Search

Introduction: In the last decade, fascia research increased significantly in various aspects such as anatomical and biomechanical features related to epimuscular force transmission. Methods: The present anatomic study focuses on macroscopic observations of the potential gracilis and semitendinosus paratenons, as well as fascial surroundings connections in the posteromedial knee region on 17 lower-limbs dissections. Results: The gracilis and semitendinosus expansions and paratenons were observed in all specimen and further connections with the fascia lata and crural fascia were demonstrated. Contrary to the previously described expansions connected to the tendons, we observed that the expansions were the edges of the paratenon tunnel and that the paratenon structure surrounded the overall muscle. Both paratenons of gracilis and semitendinosus were connected to the crural fascia and, respectively, to the sartorius fascia (part of the fascia lata), to the semimembranosus and the fascia lata. Furthermore, numerous connections between the fascia lata and the neighboring structures in the posteromedial knee region are described. Discussion–conclusion: The present study describes for the first time gracilis and semitendinosus paratenons and other surrounding fascial connections. Such macroscopic observations may represent a new basis for further characterization of the myofascial pathway of epimuscular force transmission in the knee region. [ABSTRACT FROM AUTHOR]

Various studies have examined morphometric features of the vertebrae to understand the functional aspects of the spine. Geometric analysis of vertebral zygapophyseal facets has also been related to functional and clinical aspects of the spine, but no quantitative investigation of the costotransverse joint facet is found in the literature. The costal facet geometry may partly determine the mechanical interaction between the rib cage and spine for trunk stabilization during functional tasks and during breathing. Therefore, the present study proposes a method for estimating the 3D geometric features of the costal facets of the first 10 thoracic vertebrae (Th1–Th10). Series of landmarks (95 ± 43) were placed on 258 costal facets from a sample of 14 asymptomatic individuals to determine their 3D location and orientation. The relative location of the costal facet was used to investigate symmetry and asymmetry components of the overall vertebrae shape variation among thoracic levels using 3D geometric morphometric methods. Results showed significant variation in sagittal orientation (inclination angle) between levels with a gradual cephalic orientation in the lower levels. No significant difference was observed on transverse orientation (declination angle). The shape of the costal facet was flatter at Th1 and from Th5 to Th10 and more concave from Th2 to Th4. An average difference of 7° between right and left facet orientation in both sagittal and transverse plane was demonstrated. Asymmetry of costal facet relative location was also detected and significantly influenced by the thoracic level. Nevertheless, location and orientation of the costal facets seem to be independent features of vertebrae morphology. [ABSTRACT FROM AUTHOR]

Context: The motion of the upper cervical spine (UCS) has a great interest for analyzing the biomechanical features of this joint complex, especially in case of instability. Although investigators have analyzed numerous kinematics and musculoskeletal characteristics, there are still little data available regarding several suboccipital ligaments such as occipito-atlantal, atlantoaxial, and cruciform ligaments. Objective: The aim of this study is to quantify the length and moment arm magnitudes of suboccipital ligaments and to integrate data into specific 3D-model, including musculoskeletal and motion representation. Materials and Methods: Based on a recent method, suboccipital ligaments were identified using UCS anatomical modeling. Biomechanical characteristics of these anatomical structures were assessed for sagittal and transversal displacements regarding length and moment arm alterations. Results: Outcomes data indicated length alterations >25% for occipito-atlantal, atlanto-axial and apical ligaments. The length alteration of unique ligaments was negligible. Length variation was dependent on the motion direction considered. Regarding moment arm, larger magnitudes were observed for posterior ligaments, and consistent alteration was depicted for these structures. Conclusion: These outcomes supply relevant biomechanical characteristics of the UCS ligaments in flexion-extension and axial rotation by quantifying length and moment arm magnitude. Moreover, 3D anatomical modeling and motion representation can help in the process of understanding of musculoskeletal behaviors of the craniovertebral junction. [ABSTRACT FROM AUTHOR]

