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Soft tissue artefact (STA), i.e. the motion of the skin, fat and muscles gliding on the underlying bone, may lead to a marker position error reaching up to 8.7cm for the particular case of the scapula. Multibody kinematics optimisation (MKO) is one of the most efficient approaches used to reduce STA. It consists in minimising the distance between the positions of experimental markers on a subject skin and the simulated positions of the same markers embedded on a kinematic model. However, the efficiency of MKO directly relies on the chosen kinematic model. This paper proposes an overview of the different upper limb models available in the literature and a discussion about their applicability to MKO. The advantages of each joint model with respect to its biofidelity to functional anatomy are detailed both for the shoulder and the forearm areas. Models capabilities of personalisation and of adaptation to pathological cases are also discussed. Concerning model efficiency in terms of STA reduction in MKO algorithms, a lack of quantitative assessment in the literature is noted. In priority, future studies should concern the evaluation and quantification of STA reduction depending on upper limb joint constraints.

Soft tissue artefacts (STA) introduce errors in joint kinematics when using cutaneous markers, especially on the scapula. Both segmental optimisation and multibody kinematics optimisation (MKO) algorithms have been developed to improve kinematics estimates. MKO based on a chain model with joint constraints avoids apparent joint dislocation but is sensitive to the biofidelity of chosen joint constraints. Since no recommendation exists for the scapula, our objective was to determine the best models to accurately estimate its kinematics. One participant was equipped with skin markers and with an intracortical pin screwed in the scapula. Segmental optimisation and MKO for 24-chain models (including four variations of the scapulothoracic joint) were compared against the pin-derived kinematics using root mean square error (RMSE) on Cardan angles. Segmental optimisation led to an accurate scapula kinematics (1.1° ≤ RMSE ≤ 3.3°) even for high arm elevation angles. When MKO was applied, no clinically significant difference was found between the different scapulothoracic models (0.9° ≤ RMSE ≤ 4.1°) except when a free scapulothoracic joint was modelled (1.9° ≤ RMSE ≤ 9.6°). To conclude, using MKO as a STA correction method was not more accurate than segmental optimisation for estimating scapula kinematics.

Resume Introduction Les plasties anterolaterales (PAL) sont utilisees pour diminuer le risque de rupture iterative apres reconstruction du ligament croise anterieur (LCA) chez les patients a risque. Ces plasties ajoutent un geste a la greffe isolee du LCA qui peut augmenter le temps operatoire et perturber les suites operatoires. L’objectif de cette etude etait d’evaluer le taux de complications precoces. L’hypothese etait que les plasties anterolaterales associees a une plastie du LCA n’augmentent pas le taux de complications par rapport aux plasties isolees. Materiel et methodes Il s’agit d’une etude multicentrique, prospective portant sur 392 patients dont 70 % d’hommes, âges en moyenne de 29,9 ans, operes d’une plastie du LCA avec PAL associee. L’ensemble des evenements indesirables ont ete releves. Resultats La duree moyenne d’hospitalisation a ete de 2 jours avec 46 % de chirurgie ambulatoire. La marche etait acquise en 27 jours en moyenne avec un avantage pour les patients operes avec une technique aux ischio-jambiers. Le taux de complication postoperatoire precoce etait de 12 % dont 1,7 % specifiques a la PAL : douleur, hematome, raideur en flexion et extension, infection. Cinq pour cent de re-interventions ont ete observees la premiere annee avec une majorite d’arthrolyse pour flexum. Le taux de rupture iterative etait de 2,8 % a l’issue de la premiere annee. Discussion Les complications des PAL associees aux plasties intra-articulaires ne sont pas plus importantes que pour les plasties intra-articulaires isolees, sans augmentation du taux d’infection ni de raideur. Les complications liees a la PAL sont faibles, 1,7 %, et sont a mettre en rapport avec des erreurs techniques de fixation ayant engendre des conflits avec les parties molles laterales. Niveau de preuve Niveau IV, etude multicentrique prospective.

International audience; The modeling and feature extraction of human gait motion are crucial in biomechanics studies, human localization and robotics applications. Recent studies in pedestrian navigation aim at extracting gait features based on the data of low-cost sensors embedded in handheld devices such as smartphones. The general assumption in Pedestrian Dead Reckoning (PDR) strategy for navigation application is that the presence of a device in hand does not impact the gait symmetry and that all steps are identical. This hypothesis, which is used to estimate the traveled distance, is investigated in this paper with an experimental study. Ten healthy volunteers participated in motion lab tests with a 0.190 kg device in hand. Several walking trials with different device carrying modes and several gait speeds were performed. For a fixed walking speed, it is shown that the steps differ in their duration when holding a mass equivalent to a smartphone mass, which invalidates classical symmetry hypothesis in PDR step length modeling. It is also shown that this hypothesis can lead to a 2.5 to 6.3% error on the PDR estimated traveled distance for the different walking trials.

12th ICBEN Congress on Noise as a Public Health Problem, ZURICH, SUISSE, 18-/06/2017 - 22/06/2017; Several complaints were expressed by some residents of French wind farms, putting forward infrasound and low frequency noise (ILFN) as a potential source of annoyance. Since available information on this subject are multiple and often contradictory, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) was mandated by the French Ministry of Environment to conduct an independent collective expertise on the evaluation of the health effects related to ILFN from wind farms. The objective was first to produce a complete review on auditory and non auditory health effects due to WTN, focusing on ILFN ; then, to collect experimental ILFN data from some wind farms in order to compare with data from the literature ; and finally to propose some improvements in the process of wind farm assessment or of impact studies, concerning ILFN. This paper presents the main results and conclusions of this expertise.

International audience; 12 The primary role of the shoulder joint in tennis forehand drive is at the expense of the 13 loadings undergone by this joint. Nevertheless, few studies investigated glenohumeral (GH) 14 contact forces during forehand drives. The aim of this study was to investigate GH 15 compressive and shearing forces during the flat and topspin forehand drives in advanced 16 tennis players. 3D kinematics of flat and topspin forehand drives of 11 advanced tennis 17 players were recorded. The Delft Shoulder and Elbow musculoskeletal model was 18 implemented to assess the magnitude and orientation of GH contact forces during the 19 forehand drives. The results showed no differences in magnitude and orientation of GH 20 contact forces between the flat and topspin forehand drives. The estimated maximal GH 21 contact force during the forward swing phase was 3573 ± 1383 N, which was on average 1.25 22 time greater than during the follow-through phase, and 5.8 times greater than during the 23 backswing phase. Regardless the phase of the forehand drive, GH contact forces pointed 24 toward the anterior-superior part of the glenoid therefore standing for shearing forces. 25 Knowledge of GH contact forces during real sport tasks performed at high velocity may 26 improve the understanding of various sport-specific adaptations and causative factors for 27 shoulder problems. 28 2 29

12th ICBEN Congress on Noise as a Public Health Problem, ZURICH, SUISSE, 18-/06/2017 - 22/06/2017; Objectives: Exposure to aircraft noise has been shown to have adverse effects on health and particularly on sleep. This study aimed to investigate the relationship between aircraft noise exposure and subjective sleep quality in the population living near airports in France. Methods: Sleep interview was made through a questionnaire administered to 1,244 residents of three major French airports: Paris-CDG, Lyon-Saint-Exupéry and Toulouse-Blagnac. For each participant, aircraft noise exposure was estimated at home using noise maps. Logisticregression models were used with adjustment for potential confounders. Results: Aircraft noise exposure was associated with the risk of being a short sleeper (sleep duration £ 6h), and with the feeling of tiredness while awakening in the morning. An increase of 10 dBA in aircraft noise level at night was respectively associated with an OR of 1.66 (95% CI: 1.16 to 2.35) and an OR of 1.24 (95% CI: 1.00 to 1.63). Conclusion: These findings contribute to the overall evidence suggesting that aircraft noise exposure at nighttime may decrease subjective quality of sleep.

