IMPACT OF STRENGTHENING EXERCICES ON THE SHOULDER JOINT

Strengthening of shoulder muscles in rehabilitation protocols and sport practice can be achieved by a wide range of different exercises. Very limited objective data is at disposal to emit recommendations for design of a training protocol that aims at minimizing subacromial impingement, stress on the articular cartilages or labrum and excessive tendon elongation of the rotator cuff. The purpose of this study was to evaluate the impact of shoulder rehabilitation exercises on the shoulder joint using motion capture and computer simulations of patient-specific anatomical joint structures

A motion capture study to measure the feeling of synchrony in romantic couples and in professional musicians

The feeling of synchrony is fundamental for most social activities and prosocial behaviors. However, little is known about the behavioral correlates of this feeling and its modulation by intergroup differences. We previously showed that the subjective feeling of synchrony in subjects involved in a mirror imitation task was modulated by objective behavioral measures, as well as contextual factors such as task difficulty and duration of the task performance. In the present study, we extended our methodology to investigate possible interindividual differences. We hypothesized that being in a romantic relationship or being a professional musician can modulate both implicit and explicit synchronization and the feeling of synchrony as well as the ability to detect synchrony from a third person perspective. Contrary to our hypothesis, we did not find significant differences between people in a romantic relationship and control subjects. However, we observed differences between musicians and control subjects. For the implicit synchrony (spontaneous synchronization during walking), the results revealed that musicians that had never met before spontaneously synchronized their movements earlier among themselves than control subjects, but not better than people sharing a romantic relationship. Moreover, in explicit behavioral synchronization tasks (mirror game), musicians reported earlier feeling of synchrony and had less speed errors than control subjects. This was in interaction with tasks difficulty as these differences appeared only in tasks with intermediate difficulty. Finally, when subjects had to judge synchrony from a third person perspective, musicians had a better performance to identify if they were present or not in the videos. Taken together, our results suggest that being a professional musician can play a role in the feeling of synchrony and its underlying mechanisms

The Subjective Sensation of Synchrony: an Experimental Study

People performing actions together have a natural tendency to synchronize their behavior. Consistently, people doing a task together build internal representations not only of their actions and goals, but also of the other people performing the task. However, little is known about which are the behavioral mechanisms and the psychological factors affecting the subjective sensation of synchrony, or "connecting" with someone else. In this work, we sought to find which factors induce the subjective sensation of synchrony, combining motion capture data and psychological measures. Our results show that the subjective sensation of synchrony is affected by performance quality together with task category, and time. Psychological factors such as empathy and negative subjective affects also correlate with the subjective sensation of synchrony. However, when people estimate synchrony as seen from a third person perspective, their psychological factors do not affect the accuracy of the estimation. We suggest that to feel this sensation it is necessary to, first, have a good joint performance and, second, to assume the existence of an attention monitoring mechanism that reports that the attention of both participants (self and other) is focused on the task

Utilisation pratique de l'intelligence artificielle : une classification radiologique de démences à partir d’IRM morphologiques avec assistance par des cartes issues de l'apprentissage automatique