This paper aims at contributing to the understanding of the combination of in vivo sternum displacement, sternal angle variations and sternocostal joints (SCJ) kinematics of the seven first rib pairs over the inspiratory capacity (IC). Retrospective codified spiral-CT data obtained at total lung capacity (TLC), middle of inspiratory capacity (MIC) and at functional residual capacity (FRC) were used to compute kinematic parameters of the bones and joints of interest in a sample of 12 asymptomatic subjects. 3D models of rib, thoracic vertebra, manubrium and sternum were processed to determine anatomical landmarks (ALs) on each bone. These ALs were used to create local coordinate system and compute spatial transformation of ribs and manubrium relative to sternum, and sternum relative to thoracic vertebra. The rib angular displacements and associated orientation of rotation axes and joint pivot points (JPP), the sternal angle variations and the associated displacement of the sternum relative to vertebra were computed between each breathing pose at the three lung volumes. Results can be summarized as following: (1) sternum cephalic displacement ranged between 17.8 and 19.2 mm over the IC; (2) the sternal angle showed a mean variation of 4.4° ± 2.7° over the IC; (3) ranges of rib rotation relative to sternum decreased gradually with increasing rib level; (4) axes of rotation were similarly oriented at each SCJ; (5) JPP spatial displacements showed less variations at first SCJ compared to levels underneath; (6) linear relation was demonstrated between SCJ ROMs and sternum cephalic displacement over the IC. [ABSTRACT FROM AUTHOR]

This study investigates the relationship between the motion of the first ten costovertebral joints (CVJ) and lung volume over the inspiratory capacity (IC) using detailed kinematic analysis in a sample of 12 asymptomatic subjects. Retrospective codified spiral-CT data obtained at total lung capacity (TLC), middle of inspiratory capacity (MIC) and at functional residual capacity (FRC) were analysed. CVJ 3D kinematics were processed using previously-published methods. We tested the influence of the side, CVJ level and lung volume on CVJ kinematics. In addition, the correlations between anthropologic/pulmonary variables and CVJ kinematics were analysed. No linear correlation was found between lung volumes and CVJ kinematics. Major findings concerning 3D kinematics can be summarized as follows: 1) Ranges-of-motion decrease gradually with increasing CVJ level; 2) rib displacements are significantly reduced at lung volumes above the MIC and do not differ between CVJ levels; 3) the axes of rotation of the ribs are similarly oriented for all CVJ levels. [ABSTRACT FROM AUTHOR]

The literature concerning quantification of costovertebral joint (CVJ) motion under in vivo conditions is scarce. Most papers concerning this topic are related to ex vivo loading conditions. In vivo protocols are available from the literature to determine rib and vertebra kinematics but new developments are needed to improve data processing concerning CVJ behaviour obtained from discrete breathing positions showing limiting ranges-of-motion and sensitive to noise. Data from previous work were used to implement a method analyzing mean helical axis (MHA) and pivot point parameters of the CVJ complexes. Several levels of noises were estimated within Monte-Carlo simulations to optimize MHA results. MHA parameters were then used to transform and define a CVJ-specific local coordinate system. This study proposes an improvement for CVJ kinematics processing and description from in vivo data obtained from computed tomography. This methodology emphasizes the possibility to work with variability of MHA parameters using Monte-Carlo procedures on anatomical landmark coordinates and to define a local coordinate system from this particular joint behaviour. Results from the CVJ joint model are closer to a hinge joint (secondary motions inferior to 3°) when anatomical frames are expressed from MHA orientation. MHA orientation and position data obtained from the proposed method are relevant according to angular dispersion obtained (from 7.5° to 13.9°) and therefore relevant to define behaviour of CVJ [ABSTRACT FROM AUTHOR]

To date, kinematics data analyzing continuous 3D motion of upper cervical spine (UCS) manipulation is lacking. This in vitro study aims at investigating inter- and intra-operator reliability of kinematics during high velocity low amplitude manipulation of the UCS. Three fresh specimens were used. Restricted dissection was realized to attach technical clusters to each bone (skull to C 2 ). Motion data was obtained using an optoelectronic system during manipulation. Kinematics data were integrated into specific-subject 3D models to provide anatomical motion representation during thrust manipulation. The reliability of manipulation kinematics was assessed for three practitioners performing two sessions of three repetitions on two separate days. For pre-manipulation positioning, average UCS ROM (SD) were 10° (5°), 22° (5°) and 14° (4°) for lateral bending, axial rotation and flexion–extension, respectively. For the impulse phase, average axial rotation magnitude ranged from 7° to 12°. Reliability analysis showed average RMS up to 8° for pre-manipulation positioning and up to 5° for the impulse phase. As compared to physiological ROM, this study supports the limited angular displacement during manipulation for UCS motion components, especially for axial rotation. Kinematics reliability confirms intra- and inter-operator consistency although pre-manipulation positioning reliability is slightly lower between practitioners and sessions. [ABSTRACT FROM AUTHOR]