Better understanding of the effects of growth on children’s bones and cartilage is necessary for clinical and biomechanical purposes. The aim of this study is to define the 3D geometry of children’s rib cages: including sternum, ribs and costal cartilage. Three-dimensional reconstructions of 960 ribs, 518 costal cartilages and 113 sternebrae were performed on thoracic CT-scans of 48 children, aged four months to 15 years. The geometry of the sternum was detailed and nine parameters were used to describe the ribs and rib cages. A "costal index" was defined as the ratio between cartilage length and whole rib length to evaluate the cartilage ratio for each rib level. For all children, the costal index decreased from rib level one to three and increased from level three to seven. For all levels, the cartilage accounted for 45 to 60% of the rib length, and was longer for the first years of life. The mean costal index decreased by 21% for subjects over three years old compared to those under three (p

Breathing is a vital phenomenon that implies synergy of various anatomical structures that constitute the thorax. Joint physiology remains a relatively poorly-known component of the overall thorax physiology. Quantitative literature related to in vivo thorax kinematics during breathing is scarce. The present work focuses specifically on developing and applying a methodology to reach this goal. The developed method combined processing of CT data obtained at different lung volumes and infographic techniques. Detailed ranges of motion (ROMs) and axes of movement (mean helical axes, MHAs) were obtained at costovertebral joints in 12 asymptomatic subjects; rib ROMs gradually decrease with increasing rib number; lung volume and rib level have a significant influence on rib ROM; MHAs did not differ between rib levels. In addition, the method was applied on a sample of 10 patients with cystic fibrosis. The pathological condition significantly influenced CVJ ROMs while the orientation of the MHAs did not differ. Finally, the sternal displacement, sternal angle variations and sternocostal joints (SCJ at rib1 to 7) kinematics during breathing motion were analyzed. Rib ranges of motion relative to sternum decreased with increasing rib number similarly to CVJ. Orientation of the MHAs did not differ between SCJ levels. A significant linear correlation was demonstrated between sternum vertical displacement and rib ranges of motion at both CVJ and SCJ. The present work substantially contributes to 3D modelling of human thorax in breathing at a joint level both qualitatively and quantitatively, La respiration est un phénomène vital qui implique une synergie entre diverses structures anatomiques qui constituent le thorax. La physiologie articulaire reste un parent pauvre de la physiologie et la littérature concernant la quantification de la cinématique 3D des articulations du thorax durant le mouvement respiratoire est rare. Ce travail se concentre sur le développement et l'application d'une méthodologie permettant de répondre à cet objectif. La méthode développée combine le traitement de données tomodensitométriques réalisées à trois volumes pulmonaires différents et des techniques d'infographies. Les amplitudes (ROMs) et axes de mouvements (axe hélicoïdaux moyen, AHMs) ont été obtenus au niveau des articulations costo-vertébrales de 12 sujets asymptomatiques. En résumé, les amplitudes diminuent graduellement dans les étages inférieurs ; le volume pulmonaire et l'étage costal influencent significativement les amplitudes costales ; l'orientation des AHMs ne diffère pas entre les étages costaux. En complément, la méthode a été appliquée pour un échantillon de 10 patients atteints de mucoviscidose. La condition pathologique influençait significativement les amplitudes de mouvements mais pas l'orientation des AHMs. Enfin, le déplacement sternal, les variations de l'angle sternal et la cinématique des articulations sternocostales a été analysée. Les déplacements angulaires des côtes par rapport au sternum diminuaient dans les étages inférieurs comme au niveau des articulations costo-vertébrales. L'orientation des AHMs des articulations sternocostales ne différait pas entre les étages. Une corrélation linéaire a été mise en évidence entre les déplacements verticaux du sternum et les amplitudes de mouvement costales au niveau costo-vertébral et sternocostal. Ce travail contribue de façon substantielle à la modélisation 3D du thorax humain durant le mouvement respiratoire d'un point de vue qualitatif et quantitatif

International audience; Smoking only partly explains the higher lung cancer incidence observed among socially deprived people. Occupational exposures may account for part of these inequalities, but this issue has been little investigated. We investigated the extent to which smoking and occupational exposures to asbestos, silica and diesel motor exhaust mediated the association between education and lung cancer incidence in men. We analyzed data from a large French population-based case–control study (1976 lung cancers, 2648 controls). Detailed information on lifelong tobacco consumption and occupational exposures to various carcinogens was collected. We conducted inverse probability-weighted marginal structural models. A strong association was observed between education and lung cancer. The indirect effect through smoking varied by educational level, with the strongest indirect effect observed for those with the lowest education (OR = 1.34 (1.14–1.57)). The indirect effect through occupational exposures was substantial among men with primary (OR = 1.22 (1.15–1.30) for asbestos and silica) or vocational secondary education (OR = 1.18 (1.12–1.25)). The contribution of smoking to educational differences in lung cancer incidence ranged from 22 % (10–34) for men with primary education to 31 % (−3 to 84) for men with a high school degree. The contribution of occupational exposures to asbestos and silica ranged from 15 % (10–20) for men with a high school degree to 20 % (13–28) for men with vocational secondary education. Our results highlight the urgent need for public health policies that aim at decreasing exposure to carcinogens at work, in addition to tobacco control policies, if we want to reduce socioeconomic inequalities in the cancer field.

Objective Many workers suffer from musculoskeletal disorders. In France, occupational physicians are able to set job aptitude restrictions obliging employers to adapt the worker's job. The present study explored the impact of job restriction from the point of view of the employees' supervisors. Methods A qualitative study was conducted in 3 public hospitals. 12 focus groups were organized, involving 61 charge nurses and head nurses supervising 1 or more workers restricted for heavy lifting or repetitive movements. Discussions were recorded for qualitative thematic analysis. Results Charge and head nurses complained that aptitude restrictions were insufficiently precise, could not be respected and failed to mention residual capability. A context of personnel cuts, absenteeism and productivity demands entailed a need for polyvalence and reorganization threatening the permanence of adapted jobs. Job restrictions had several negative consequences for the charge and head nurses, including overwork, increased conflict, and feelings of isolation and organizational injustice. Conclusion Protecting the individual interests of workers with health issues may infringe on the interests of their supervisors and colleagues, whose perception of organizational justice may go some way to explaining the support or rejection they show toward restricted workers. This paradox should be explicitly explored and discussed.; L'étude explore l'impact de la restriction d'aptitude du point de vue des supérieurs des employés concernés.

International audience; OBJECTIVES: We investigated the relationship between lung cancer and occupational exposure to welding activity in ICARE, a population-based case-control study. METHODS: Analyses were restricted to men (2276 cases, 2780 controls). Welding exposure was assessed through detailed questionnaires, including lifelong occupational history. ORs were computed using unconditional logistic regression, adjusted for lifelong cigarette smoking and occupational exposure to asbestos. RESULTS: Among the regular welders, welding was associated with a risk of lung cancer (OR=1.7, 95% CI 1.1 to 2.5), which increased with the duration (OR=2.0, 95% CI 1.0 to 3.9 when duration \textgreater10 years), and was maximum 10-20 years since last welding. The risk was more pronounced in case of gas welding (OR=2.0, 95% CI 1.2 to 3.3), when the workpiece was covered by paint, grease, or other substances (OR=2.0, 95% CI 1.2 to 3.4) and when it was cleaned with chemical substances before welding. No statistically significant increase in lung cancer risk was observed among occasional welders. CONCLUSIONS: Although these results should be confirmed, we showed that type of welding and mode of workpiece preparation are important determinants of the lung cancer risk in regular welders

International audience; Objective The objective of the study was to investigate the joint effect of occupational exposure to asbestos, and tobacco and alcohol consumption, on the risk of laryngeal cancer among men. Methods We used data from a large population-based case–control study conducted in France. We estimated two-way and three-way interactions between asbestos exposure (never vs ever exposed), tobacco consumption (\textless20 vs ≥20 pack-years) and alcohol consumption (\textless5 vs ≥5 drinks per day). The interaction on an additive scale was assessed by estimating the relative excess risk due to interaction (RERI) and the attributable proportion due to interaction, and the interaction on a multiplicative scale was assessed by estimating the multiplicative interaction parameter (ψ). Multiplicative interactions were also assessed using fractional polynomials for alcohol drinking, tobacco smoking and asbestos exposure. Results When compared with light-to-moderate smokers and drinkers never exposed to asbestos, the increase in laryngeal cancer risk was smallest among light-to-moderate drinkers and smokers exposed to asbestos (OR=2.23 (1.08 to 4.60)), and highest among heavy smokers and drinkers ever exposed to asbestos (OR=69.39 (35.54 to 135.5)). We found an additive joint effect between asbestos exposure and alcohol consumption (RERI=4.75 (−4.29 to 11.12)), whereas we observed a more than additive joint effect between asbestos exposure and tobacco consumption (RERI=8.50 (0.71 to 23.81)), as well as between asbestos exposure, and tobacco and alcohol consumption (RERI=26.57 (11.52 to 67.88)). However, our results did not suggest any interaction on a multiplicative scale. Conclusions Our results suggest that asbestos exposure, in combination with tobacco and alcohol exposure, accounted for a substantial number of laryngeal cancer cases. Our findings therefore highlight the need for prevention in activities, such as construction work, where exposure to asbestos-containing materials remains

Postpartum hemorrhage affects 5% of parturients. Its prevention relies mainly on the administration of oxytocin derivatives. Carbetocin is a newly available analogue of oxytocin but has a considerable incidence of side effects.; L'hémorragie du post-partum affecte 5 % des parturientes. Sa prévention repose entre autres, sur l'administration de dérivés ocytociques. La carbétocine est une molécule analogue de l'ocytocine, récemment disponible mais qui présente une fréquence d'évènements secondaires importante.