Background: many artificial intelligence tools are currently being developed to assist diagnosis of dementia from magnetic resonance imaging (MRI). However, these tools are so far difficult to integrate in the clinical routine workflow. In this work, we propose a new simple way to use them in neuroradiological routine and assess its utility for improving diagnostic accuracy. Materials and methods: we studied 34 patients with early-onset Alzheimer’s disease (EOAD), 49 with late-onset AD (LOAD), 39 with frontotemporal dementia (FTD) and 24 with depression from the pre-existing cohort CLIN-AD. Support vector machine (SVM) automatic classifiers using 3D T1 MRI were trained to distinguish: LOAD vs Depression, FTD vs LOAD, EOAD vs Depression, EOAD vs FTD. We extracted SVM weight maps, which are tridimensional representations of discriminant atrophy patterns used by the classifier to take its decisions and printed posters of these maps. Four radiologists (2 senior neuroradiologists and 2 unspecialized junior radiologists) performed a visual classification of the 4 diagnostic pairs using 3D T1 MRI. Classifications were performed twice: first with standard radiological reading and then using SVM weight maps as a guide. Results: diagnostic performance was significantly improved by the use of the weight maps for the two junior radiologists in the case of FTD vs EOAD. Improvement was over 10 points of diagnostic accuracy. Conclusion: this tool can improve the diagnostic accuracy of junior radiologists and is easy to integrate in the clinical routine workflow.Introduction : de nombreux outils basés sur l'intelligence artificielle sont en cours de développement pour aider au diagnostic des démences en IRM. Cependant, ces outils sont jusqu'à présent difficiles à intégrer dans un flux de travail clinique de routine. Nous proposons une nouvelle façon simple, d’utiliser des outils issus de l’IA dans la pratique clinique neuroradiologique et d'évaluer leur impact sur les performances diagnostiques. Matériels et méthodes : nous avons étudié 34 patients atteints de la forme précoce de la maladie d'Alzheimer (EOAD), 49 de la forme tardive de la maladie d'Alzheimer (LOAD), 39 de démence fronto-temporale (DFT) et 24 de dépression ; issus de la cohorte préexistante CLIN-AD. A partir de séquences IRM 3D T1 des classifications automatiques par SVM (Support vector machine) ont été réalisées sur quatre paires de diagnostics : LOAD vs Dépression, FTD vs LOAD, EOAD vs Dépression, EOAD vs FTD. Nous avons extrait des cartes (Weight Maps : WMs) faisant apparaitre la pondération de la classification SVM, qui sont en pratique des représentations tridimensionnelles de modèles d'atrophie discriminants utilisés par le classificateur pour prendre ses décisions. Ces cartes furent imprimées afin que quatre radiologues (2 neuroradiologues et 2 internes) réalisent des classifications radiologiques des 4 paires diagnostiques, basées seulement sur les séquences 3 DT1. Deux séries de classifications ont été effectuées : d'abord avec une lecture radiologique standard et ensuite en utilisant les WMs comme guide. Résultats : les performances diagnostiques des deux internes ont été considérablement améliorées (plus de 10 points d’accuracy) par l'utilisation des WMs dans le cas DFT vs EOAD. Conclusion : cet outil permet d’améliorer la précision du diagnostic des internes en radiologie et est facile à intégrer dans un flux de travail clinique

Non-Hemorrhagic Adrenal Infarction during Pregnancy: The Diagnostic Imaging Keys

Background: non-hemorrhagic adrenal infarction (NHAI) is a rare cause of acute abdominal/flank pain during pregnancy; in order to ensure prompt and appropriate treatment, this diagnosis should not be overlooked. This case series highlights pertinent imaging findings, including ultrasounds (USs), computed tomography (CT), and magnetic resonance imaging (MRI) of recent NHAI cases. Methods: we compiled all consecutive NHAI cases from two university hospitals over a two-year period and checked the relevant clinical, laboratory, and imaging findings. Relevant articles on NHAI published from January 2010 to March 2021 were analyzed. Results: six cases were found in our database. CT-scans typically showed enlarged, hypodense, and non-enhanced adrenal glands. Unenhanced MRIs allowed for diagnoses and showed enlarged adrenal glands in the signal hyperintensity on T2 and diffusion-weighted imaging, without any signal hyperintensity on T1. In two of our six cases, USs showed swollen adrenal glands with fluid collection. Conclusion: NHAI and its differential diagnosis—in cases of acute pain during pregnancy—highlight the crucial roles of integrated radiological examination and cooperation between obstetricians and radiologists, both of whom should consider the location of the pain, the accessibility and tolerance of MRI, and the radiation exposure of CT. Despite its supposed poor sensitivity, an US performed because the patient reports pain should also be used to examine the adrenal gland regions. Non-enhanced MRI is clearly of value and access to it in emergencies is important to avoid radiation exposur

Impact of invasive plants in Mediterranean habitats: disentangling the effects of characteristics of invaders and recipient communities

