0000000000262756
AUTHOR
Joaquín L. Sancho-bru
Kinematics reduction applied to the comparison of highly-pronated, normal and highly-supinated feet during walking
Abstract Background Kinematic analysis could help to study how variations in the static foot posture affect lower limb biomechanical function. The analysis of foot kinematics is complex because it involves managing the time-dependent joint angles in different joints and in all three planes of motion. But it could be simplified if joint angles are coordinated. Methods The kinematics of the ankle, midtarsal and metatarsophalangeal joints were registered in 20 highly-pronated, 30 normal and 20 highly-supinated subjects (assessed by the Foot Posture Index – FPI) as they walked barefoot. Coordination for each sample was analysed through principal component analysis applied to the dorsiflexion, a…
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.
Análisis cinético y cinemático de las articulaciones del mediopié durante la marcha en sujetos sanos: consideraciones clínicas
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…
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 r…
Influence of material and diameter of pre-fabricated posts on maxillary central incisors restored with crown.
Summary Numerous research works have studied the effect of post-design parameters on the mechanical behaviour of restored teeth without reaching any clear conclusions. Previous works by the authors ascertained the effect of material and post-dimensions for non-crowned restored teeth. The aim of this work was to study the effect of post-material and diameter for crowned teeth. First, an experimental fracture strength test was performed on eighteen extracted human maxillary central incisors. Teeth were decoronated, treated endodontically and restored (nine with glass fibre posts and nine with stainless steel posts). Several post-diameters were used. The final crown restoration was carried ou…
Influence of prefabricated post dimensions on restored maxillary central incisors
summary The aim of this study was to test the following hypothesis: biomechanical performance (fracture strength and stress distribution) of restored teeth is less sensitive to post diameter and post length when using glass fibre posts than when using stainless steel posts. First, an experimental fracture strength test was performed on 80 extracted human maxillary central incisors. Teeth were decoronated, treated endodontically and restored (40 with glass fibre posts and 40 with stainless steel posts), and the length and diameter of the posts varied uniformly. Failure loads were recorded and results were compared using an ancova analysis. Secondly, the finite element technique was used to …
Experimental strength of restorations with fibre posts at different stages, with and without using a simulated ligament
The aim of this study was to analyse the strength and failure mode of teeth restored with fibre posts under retention and flexural-compressive loads at different stages of the restoration and to analyse whether including a simulated ligament in the experimental setup has any effect on the strength or the failure mode. Thirty human maxillary central incisors were distributed in three different groups to be restored with simulation of different restoration stages (1: only post, 2: post and core, 3: post-core and crown), using Rebilda fibre posts. The specimens were inserted in resin blocks and loaded by means of a universal testing machine until failure under tension (stage 1) and 50o flexion…