Background In the present work, we aim to transfer to the field of virtual screening the predictiveness curve, a metric that has been advocated in clinical epidemiology. The literature describes the use of predictiveness curves to evaluate the performances of biological markers to formulate diagnoses, prognoses and assess disease risks, assess the fit of risk models, and estimate the clinical utility of a model when applied to a population. Similarly, we use logistic regression models to calculate activity probabilities related to the scores that the compounds obtained in virtual screening experiments. The predictiveness curve can provide an intuitive and graphical tool to compare the predictive power of virtual screening methods. Results Similarly to ROC curves, predictiveness curves are functions of the distribution of the scores and provide a common scale for the evaluation of virtual screening methods. Contrarily to ROC curves, the dispersion of the scores is well described by predictiveness curves. This property allows the quantification of the predictive performance of virtual screening methods on a fraction of a given molecular dataset and makes the predictiveness curve an efficient tool to address the early recognition problem. To this last end, we introduce the use of the total gain and partial total gain to quantify recognition and early recognition of active compounds attributed to the variations of the scores obtained with virtual screening methods. Additionally to its usefulness in the evaluation of virtual screening methods, predictiveness curves can be used to define optimal score thresholds for the selection of compounds to be tested experimentally in a drug discovery program. We illustrate the use of predictiveness curves as a complement to ROC on the results of a virtual screening of the Directory of Useful Decoys datasets using three different methods (Surflex-dock, ICM, Autodock Vina). Conclusion The predictiveness curves cover different aspects of the predictive power of the scores, allowing a detailed evaluation of the performance of virtual screening methods. We believe predictiveness curves efficiently complete the set of tools available for the analysis of virtual screening results. Electronic supplementary material The online version of this article (doi:10.1186/s13321-015-0100-8) contains supplementary material, which is available to authorized users.

OBJECTIVES This study aimed to explore potential risk factors for work-related stress by, detailing working conditions and subjective hardship according to occupational category in health-care staff working with elderly patients. METHODS A cross-sectional descriptive survey was conducted in 105 nursing homes for the elderly in France. Data on nursing home working conditions were collected by occupational physicians. The study population was limited to those in direct contact with the elderly, who were divided into 3 occupational groups defined by qualifications and tasks: housekeepers (HKs), nursing assistants (NAs) and nurses (Ns). Employees answered a questionnaire on their perceived working conditions and vocational training courses. Psychosocial stress was assessed with the Siegrist questionnaire. RESULTS The subjects included 706 HKs, 1,565 NAs and 378 Ns, and the findings showed confusion of tasks and responsibilities in the study population. Verbal abuse by residents was reported by 60.9% of HKs (versus 76.2% of NAs and 76.7% of Ns, p

To describe training given and training desired and to assess the relation between training and perceived hard working conditions as experienced by female staff working in direct contact with the elderly in nursing homes. A transverse descriptive study was conducted with the involvement of 78 occupational physicians, and included staff in 105 nursing homes in the Rhône-Alpes Region of France. Data on training received during the previous 5 years and on training needs were collected from staff by self-administered questionnaire. 1,446 nursing assistants, 667 housekeepers and 348 nurses were included. The most frequent form of training during the previous 5 years was in handling. Staff most frequently desired training in palliative care and psychological approaches to residents. Part-time workers had less frequently had training during the previous 5 years. Staff with daytime hours significantly more often had training in the reception of and activities for the elderly and in hygiene than did night-staff. Almost half of respondents reported very hard working conditions related to physical handling of residents or to the physical deterioration of elderly persons. More than two-thirds reported very hard working conditions related to death. In all occupational categories, respondents who had had training in palliative care less often reported experiencing very hard working conditions related to death. Better adaptation of the training offer to the needs expressed by employees could improve the experience of working conditions in nursing homes. A longitudinal study could assess the impact of training in palliative care on reported hard working conditions related to death.; Objectif : décrire les formations reçues et souhaitées et évaluer la relation entre ces formations et la pénibilité ressentie par le personnel féminin des établissements d'hébergement pour personnes âgées dépendantes (Ehpad). Méthodes. Une étude transversale descriptive a été menée avec la participation de 78 médecins du travail auprès des salariées de 105 Ehpad de la Région Rhône-Alpes. Les informations auprès des salariés ont été recueillies par auto-questionnaire. Résultats. 1 446 agents de soins, 667 agents de service et 348 infirmières ont été inclus. Les formations à la manutention sont celles qui ont été le plus fréquemment suivies au cours des 5 dernières années. Les formations aux soins palliatifs et à l'approche psychologique des résidents sont le plus fréquemment souhaitées par les agents. Plus de deux tiers des sujets décrivent un fort niveau de pénibilité liée à la mort. Quelle que soit la catégorie professionnelle, les sujets ayant bénéficié d'une formation aux soins palliatifs expriment moins fréquemment un fort niveau de pénibilité liée à l'approche de la mort. Conclusion. Une meilleure adaptation des formations proposées aux besoins exprimés des salariées pourrait contribuer à un meilleur vécu des conditions de travail en maison de retraite

Analyzing datasheets for selecting soft soaps for healthcare establishments. For tender for soaps issued by the UNIHA hospital purchasing group, a procedure was drawn up for analyzing datasheets to determine tolerance indicators. Method. This was a two-step procedure. Before the tender was issued, a student pharmacist analyzed and summarized the datasheets. When the call for tender was issued, a specification was drawn up and the tenders received were analyzed by a multidisciplinary group. Results. The 20 datasheets available before the tenders were summarized to provide information on the suppliers, the tests carried out and the composition of the soaps. This summary formed the basis, of tender, for determining the assignment, the specifications and the scoring method (taking account of the tests and down-scoring for particular components). The tests taken into account concerned dermal and ocular tolerance and resistance to microbial contamination. Discussion. This procedure avoided field trials while maintaining a satisfactory standard to ensure the tolerance of the soaps supplied. This study will be followed up by monitoring user cohorts and comparing the datasheet analyses with the field test results for the previous local calls for tender. This approach must be continued to assess the relevance and reproducibility of these criteria and to improve tenders from suppliers., Dans le cadre de l'appel d'offres «savons» passé en groupement de commandes UNIHA (Union des hôpitaux pour les achats), une méthode d'analyse des dossiers techniques a été développée pour identifier des indicateurs prédictifs de bonne tolérance. Méthodes. Les travaux ont été menés en deux temps : en pré campagne, analyse et synthèse des dossiers techniques par un étudiant en pharmacie ; au moment de l'appel d'offres, constitution du cahier des charges et analyse des offres reçues en groupe pluridisciplinaire. Résultats. L'étude de 20 dossiers a abouti à la synthèse d'informations relatives aux fournisseurs, aux tests effectués et aux compositions. Cette synthèse a permis de définir dans le cadre de l'appel d'offres, l'allotissement, le cahier des charges, et les méthodes de notation (prise en compte des tests et notation dégressive des composants). Les tests pris en compte concernaient la tolérance cutanée et oculaire, et la résistance à la contamination microbienne. Discussion. La méthode développée a permis de s'affranchir des essais de terrain tout en gardant un niveau d'exigence satisfaisant pour garantir la fourniture de savons bien tolérés. Ce travail sera complété par un suivi des cohortes d'utilisateurs et par une confrontation de l'analyse des dossiers techniques avec les résultats des essais de terrain des précédents appels d'offres locaux. Le travail doit être poursuivi afin d'évaluer la pertinence et la reproductibilité de ces critères et faire évoluer l'offre des fournisseurs.

International audience; The variability assessment of the rib bone mechanical properties during the growth process is still missing. These properties could not be obtained in vivo on children. Relationships have been obtained between Hounsfield Units from computed tomography (CT) and mechanical properties (e.g. for the cortical bone on adults). As a first step for investigation of the mechanical properties of child ribs, the aim of this study was to determine the Hounsfield Units variation of child ribs from CT‐scan data, by rib level, along the rib and within the rib sections. Twenty‐seven right ribs of levels 4, 6 and 9 were processed from 11 thoracic CT scans of children without bone lesions aged between 1 and 10 years. A first set of 10 equidistributed cross‐sections normal to the rib midline were extracted. Sixteen equally distributed elements defined 4 areas into the cortical band: internal, external, caudal and cranial. Within the rib sections, Hounsfield Units were found significantly higher in internal and external areas than in caudal and cranial. In a further step using calibrated CT scans, it would be possible to derive the mechanical properties of in vivo child ribs using bone density correlation with Hounsfield Units.

