugar se analizan las diferencias entre pies normales, altamente pronados y altamente supinados mediante gráficos de evolución temporal de rotaciones y momentos articulares en los tres planos de movimiento. Asimismo, se proporcionan valores estadísticos para los parámetros descriptivos de dichas curvas, y a partir de ellos, para pies normales, se identifican patrones normales de marcha. Por otra parte, se identifican y comparan las sinergias cinemáticas y cinéticas en pies normales y altamente supinados, y se analizan las diferencias en sus evoluciones temporales. Finalmente, se estudia la rigidez articular dinámica a flexión durante la marcha en pies normales, altamente pronados y altamente supinados, identificando diferentes fases con rigidez aproximadamente constante. Se analiza la variabilidad de la rigidez en dichas fases, y en particular el efecto de la velocidad de marcha. Y se detallan las diferencias de rigidez dinámica entre los distintos tipos de pie.This thesis is presented as a compendium of publications, and it consists of different characterization studies of the dynamics of the joints of the medial column of the foot (ankle, midtarsal and metatarsophalangeal joints) with different postural indexes. First, the differences between normal, highly pronated and highly supinated feet are analyzed looking at the plots of joint rotations and moments vs time, in the three planes of movement. Statistical values ​​are also provided for the descriptive parameters of these curves, and used afterwards to identify gait patterns for normal feet. On the other hand, kinematic and kinetic synergies are identified and compared in normal and highly supinated feet, and the differences in their temporal evolutions are analyzed. Finally, dynamic joint stiffness in the flexural plane is studied during gait in normal, highly pronated and highly supinated feet, having identified different phases with approximately constant stiffness. The variability of the stiffness in these phases, and in particular the effect of the walking speed, is also analyzed. And the differences of dynamic stiffness between the different types of foot are detailed.Programa de Doctorat en Tecnologies Industrials i Material

Kinetic and kinematic analysis of midfoot joints of healthy subjects during walking: Clinical considerations

Introducción: No existe todavía suficiente evidencia en estudios clínicos respecto al comportamiento del mediopié en situaciones dinámicas como la marcha o la carrera. El presente estudio pretende analizar el comportamiento mecánico de las articulaciones del mediopié mediante un modelo multisegmental del pie, con especial atención a los momentos articulares y sus repercusiones clínicas. Sujetos y métodos: Se realizó un estudio computarizado de la marcha sobre 30 sujetos adultos sanos (27,13 ± 3,82 a˜nos) con un índice de postura del pie (FPI) neutro (entre 0 y +5). Se estimaron los ángulos y momentos articulares externos en 3 dimensiones mediante un modelo que considera 3 segmentos (antepié, retropié y hallux) y se analizó la evolución de dichas variables durante la marcha sobre la articulación del mediopié (articulación que conecta antepié y retropié) del pie derecho de todos los sujetos. Resultados: Los mayores momentos articulares observados se dieron en el plano sagital en flexión dorsal produciendo una tendencia al colapso o aplanamiento del pie durante la fase de apoyo de la marcha. Los momentos articulares registrados en los planos frontal y transverso fueron de una magnitud mucho menor que la observada en el plano sagital y de menor relevancia clínica. Discusión: El presente estudio aporta datos sobre el comportamiento mecánico de las articulaciones del mediopié en una muestra de 30 sujetos sanos con un FPI neutro. Este estudio muestra la importancia del estrés tensional al que se encuentran sometidas las estructuras blandas plantares durante la fase de apoyo de la marcha.Introduction: There is not enough evidence in form of clinical studies regarding the behavior of the midfoot joints in dynamic situations such us walking or running. The present work aims to study the mechanical behavior of midfoot joints with a multisegmented foot model with special interest in joint moments and their clinical significance. Subjects and methods: A computerized 3-dimensional gait study was performed on 30 healthy male adult subjects (27.13 ± 3.82 years) with a neutral Foot Posture Index (FPI) (from 0 to +5) during walking. Joint angle and external moments were estimated with a multisegment foot model that considers three separate segments (forefoot, rearfoot and hallux) and graphs and values of midfoot joint (joint connecting forefoot to rearfoot) were analyzed for the right foot of all participants. Results: Highest external moments were observed in the sagittal plane in dorsiflexion direction which tend to collapse the longitudinal arch during the stance phase. Moments registered in frontal and transverse planes were much lower than those observed in the sagittal plane and seemed to have lower clinical relevance. Discussion: The present study provides data about the mechanical behavior of midfoot joints in a healthy adult population with a neutral FPI. This work shows that plantar soft tissues are subjected to important tensional stress during the stance phase of walking

