Search results for "T joint"
showing 10 items of 60 documents
Effect of active heating and cooling on microstructure and mechanical properties of friction stir–welded dissimilar aluminium alloy and titanium butt…
2019
A butt joint configuration of AA6061–pure Ti was welded using friction stir welding (FSW) with an assisted cooling and heating conditions, aiming to attain a flawless joint. Cooling-assisted friction stir welding (CFSW) was carried out with a different cooling medium such as CO2, compressed air and water at controlled flow rate. However, heating-assisted friction stir welding (HFSW) was performed with heating source of GTAW torch just before FSW tool at different current density. Prepared specimens were subjected to optical microscopy (OM), scanning electron microscopy (SEM) and electrodischarge spectroscopy (EDS) for microstructural characterizations. The tensile strength and microhardness…
Las coaliciones tarsianas como causa de dolor en el pie infantil: opciones terapéuticas
2022
Resumen Antecedentes y objetivo La coalicion tarsiana puede ser causa de dolor de medio-retropie en ninos mayores. El objetivo es analizar los tipos de coalicion tratados en nuestro centro hospitalario de 2010 a 2019 asi como el tratamiento realizado. Material y metodo Estudio observacional, descriptivo y retrospectivo de 18 pacientes con coalicion tarsiana, 8 mujeres y 10 hombres, de 11,9 ± 2,6 anos de edad. Se recogieron datos epidemiologicos, hallazgos clinicos y de pruebas de imagen y tratamiento realizado. Resultados Se revisaron 25 pies (38,8% bilaterales). El principal sintoma fue el dolor. Un 64% se asociaba a pie plano-valgo. El 52% se localizaba en la articulacion calcaneo-escafoi…
Effect of static foot posture on the dynamic stiffness of foot joints during walking
2018
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…
Variability of the Dynamic Stiffness of Foot Joints: Effect of Gait Speed
2019
Background:Comparison of dynamic stiffness of foot joints was previously proposed to investigate pathologic situations with changes in the properties of muscle and passive structures. Samples must be controlled to reduce the variability within groups being compared, which may arise from different sources, such as gait speed or Foot Posture Index (FPI).Methods:Variability in the measurement of the dynamic stiffness of ankle, midtarsal, and metatarsophalangeal joints was studied in a controlled sample of healthy men with normal FPI, and the effect of gait speed was analyzed. In experiment 1, dynamic stiffnesses were obtained in three sessions, five trials per session, for each participant, ta…
3D characterisation of the dynamics of foot joints of adults during walking. Gait pattern identification
2017
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.
Maintenance of Integrity of Upper Facet Joints during Simulated Percutaneous Pedicle Screw Insertion Using 2D versus 3D Planning
2019
Background No studies have directly and quantitatively compared two-dimensional (2D) and three-dimensional (3D) planning as applied during conventional percutaneous or navigated percutaneous pedicle screw placement. Study Aims This lumbar pedicle-based stabilization simulation study aimed to investigate the risk of upper facet joint violation (FJV) during posterior percutaneous pedicle screw placement with conventional 2D planning of screw implantation (as a model for fluoroscopically guided screws) compared with 3D planning (as used with navigation techniques). Methods The placement of monosegmental lumbar pedicle screws using the data sets of 250 consecutive patients was simulated. Conve…
Kinematics reduction applied to the comparison of highly-pronated, normal and highly-supinated feet during walking
2019
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…
Hand trajectory formation during whole body reaching movements in man.
1998
End-effector trajectory formation was studied during a reaching movement using the whole body. The movements of various parts of the body were measured with the optoelectronic ELITE system. Wrist reaching movement paths showed noticeable curvatures. The analysis of various marker onset latencies revealed that the wrist was the last to move, always after the head, knee or trunk, suggesting a subordinate role of the focal component with respect to the primary role of the equilibrium component. These results suggest that reaching wrist movements are subjected to whole-body equilibrium constraints in addition to constraints placed upon end-effector kinematics or the dynamic optimization of uppe…
Radiofrequency Ablation for Chronic Lumbar Zygapophyseal Joint Pain Using a V-Shaped Active Tip Needle: An Observational Retrospective Study
2023
Giuliano Lo Bianco,1,2 Giovanni Misseri,2 Agnes R Stogicza,3 Gregoretti Cesare,2,4 Sean Li,5 Miles Day,6 David J Kennedy,7 Michael E Schatman8,9 1Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy; 2Anesthesiology and Pain Department, Fondazione Istituto âG. Giglioâ, Cefalù, Palermo, Italy; 3Anesthesia and Pain, Saint Magdolna Private Hospital, Budapest, Hungary; 4Department of Surgical, Oncological and Oral Science (Di.Chir.On.S.), University of Palermo, Palermo, Italy; 5National Spine and Pain Centers, Shrewsbury, NJ, USA; 6Pain Research, The Pain Center at Grace Clinic, Texas Tech University HSC, Lubbock, TX, USA; 7Department of PM&R, V…
A New Myohaptic Device to Assess Wrist Function in the Lab and in the Clinic – The Wristalyzer
2008
Wristalyzer is a portable robotic device combining haptic technology with electromyographic assessment. It allows to assess wrist motion in physiological and pathological conditions by applying loads and mechanical oscillations, taking into account the ergonomy and the angular positioning of the joints. The wristalyzer works in a free or loaded mode for assessment of metrics of motion and tremor, analyzes the behavior of the wrist joints and the associated muscle activities during delivery of mechanical oscillations, estimates the maximal voluntary contraction, assesses automatically the impedance of the wrist for assessment of rigidity or spasticity. Position, torques and electromyographic…