International audience; OBJECTIVES: The aim of the study was to determine whether self-reported occupational exposure to cleaning/disinfecting agents in hospital workers is accurate, in comparison to expert assessment, taken to be the gold standard. METHODS: In the Epidemiological Study of the Genetics and Environment of Asthma (EGEA), participants were interviewed on occupation with a specific questionnaire for hospital workers regarding tasks and cleaning/disinfecting agents. Two estimates of exposure were available: self-report and expert assessment. The expert assessment involved a standardised procedure to estimate intensity, frequency and probability of exposure for each job. The present analysis focused on eight exposures: formaldehyde, glutaraldehyde, bleach/chlorine, alcohol, quaternary ammonium components, ammonia, sprays and latex gloves. Agreement and differences between self-reported and expert estimates were studied by kappa and phi coefficients and McNemar tests, respectively. RESULTS: In the survey of 1571 adults, 176 ever hospital workers (327 occupations) with both self-reported and expert exposure assessments were studied. An underestimation of self-reported exposure was observed especially for formaldehyde (26.5% vs 32.7%, p=0.01), ammonia (7.4% vs 18.8%, p

39ème Congrès de la Société de Biomécanique, Valenciennes, France, 27-/08/2014 - 29/08/2014; Previous study showed that kinematic patterns reveal very little variability over repeated tennis strokes for individual player (Knudson 1990). Sport media, however, regularly show difficulties encountered by elite athletes in being accustomed to new equipment, especially in tennis activity. The stability of the pattern would thus be altered by changes in racket specifications. During overhead motion, the shoulder complex has a predominant function as it funnels the energy generated by the lower limbs and trunk to the upper limb and then to the racket, through the so-called kinetic chain (Sciascia et al. 2012). The variability of shoulder kinematic patterns could thus be a key point in habituation to a new equipment. The aim of this study was to explore the variability of the humerothoracic joint kinematic pattern in a highly skilled player when serving with his own racket and with another one. It was hypothesised that the kinematic pattern would be more variable when serving with another racket than with the regular one

Background Revision total hip arthroplasty (rTHA) is a challenging surgery with a higher rate of complications than primary arthroplasty, particularly instability and aseptic loosening. The purpose of this study is to compare dual mobility cup (DMC) and standard mobility cup (SMC) in all rTHAs performed at our institution over a decade with a 1 year minimum follow-up. Methods Two hundred ninety-five rTHAs (acetabular only and bipolar revisions) between 2006 and 2016 were retrospectively reviewed. These were divided into those with a DMC (184 revisions) or SMC (111 revisions). Dislocation and complications requiring re-revision were reported. Results The rTHA mean age was 69 years ± 13.9 (19-92) and the mean follow-up was 2.3 years. Dislocation risk was statistically lower (P = .01) with a DMC (3.8%; 7/184) than with an SMC (13.5%; 15/111). DMC required re-rTHA in 24/184 (13%) for any reason compared to SMC in 19/111 (17.1%) (P = .34). There was no significant difference in early aseptic loosening (P = .28) between the 2 groups. For young patients (≤55 years), results were similar with a lower dislocation rate in the DMC group (P = .24) and no increased risk of early aseptic loosening (P = .49). Conclusion This study demonstrates that for all rTHA indications DMC compared to SMC has a significantly decreased risk of postoperative dislocation without risk of early aseptic loosening at medium term follow-up. The use of DMC in rTHA is an important consideration particularly with the predicted increased incidence of both primary and revision THA globally.

International audience

A lot of attention has been paid to wearable inertial sensors regarded as an alternative solution for outdoor human motion tracking. Relevant joint angles can only be calculated from anatomical orientations, but they are negatively impacted by soft tissue artifact (STA) defined as skin motion with respect to the underlying bone; the accuracy of measured joint angle during movement is affected by the ongoing misalignment of the sensor. In this work, a new sensor-to-segment calibration using inertial measurement units is proposed. Inspired by the multiple calibration for a cluster of skin markers, it consists in performing first multiple static postures of the upper limb in all anatomical planes. The movements that affect sensor alignment are identified then alignment differences between sensors and segment frames are calculated for each posture and linearly interpolated. Experimental measurements were carried out on a mechanical model and on a subject who performed different movements of right elbow and shoulder. Multiple calibration showed significant improvement in joint angle measurement on the mechanical model as well as on human joint angle comparing to those obtained from attached sensors after technical calibration. During shoulder internal-external rotation, the maximal error value decreased more than 50% after correction. Graphical abstract Elbow flexion-extension joint angle values obtained from IMUs are well-corrected after applying multiple calibration procedure. Though shoulder internal-external rotation joint angle is more affected by soft tissue artifact, multiple calibration procedure improves the angle values obtained from IMUs.

Introduction Variations in the length of lateral extra-articular reconstruction (LER) have been widely investigated during knee flexion but there is no information about length changes during pivot shift. This study sought to assess the changes in LER tension during weightbearing knee flexion in a normal knee and in a computer-simulated pivot-shift scenario. Hypothesis Placing the femoral tunnel posterior and proximal to the lateral femoral epicondyle allows the LER to tighten early in the flexion range during weightbearing (squatting motion) and simulated pivot-shift. Material and methods A computer model was used to simulate weightbearing knee flexion and pivot shift scenarios. Changes in LER tension were calculated in both scenarios by estimating the distance between six femoral attachment sites (posterior and proximal to the lateral femoral epicondyle) and two tibial tunnel locations: Gerdy's tubercle (GT) and the anterolateral ligament (ALL) anatomic attachment site. Results Independent of the location of the femoral and tibial tunnels, the LER tightened by up to 22% of its resting length during the early portion of weightbearing knee flexion and then relaxed from 40° to 60° of knee flexion. The ALL tibial tunnel position allowed complete LER relaxation at 60° flexion whereas LER using the GT tibial tunnel position remained tighter. In the simulated pivot-shift test, and for all femoral tunnel locations, the LER tightened by 20% to 34% of its resting value for the GT tibial tunnel position and by 11% to 26% for the ALL tibial tunnel position. Discussion During weightbearing knee flexion, placing the femoral tunnel proximal and posterior to the femoral epicondyle was associated with LER tightening in the early degrees of flexion and LER relaxation between 40 and 60° flexion. LER tightening occurred during a simulated pivot-shift test supporting the concept that a posterior and proximal femoral LER tunnel position is most effective during weightbearing knee flexion and altered knee kinematics.

Resume Bien que les protocoles individuels (a cas-unique) semblent etre une methode idoine pour les psychologues praticiens tant ils s’inscrivent parfaitement bien dans la logique de la pratique psychologique basee sur la preuve, leur utilisation demeure quasi-anecdotique en psychologie. Le present article se propose de presenter leurs avantages et de demontrer la facilite de leur mise en place. Une prise en main du logiciel gratuit SCDA pour analyser les donnees d’un protocole cas-unique est proposee. Les principaux aspects relatifs aux resultats d’un protocole cas-unique sont presentes et illustres a travers un exemple concret. La maniere d’integrer ces protocoles dans la pratique clinique est discutee. Il est loisible de croire que ce tutoriel encouragera l’utilisation de cette methode de recherche et d’intervention clinique.

Mass-spring systems (MSS) simulating elastic materials obey constraints known in elasticity as the Cauchy relations, restricting the Poisson ratio of isotropic systems to be exactly $$\nu =1/4$$. We remind that this limitation is intrinsic to centrosymmetric spring systems (where each node is a center of symmetry), forbidding them for instance to simulate incompressible materials (with $$\nu =1/2$$). To overcome this restriction, we propose to supplement the spring deformation energy with an energy depending on the volume only, insensitive to change of shape, permitting MSS to simulate any real isotropic materials. In addition, the freedom in choosing the spring constants realizing a given elastic behavior allows to manage instabilities. The proposed hybrid model is evaluated by comparing its response to various deformation geometries with analytical model and/or finite element model. The results show that the hybrid MSS model allows to simulate any compressible isotropic elastic material and in particular the nearly incompressible (Poisson ratio $$\nu \simeq 1/2$$) biological soft tissues to which it is dedicated.

Background Although cements are widely used during arthroplasty procedures, few recommendations exist regarding their optimal usage modalities, which, nevertheless, govern the long-term surgical outcomes. No detailed information is available on how cements are used in French hospitals. The objectives of this questionnaire survey among surgeons working at a multi-site university hospital in France were to describe practices, determine whether these varied with surgeon experience, and look for differences compared to recommendations. Hypothesis Cementing techniques vary widely among surgeons at a university hospital. Material and methods A questionnaire was sent to the five orthopaedic departments of our university hospital to collect data on the surgeons (age, sex, years of experience), their practice (type of implants used, annual number of arthroplasties with each arthroplasty type and each indication, and proportion of cemented arthroplasties), the type of cement used, and the cementing technique. Results Of the 34 surgeons, 21 completed the questionnaire, 20 males and 1 female with a mean age of 41 years (range, 31–59 years) and a mean of 11 years (range, 1–29 years) of experience. High-viscosity antibiotic-loaded cement was preferred by 20 (95%) surgeons, notably for knee arthroplasties, of which the median annual numbers were 55 (range, 0–218) and 8 (range, 1–40) for primary and revision cemented procedures, respectively. Various cementing techniques in ambient air were used: 12/21 (57%) surgeons used pulsed lavage to prepare the bone before cementation and 18/21 (86%) applied the cement to both the bone cuts and the implant. Of the 18 surgeons who performed knee arthroplasties, 12 used pulsed lavage, including 9 of the 11 surgeons with more than 5 years of experience and only 3 of the 7 less experienced surgeons. Similarly, of the 12 surgeons who used pulsed lavage for cemented arthroplasties, 11 were among the 12 surgeons who performed more than 15 cemented arthroplasties annually and 1 was among the 6 who performed fewer cemented arthroplasties. Discussion Cementing techniques varied widely, reflecting the dearth of recommendations and controversial results of published studies. In our centre, the use of pulsed lavage to improve bone preparation and cement application to both the bone and the implant should be promoted, as both techniques are universally advocated. Our study demonstrates the need to provide surgeons with opportunities to exchange their experiences about the other aspects of cementing in order to harmonise practices and to optimise the use of cement. Level of evidence IV, questionnaire survey.

