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Muscle morphological parameters such as fascicle length (FL), pennationangle (PA) and physiologic cross-sectional area (PCSA) can provide an insightinto the reasons of the deteriorated muscle functions caused by pathologies.This study investigates the 3D structure of the lower leg muscles using 3Dfreehand ultrasound (3DfUS). This imaging modality uses a motion capturesystem to track the position of the US probe during acquisition and thusreconstruct the structure of the tissues in 3D. In this study, two subjects werescanned on the medial gastrocnemius (MG) and tibialis anterior (TA) musclesin the lower leg using 3DfUS system. The FL and PA of the muscles werecalculated and compared with the values previously measured using diffusiontensor imaging (DTI). The results using 3DfUS were averagely 19.2% largerin FL and 2.9%larger in PA. In conclusion, 3DfUS can successfully determinemuscle morphological parameters within a physiologically acceptable range.But the differences in FL observed between the two imaging modalities werequite big, which probably was due to the differences in sample size and area.The values can also differ greatly within the 3DfUS measurements as a resultof different manipulations during data processing, and the 3DfUS protocolneeds to be further improved in future studies.

Background: The risk of future injury appears to be influenced by agonist fascicle length (FL), joint range of motion (ROM) and eccentric strength. Biomechanical observations of the torque-angle-relationship further reveal a strong dependence on these factors. In practice, a longer FL improves sprinting performance and lowers injury risk. Classical stretching is a popular and evidenced-based training for enhancing ROM but does not have any effects on FL and injury risk. However, recent studies show that eccentric-only training (ECC) improves both flexibility and strength, and effectively lowers risk of injury. Objectives: To review the evidence on benefits of ECC for flexibility and strength. Methods: COCHRANE, PUBMED, SCOPUS, SPOLIT, and SPONET were searched for laboratory trials that compare ECC to at least one comparison group. Studies were eligible if they examined both strength and flexibility metrics in a healthy sample (<65 years) and met criteria for controlled or randomized clinical trials (CCT, RCT). 18 studies have been included and successfully rated using the PEDro scale. Results: 16 of 18 studies show strong evidence of strength and flexibility enhancements for the lower limb. While improvements between ECC and concentric training (CONC) were similar for eccentric (+19 ± 10% vs. +19 ± 11%) and isometric strength (+16 ± 10% vs. +13 ± 6%), CONC showed larger improvements for concentric strength (+9 ± 6% vs. +16 ± 7%). While for ROM ECC showed improvements (+9 ± 7%), no results could be found for CONC. The overall effectiveness of ECC seems to be higher than of CONC. Conclusion: There is clear evidence that ECC is an effective method for changes in muscle architecture, leading to both flexibility and strength improvements for the lower limb. Due to limited data no shoulder study could be included. Further research is needed for the upper body joints with a focus on functional and structural adaptions.

Background: Muscle thickness, pennation angle, and fascicle length describe the architecture of a muscle. These properties can be observed alongside subcutaneous fat thickness using ultrasonography; however, measurement is sensitive to the angle of the transducer against the skin. Typically, the transducer is held perpendicular to skin for imaging. Nonetheless, a convenient, reliable method to ensure transducer angle consistency has not been reported. Objectives: The purpose of this study was to determine the influence of transducer angle on muscle architecture and subcutaneous fat measurements of quadriceps muscles (vastus lateralis and rectus femoris) in healthy young adults. A secondary objective was to determine intra- and inter-rater reliability. Methods: Thirty men and women were recruited (25±2.5 years; BMI: 22.6±3.0 kg/m2). Ultrasound images were acquired from two muscles. An image was taken at an estimated perpendicular angle to the skin. Then, using a 3D-printed device with a protractor that attached to the ultrasound transducer, images were taken at measured angles 5-10˚ medial and lateral to perpendicular. Agreement and error were determined using intraclass correlation coefficients (ICCs) and standard error measurements (SEMs). Results: Good to excellent agreement was demonstrated for muscle and fat thicknesses regardless of transducer angle (ICC >0.66). Intra-rater reliability was excellent for all outcomes within both muscles (ICC >0.89). Inter-rater reliability for the rectus femoris was good to excellent for all transducer angles except for measurements of fascicle lengths at 85° (ICC: 0.33–0.99). Inter-rater reliability improved >20% for the vastus lateralis with the device. Conclusion: Measurements of muscle pennation angle and fascicle lengths, but not muscle or subcutaneous fat thicknesses, were sensitive to transducer angle. Reliability of pennation angle and fascicle lengths improved with the use of our device. Using our device, reliable muscle architecture measures can be made for the rectus femoris and the vastus lateralis in healthy young adults. / Thesis / Master of Science (MSc) / The arrangement of small muscle components, known as fascicles, can be observed in humans using ultrasound imaging. These fascicle arrangements can be measured to improve understanding of muscle function and disease processes. A potential problem of viewing muscle with ultrasound is that the angle of the probe head against the skin can alter the appearance of the muscle fascicles. The goal of this research was to improve current methods of ultrasound imaging of two thigh muscles. We have created a novel 3D-printed device to attach to the existing ultrasound probe. This 3D-printed device stabilizes the ultrasound probe head; and accurately determines the angles between the ultrasound probe head and the surface of the skin. In this study, the use of this device improved reliability of our ultrasound images by >20%. Future use of this device may improve measurements of muscle fascicles acquired with ultrasound imaging.