Abstract: Background: The costovertebral joint complex is mechanically involved in both respiratory function and thoracic spine stability. The thorax has been studied for a long time to understand its involvement in the physiological mechanism leading to specific gas exchange. Few studies have focused on costovertebral joint complex kinematics, and most of them focused on experimental in vitro analysis related to loading tests or global thorax and/or lung volume change analysis. There is however a clinical need for new methods allowing to process in vivo clinical data. This paper presents results from in vivo analysis of the costovertebral joint complex kinematics from clinically-available retrospective data. Methods: In this study, in vivo spiral computed tomography imaging data were obtained from 8 asymptomatic subjects at three different lung volumes (from total lung capacity to functional residual capacity) calibrated using a classical spirometer. Fusion methods including 3D modelling and kinematic analysis were used to provide 3D costovertebral joint complex visualization for the true ribs (i.e., first seven pairs of ribs). Findings: The 3D models of the first seven pairs of costovertebral joint complexes were obtained. A continuous kinematics simulation was interpolated from the three discrete computerized tomography positions. Helical axis representation was also achieved. Interpretation: Preliminary results show that the method leads to meaningful and relevant results for clinical and pedagogical applications. Research in progress compares data from a sample of healthy volunteers with data collected from patients with cystic fibrosis to obtain new insights about the costovertebral joint complex range of motion and helical axis assessment in different pathological conditions. [Copyright &y& Elsevier]

Purpose: The lacertus fibrosus (LF) is involved in various surgeries. However, the biomechanical contribution of the LF remains unclear. The aim of this study was to determine the role of the lacertus fibrosus on the elbow and forearm kinematics and on the biceps brachii muscle lever arms. Methods: This biomechanical study was performed on seven fresh-frozen upper limbs of cadavers. Elbow flexion, forearm supination, and biceps brachii muscle lever arms were analyzed in the intact conditions (I) and after superficial (R) and deep part (R2) of the lacertus fibrosus release, respectively. Results: Elbow flexion shows a significant difference (p < 0.0001) between I, R, R2. Abduction/adduction shows a significant difference between I-R (p < 0.0001) and I-R2 (p < 0.0001). Supination does not show a significant difference in mean maximum amplitude, but between 40 and 70%, there are significant differences. There is a significant mean decrease of lever arm in flexion (28%) and supination (50%) after superficial and deep part of the lacertus fibrosus release. Conclusion: The results of this study show that the lacertus fibrosus increases the lever arm during flexion and supination. It limits the flexion and abduction of the elbow and supination of the forearm. Lacertus fibrosus maintains the rhythmicity between the elbow flexion and supination of the forearm. Level of evidence: Basic science study, biomechanics [ABSTRACT FROM AUTHOR]

Introduction Les amplitudes de mouvements du rachis cervical peuvent être modifiées en fonction de la vitesse d’exécution des taches réalisées (1). Cela peut aussi influencer la coordination lombo-pelvienne chez le sujet sains (2). Cependant, aucune étude n’a analysé l’effet de la vitesse d’exécution au niveau du rachis lombo-pelvien chez des patients ayant bénéficié d’une intervention chirurgicale du rachis. Matériel et méthodes Quarante-deux sujets asymptomatiques et 20 patients opérés par arthrodèse de la colonne lombaire ont été inclus dans l’étude. En complément de divers marqueurs anatomiques, deux clusters ont été placés au niveau du bassin et au niveau de la charnière thoracolombaire. La cinématique des clusters a été calculée lors de mouvements de flexion/extension, inclinaisons latérales et rotations lors de mouvements réalisés selon deux vitesses d’exécution : préférentielle (BEST) et rapide (FAST). Résultats Chez les sujets sains, la vitesse d’exécution a une influence seulement sur les amplitudes de rotation. Chez les sujets arthrodésés, les amplitudes de mouvement sont significativement supérieures lors de la modalité FAST, ceci dans les trois plans. En comparaison avec les sujets sains, lors de la modalité BEST, les sujets arthrodésés ont une limitation significative des amplitudes de l’ordre de 51 % en flexion-extension, 53 % en inclinaisons latérales et 67 % en rotation. Lors de la modalité FAST, les sujets arthrodésés présentent des amplitudes limitées seulement en flexion/extension. Discussion–conclusion Les résultats préliminaires montrent l’intérêt d’évaluer la cinématique et la coordination lombo-pelvienne selon des modalités d’exécution différentes. En effet, les différences significatives d’amplitudes dans les trois plans sont observées seulement lors d’une tâche réalisée à vitesse préférentielle. Cependant, les résultats doivent être pris avec précaution. En effet, les classes d’âge des deux échantillons diffèrent. La taille de l’échantillon de sujets sains de même classe d’âge que les sujets arthrodésés sera augmentée dans une étude ultérieure. [ABSTRACT FROM AUTHOR]

