Search results for "biomechanics"

Sind winkelstabile Plattensysteme mit elastischen Eigenschaften für die Stabilisierung der Oberarmkopffraktur vorteilhaft? / Eine in-vitro biomechani…

2004

AbstractWinkelstabile Platten werden mit zunehmender Häufigkeit zur Stabilisierung von Oberarmkopfbrüchen verwendet. Rigide Implantate führen bei osteoporotischen Knochenverhältnissen u. U. aber häufiger zum Versagen. Um den Effekt der Implantatelastizität zu beurteilen wurden in einer in-vitro Studie die biomechanischen Eigenschaften eines rigiden und eines elastischen winkelstabilen Plattensystems vergleichend analysiert. An 8 Humeruspaaren wurde eine instabile subkapitale Fraktur simuliert. Die Proben wurden axial- und torsions-belastet. Analysiert wurden die Steifigkeit, das Setzverhalten unter Dauerlast und die Versagensbelastung.Das elastische Plattensystem kennzeichnete sich durch ei…

Biomechanical Study of the Osteoporotic Spine Fracture: Optical Approach

2021

Background and objectives: Osteoporotic spine fractures represent a significant factor for decreasing quality of life in the elderly female population. Understanding the mechanisms involved in producing these fractures can improve their prevention and treatment. This study presents a biomechanical method to produce a vertebral fracture, conducted on a human spine segment, observing the displacements and strains in the intervertebral disc, endplate, and vertebral body. Materials and Methods: We performed two tests, one corresponding to an extension loading, and the second to an axial loading. Results: The maximum displacement in the target vertebral body presented higher values in the case o…

Osteosynthese am proximalen Humerus mittels winkelstabiler Platte oder Doppelplatte: eine vergleichende biomechanische Untersuchung / Angle-fixed pla…

2008

Internal fixation of fractures of the proximal humerus needs a high stability of fixation to avoid secondary loss of fixation. This is especially important in osteoporotic bone. In an experimental study, the biomechanical properties of the angle-fixed Philos plate (internal fixator) and a double-plate osteosynthesis using two one-third tubular plates were assessed. The fracture model was an unstable three-part fracture (AO type B2). Eight pairs of human cadaveric humeri were submitted to axial load and torque. In the first part of the study, it was assessed to which degree the original stiffness of the humeri could be restored after the osteotomy by the osteosynthesis procedure. Subsequentl…

Stress distribution in fixed mandibular prostheses fabricated by CAD/CAM and conventional techniques: Photoelastic and strain gauge analyses

2019

Made available in DSpace on 2020-12-12T00:55:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-01 The aim of this study was to evaluate the distribution of stress in complete fixed mandibular prostheses with infrastructures (IE) fabricated with different materials and techniques, under compressive force. A model of an edentulous mandible, which received five 4x11 mm external hexagon implants between the mental foramens, was fabricated. The groups were divided into: Group I - IE in nickel-chromium with an acrylic resin occlusal coating; Group II - IE in nickel-chromium with a ceramic occlusal coating; Group III - IE milled in zirconia with a ceramic coating. For the photoelastic m…

A review on biomechanics of the hallux valgus pathology and its surgical treatments

2021

Abstract The present paper aims at an interdisciplinary field, regarding biomechanics aspects of the Hallux Valgus, which is a frequent deformity in our days. Owing to the importance of the study theme and the social impact, we consider it very important that the state of the art should be as detailed as possible, due to this condition being frequent in women and older people. The review will target recent research of the biomechanics of the foot, the test subjects being in normal conditions and also patients affected by Hallux valgus deformities; likewise, it will define important geometrical elements, which are required for the engineering approach of the issue. As well, the 3D modelling …

A Laboratory for Biomechanical Analysis of the Traumatology of Ski Falls

2009

Gait Symmetry Analysis in Patients after Treatment of Pilon Fractures by the Ilizarov Method

2021

The aim of this study was to comprehensively assess the gait parameters in patients who had undergone treatment of pilon fractures by the Ilizarov method. We analyzed gait parameters in patients who had undergone treatment for pilon fractures by the Ilizarov method

Force-Time Characteristics and Running Velocity of Male Sprinters during the Acceleration Phase of Sprinting

1988

Abstract In an effort to investigate the force-time characteristics during the acceleration phase of the sprint start, eight male sprinters were used as subjects. Runs up to 3 m were analyzed from film, and force-time parameters were measured on a force platform. In a starting stance the reaction time of the group was .118 ± .016 s and the force production lasted .342 ± .022 s. The maximal resultant force at the moment of maximal horizontal force was 19.3 ± 2.2 N x kg1, and the direction of the force was 32 ± 7°. In the very last instant before leaving the blocks the velocity of the center of gravity was 3.46 ± .32 m x s−1. In the first contact after leaving the blocks there was a braking p…

Force-, power-, and elasticity-velocity relationships in walking, running, and jumping

1980

Ground reaction forces and mechanical power were investigated when the subjects walked normally, while they were racing or running at four speeds, and when they performed the running long jump take-off. In addition, the apparent spring constants of the support leg in eccentric and concentric phases were investigated at the four running speeds, during the running long jump take-off, and in the triple jump. Six club level track and field athletes, four national level long jumpers, and six national level triple jumpers took part in the study. Cinematographic technique and a mathematical model of hopping (Alexander and Vernon 1975) were employed in the analysis. Force and power values were foun…

Stiff landings are associated with increased ACL injury risk in young female basketball and floorball players

2016

Background: Few prospective studies have investigated the biomechanical risk factors of anterior cruciate ligament (ACL) injury. Purpose: To investigate the relationship between biomechanical characteristics of vertical drop jump (VDJ) performance and the risk of ACL injury in young female basketball and floorball players. Study Design: Cohort study; Level of evidence, 3. Methods: At baseline, a total of 171 female basketball and floorball players (age range, 12-21 years) participated in a VDJ test using 3-dimensional motion analysis. The following biomechanical variables were analyzed: (1) knee valgus angle at initial contact (IC), (2) peak knee abduction moment, (3) knee flexion angle at …