3D characterisation of the dynamics of foot joints of adults during walking. Gait pattern identification

A detailed description of the kinematics and kinetics of the ankle, midtarsal and metatarsophalangeal joints of the feet of a healthy adult male population during barefoot walking is provided. Plots of the angles and moments in each plane during the stance phase are reported, along with the mean and standard deviation values of 87 different parameters that characterise the 3D dynamics of the foot joints. These parameters were used to check for similarities between subjects through a hierarchical analysis that allowed three different gait patterns to be identified, most of the differences corresponding to the frontal and transverse planes

Effect of static foot posture on the dynamic stiffness of foot joints during walking

Background The static foot posture has been related to the development of lower limb injuries. Research question This study aimed to investigate the dynamic stiffness of foot joints during gait in the sagittal plane to understand the role of the static foot posture in the development of injuries. Methods Seventy healthy adult male subjects with different static postures, assessed by the Foot Posture Index (FPI) (30 normal, 20 highly pronated and 20 highly supinated), were recruited. Kinematic and kinetic data were recorded using an optical motion capture system and a pressure platform, and dynamic stiffness at the different stages of the stance was calculated from the slopes of the linear regression on the flexion moment-angle curves. The effect of foot type on dynamic stiffness and on ranges of motion and moments was analysed using ANOVAs and post-hoc tests, and linear correlation between dynamic stiffness and FPI was also tested. Results Highly pronated feet showed a significantly smaller range of motion at the ankle and metatarsophalangeal joints and also a larger range of moments at the metatarsophalangeal joint than highly supinated feet. Dynamic stiffness during propulsion was significantly greater at all foot joints for highly pronated feet, with positive significant correlations with the squared FPI. Highly supinated feet showed greater dynamic stiffness than normal feet, although to a lesser extent. Highly pronated feet during normal gait experienced the greatest decrease in the dorsiflexor moments during propulsion, normal feet being the most balanced regarding work generated and absorbed. Significance Extreme static foot postures show greater dynamic stiffness during propulsion and greater absorbed work, which increases the risk of developing injuries. The data presented may be used when designing orthotics or prostheses, and also when planning surgery that modifies joint stiffness

Componentes principales aplicados al estudio de la dinámica del pie supinado y normal durante la marcha

Comunicación presentada en el XXI Congreso Nacional de Ingeniería Mecánica, celebrado en Elche en Noviembre de 2016.Las variaciones en el índice postural del pie (pronados, supinados) suelen asociarse con una incorrecta función del miembro inferior que lo predispone a lesiones. El análisis riguroso de la dinámica del pie es complejo, pues han de manejarse simultáneamente las evoluciones temporales de ángulos y momentos durante la marcha en sus diferentes articulaciones, y en los tres planos de movimiento. Por ello, los análisis comparativos que pueden encontrarse en la literatura se han acometido sobre determinados parámetros específicos de la marcha, y no de forma sistemática. Aunque la marcha es una actividad compleja, diferentes trabajos han puesto de manifiesto la coordinación cinemática existente entre cadera, rodilla y tobillo mediante el uso del análisis de componentes principales (ACP). Sin embargo, la coordinación de ángulos y momentos en las articulaciones del pie durante la marcha ha sido poco explorada hasta ahora. En este trabajo se propone el análisis sistemático de las diferencias en la dinámica de pies supinados frente a pies normales, por aplicación de la reducción dimensional mediante el uso del ACP. Para ello se registró la dinámica del tobillo y de las articulaciones mediotarsiana y metatarsofalángica de 30 sujetos con pies normales y de 20 con pies supinados, mientras caminaban descalzos a lo largo de un pasillo de 7 m. La aplicación de ACPs (valores propios> 1, rotación varimax) sobre los sujetos con pies normales permitió identificar 3 componentes principales (CPs) explicando el 68% de la varianza de los ángulos articulares, y 3 CPs explicando el 87% de la varianza de los momentos, reduciendo las 18 variables temporales originales (9 ángulos y 9 momentos) a 6 factores. Las evoluciones temporales de estos factores permitieron identificar un conjunto de parámetros que se proponen para el análisis sistemático de la dinámica del pie durante la marcha. En el trabajo se presenta cuáles de esos parámetros se ven afectados por el índice postural del pie (mediante ANOVAs), así como las diferencias en la coordinación entre pies normales y supinados (comparando componentes principales de ambos grupos de sujetos), y se discuten sus posibles repercusiones clínicas