Introduction De précédentes études ont analysé la cinématique segmentaire des articulations costo-vertébrales en lien avec les volumes pulmonaires déplacés durant la respiration (Beyer et al., 2014, 2016). Les études chez l’humain rapportant une analyse quantifiée du mouvement du sternum, de l’angle sternal ainsi que de la cinématique des articulations sternocostales durant la respiration sont rares. Le but de ce travail était d’obtenir une reconstruction 3D de ces paramètres couplant visualisation et quantification. Matériel et méthodes Des données tomodensitométriques in vivo réalisées à trois volumes pulmonaires (à la capacité pulmonaire totale [CPT], la moitié de la capacité inspiratoire [CIM] et à la capacité résiduelle fonctionnelle [CRF]) ont été analysées chez 12 sujets sains. Des référentiels anatomiques ont été créés par la méthode de palpation virtuelle de marqueurs anatomiques sur les reconstructions 3D des structures osseuses d’intérêt, en se focalisant sur les côtes dites « sternales ». La cinématique a été calculée par les méthodes de l’axe hélicoïdal fini (AHF) et moyen (AHM) à l’aide du logiciel lhpFusionbox (Van Sint Jan et al., 2013). Résultats Les amplitudes de mouvement sternocostales diminuent graduellement au niveau des côtes inférieurs. L’orientation des AHM ne diffère pas en fonction de l’étage costal considéré. La dispersion des centres instantanés de rotation augmente graduellement dans les étages inférieurs. L’angle sternal varie durant le mouvement respiratoire. Il existe une corrélation significative entre les amplitudes de mouvement costaux segmentaires et le déplacement vertical du sternum. Discussion–conclusion Cette étude est la première rapportant une analyse quantifiée de la cinématique des jonctions sternocostales couplée à une représentation 3D. Les résultats indiquent des mouvements plus contraints au niveau du premier étage sternocostal. Ces résultats pourraient être utiles pour la modélisation du thorax dans des contextes pathologiques. Cette étude ouvre des pistes de réflexion en rapport à l’évaluation des mouvements respiratoires à partir du déplacement vertical du sternum. [ABSTRACT FROM AUTHOR]

Biomechanical simulation of the human thorax, e.g. for 3D-printed rib implant optimisation, requires an accurate knowledge of the associated articulation and tissue stiffness. The present study is focusing on determining the stiffness of the costo-vertebral articulations. Specimens of rib segments including the adjacent thoracic vertebrae and ligaments were obtained from two human post-mortem bodies at four different rib levels. The rib samples were loaded with a tensile force in the local longitudinal, sagittal and transverse direction and the resulting displacement was continuously measured. The moment–angle response of the rib articulations was also determined by applying a load at the rib end in the cranial – caudal direction and measuring the resulting displacement. The torsional load response of the costo-vertebral articulations at an applied moment between −0.1 Nm and 0.1 Nm corresponded to a median range of motion of 13.2° (6.4° to 20.9°). An almost uniform stiffness was measured in all tensile loading directions. The median displacement at the defined force of 28 N was 1.41 mm in the longitudinal, 1.55 mm in the sagittal, and 1.08 mm in the transverse direction. The measured moment–angle response of the costo-vertebral articulation is in line with the data from literature. On the contrary, larger displacements in longitudinal, sagittal and transverse directions were measured compared to the values found in literature. [ABSTRACT FROM AUTHOR]

• The diaphragm of extinct Homo might have been deeper and flatter than that of H. sapiens. • Size of fossil diaphragm estimations are within the H. sapiens range of variation. • Breathing kinematics might have been different in fossil Homo. [ABSTRACT FROM AUTHOR]

