Back muscles activity and scoliosis in ataxic and dystrophic patients

To investigate the role of muscles in the development of adolescent idiopathic scoliosis (AIS), our group was initially interested in Duchenne muscular dystrophy (DMD) diseases where a muscular degeneration often leads to scoliosis. Few years ago the studies with those patients provided interesting results but were obtained only from few patients. To increase that number, the present project was initiated but recruitment of new DMD patients from Marie-Enfant hospital was found impossible. As an alternative, patients with Friedreich’s ataxia (FA) were recruited since they also suffer from a muscular deficiency which often induces a scoliosis. So, 4 FA patients and 4 healthy controls have been chosen to closely match the age, weight and body mass indexes (BMI) of the patients were enrolled in our experiments. As in the previous study, electromyography (EMG) activity of paraspinal muscles were recorded on each side of the spine during three types of contraction at 2 different maximum voluntary contractions (MVC). Moreover, the volume and skinfold thickness of these muscles were determined from ultrasound images (US) in order to facilitate the interpretation of EMG signals recorded on the skin surface. For the 3 FA right scoliotic patients, EMG activity was most of the time larger on the concave side of the deviation. The opposite was found for the 4th one (P4, left scoliosis, 32°) for whom EMG activity was larger on the convex side; it should however be noted that all his signals were of small amplitude. This was associated to a muscle weakness and a large skinfold thickness (12 mm) vs 7 mm for the 3 others. As for the paraspinal muscle volume, it was present on the convex side of P1, P3 and P4 and on the concave side for P2. As for skinfold thickness over this muscle, it was larger on the concave side for P1 and P2 and the opposite for P3 and P4. At the apex of each curve, the volume and skinfold thickness differences were the largest. Although the study covers only a small number of FA patients, the presence of larger EMG signals on the concave side of a spinal deformation is similar to pre-scoliotic DMD patients for whom the deformation is in its initial stage. It thus seems that our FA patients with more EMG activity on their concave side could see progression of their spinal deformation in the coming months in spite of their already important Cobb angle.Pour étudier le rôle des muscles dans le développement de la scoliose idiopathique de l’adolescent (SIA), d’abord notre groupe était intéressé par la myopathie de Duchenne (DMD) où une dégénérescence musculaire conduit souvent à la scoliose. Il y a quelques années, des résultats intéressants étaient obtenus par les études avec ces patients, mais seulement de quelques patients. Pour augmenter ce nombre, le présent projet a été lancé, mais le recrutement de nouveaux patients atteints de DMD a été trouvé impossible dans l’hôpital de Marie-Enfant. Comme alternative, les patients atteints de l’ataxie de Friedriech (AF) ont recruté qui provoque un affaiblissement musculaire menant souvent à une scoliose. Ainsi, 4 patients AF et 4 jeunes sains asymptomatiques constituant le groupe contrôle ont été recruté dans nos expériences. Comme dans l’étude précédente, les signaux électromyographiques (EMG) des muscles paraspinaux ont été captés lors de 3 types de contraction à deux différentes contractions volontaires maximales. En outre, l'épaisseur du pli cutané et du volume de ces muscles ont été déterminées à partir des images échographiques en vue de faciliter l’interprétation des signaux EMG enregistrés à la surface de la peau. Pour les 3 patients présentaient une scoliose à droite, une activité EMG a été la plupart du temps plus grande sur le côté concave de la déviation. Le contraire a été trouvé chez le 4ième patient (scoliose à gauche, 32°) chez qui l’activité EMG était plus grande sur le côté convexe. Il est à noter que ses signaux EMG étaient très faibles dû à une faiblesse musculaire et à une épaisseur du pli cutané plus grande (12 mm vs 7 mm) pour les 3 autres. En ce qui concerne le volume des muscles paraspinaux, il était plus grand du côté convexe pour P1, P3 et P4 et du côté concave pour P2. Quant à l'épaisseur du pli cutané au-dessus des paraspinaux, il était plus grand du côté concave pour P1 et P2 et c’était l'inverse pour P3 et P4. Ces différences de volume et d'épaisseur du pli cutané étaient plus grandes au voisinage de l’apex des courbes scoliotiques. Bien que l'étude ne porte que sur un petit nombre de patients atteints de l’ataxie de Friedreich (AF), la présence de signaux EMG plus grands du côté concave de leur déformation vertébrale est à le semblable de ce que nous avons observé chez les patients DMD chez qui une scoliose débutait, une plus grande activité EMG a été détectée sur le côté concave. Il semble donc que les patients AF ayant une activité EMG plus grande du côté concave, pourraient voir leur déformation progresser au cours des prochains mois malgré le fait que leur angle de Cobb soit déjà important

Advancements and Breakthroughs in Ultrasound Imaging

Ultrasonic imaging is a powerful diagnostic tool available to medical practitioners, engineers and researchers today. Due to the relative safety, and the non-invasive nature, ultrasonic imaging has become one of the most rapidly advancing technologies. These rapid advances are directly related to the parallel advancements in electronics, computing, and transducer technology together with sophisticated signal processing techniques. This book focuses on state of the art developments in ultrasonic imaging applications and underlying technologies presented by leading practitioners and researchers from many parts of the world

Développement de techniques de mesure dans le volume : photoélasticimétrie 3D pardécoupage optique et corrélation volumique par tomographie optique et rayons X.Application à l’étude des effets mécaniques 3D dans les structures et les biomatériaux.

