Effects of ankle and hip muscle fatigue on postural sway and attentional demands during unipedal stance

AbstractThe effect of muscle fatigue on quiet standing is equivocal, including its duration/recovery and whether it leads to an increase in attentional demands. The purpose of this study was to assess the effects of ankle and hip muscle fatigue on postural sway and simple reaction time during a unipedal task. Two groups of 14 young adults (mean age=22.50±3.23) had to stand on their dominant leg for 30-s trials before and after fatigue of hip or ankle flexors and extensors. Half of the unipedal trials were performed in a dual-task condition where subjects, in addition to standing, had to respond verbally to an auditory stimulus. Sway area, and sway variability and velocity in the AP and ML planes were calculated using center of pressure data obtained from a force platform. Voice reaction time was recorded seated and during the dual-task condition to assess attentional demands. A main effect of fatigue was found for AP sway variability (p=0.027), AP sway velocity (p=0.017) and ML sway velocity (p=0.004). Both groups showed increased sway velocity in both directions and in reaction time during the dual-task condition (p<0.001), but reaction time did not increase with fatigue. A group by fatigue interaction was found significant for ML sway velocity (p=0.043). Results suggest that hip and ankle fatigue affected postural control in the fatigued plane (AP) but only hip fatigue affected postural control in the non-fatigued plane (ML sway velocity). However, fatigue did not lead to an increase in attentional demands and increased AP and ML sway velocity had recovered within 30min

Effects of fatiguing isometric and isokinetic ankle exercises on postural control while standing on firm and compliant surfaces

Abstract Background Fatiguing exercises used across studies to induce alterations in postural control are diverse and may explain the different findings reported. This study aimed to compare the effects of two types of fatiguing plantarflexion exercises on postural control on a firm and a compliant surface. Ten healthy young men (29 ± 4 years) were asked to stand as steadily as possible for 30 s, blindfolded with feet together, on a firm and a compliant surface before and immediately after an isometric and an isokinetic fatiguing exercise. Results Maximal force reduction due to fatigue was found significant but similar between exercises. No significant difference was found between the fatiguing exercises on all Center of Pressure (CoP) parameters. Both fatiguing exercises induced increases in CoP excursion area, CoP variability and CoP velocity in both planes (antero-posterior, mediolateral) on the compliant surface. On the firm surface, both fatiguing exercises only induced increases in CoP variability and CoP velocity in the fatigued plane (antero-posterior). Conclusions Isometric and isokinetic fatiguing exercises, when producing a similar level of force reduction, induce similar decreases in postural control. The effects of fatigue on postural control in healthy young men are more pronounced when standing on a compliant surface, i.e. when proprioceptive information at the ankle is altered.</p

Estimation of the tritium retention in ITER tungsten divertor target using macroscopic rate equations simulations

International audienceBased on macroscopic rate equation simulations of tritium migration in an actively cooled tungsten (W) plasma facing component (PFC) using the code MHIMS (migration of hydrogen isotopes in metals), an estimation has been made of the tritium retention in ITER W divertor target during a non-uniform exponential distribution of particle fluxes. Two grades of materials are considered to be exposed to tritium ions: an undamaged W and a damaged W exposed to fast fusion neutrons. Due to strong temperature gradient in the PFC, Soret effect's impacts on tritium retention is also evaluated for both cases. Thanks to the simulation, the evolutions of the tritium retention and the tritium migration depth are obtained as a function of the implanted flux and the number of cycles. From these evolutions, extrapolation laws are built to estimate the number of cycles needed for tritium to permeate from the implantation zone to the cooled surface and to quantify the corresponding retention of tritium throughout the W PFC

Incidence and outcomes of infective endocarditis after transcatheter aortic valve implantation versus surgical aortic valve replacement

International audienceObjectives: Transcatheter aortic valve implantation (TAVI) is an alternative to surgical aortic valve replacement (AVR) in aortic stenosis (AS). Infective endocarditis (IE) in patients with prosthetic heart valves is associated with significant morbidity and mortality. Data on the incidence, risk factors, and outcomes of IE after TAVI are conflicting. We evaluated these issues in patients with percutaneous TAVI vs. isolated surgical AVR (SAVR) at a nationwide level.Methods: Based on the administrative hospital discharge database, the study collected information for all patients with aortic stenosis treated with AVR in France between 2010 and 2018.Results: A total of 47 553 patients undergoing TAVI and 60 253 patients undergoing isolated SAVR were identified. During a mean follow-up of 2.0 years (median (25th to 75th percentile) 1.2 (0.1-3.4) years), the incidence rates of IE were 1.89 (95% confidence interval (CI) 1.78-2.00) and 1.40 (95% CI 1.34-1.46) events per 100 person-years in unmatched TAVI and SAVR patients, respectively. In 32 582 propensitymatched patients (16 291 with TAVI and 16 291 with SAVR), risk of IE was not different in patients treated with TAVI vs. SAVR (incidence rates of IE 1.86 (95% CI 1.70-2.04) %/year vs 1.71 (95% CI 1.58-1.85) %/year respectively, relative risk (RR) 1.09, 95% CI 0.96-1.23). In these matched patients, total mortality was higher in TAVI patients with IE (43.0% 95% CI 37.3-49.3) than in SAVR patients with IE (32.8% 95% CI 28.6 -37.3; RR 1.32, 95% CI 1.08-1.60).Discussion: In a nationwide cohort of patients with AS, treatment with TAVI was associated with a risk of IE similar to that following SAVR. Mortality was higher for patients with IE following TAVI than for those with IE following SAVR. (C) 2020 European Society of Clinical Microbiology and Infectious Diseases

Additional file 4 of Assessing the feasibility of a clinical trial to evaluate an advanced practice physiotherapy model of care in chronic pain management: a feasibility study

Additional file 4. Quality of care for patients with chronic pain

Additional file 2 of Assessing the feasibility of a clinical trial to evaluate an advanced practice physiotherapy model of care in chronic pain management: a feasibility study

Additional file 2. Advanced Practice Physiotherapist Competency Evaluation Form

Additional file 1 of Assessing the feasibility of a clinical trial to evaluate an advanced practice physiotherapy model of care in chronic pain management: a feasibility study

Additional file 1. Modified SPIRIT checklist

Additional file 3 of Assessing the feasibility of a clinical trial to evaluate an advanced practice physiotherapy model of care in chronic pain management: a feasibility study

Additional file 3. Advanced practice physiotherapist fidelity checklist