Les résultats des chirurgies orthopédiques correctrices sont difficilement prévisibles et, malheureusement, parfois infructueux. D’autres maladies résultantes d’un handicap majeur tel que l’escarre sont encore très peu comprises. Malgré une prévalence dans la population conséquente, peu d’études ont été menées sur ces thèmes. L’étude volumétrique du muscle en tant que tissu mou actif manque d’informations détaillées. Particulièrement les déformations et raideurs subséquentes aux contractions de muscles à arrangement de fascicules complexes. La modélisation volumétrique des muscles, fournirait un outil puissant pour la simulation personnalisée des contraintes subies par le corps, durant des contactes prolongés ou récurrents avec des dispositifs médicaux standards et inadaptés à la morphologie, mais aussi la planification d’opérations chirurgicales ou de séquences de stimulation électrique fonctionnelle. Il n’existe actuellement aucun logiciel permettant la reconstruction automatique de l’architecture des fascicules, aponévroses et tendons à partir d’acquisitions IRM d’un patient spécifique. La méthode actuelle de modélisation volumétrique du muscle est coûteuse en temps de calcul, donc inefficaces pour des simulations temps-réel du comportement du système musculo-squelettique avec représentation des fonctions physiologiques. Cette thèse est dirigée par les contributions nombreuses qui restent encore à apporter dans le domaine. Les méthodes de modélisation actuelles basées sur la méthode des éléments finis classique sont complexes, manquent de flexibilité ou de précision en temps-réel. Nous proposons une approche multi-modèles basée sur le mapping barycentrique qui découple la fonction de densité d’énergie de déformations du muscle en un ensemble de modèles indépendants de moindre complexité, avec les objectifs suivants : - Améliorer la reconstruction de l’architecture musculaire à partir des acquisitions IRM en terme de complexité et flexibilité. - Séparer la modélisation du muscle en modèles simple et indépendants, de manière à offrir plus de flexibilité, en réduisant la complexité, qui permettront de découpler les résolutions des éléments déformables des éléments actifs du muscle. - En diminuant le nombre d’éléments finis garantissant la cohérence des résultats, nous diminuons le temps de calcul nécessaire à chaque pas de simulation .Nos méthodes s’inspirent des travaux précédents sur la représentation tri-dimensionnelle de la géométrie et l’architecture complexes des muscles de [Blemker and Delp, 2005]. De plus, la définition mathématique est étudiée [Chi et al., 2010] pour caractériser la densité d’énergie de déformations du muscle squelettique. En rapport avec les méthodes précédentes, nous revendiquons les avancées suivantes : - Amélioration de la représentation 3D des muscles de patients spécifiques avec architecture et géométrie complexes, à partir de mesures IRM. La méthode est plus flexible et rapide que les précédentes. - Une nouvelle méthode de modélisation des déformations musculaires via la modélisation découplée des différents tissus musculaires. Cette nouvelle approche permet une définition indépendante des fascicules musculaires, tissus conjonctifs, tendons et aponévroses en gardant une grande précision de déformations. Les performances sont confrontées au rendement de la méthode FEM classique. - Nous atteignons des vitesses de simulation élevées de muscles complexes sur des machines standards par rapport à la FEM. Les performances nous ont permis de simuler en temps-réel la force et les déformations d’un muscle d’individus spécifiques, avec une entrée d’activation actualisée en temps-réel à partir de mesures EMG. - La modélisation d’un muscle nécessite plus de compétence qu’une équipe de recherche peut envisager maitriser. L’approche multi-modèles permet un travail collaboratif, où chaque spécialiste se focalise uniquement sur son domaine de compétence. La modélisation en est extrêmement simplifiée. / Corrective orthopedic surgeries results are difficult to be predicted and, unfortunately, sometimes unsuccessful. Other diseases resulting from a motor disability as bedsores are still poorly understood, despite a significant prevalence in the population. However, studies on these topics still insufficient especially for the analysis considering the muscle as a soft tissue volumetric organ. Muscle fascicule architectures and their correlation with movement efficiency is poorly documented, it lack of the detailed information regarding