Search results for "Quadric"
showing 10 items of 143 documents
Posterior compartment of the lower leg reconstruction with free functional rectus femoris transfer after sarcoma resection.
2009
A 72-year-old man with the third recurrence of a low-grade liposarcoma of the right lower leg came to our attention seeking limb-salvage surgery. The tumour was removed en bloc with all the superficial posterior compartment of the leg. Appropriate foot flexion was restored by means of a free-functional rectus femoris musculocutaneous flap harvested from the ipsilateral thigh. The patient was kept on a postoperative splint for 6 weeks. Three months after the operation, clinical and elecromyographic signs of reinnervation were observed. The patient was able to walk, run and climb stairs and no donor-site morbidity was observed. Thigh extension was rated M4, comparable to the contralateral thi…
Changes in cortico-spinal excitability following uphill versus downhill treadmill exercise
2017
International audience; An acute bout of aerobic exercise induces neuroplasticity in the motor cortex. Moreover, paired associative stimulation (PAS) is known to induce neuroplasticity in M1. However, the possible influence of the type of exercise on the neuroplastic changes remains unknown. The present study investigated the effects of two different modes of muscle contraction produced during locomotor exercise on changes in corticospinal (CS) excitability. Subjects performed two 30-min treadmill exercises at an intensity corresponding to 60% of their maximal heart rate with either a +10% (uphill) or -10% (downhill) slope. These exercises were followed or not by paired associative stimulat…
The effects of skin and core tissue cooling on oxygenation of the vastus lateralis muscle during walking and running
2016
Skin and core tissue cooling modulates skeletal muscle oxygenation at rest. Whether tissue cooling also influences the skeletal muscle deoxygenation response during exercise is unclear. We evaluated the effects of skin and core tissue cooling on skeletal muscle blood volume and deoxygenation during sustained walking and running. Eleven male participants walked or ran six times on a treadmill for 60 min in ambient temperatures of 22°C (Neutral), 0°C for skin cooling (Cold 1), and at 0°C following a core and skin cooling protocol (Cold 2). Difference between oxy/deoxygenated haemoglobin ([diffHb]: deoxygenation index) and total haemoglobin content ([tHb]: total blood volume) in the vastus lat…
Efficient Pruning LMI Conditions for Branch-and-Prune Rank and Chirality-Constrained Estimation of the Dual Absolute Quadric
2014
International audience; We present a new globally optimal algorithm for self- calibrating a moving camera with constant parameters. Our method aims at estimating the Dual Absolute Quadric (DAQ) under the rank-3 and, optionally, camera centers chirality constraints. We employ the Branch-and-Prune paradigm and explore the space of only 5 parameters. Pruning in our method relies on solving Linear Matrix Inequality (LMI) feasibility and Generalized Eigenvalue (GEV) problems that solely depend upon the entries of the DAQ. These LMI and GEV problems are used to rule out branches in the search tree in which a quadric not satisfy- ing the rank and chirality conditions on camera centers is guarantee…
Symmetric locally free resolutions and rationality problems
2022
We show that the birationality class of a quadric surface bundle over $\mathbb{P}^2$ is determined by its associated cokernel sheaves. As an application, we discuss stable-rationality of very general quadric bundles over $\mathbb{P}^2$ with discriminant curves of fixed degree. In particular, we construct explicit models of these bundles for some discriminant data. Among others, we obtain various birational models of a nodal Gushel-Mukai fourfold, as well as of a cubic fourfold containing a plane. Finally, we prove stable irrationality of several types of quadric surface bundles.
Effects of different recovery parameters during resistance training exercices
2012
The high frequency of resistance training sessions induces heavy strain and fatigue phenomenon, which could be prejudicial for subsequent performance. In this context, it appears necessary to apply proper recovery strategies in order to improve the athlete’s ability to regain an adequate working state for subsequent training.Active recovery is widely described in the literature as the most efficient method for this purpose. It consists in low-intensity exercises, which could improve metabolites washout by increasing peripheral blood flow. To our knowledge, active recovery is usually applied globally, with exercises involving the whole body (light pedalling or running) but little is known re…
Dynamics of Quadriceps Muscles during Isometric Contractions : Velocity-Encoded Phase Contrast MRI Study
2021
Objective: To quantify the spatial heterogeneity of displacement during voluntary isometric contraction within and between the different compartments of the quadriceps. Methods: The thigh muscles of seven subjects were imaged on an MRI scanner while performing isometric knee extensions at 40% maximal voluntary contraction. A gated velocity-encoded phase contrast MRI sequence in axial orientations yielded tissue velocity-encoded dynamic images of the four different compartments of the thigh muscles (vastus lateralis (VL), vastus medialis (VM), vastus intermedius (VI), and rectus femoris (RF)) at three longitudinal locations of the proximal–distal length: 17.5% (proximal), 50% (middle), and 7…
Postmenopausal women with osteopenia and a healed wrist fracture have reduced physical function and quality of life compared to a matched, healthy co…
2014
Background: Fractures lead to reduced physical function and quality of life (QOL), but little is known about postmenopausal women with osteopenia and a healed wrist fracture. The purpose was to evaluate physical function in terms of quadriceps strength, dynamic balance, physical capacity and QOL in postmenopausal women with osteopenia and a healed wrist fracture compared to a matched, healthy control group with no previous fracture. Methods: Eighteen postmenopausal women with osteopenia (patients) (mean age 59.1 years, range 54 – 65) and a healed wrist fracture were matched to 18 healthy control subjects on age (mean age 58.5 years, range 51 – 65), height, weight and body mass index (BMI). …
A 3-D marker-free system for the analysis of movement disabilities--an application to the legs.
2001
The aim of this paper is to describe an approach allowing the analysis of human motion in three-dimensional (3-D) space. The system that we developed is composed of three charge-coupled-device cameras that capture synchronized image sequences of a human body in motion without the use of markers. Characteristic points belonging to the boundaries of the body in motion are first extracted from the initial images. Two-dimensional superquadrics are then adjusted on these points by a fuzzy clustering process. After that, the position of a 3-D model based on a set of articulated superquadrics, each of them describing a part of the human body, is reconstructed. An optical flow process allows the pr…
Progressive active mobilization with dose control and training load in critically ill patients (PROMOB): Protocol for a randomized controlled trial
2020
The dose of progressive active mobilization is still uncertain. The purpose of this study is to identify if the addition of a protocol of progressive active mobilization with dose and training load control to usual care is effective in reducing the length of stay in intensive care unit (ICU) and the improvement of the functioning, incidence of ICU-acquired weakness (ICUAW), mechanical ventilation duration and mortality rate in patients hospitalized in ICU. It is Double-blind randomised clinical trial. The setting for this trial will be medical and surgical ICU of a university hospital. The study participants will be 118 patients aged> 18 years admitted to ICU for less than 72 hours. Partici…