International audience; Human cortical bone fracture toughness depends on the anatomical locations under quasi-static loading. Recent results also showed that under fall-like loading, cortical bone fracture toughness is similar at different anatomical locations in the same donor. While cortical bone toughening mechanisms are known to be dependent on the tissue architecture under quasi-static loading, the fracture mechanisms during a fall are less studied. In the current study, the structural parameters of eight paired femoral diaphyses, femoral necks and radial diaphyses were mechanically tested under quasi-static and fall-like loading conditions (female donors, 70 ± 14 y.o., [50–91 y.o.]). Synchrotron radiation micro-CT imaging was used to quantify the amount of micro-cracks formed during loading. The volume fraction of these micro-cracks was significantly higher within the specimens loaded under a quasi-static condition than under a loading representative of a fall. Under fall-like loading, there was no difference in crack volume fraction between the different paired anatomical locations. This result shows that the micro-cracking toughening mechanism depends both on the anatomical location and on the loading condition.

Background Excessive Knee Flexion Gait Pattern (KFGP) is a common gait deviation in many pathological conditions. The contractures of the muscles that have been identified as being responsible of KFGP are: iliopsoas, hamstring and gastrocnemius. Research question How do isolated contractures of the iliopsoas, hamstrings and gastrocnemius impact knee flexion during gait? Methods Three levels of contracture (mild, moderate and severe) were simulated bilaterally using an exoskeleton on 10 healthy participants for iliopsoas, hamstring and gastrocnemius muscles. A gait analysis session was performed to evaluate the joint kinematics according to the different simulated contractures. Thirty one parameters were chosen to analyze the kinematics of the thorax, pelvis, hip, knee and ankle. A principal component analysis (PCA) was used to determine the kinematic parameters influenced by contractures. Results In addition to a permanent knee flexion observed for the three muscles with contracture: the contracture of the iliopsoas induces a large hip flexion with pronounced anterior pelvis tilt; the contracture of the hamstrings induces an ankle dorsiflexion during the support phase with a posterior pelvis tilt; the contracture of the gastrocnemius induces an absence of first and second rocker of the ankle with a slight flexion of hip and a slight anterior pelvis tilt. Significance These results support the identification of the muscles responsible for a KFGP. A better knowledge of the interactions between contractures and associated joint kinematics of the same and adjacent joints will support the interpretation of gait analyses by more precisely and faster targeting the concerned muscle.

Background: Noise in the vicinity of airports is a crucial public health issue. Exposure to aircraft noise has been shown to have adverse effects on health and particularly on sleep. Many studies support the hypothesis that noise at night can affect subjective sleep quality. Fewer studies, however, have performed objective measurements of sleep. Objectives: The aim of the present study was to investigate the relationship between aircraft noise exposure and objective parameters assessed by actigraphy of sleep quality in the population living near two French airports. Methods: This study includes 112 participants living in the vicinity of Paris-Charles de Gaulle and Toulouse-Blagnac airports. Wrist actigraphy measurements were performed during eight nights to evaluate objective parameters of sleep quality such as sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), time in bed (TB) and sleep efficiency (SE). Acoustic measurements were made simultaneously both inside the participants' bedrooms and outside (at the exterior frontage) in order to estimate aircraft noise levels. Energy indicators related to the sound energetic average for a given period of time, as well as indicators related to noise events (such as the number of events that exceed a given threshold for example) were estimated. Logistic and linear regression models were used, taking into account potential confounders: age; gender; marital status; education; and body mass index (BMI). Results: Energy indicators, and more particularly indicators related to noise events, were significantly associated with objective parameters of sleep quality. Increased levels of aircraft noise and increased numbers of aircraft noise events increased the time required for sleep onset (SOL) and the total wake time after sleep onset (WASO), and decreased sleep efficiency (SE). An association was also observed between aircraft noise exposure and an increase in total sleep time (TST) and time in bed (TB). Conclusion: The findings of the present study contribute to the overall evidence suggesting that nocturnal aircraft noise exposure may decrease objective quality of sleep. Aircraft noise exposure affects objective parameters of sleep quality, not only in terms of noise levels but also in terms of number of events. Mechanisms for adapting to sleep deprivation could be observed.

The objective of this prospective study was to assess the effect of CPAP therapy on job productivity and work quality for patients with severe obstructive sleep apnea (OSA). A convenience sample of patients diagnosed with severe OSA using polysomnography or polygraphy and with a therapeutic indication for CPAP was enrolled in our study. Patients completed two self-administered questionnaires: the first before CPAP therapy and the second during the first 6 months after CPAP treatment. OSA symptoms were evaluated through self-administered questionnaires assessing potential effects on occupational activity: excessive daytime sleepiness was rated by the Epworth Sleepiness Scale (ESS), emotional status was rated by the Hospital Anxiety and Depression (HAD) scale, work quality was rated by the Work Role Functioning Questionnaire (WRFQ). Forty patients (30 men, mean age 47.3 ± 8.3, mean BMI 31.6 ± 7.4, mean apnea-hypopnea index 51.8 ± 16.3) showed a beneficial effect of CPAP therapy on ESS score (mean 11.6 to 8.2, p

OBJECTIVES: The aim of this article is to report on the possible relationships between tramway front-end geometry and pedestrian injury risk over a wide range of possible tramway shapes. METHODS: To study the effect of tramway front-end shape on pedestrian injury metrics, accidents were simulated using a custom parameterized model of tramway front-end and pedestrian models available with the MADYMO multibody solver. The approach was automated, allowing the systematic exploration of tramway shapes in conjunction with 4 pedestrian sizes (e.g., 50th percentile male or M50). RESULTS: A total of 8,840 simulations were run, showing that the injury risk is more important for the head than for other body regions (thorax and lower extremities). The head of the M50 impacted the windshield of the tramway in most of the configurations. Two antagonist mechanisms affecting impact velocity of the head and corresponding head injury criterion (HIC) values were observed. The first is a trunk rotation resulting from an engagement of the lower body that can contribute to an increase in head velocity in the direction of the tram. The second is the loading of the shoulder, which can accelerate the upper trunk and head away from the windshield, resulting in lower impact velocities. Groups of design were defined based on 2 main parameters (windshield height and offset), some of which seem more beneficial than others for tramway design. The pedestrian size and tramway velocity (30 vs. 20?km/h) also affected the results. CONCLUSIONS: When considering only the front-end shape, the best strategy to limit the risk of head injury due to contact with the stiff windshield seems to be to promote the mechanism involving shoulder loading. Because body regions engaged vary with the pedestrian size, none of the groups of designs performed equally well for all pedestrian sizes. The best compromise is achieved with a combination of a large windscreen offset and a high windscreen. Conversely, particularly unfavorable configurations are observed for low windshield heights, especially with a large offset. Beyond the front-end shape, considering the stiffness of the current windshields and the high injury risks predicted for 30?km/h, the stiffness of the windshield should be considered in the future for further gains in pedestrian safety.

The dispersive nature of the longitudinal wave propagation in rods has been studied extensively theoretically as well as experimentally by many authors (see e.g. [1] or [2]). Split Hopkinson Pressure Bars (SHPB) is employed to dynamically characterize materials in the intermediate range of strain rate and the post-processing of the SHPB tests requires the knowledge of the dispersion in the bars [3] [4] [5]. Simplified models of longitudinal wave propagation have been proposed by Love [6] and later by Mindlin et al. [7]. In his paper published in 2006, Anderson [8] developed a rod theory for the propagation of longitudinal waves in slender rods of circular cross section and it is an improvement from the previous works in [7]. In the approximation of the longitudinal and radial displacements he uses only the first two modes of the given basis for each displacement, this leads to the four-mode equation. The four-mode equation is a polynomial whose root is the wave longitudinal velocity. This equation is therefore easier to solve than the Pochhammer equation [1] because the latter is transcendental. However we noticed an error in one of the coefficients of the four-mode equation [8], and this error is not a mere typo. This error was also repeated in [9]. The aim of this paper is threefold. First we want to give the correct four-mode equation and the associated dispersion curve. Secondly, we wanted to examine the convergence of the approximation at higher orders then given by Anderson. Thirdly, this is the occasion to give dimensionless equations. The paper is organised as follows: Section 2 details how to obtain the dimensionless approximation for longitudinal waves. Section 3 recalls the Pochhammer dispersion equation for slender rods -which is later used to compute the reference dispersion curve- and details the way it is solved. Section 4 then gives the correct dispersion curve for the four-mode equation and examines the convergence of the approximate dispersion curves with an increasing number of degrees of freedom (modes). Lastly, Section 5 contains a discussion on the advantages and drawbacks of using either directly the Pochhammer equation or the Jacobi polynomial approximation, we also discuss the computation cost of both methods.