its volumetric deformations and stiffness changes along with muscle contractions.Muscle volumetric modeling, would provide a powerful tool for the personalized accurate simulation of body stresses of disabled or SCI patients during prolonged or friction contacts with standard medical devices non-adapted to particular morphologies, but also the planning of surgeries or functional electrical stimulation sequences.There is currently no software for automatic reconstruction of the architecture of fascicles, aponeurosis and tendons from MRI acquisitions of a specific subject. Actual volumetric muscle modeling is expensive in computational time, and not effective for real-time simulations of musculoskeletal system behavior with representation of physiological functions. The objective of this thesis is directed by the many contributions that have yet to make in the area. The current modeling methods based on the conventional finite element method are complex, inflexible or inaccurate in real-time. We propose a multi-model based on barycentric mapping approach that decouples the muscle strain density energy function into a set of independent less complex models, with the following objectives:- Improve complex muscle architecture reconstruction from the MRI acquisitions in term of complexity and flexibility.- Split muscle modeling into simple independent models, to offer more flexibility and reducing complexity of modeling which allows to have independent resolutions between deformable elements and muscle fiber elements..- By reducing the number of finite elements ensuring consistency of results of force and deformations, we reduce the computation time required for each simulation.Our methods are inspired by the previous work on the three-dimensional representation of the geometry and the complex architecture of muscles [Blemker and Delp, 2005]. In addition, the mathematical definition is studied [Chi et al., 2010] to characterize the energy density of deformations of skeletal muscle.Related with the above methods, we demand the following advances:- Improved three-dimensional representation of specific patients with muscle architecture and complex geometry from MRI measurement for personalized modeling. The method is more flexible and faster than previous.- A novel modeling method for muscle deformation via decoupled modeling of solid and muscle fiber mechanics is established. This new modeling allowed independent definitions between deformable elements and fiber force generation elements while keeping its muscle deformation accuracy. The performance is compared to conventional FEM method. - We reach high computational speed on standard machines for muscle complex simulations compared to FEM. Real-time simulation of specific person’s muscle strain and force is performed with an activation input updated in real-time from surface EMG measures.- Muscle modeling requires interdisciplinary knowledge from different research team members. The multi-model approach allows collaborative work, where each specialist focuses only on its area of expertise thanks to the modular designed modeling.

The Heart's Portrait is a twelve movement composition for SATB choir and string quartet. The eight poems selected as the text for this work were penned by the eminent American poet Emily Dickinson. The text for the first movement, Dickinson's poem "If I can stop one Heart from breaking," succinctly describes the themes she commonly expounded upon in her writings: life, love, aching, pain, and purpose through faith. The remaining seven poems were chosen because they also explore these elemental themes. The main poem returns in variation throughout the piece, resulting in a modified rondo. To complement the four-part consort of voices, I selected a consort of strings in the form of a string quartet. The role of the quartet varies throughout the work from subservient to the vocal part, to dominant of the entire texture, to an equal partnership with the voices; these relationships are dictated by the text. Throughout the movements, I was able to explore a range of compositional techniques, both traditional and contemporary, while maintaining the primary purpose of unifying the text and music. This paper illustrates the initial compositional decisions made to begin the piece, the texts chosen and their placement within the work, the poet's history as it relates to the composition, a brief discussion on composers who have set Dickinson's words, and a thorough analysis of the work itself.

