Search results for "BIOMECHANICS"
showing 10 items of 281 documents
Determination of the Optimal Saddle Height for Leisure Cycling (P188)
2008
Several studies have been done on road racing cycling and triathlon to determine the optimal saddle height (LINF) in terms of efficiency. However, cycling is becoming nowadays not only a popular sport but also a mass mean of transport were comfort takes priority over efficiency. The aim of this study is to determine an optimal saddle height (LINF) to improve comfort in leisure cycling. Five male subjects (height mean=172.2 cm, std=1.34 cm; crotch height mean=81.25cm, std=0.88cm) tested 9 prototypes of the company ORBEA with 3 levels of LINF. The test consisted in one hour cycling in lab conditions and four different techniques were used to evaluate the LINF: 3-D movement analysis was used t…
Effect of suturing the femoral portion of a four-strand graft during an ACL reconstruction
2014
Purpose A suture passed along the part of the graft that will be inserted into the femoral tunnel is widely used by surgeons, because it could prevent the graft sliding on the femoral fixation device during pulling from the tibial side. The aim of this study was to evaluate the biomechanical effects of suturing the intratunnel femoral part of the graft during an anterior cruciate ligament (ACL) reconstruction. Methods Bovine digital extensor tendons and tibias were harvested from 20 fresh-frozen mature bovine knees ranging in age from 18 to 24 months. Quadruple-strand bovine tendons were passed through the tibial tunnel and secured distally with a bioabsorbable interference screw. In one ha…
Screw fixation of radial head fractures: Compression screw versus lag screw—A biomechanical comparison
2009
Abstract Introduction Secondary loss of reduction and pseudarthrosis due to unstable fixation methods remain challenging problems of surgical stabilisation of radial head fractures. The purpose of our study was to determine whether the 3.0 mm Headless Compression Screw (HCS) provides superior stability to the standard 2.0 mm cortical screw (COS). Materials and methods Eight pairs of fresh frozen human cadaveric proximal radii were used for this paired comparison. A standardised Mason II-Fracture was created with a fragment size of 1/3 of the radial head's articular surface that was then stabilised either with two 3.0 mm HCS (Synthes) or two 2.0 mm COS (Synthes) according to a randomisation …
Motor and Cognitive Performance in Patients with Liver Cirrhosis with Minimal Hepatic Encephalopathy
2020
Minimal hepatic encephalopathy (MHE) is associated with mild cognitive impairment and frailty. This study aims to identify cognitive and motor differences in cirrhotic patients with and without MHE, and the correlations between motor signs and cognitive performance. Gait, balance, hand strength and motor speed performance were evaluated in 66 cirrhotic patients (38 without and 28 with MHE, according to the Psychometric Hepatic Encephalopathy Score (PHES). Cognitive performance was measured with the Mini-Mental State Examination, Verbal Fluency Test, Aprendizaje Verbal España-Complutense Test (TAVEC), Wechsler Adult Intelligence Scale III, Hamilton Depression and Anxiety Rating Scale and Fun…
Treadmill and Running Speed Effects on Acceleration Impacts: Curved Non-Motorized Treadmill vs. Conventional Motorized Treadmill
2021
An increase in the popularity of running can be seen over the last decades, with a large number of injuries on it. Most of the running injuries are related to impact accelerations and are due to overuse. In order to reduce the risk of injury or to improve performance and health new treadmill designs have been created, as it can be the curved non-motorized treadmill. The aim of this study was to analyse impact accelerations, spatio-temporal parameters and perceptual differences while running on curved non-motorized treadmill (cNMT) compared to motorized treadmill (MT) at different speeds. Therefore, 27 recreational runners completed two tests consisting of 10 min warm-up and three bouts of 8…
A biomechanical evaluation of methods of distal humerus fracture fixation using locking compression plates versus conventional reconstruction plates.
2004
OBJECTIVES To examine the biomechanical behavior of 2 techniques of double-plate osteosynthesis for fractures of the adult distal humerus using conventional reconstruction plates and locking compression plates. DESIGN Basic science study. SETTING Experimental in vitro study. PATIENTS/PARTICIPANTS Forty fresh-frozen human distal humeri specimens. INTERVENTION Four matched groups with 10 humeri each, median age 74 years (46-95), were created using similar bone mineral density values. Two standard configurations of double-plate osteosynthesis (dorsal or 90 degrees configuration) with either conventional reconstruction plates or locking compression plates were studied for biomechanical properti…
Trunk kinematics during cross country sit-skiing ergometry: Skiing strategies associated to neuromusculoskeletal impairment
2016
Since trunk function plays a major role in propulsion in sit-skiers and athletes belonging to distinct classes have different abilities to control trunk muscles, the aim of this study is to evaluate how athletes personalized their skiing strategy to compensate their impairment and improve skiing effectiveness. Sixteen Paralympic sit-skiers belonging to different classes volunteered as participant. Each athlete executed two double poling tests on a ski ergometer at the maximal speed he/she can reach and the best, identified as the fastest, was considered in the analysis. A set of two passive reflective markers was used for kinematic analysis: the first marker was placed on the athlete should…
Similar biomechanical properties of four tripled tendon graft models for ACL reconstruction
2021
Abstract Purpose The present study tested and compared the biomechanical properties of four different triplicate graft tendon techniques. Methods 32 tripled tendons from the common extensor muscle of bovine fingers were tested on a material testing machine, passing the end loop over a metal rod of a clevis connected to the load cell on the upper side, and fixing the lower end to a clamp. The samples were divided into four groups: (A) tripled with a free end sutured only to one of the two fixed bundles (B) tripled with a free end positioned between the two fixed strands and sutured to both (C) tripled with an S-shape and all the three strands sutured together at the upper and lower extremiti…
Impact of Aortic Stenosis on Myofiber Stress: Translational Application of Left Ventricle-Aortic Coupling Simulation
2020
The severity of aortic stenosis (AS) has traditionally been graded by measuring hemodynamic parameters of transvalvular pressure gradient, ejection jet velocity, or estimating valve orifice area. Recent research has highlighted limitations of these criteria at effectively grading AS in presence of left ventricle (LV) dysfunction. We hypothesized that simulations coupling the aorta and LV could provide meaningful insight into myocardial biomechanical derangements that accompany AS. A realistic finite element model of the human heart with a coupled lumped-parameter circulatory system was used to simulate AS. Finite element analysis was performed with Abaqus FEA. An anisotropic hyperelastic mo…
The proprioceptive insole: A therapeutic aid for the diabetic patient in prevention?
2021
The diabetic foot represents one of the most common complications among patients with type 2 diabetes mellitus. Prevention of the diabetic foot is therefore essential both to ensure the patient a better quality of life and to reduce the costs borne by the NHS and this requires a multidisciplinary approach. It is important to underline that the major complications of the diabetic foot are due to biomechanical, vascular and neuropathic alterations. Diabetic patients are less likely to perform physical exercises and tend to walk less, adopting compensatory strategies based on the type of terrain they find. They walk slower, tend to take shorter steps with a wider base of support, have limited …