Outdoor air pollution is a leading environmental cause of death and cancer incidence in humans. We aimed to estimate the fraction of lung cancer incidence attributable to fine particulate matter (PM2.5) exposure in France, and secondarily to illustrate the influence of the input data and the spatial resolution of information on air pollution levels on this estimate. The population attributable fraction (PAF) was estimated using a nationwide spatially refined chemistry-transport model with a 2-km spatial resolution, neighbourhood-scale population density data, and a relative risk from a published meta-analysis. We used the WHO guideline value for PM2.5 exposure (10 μg/m3) as reference. Sensitivity analyses consisted in attributing the nation-wide median exposure to all areas and using alternative input data such as reference of PM2.5 exposure level and relative risk. Population-weighted median PM2.5 level in 2005 was 13.8 μg/m3; 87% of the population was exposed above the guideline value. The burden of lung cancer attributable to PM2.5 exposure corresponded to 1466 cases, or 3.6% of all cases diagnosed in 2015. Sensitivity analyses showed that the use of a national median of PM2.5 exposure would have led to an underestimation of the PAF by 11% (population-weighted median) and by 72% (median of raw concentration), suggesting that our estimates would have been higher with even more finely spatially-resolved models. When the PM2.5 reference level was replaced by the 5th percentile of country-scale exposure (4.9 μg/m3), PAF increased to 7.6%. Other sensitivity analyses resulted in even higher PAFs. Improvements in air pollution are crucial for quantitative health impacts assessment studies. Actions to reduce PM2.5 levels could substantially reduce the burden of lung cancer in France. Keywords: Air pollution, Lung cancer, Population attributable fraction, France

Objectifs L’epuisement academique est un probleme majeur de sante publique, a fortiori chez les etudiants en these qui font figure de population particulierement vulnerable au syndrome. Si un reperage precoce du burnout previendrait ses effets sur la sante mentale et la performance academique, la validation d’un tel instrument en langue francaise adapte aux particularites des doctorants restait encore a etablir. Materiel et methodes La presente etude propose la validation d’une echelle d’epuisement academique doctorant (la MBI-SS-D) adaptee de la version francaise de la Maslach Burnout Inventory–Student Survey (MBI-SS). Pas moins de 1150 doctorants issus de plus d’une dizaine de cursus en France ont repondu au questionnaire en ligne. Ils etaient encore 862 au retest six mois plus tard. Resultats Les analyses factorielles exploratoires et confirmatoires aux deux temps ont invariablement permis de retrouver la structure tridimensionnelle du burnout (epuisement emotionnel, cynisme, auto-efficacite academique). Les indices alpha et omega proches de .80 et les coefficients split-half entre .70 et .89 renforcaient cette observation. Par ailleurs, les tests d’invariance metrique et structurale prouvaient la grande stabilite test-retest du MBI-SS-D jusqu’au critere le plus strict. Concernant la validite divergente, la mesure du burnout etait liee negativement avec aussi bien l’optimisme (rs = − .41 ; p < .001) que la resilience (rs = − .32 ; p < .001). Conclusions Le MBI-SS-D demontre de reelles qualites psychometriques. Il constitue a l’heure actuelle le seul outil en langue francaise permettant une mesure valide de l’epuisement academique a des fins de recherche ou de pratique clinique chez les doctorants.

Context and objective Among the different products and protective gear used by riders of two-wheeled motorized vehicles, back protectors that are designed to prevent damage to the spinal column are widely used today compared other protections. However, few studies measure their effectiveness. Can their effectiveness be measured? How do they help decrease or change the nature of thoracolumbar traumas that occur? To address these questions and remedy the lack of objective data regarding these products, an epidemiological, clinical, and biomechanical analysis of motorcycle riders who were admitted to a French trauma center after an accident was performed. So, this study investigates the effectiveness of back protectors, including their ability to prevent specific mechanisms of thoracic and lumbar spinal injuries related to TWMV accidents. Method A questionnaire was administered to victims of accidents involving two-wheeled motorized vehicles who were admitted to the trauma room at the Marseille trauma center over the course of 2016. Collect data are related to the victim, the accident scenario, and a detailed description of the observed injuries using AIS (Abbreviated Injury Scale) coding and Magerl classification. Univariate analyses and Fisher tests were performed for victims who were or were not wearing back protectors. Results This study collected data from 124 victims. Almost half of the victims were wearing a back protector at the time of the accident (53 victims, thus 43% of riders). Collectively, twenty-nine victims who were wearing back protectors had 57 thoracolumbar injuries, and twenty eight victims who were not wearing back protectors had 75 thoracolumbar lesions. The results from this study show that there is no significant difference in the nature and mechanism of thoracolumbar injuries as a function of back protection. The majority of the thoracolumbar injuries were not severe. They were primarily bone injuries, essentially compression fractures, regardless of whether a back protector was worn. Conclusion This study shows that the use of back protection does not decrease the number, type, or mechanism of thoracolumbar injuries associated with accidents involving two-wheeled motorized vehicles. However, it suggests that lumbar vertebral injuries are deflected towards the thoracic vertebrae when back protectors are worn. Finally, it suggests that the design of back protectors should be reconsidered to better protect riders from what are referred to as compression fractures (craniocaudal force), which remain the primary form of fracture regardless of the rider’s characteristics, based on the data analyzed.

A few experimental studies suggest that atmospheric pollutants could affect the endocrine system, and in particular stress hormones and the hypothalamic-hypophyseal-ovarian axis, which could in turn influence menstrual cycle function. We aimed to study the possible short-term effects of atmospheric pollutants on the length of the follicular and luteal phases and on the duration of the menstrual cycle in humans. To do so, from a nation-wide study on couples' fecundity, we recruited 184 women not using contraception who collected urine samples at least every other day during one menstrual cycle, from which a progesterone metabolite was assayed, allowing estimation of the duration of the follicular and luteal phases of the cycle. Atmospheric pollution (nitrogen dioxide and particulate matter with an aerodynamical diameter below 10?m, PM10) levels were estimated from a dispersion model with a 1-km resolution combined with permanent monitoring stations measurements, allowing to estimate exposures in the 30-day, 1-10 and 11-30-day periods before the start of the menstrual cycle. Regression models allowed to quantify the change in cycle duration associated with atmospheric pollutants and adjusted for potential confounders. Follicular phase duration increased on average by 0.7 day (95% confidence interval, CI, 0.2; 1.3) for each increase by 10?g/m3 in NO2 concentration averaged over the 30 days before the cycle and by 1.6 day (95% CI, 0.3; 2.9) for each increase by 10?g/m3 in PM10. There was no strong evidence of associations of exposures in this time window with luteal phase or with total menstrual cycle durations (p>0.2). Exposures in the 1-10 day period before the cycle start were also associated with increased follicular phase duration. This study is one of the first prospective studies to suggest short-term alterations in follicular phase duration following atmospheric pollutants exposure.

The aim of this systematic review with meta-analysis was to determine the change in gait biomechanics after total ankle replacement and ankle arthrodesis for end-stage osteoarthritis. Methods Electronic databases were searched up until May 2019. Peer-reviewed journal studies including adult participants suffering from end-stage ankle osteoarthritis and reporting pre- and post-operative kinematics, kinetics and spatio-temporal effects of total ankle replacement and ankle arthrodesis during walking were included with a minimum of 12months follow-up. Seventeen suitable studies were identified and assessed according to methodological and biomechanical qualities. Meta-analysis was performed by calculating the effect size using standard mean differences between pre- and post-operative gait status. Findings Seventeen studies with a total of 883 patients were included. Meta-analysis revealed moderate evidence of an improvement in lower limb kinematics, kinetics and spatio-temporal parameters after total ankle replacement. Moderate evidence indicated an increase in ankle moment, hip range of motion and walking speed after ankle arthrodesis. Interpretation The currently available evidence base of research papers evaluating changes in gait biomechanics after total ankle replacement and ankle arthrodesis is limited by a lack of prospective research, low sample sizes and heterogeneity in the patho-etiology of ankle osteoarthritis. Following total ankle replacement, improvements were demonstrated for spatio-temporal, kinematic and kinetic gait patterns compared to the pre-operative measures. Improvements in gait mechanics after ankle arthrodesis were limited to walking speed and ankle moment. Increased hip range of motion after ankle arthrodesis could represent a sign of compensation for the lack of ankle motion.