La parésie spastique est souvent envisagée comme une atteinte de la commande motrice, comportant une parésie de l’agoniste et une hyperactivité de l’antagoniste. Cependant, une seconde affection d’ordre musculaire - la myopathie spastique, apparait rapidement, pendant la phase aigüe après la lésion. L’hypomobilisation en position courte de certains muscles dans le contexte d’une parésie des muscles opposés s’accompagne d’une perte de leur tension longitudinale, première étape d’une cascade de transformations génétiques, structurelles, biomécaniques puis physiologiques des muscles hypomobilisés, incluant entre autres une perte de leur extensibilité et de leur longueur. Aux stades subaigu puis chronique du syndrome, les affections neurologique et musculaire coexistent, et semblent s’entretenir mutuellement.Sur le plan physiopathologique, ce travail de recherche s’est d’abord intéressé à ces intrications entre les affections neurologique et musculaire, et à la part de responsabilité potentielle de la myopathie spastique dans la fonction active. Ce premier travail a montré que le degré d’hypoextensibilité musculaire d’un antagoniste, au-delà d’un certain seuil, est corrélé au degré de perturbation de la commande motrice dirigée sur l’agoniste. La chronologie des différents événements établie dans la littérature, avec des anomalies histologiques musculaires qui apparaissent toujours avant les premières manifestions d’hyperactivité motoneuronale, amène à suggérer une responsabilité causale de la maladie du muscle dans une partie des perturbations ultérieures de la commande neuronale descendante. Ce rôle probablement essentiel de la maladie musculaire au sein de la parésie spastique doit inciter le clinicien à orienter une part significative de son traitement vers une stimulation optimale de la plasticité musculaire pour tenter de prévenir ou d’inverser le processus de myopathie spastique.Si l’étirement est depuis très longtemps une technique courante, sa capacité à augmenter durablement l’extensibilité musculaire est aujourd’hui controversée, même si ses effets à long terme, i.e. au-delà de six mois d’application quotidienne, n’ont pas été explorés.La deuxième partie, thérapeutique, de ce travail a donc été l’étude des effets à long terme d’un programme quotidien d’auto-étirements de haute intensité au sein de la méthode des Contrats d’Autorééducation Guidée, pendant un an ou plus. Il a d’abord été rétrospectivement montré que ce programme avait permis, sur trois années de suivi de sujets parétiques, une amélioration progressive importante de l’extensibilité musculaire mesurée cliniquement. Un essai randomisé contrôlé contre la kinésithérapie conventionnelle avec mesures échographiques de paramètres structuraux des muscles étirés a ensuite établi que l’application de ce programme durant un an chez des sujets atteints d’hémiparésie chronique sur AVC générait une augmentation de la longueur fasciculaire des muscles fléchisseurs plantaires, parallèlement à une amélioration de la fonction active, de façon nettement plus importante que la thérapie conventionnelle.L’ensemble de ces résultats doit participer à une meilleure prise en compte des altérations passives structurelles évolutives du muscle comme une entité nosologique, la myopathie spastique, méritant un traitement spécifique au sein de la parésie spastique, afin de limiter ses interactions avec la maladie neurologique et de réduire les déficits fonctionnels. La pratique quotidienne de postures d’auto-étirement à haute intensité, guidée par un thérapeute et auto-documentée par le patient sur un registre, peut être prescrite et réalisée sur le long terme, afin de traiter la myopathie spastique. / Spastic paresis is often understood as a neurologic disorder of the motor command that includes agonist paresis and antagonist overactivity. However, a second disorder, involving the muscle and named spastic myopathy, appears rapidly during the acute phase after the lesion. Hypo-mobilization in shortened position of some muscles of the paretic limbs, in the context of paresis of their antagonists, will reduce their longitudinal tension, which acts as the first event of a cascade of transformations involving genetic, structural, biomechanical, and then physiological mechanisms, leading to loss of muscle extensibility and length. At the subacute and chronic stages of this syndrome, the neurological and the muscular disorders coexist, seemingly feeding on each other.From a pathophysiological point of view, this