Introduction En stéréophotogrammétrie optoélectronique, les angles articulaires et planaires sont obtenus à partir des marqueurs placés sur le sujet. Dans la réalité clinique (âge, pathologies…), répondre aux exigences de placement d’un modèle de segmentation du pied n’est pas toujours chose aisée. Le choix d’un modèle (Rizzoli, Oxford, Milwaukee, Heidelberg, Mac Williams, L.A.B.O.) masque la similitude des sets de marqueurs utilisés. Notre modèle a donc été optimisé afin de permettre le calcul de ces angles en fonction des marqueurs présents (liés à la taille et aux déformations du pied) et de répondre à la question posée. Cette approche permet également la comparaison de certains de ces modèles. Matériel et méthodes Ce set comprend un cluster et seize marqueurs placés sur les repères anatomiques du pied. Il s’intègre à un modèle complet de la marche et au Plug-in-Gait . Les trajectoires de marqueurs ont été enregistrées par 8 caméras T40s (VICON). Les angles articulaires et planaires des patients sont comparés à deux bases de données normatives : l’une à partir d’un groupe contrôle de 25 adultes et l’autre de 17 enfants, tous asymptomatiques. Chaque sujet a réalisé une acquisition statique et cinq marches. Résultats Pour exemple, chez l’adulte, l’arche longitudinale médiale est calculée en statique et lors de la phase d’appui selon : – Rizzoli : statique : 136° (9°) ; dynamique : 138° (8°) ; ROM : 4° (2°) ; – Heidelberg : statique : 144° (8°) ; dynamique : 144° (7°) ; ROM : 4° (2°) ; – clinique : statique : 158° (8°) ; dynamique : 157° (8°) ; ROM : 5° (3°). Discussion–conclusion Opter pour une approche « set de marqueurs » plutôt que modèle-dépendant permet plus de souplesse dans la description de la cinématique multisegment du pied. Constituer une base de données normatives « multimodale » est une de nos options future. [ABSTRACT FROM AUTHOR]

Surgical resection of chest wall tumours may lead to a loss of ribcage stability and requires reconstruction to allow for physical thorax functioning. When titanium implants are used especially for larger, lateral defects, they tend to break. Implant failures are mainly due to specific mechanical requirements for chest-wall reconstruction which must mimic the physiological properties and which are not yet met by available implants. In order to develop new implants, the mechanical characteristics of ribs, joints and cartilages are investigated. Rib loading is highly dependent on the global thorax kinematics, making implant development substantially challenging. Costal cartilage contributes vastly to the entire thorax load-deformation behaviour, and also to rib loading patterns. Computational models of the thoracic cage require mechanical properties on the global stiffness, to simulate rib kinematics and evaluate stresses in the ribs and costal cartilage. In this study the mechanical stiffness of human costal cartilage is assessed with bending, torsion and tensile tests. The elastic moduli for the bending in four major directions ranged from 2.2 to 60.8 MPa, shear moduli ranged from 5.7 to 24.7 MPa for torsion, and tensile elastic moduli ranging from 5.6 to 29.6 MPa. This article provides mechanical properties for costal cartilage. The results of these measurements are used for the development of a whole thorax finite element model to investigate ribcage biomechanics and subsequently to design improved rib implants. [ABSTRACT FROM AUTHOR]

Introduction Les mesures cliniques pour déterminer le type de pied sont toutes réalisées en position statique. Deux conditions doivent être réunies pour qu’une mesure statique du pied soit pertinente à intégrer dans un examen clinique : son haut degré de reproductibilité inter- et intra-examinateur (Van Gheluwe, 2012) et sa valeur prédictive dans le comportement dynamique du pied (Mac Poil, 2005). Le set de marqueurs de notre modèle de segmentation du pied (MSP) a donc été optimisé afin de calculer différentes mesures cliniques entre 20 % et 45 % du cycle de marche (Sangeux, 2015) et de les corréler à la posture du pied. Matériel et méthodes Notre MSP est construit à partir d’un cluster et 13 marqueurs placés sur des repères anatomiques. La trajectoire des marqueurs a été enregistrée par stéréophotogrammétrie optoélectronique (VICON T40s) afin de calculer les angles cinématiques et planaires. Dix-neuf adultes asymptomatiques ont réalisé une acquisition statique et cinq marches. Le type de pied a été déterminé par le Foot Posture Index (FPI) (Redmond, 2005). Résultats Le score total du FPI est corrélé de manière hautement significative, en statique et dynamique respectivement, avec la hauteur de la tubérosité du naviculaire ( r = 0,704 et r = 0,562), l’angle de l’arche longitudinale médiale ( r = 0,626 et r = 0,624) et celui du varus-valgus de l’avant-pied ( r = 0,610 et r = 0,456). L’amplitude de mouvement de l’arche transversale antérieure est corrélée de manière significative au score totale du FPI ( r = 0,415). Discussion–conclusion Les mesures cliniques les plus pertinentes semblent être la hauteur du naviculaire, l’arche longitudinale médiale et le varus-valgus de l’avant-pied. La mobilité de l’arche transversale antérieure semble plus importante dans les pieds supinateurs. L’analyse des angles cinématiques est en progression. [ABSTRACT FROM AUTHOR]