Currently, approximately 90% of the human population is right-handed. This handedness is due to the lateralization of the cerebral hemispheres and is controlled by brain areas involved in complex motor tasks such as making stone tools or in language. In addition to describing the evolution of laterality in humans, identifying hand preference in fossil hominids can improve our understanding of the emergence and development of complex cognitive faculties during evolution. Several fields of prehistory like palaeoanthropology or lithic analysis have already investigated handedness in fossils hominins but they face limitations due to either the incomplete or the composite state of the skeleton remains or to results replication or method application failure. Wear analysis could provide new complementary data about hand preference evolution and the development of certain complex cognitive functions using indirect evidence (use traces, micro-scars in particular) of the hand holding the stone tool during use. Controlled experiment has been carried out in order to establish a reference collection of tools used with the left and tools used with the right hand. Wear analysis was performed on this corpus using “classical” microscopic approach and geometric morphometric analysis. A machine learning algorithm, the k-NN method, was applied to verify if use traces (micro-scars) could help determine the hand holding the tool during use. The best model, based on parameters referring to invasiveness of micro-scars, was able to correctly determine the hand holding the tool with 75% accuracy.

International audience; ObjectivesAcademic burnout is a major public health issue, especially among PhD students who are particularly vulnerable to the syndrome. Although early identification of burnout would prevent its effects on mental health and academic performance, the validation of such instrument in French adapted to the specificities of PhD students still had to be established.Materiel and methods This study proposes the validation of a PhD student academic burnout scale (MBI-SS-D) adapted from the French version of the Maslach Burnout Inventory-Student Survey (MBI-SS). No less than 1150 PhD students from more than ten courses in France answered the online questionnaire. There were still 862 of them at the retest 6 months later.ResultsExploratory and confirmatory factorial analyses at both times irremediably confirmed the three-dimensional structure of burnout (emotional exhaustion, cynicism, academic self-efficacy). The alpha and omega indices close to.80 and the split-half coefficients between.70 and.89 reinforced this observation. In addition, the metric and structural invariance tests proved the high test-retest stability of MBI-SS-D up to the most stringent criterion. Regarding divergent validity, the burnout measure was negatively related to both optimism (Rs = − .41; P < .001) and resilience (Rs = − .32; P < .001).ConclusionsThe MBI-SS-D shows real psychometric qualities. It is currently the only French-language tool that provides a valid measure of academic burnout for research or clinical practice purposes among PhD students.; ObjectifsL’épuisement académique est un problème majeur de santé publique, a fortiori chez les étudiants en thèse qui font figure de population particulièrement vulnérable au syndrome. Si un repérage précoce du burnout préviendrait ses effets sur la santé mentale et la performance académique, la validation d’un tel instrument en langue française adapté aux particularités des doctorants restait encore à établir.Matériel et méthodesLa présente étude propose la validation d’une échelle d’épuisement académique doctorant (la MBI-SS-D) adaptée de la version française de la Maslach Burnout Inventory–Student Survey (MBI-SS). Pas moins de 1150 doctorants issus de plus d’une dizaine de cursus en France ont répondu au questionnaire en ligne. Ils étaient encore 862 au retest six mois plus tard.RésultatsLes analyses factorielles exploratoires et confirmatoires aux deux temps ont invariablement permis de retrouver la structure tridimensionnelle du burnout (épuisement émotionnel, cynisme, auto-efficacité académique). Les indices alpha et oméga proches de .80 et les coefficients split-half entre .70 et .89 renforçaient cette observation. Par ailleurs, les tests d’invariance métrique et structurale prouvaient la grande stabilité test-retest du MBI-SS-D jusqu’au critère le plus strict. Concernant la validité divergente, la mesure du burnout était liée négativement avec aussi bien l’optimisme (rs = − .41 ; p < .001) que la résilience (rs = − .32 ; p < .001).ConclusionsLe MBI-SS-D démontre de réelles qualités psychométriques. Il constitue à l’heure actuelle le seul outil en langue française permettant une mesure valide de l’épuisement académique à des fins de recherche ou de pratique clinique chez les doctorants.

Characterizing the time-domain response of a random multiple-degree-of-freedom dynamical system is challenging and often requires Monte Carlo simulation (MCS). Differential equations must therefore be solved for each sample, which is time-consuming. This is why polynomial chaos expansion (PCE) has been proposed as an alternative to MCS. However, it turns out that PCE is not adapted to simulate a random dynamical system for long-time integration. Recent studies have shown similar issues for the frequency response function of a random linear system around the deterministic eigenfrequencies. A Padé approximant approach has been successfully applied; similar interesting results were also observed with a random mode approach. Therefore, the latter two methods were applied to a random linear dynamical system excited by a dynamic load to estimate the first two statistical moments and probability density function at a given instant of time. Whereas the random modes method has been very efficient and accurate to evaluate the statistics of the response, the Padé approximant approach has given very poor results when the coefficients were determined in the time domain. However, if the differential equations were solved in the frequency domain, the Padé approximants, which were also calculated in the frequency domain, provided results in excellent agreement with the MCS results.

Summary The analysis of case–control studies with several disease subtypes is increasingly common, e.g. in cancer epidemiology. For matched designs, a natural strategy is based on a stratified conditional logistic regression model. Then, to account for the potential homogeneity among disease subtypes, we adapt the ideas of data shared lasso, which has been recently proposed for the estimation of stratified regression models. For unmatched designs, we compare two standard methods based on $L_1$-norm penalized multinomial logistic regression. We describe formal connections between these two approaches, from which practical guidance can be derived. We show that one of these approaches, which is based on a symmetric formulation of the multinomial logistic regression model, actually reduces to a data shared lasso version of the other. Consequently, the relative performance of the two approaches critically depends on the level of homogeneity that exists among disease subtypes: more precisely, when homogeneity is moderate to high, the non-symmetric formulation with controls as the reference is not recommended. Empirical results obtained from synthetic data are presented, which confirm the benefit of properly accounting for potential homogeneity under both matched and unmatched designs, in terms of estimation and prediction accuracy, variable selection and identification of heterogeneities. We also present preliminary results from the analysis of a case–control study nested within the EPIC (European Prospective Investigation into Cancer and nutrition) cohort, where the objective is to identify metabolites associated with the occurrence of subtypes of breast cancer.

Successive implementation of seven-valent then 13-valent pneumococcal conjugate vaccines (PCVs) led to a marked decrease in pneumococcal disease burden, including pneumococcal meningitis. We assessed the long-term effect of implementation of PCVs on incidence of pneumococcal meningitis in children in France over a 16-year period.We did a quasi-experimental, population-based interrupted time-series analysis with a nationwide prospective survey over 16 years in France, recruiting children aged younger than 15 years from 227 paediatric wards from January, 2001, to December, 2016. The main outcome by the time-series model was the estimated incidence of pneumococcal meningitis per 100 000 children (of a population of 12·6 million children in 2017) before and after PCV7 and PCV13 implementation. The time-series model was based on segmented regression with autoregressive error.We enrolled 1778 children with pneumococcal meningitis. PCV13 implementation led to a significant reduction in monthly incidence of pneumococcal meningitis from 0·12 per 100 000 children before PCV13 to a nadir of 0·07 in December, 2014 (-38%, 95% CI -56·1 to -20·4; p0·0001). A sharp increase occurred during 2015 and 2016, (+2·3% per month, incidence of 0·13 per 100 000 children at the end of the study period, p=0·0002), mainly related to an increase of serotype 24F, which was frequently penicillin resistant.The early effect of PCV13 implementation greatly reduced the incidence of pneumococcal meningitis in children less than 15 years old. However, a sharp rebound in incidence linked to the emergence of serotype 24F compromised the long-term PCV efficacy. If confirmed in future studies and in other countries, pneumococcal meningitis incidence rebound and 24F emergence should be considered when developing next-generation PCVs.The French Pediatric Infectious Diseases Group, Association Clinique et Thérapeutique Infantile du Val de Marne, Pfizer, and for the National Reference Centre for Pneumococci, the French National Health Agency.