research work started by exploring the entanglements between the neurological and muscular disorders, and the potential responsibility of spastic myopathy in the impairment of active function. The first study demonstrated that the loss of muscle extensibility in antagonists, when above a certain threshold, correlates with the degree of disturbance of the motor command directed to the agonist. The chronology of events established in the literature, with histological muscle abnormalities emerging always before the first expressions of motoneuronal overactivity, suggests a causal role of the muscle disorder in a part of the descending command disorder. The crucial role of the muscle disorder in the syndrome of spastic paresis should encourage clinicians to direct treatment towards techniques to stimulate muscle plasticity.Despite the classic use of muscle stretching in daily practice, its potential to increase muscle extensibility remains a subject of controversy, even though its long-term effects, i.e. over six months of daily implementation, have not been investigated. The second part of this work was thus therapeutic. We retrospectively explored the long-term effects of a daily, high load self-stretching programme within the Guided Self-rehabilitation Contract method, for at least a year. This work showed that this programme, applied over three years in paretic subjects, was increasingly associated with major gains in clinical muscle extensibility. A randomized controlled trial against conventional therapy, which used ultrasound exploration of structural parameters in the stretched muscles, demonstrated that this programme, applied over one year in subjects with stroke-induced chronic hemiparesis, enabled greater increase in plantar flexor fascicle length and active function improvement than conventional therapy.Taken together, these results will contribute to enhancing the knowledge about the evolving structural and mechanical muscle changes in spastic paresis, as a pathologic entity, spastic myopathy. Spastic myopathy needs to be specifically addressed, as it interacts with the neurological disorder and worsens functional impairment. Daily postures of high load self-stretch, guided by the therapist and self-monitored on a diary, should be prescribed and practiced over the long term, in order to treat spastic myopathy in subjects with spastic paresis.

In der vorliegenden Studie wurde daher den Einfluss exzentrischen Trainings, mit unterschiedlicher Reizmagnitude, Bewegungsgeschwindigkeit und Muskellänge bei Reizapplikation, auf die Adaptation des M. vastus lateralis (VL) untersucht. Die 31 Studienteilnehmer wurden randomisiert in zwei Trainings- und eine Kontrollgruppe aufgeteilt. Die Trainingsgruppen führten 30 Trainingseinheiten mit exzentrischem Training der Knieextensoren an einem Isokineten durch. Gruppe 1 (n=10) trainierte ein Bein mit 65% der maximalen willkürlichen isometrischen Kontraktion (MVC) und das andere Bein mit 100% MVC, bei einer Winkelgeschwindigkeit von 90°/s und einem Kniewinkel von 25°-100°. Gruppe 2 (n=10) trainierte beide Beine mit 100% MVC, ein Bein aber mit einer Winkelgeschwindigkeit von 90°/s in einem Kniewinkel von 25°-65° und das andere Bein mit 240°/s und 25°-100°. In der Pre- und Postmessung wurde die VL Muskelfaserlänge mittels Ultraschall bestimmt und die Moment-Winkel- und Leistungs-Winkelgeschwindigkeitsrelation mit einem Dynamometer erfasst. Die Ergebnisse zeigen nur für Bein mit 240°/s eine signifikante (p / The present study investigated the effects of magnitude, velocity and muscle length at which the eccentric stimulus is applied on the longitudinal adaptation of the vastus lateralis muscle (VL). The 31 participants were randomly assigned into two experimental groups to perform 30 sessions of eccentric training for the knee extensors (3 times/week) and one control group. The first experimental group (n=10) exercised one leg at 65% of maximum voluntary isometric contraction (MVC) and the second leg at 100% MVC at 90°/s from 25° to 100° knee angle on an isokinetic device (Biodex 3). The second experimental group (n=10) exercised one leg at 100% MVC at 90°/s from 25° to 65° knee angle and the other leg at 100% MVC at an angular velocity of 240°/s from 25° to 100° knee angle. In pre and post measurements the fascicle length of the VL was examined by ultrasonography and the moment-angle and power-angular velocity relationship of the knee extensors with a dynamometer. The results showed an increase (p