This work is about developments of volume measurement techniques. Three approaches have been developed tostudy 3D mechanical effects in materials and structures. The first approach is the 3D photoelasticity technique byoptical slicing which enables us to observe principal stress or strain differences in transparent structures. Thesecond approach is the digital volume correlation (DVC) coupled with optical scanning tomography. DVC,which is the 3D extension of the Digital Image correlation (DIC), gives full 3D displacement and strain fields.Optical scanning tomography is a technique which generates volume images in transparent materials. The lastapproach is the DVC method coupled with X-ray micro-computed tomography. With this technique, it ispossible to generate volume images in non-transparent materials.Several mechanical tests with imposed displacement or deformation are presented in order to compare thesethree methods and to determine their application fields, theirs performances, their advantages and disadvantages.Concerning applications, 3D photoelasticity and DVC by optical slicing have been used for the experimentalanalysis of aeronautical spherical plain bearing behaviour in order to make more realistic a numerical simulation.Concerning non transparent materials, DVC and X-ray micro-computed tomography have been employed tostudy mechanical behaviour of cancellous bone.Le travail présenté dans ce mémoire concerne le développement de techniques de mesures dans le volume. Troisapproches ont été développées pour étudier les effets mécaniques 3D dans les matériaux et les structures. Lapremière est la photoélasticimétrie 3D par découpage optique qui permet d’observer les différences decontraintes ou de déformations principales au coeur de structures fabriquées dans un matériau transparent. Ladeuxième approche est la Corrélation d’Images Volumiques (CIV) associée à la tomographie par découpageoptique. La CIV, qui est l’extension en 3D de la corrélation d’images numériques, fournit les champsvolumiques des déplacements et des déformations. La tomographie par découpage optique est une techniqued’acquisition d’images volumiques dans les matériaux transparents. La dernière approche est la CIV associée àla microtomographie par rayons X. Celle-ci permet d’acquérir des images volumiques dans les matériaux nontransparents.Plusieurs essais expérimentaux de déplacements et de déformations sont présentés dans le but de confronter cestrois méthodes et afin de déterminer leurs champs d’applications, leurs performances, leurs avantages etinconvénients.En termes d’applications, la photoélasticimétrie 3D et la CIV par découpage optique sont utilisées pour l’analyseexpérimentale du comportement mécanique de rotules aéronautiques dans le but de rendre plus réaliste lamodélisation numérique des éléments rotulés. Concernant les matériaux non-transparents, la corrélationvolumique et la microtomographie par rayons X sont employées pour étudier le comportement mécanique de l’osspongieux

A Qualitative Exploration of the Experience and the Impact of HIV/STIs Among Polygamous Women in Muslim Society of Nigeria

Background The rationale for this study was developed from the personal and professional experience of the researcher living in a Muslim community in Nigeria where HIV/STIs are major health and social care problems. Most literature reviews on HIV/STIs and polygamy in Nigeria and in sub-Saharan Africa, have focused mainly on case studies and surveys. Aim This study explores the experience and impact of HIV/STIs on Muslim women living in polygamous marriages in Nigeria. The objectives of this study are to explore their perceptions, knowledge and awareness of HIV/STIs, examine the effect of polygamy and identify factors to empower Muslim women to protect themselves. Method The study adopts a qualitative approach, consisting of one-to-one in-depth interviews, within a feminist framework, with 20 women living in polygamous marriages in Nigeria. The qualitative approach was valuable because the words of the women who live in polygamous relationships cannot be quantified. A narrative, descriptive approach to the one-to-one in-depth interviews helped the researcher to listen and to describe their perspective; this was necessary because it is about their lived experience in polygamy. Using feminism, as the theoretical framework, offers an understanding of how polygamous women can be understood in relation to the dominant ideologies existing within a particular socio structure and it provides the lens to review the situation and suggest the necessary changes. The extract from the interview transcript was used to illustrate how the polygamous women’s accounts were explored in their own vernacular ways of speaking. Through the use of thematic analysis ten themes emerged. Findings Ten themes were initially identified and four concepts finally emerged after coding and recoding of the similarities. These are the four concepts that emerged. They are; Education, Testing, Condom usage and an Economic empowerment (ETCE) approach. This means that there is a need for education, especially sex education as well as economic empowerment. The women’s accounts in this study area highlight the problems that polygamous women frequently experience such that, they cannot negotiate their sexual needs and cannot refuse their husbands taking on additional wives, within this kind of marriage system. The knowledge systems of polygamous women were evaluated and positioned in terms of women’s subjectivity and experiential knowledge. This study reveals that polygamy creates asymmetrical positioning, such asymmetrical positioning creates unequal power positions, not only among spouses, but among the co-wives within the polygamous marriage. The ways in which these social relations are negotiated and experienced are shaped by religion and traditions. This study also reveals that power and gender issues are critical factors in disempowering polygamous women, as they appear to be voiceless on issues that affect them in their polygamous marriage. Therefore, this means that there is a need for sexual education and for an improvement in the socio-economic status of women. Conclusions Power and gender issues are critical factors in subordinating and disempowering polygamous women in their community; they are voiceless on their reproductive rights and limited in their option to control the spread of HIV/STIs. This study therefore, calls upon policy makers in Nigeria to consider these four concepts of Education, Testing, Condom Use and Economic empowerment (ETCE), as identified in the study, to help enhance the issue of economic empowerment of the polygamous women. Also this is to say that a window of opportunity exists; planners should develop partnerships with religious and community leaders to change the detrimental behaviours of polygamous men and women on issues of prevention and the control of HIV/STIs