International audienceWhile the effects of an invasive alien plant that has become dominant in a community may seem obvious, there are few studies that attempt to understand how impacts vary according to the characteristics of invaders and recipient communities. For this purpose, the vegetation of invaded and non-invaded plots was sampled for eight different invasive species in a variety of habitats within the French continental Mediterranean region. Most of the observed impact variation was species-specific, with greater effects on community-level metrics found for Carpobrotus spp. and Reynoutria x bohemica and lower effects for Amorpha fruticosa, Ambrosia artemisiifolia and Phyla filiformis. Some trends were consistent with competition-driven processes, with higher impact found in the presence of rhizomatous and creeping perennial invasive species compared to annuals, or in habitats with sparse vegetation. The importance of community characteristics such as the cover of the invasive plant or the differences in cover between the invader and the native dominant species confirmed previous results obtained in Central Europe. Therefore, such variables, easy to measure and with a generic value, could be profitably integrated into risk assessment methods to improve the prediction of the most threatened habitats. Beyond the overall decline in species diversity, the presence of some invasive species was associated with significant changes in species composition, with a filtering toward more shade-tolerant and nitrophilous ruderal species. Managers should consider replacement of resident species by species with different ecological preferences together with simple community-level metrics, to decide whether management is justified

MyHip: supporting planning and surgical guidance for a better total hip arthroplasty: A pilot study

Purpose: Total hip arthroplasty (THA) aims to restore patient mobility by providing a pain-free and stable artificial joint. A successful THA depends on the planning and its execution during surgery. Both tasks rely on the experience of the surgeon to understand the complex biomechanical behavior of the hip. We investigate the hypothesis that a computer-assisted solution for THA effectively supports the preparation and execution of the planning. Methods: We devised MyHip as a computer-assisted framework for THA. The framework provides pre-operative planning based on medical imaging and optical motion capture to optimally select and position the implant. The planning considers the morphology and range of motion of the patient's hip to reduce the risk of impingements and joint instability. The framework also provides intra-operative support based on patient-specific surgical guides. We performed a post-operative analysis on three patients who underwent THA. Based on post-operative radiological images, we reconstructed a patient-specific model of the prosthetic hip to compare planned and effective positioning of the implants. Results: When the guides were used, we measured non-significant variations of planned executions such as bone cutting. Moreover, patients' hip motions were acquired and used in a dynamic simulation of the prosthetic hip. Conflicts prone to implant failure, such as impingements or subluxations, were not detected. Conclusions: The results show that MyHip provides a promising computer assistance for THA. The results of the dynamic simulation highlighted the quality of the surgery and especially of its planning. The planning was properly executed since non-significant variations were detected during the radiological analysis

MyHip ::supporting planning and surgical guidance for a better total hip arthroplasty

Purpose : Total hip arthroplasty (THA) aims to restore patient mobility by providing a pain-free and stable artificial joint. A successful THA depends on the planning and its execution during surgery. Both tasks rely on the experience of the surgeon to understand the complex biomechanical behavior of the hip. We investigate the hypothesis that a computer-assisted solution for THA effectively supports the preparation and execution of the planning. Methods : We devised MyHip as a computer-assisted framework for THA. The framework provides pre-operative planning based on medical imaging and optical motion capture to optimally select and position the implant. The planning considers the morphology and range of motion of the patient’s hip to reduce the risk of impingements and joint instability. The framework also provides intra-operative support based on patient-specific surgical guides. We performed a post-operative analysis on three patients who underwent THA. Based on post-operative radiological images, we reconstructed a patient-specific model of the prosthetic hip to compare planned and effective positioning of the implants. Results : When the guides were used, we measured non-significant variations of planned executions such as bone cutting. Moreover, patients’ hip motions were acquired and used in a dynamic simulation of the prosthetic hip. Conflicts prone to implant failure, such as impingements or subluxations, were not detected. Conclusions : The results show that MyHip provides a promising computer assistance for THA. The results of the dynamic simulation highlighted the quality of the surgery and especially of its planning. The planning was properly executed since non-significant variations were detected during the radiological analysis