Human Endometrial Side Population Cells Exhibit Genotypic, Phenotypic and Functional Features of Somatic Stem Cells

During reproductive life, the human endometrium undergoes around 480 cycles of growth, breakdown and regeneration should pregnancy not be achieved. This outstanding regenerative capacity is the basis for women's cycling and its dysfunction may be involved in the etiology of pathological disorders. Therefore, the human endometrial tissue must rely on a remarkable endometrial somatic stem cells (SSC) population. Here we explore the hypothesis that human endometrial side population (SP) cells correspond to somatic stem cells. We isolated, identified and characterized the SP corresponding to the stromal and epithelial compartments using endometrial SP genes signature, immunophenotyping and characteristic telomerase pattern. We analyzed the clonogenic activity of SP cells under hypoxic conditions and the differentiation capacity in vitro to adipogenic and osteogenic lineages. Finally, we demonstrated the functional capability of endometrial SP to develop human endometrium after subcutaneous injection in NOD-SCID mice. Briefly, SP cells of human endometrium from epithelial and stromal compartments display genotypic, phenotypic and functional features of SSC

Foot sole contact forces vs. ground contact forces to obtain foot joint moments for in-shoe gait-A preliminary study

In-shoe models are required to extend the clinical application of current multisegment kinetic models of the bare foot to study the effect of foot orthoses. Work to date has only addressed marker placement for reliable kinematic analyses. The purpose of this study is to address the difficulties of recording contact forces with available sensors. Ten participants walked 5 times wearing two different types of footwear by stepping on a pressure platform (ground contact forces) while wearing in-shoe pressure sensors (foot sole contact forces). Pressure data were segmented by considering contact cells' anteroposterior location, and were used to compute 3D moments at foot joints. The mean values and 95% confidence intervals were plotted for each device per shoe condition. The peak values and times of forces and moments were computed per participant and trial under each condition, and were compared using mixed-effect tests. Test-retest reliability was analyzed by means of intraclass correlation coefficients. The curve profiles from both devices were similar, with higher joint moments for the instrumented insoles at the metatarsophalangeal joint (~26%), which were lower at the ankle (~8%) and midtarsal (~15%) joints, although the differences were nonsignificant. Not considering frictional forces resulted in ~20% lower peaks at the ankle moments compared to previous studies, which employed force plates. The device affected both shoe conditions in the same way, which suggests the interchangeability of measuring joint moments with one or the other device. This hypothesis was reinforced by the intraclass correlation coefficients, which were higher for the peak values, although only moderate-to-good. In short, both considered alternatives have drawbacks. Only the instrumented in-soles provided direct information about foot contact forces, but it was incomplete (evidenced by the difference in ankle moments between devices). However, recording ground reaction forces offers the advantage of enabling the consideration of contact friction forces (using force plates in series, or combining a pressure platform and a force plate to estimate friction forces and torque), which are less invasive than instrumented insoles (which may affect subjects' gait)