Ankle osteoarthritis is a degenerative joint disease characterized by significant pain and disability. Although gait is improved after surgery, patients still experience impaired lower limb function. Therefore, this doctoral project compared outcomes following common surgical procedures for ankle osteoarthritis by analyzing patients’ perception of recovery. Evidence showed that half of the patients were still experiencing functional impairments after surgery. To increase our understanding of functional impairment experienced by these patients, a meta-analysis was performed to assess the biomechanical effects of total ankle replacement and ankle arthrodesis during gait. It showed that characterization of ankle osteoarthritis is lacking in gait studies and that functional consequences are difficult to define without considering the morphological and structural changes associated with this pathology. Therefore, homogenous study groups of patients were recruited based on the aetiology of ankle osteoarthritis and the presence of concomitant foot deformities. Analyzing the kinetics of the intrinsic foot joints of ankle osteoarthritis patients revealed that the impairment in foot mechanics was not restricted to the painful ankle joint, but also affected neighboring foot joints. Further evidence showed that malalignment of the hindfoot and the ankle does indeed influence foot mechanics during gait. Finally, a pilot study providing a first estimation of how total ankle replacement benefits the biomechanical performance of patients, revealed that ankle mechanics after surgery resembles that of unaffected ankles, but remain impaired compared to control subjects, L'arthrose de cheville est une dégénérescence progressive du cartilage caractérisée par une douleur et une incapacité fonctionnelle importante. Cependant, bien que la marche soit améliorée suite à une arthrodèse ou à une prothèse totale de cheville, les patients présentent toujours une altération de la fonction du membre inférieur. Afin d'améliorer notre compréhension des déficiences fonctionnelles associées à cette pathologie et à ces traitements chirurgicaux connexes, une revue systématique de la littérature a été réalisée. Celle-ci démontre un manque de caractérisation de cette pathologie dans les études d'analyse de marche. Cela signifie que les conséquences fonctionnelles sont difficiles à définir sans tenir compte des changements morphologiques et structurels du pied liés à l’arthrose. Par conséquent, des groupes homogènes de patients ont été recrutés sur base de l’étiologie de l’arthrose et de la présence de déformations concomittantes. L’analyse cinétique des articulations intrinsèques du pied chez ces patients a montré que les altérations de la fonction n’étaient pas limitées à la cheville douloureuse, mais affectaient également les articulations adjacentes du pied. De plus, les déformations du pied associées à l’arthrose de cheville influencent la mécanique du pied durant la marche. Enfin, une étude pilote a été réalisée pour donner une première évaluation de la prothèse totale de cheville sur la performance biomécanique des patients souffrant d'arthrose. Nos résultats ont révélé que la mécanique de la cheville après prothèse ressemble à celle des chevilles saines mais que leurs performances biomécaniques restent diminuées par rapport à des sujets asymptomatiques

Ankle osteoarthritis is a degenerative joint disease characterized by significant pain and disability. Although gait is improved after surgery, patients still experience impaired lower limb function. Therefore, this doctoral project compared outcomes following common surgical procedures for ankle osteoarthritis by analyzing patients’ perception of recovery. Evidence showed that half of the patients were still experiencing functional impairments after surgery. To increase our understanding of functional impairment experienced by these patients, a meta-analysis was performed to assess the biomechanical effects of total ankle replacement and ankle arthrodesis during gait. It showed that characterization of ankle osteoarthritis is lacking in gait studies and that functional consequences are difficult to define without considering the morphological and structural changes associated with this pathology. Therefore, homogenous study groups of patients were recruited based on the aetiology of ankle osteoarthritis and the presence of concomitant foot deformities. Analyzing the kinetics of the intrinsic foot joints of ankle osteoarthritis patients revealed that the impairment in foot mechanics was not restricted to the painful ankle joint, but also affected neighboring foot joints. Further evidence showed that malalignment of the hindfoot and the ankle does indeed influence foot mechanics during gait. Finally, a pilot study providing a first estimation of how total ankle replacement benefits the biomechanical performance of patients, revealed that ankle mechanics after surgery resembles that of unaffected ankles, but remain impaired compared to control subjects; L'arthrose de cheville est une dégénérescence progressive du cartilage caractérisée par une douleur et une incapacité fonctionnelle importante. Cependant, bien que la marche soit améliorée suite à une arthrodèse ou à une prothèse totale de cheville, les patients présentent toujours une altération de la fonction du membre inférieur. Afin d'améliorer notre compréhension des déficiences fonctionnelles associées à cette pathologie et à ces traitements chirurgicaux connexes, une revue systématique de la littérature a été réalisée. Celle-ci démontre un manque de caractérisation de cette pathologie dans les études d'analyse de marche. Cela signifie que les conséquences fonctionnelles sont difficiles à définir sans tenir compte des changements morphologiques et structurels du pied liés à l’arthrose. Par conséquent, des groupes homogènes de patients ont été recrutés sur base de l’étiologie de l’arthrose et de la présence de déformations concomittantes. L’analyse cinétique des articulations intrinsèques du pied chez ces patients a montré que les altérations de la fonction n’étaient pas limitées à la cheville douloureuse, mais affectaient également les articulations adjacentes du pied. De plus, les déformations du pied associées à l’arthrose de cheville influencent la mécanique du pied durant la marche. Enfin, une étude pilote a été réalisée pour donner une première évaluation de la prothèse totale de cheville sur la performance biomécanique des patients souffrant d'arthrose. Nos résultats ont révélé que la mécanique de la cheville après prothèse ressemble à celle des chevilles saines mais que leurs performances biomécaniques restent diminuées par rapport à des sujets asymptomatiques

In this work, reconstruction and location in time domain of multiple forces acting on a linear elastic structure are achieved through a Bayesian approach to solve an inverse problem. The Bayesian solution of the inverse problem is provided in the form of a posterior probability density function. The unknown forces are determined through Markov chain Monte Carlo method, the Gibbs algorithm. This posterior density integrating both the likelihood and prior information was considered for the particular case of a linear elastic structure. The measurements are affected by an additive random noise. Two particular cases were analysed: unperturbed and uncertain model representing the structure. The unperturbed model was used to identify a single force. When the model is uncertain, compressed sensing technique was used to provide an adequate sparse representation of the inverse problem through a wavelet basis. With this sparse representation, the possibility of achieving automatic location of the forces was investigated. This requires to identify all the degrees of freedom along with the identified actions are not vanishing. Also, the possibility of force identification with less sensors than forces was studied. The proposed approach is illustrated and validated on numerical examples. This proposed approach is compared with classical approach of force identification based on Tikhonov regularization associated with the GCV criterion.

The lower limb passive actions representing the actions of all the passive periarticular structures have been shown to have a significant contribution to the power generation and absorption during gait. However, the respective magnitude of its different components was not established, although models of ligament moment were implemented in some musculoskeletal models. These ligament moments have shown to have an influence on the musculo-tendon forces and contact forces but the models used were never specifically evaluated, that is, compared to the passive and net joint moments. Two models of passive joint moments and three models of ligament moments were selected from the literature. Ten subjects (23–29 years old, 79.8 ± 9.5 kg, 1.85 ± 0.06 m) participated in the study. Each subject performed three gait cycles in a gait laboratory to acquire the kinematics and ground reaction forces and to compute the ligament, passive and net moments of the right lower limb joints. The contributions of the passive joint moments to the net joint moments were in accordance with the literature, although time shifts appeared for peaks in the hip and knee powers. Two of the models of ligament moments seemed, in fact, to represent the passive joint moments as their contributions were very similar while the third model of ligament moments seemed to represent only penalty-based joint limits. As a conclusion, this study showed that the models of ligament moments existing in the literature do not seem reliable. This study also demonstrated that the use of non-subject-specific models of the passive joint moments could be a valid approach for healthy subjects.

PURPOSE: Surgeons mainly consider the anterior anatomy of the distal femur in the treatment of patellar instability (PI) with trochlear dysplasia (TD). Through this research, the idea was to analyse the posterior femoral condyle length in TD. The research team posited the presence of morphological differences in the posterior part of the femoral epiphysis in TD compared to a control group. They also postulated that the posterior bicondylar angle (PCA), in the axial plane, was increased in TD. METHODS: This is a single-centre morphological study of 100 patients who had a computed tomography (CT) using the same protocol. 50 patients with PI (25 dysplasias A and 25 B-C-D according to the Dejour classification), and 50 controls were included. All patients presenting a clinical PI were considered for the study. None of these patients had undergone a surgical treatment prior to imaging. Demographic characteristics, BMI, and laterality were comparable in all patients. 20 pilot CT scans were used to establish the methodology. The following measurements were performed: anterior bicondylar angle, PCA, and condylar lengths with respect to the surgical transepicondylar axis. Ratios were calculated in relation to the femoral width. TD was classified according to the Dejour classification in grade A or grades B-C-D. An analysis of variance and a linear model were performed within some groups to investigate which parameters correlated with the classification's grade. RESULTS: This study showed a link between TD and the PCA: control group (1.4?±?0.2°), type A group (1.6?±?0.3°), and types B, C, D group (2.6?±?0.3°) (p?=?0.01). The difference between the control group and types B, C, D TD group was significant (p?=?0.002). In groups B, C, D, the PCA was more important, which proves that in these groups the posterior part of the lateral condyle was relatively shorter compared to the medial condyle. The greater the dysplasia, the longer the medial condyle was in the anterior posterior (p?=?0.02). CONCLUSIONS: This study shows not only an anterior but also a posterior anomaly in PI with TD. There is a correlation between the severity of the anterior deformation and the PCA: in other words, the knee is placed in valgus in flexure which promotes the external dislocation of the patella. This anatomical study could open a field of research on the development of surgical treatments based on the correction of posterior condylar femoral anomalies in PI. LEVEL OF EVIDENCE: III.

Hospitalizations for anaphylaxis have been increasing steadily in many countries, whereas the anaphylaxis mortality rate has remained low and stable over the past 20 years.1-3 A small proportion of patients experiencing anaphylactic reactions are hospitalized in an intensive care unit (ICU). In the United States, this proportion was 5% of the patients seen in the emergency department for anaphylaxis.4 In the United Kingdom, 81 pediatric anaphylaxis cases were collected between 2005 and 2009, with a steady yearonyear increase.