Muscle Shape Research Articles

B-PO04-132 INCREASED CATHETER STABILITY FOR ACTIVATION MAPPING OF PAPILLARY MUSCLE PVCS UTILIZING THE ABBOTT HD GRID MAPPING CATHETER

Catheter ablation of papillary muscle PVCs is challenging. It often requires multiple ablation lesions and frequently recurs. Independent motion of the papillary muscle, respiratory and cardiac motion make catheter stability difficult. The presence of purkinje fibers within the papillary muscles results in rapid conduction and minimal difference in activation timing between neighboring sites. The shape of the papillary muscle often makes it difficult to perform a detailed activation map demonstrating only one site of earliest exit. Efforts to overcome these challenges have focused on ablation techniques (high power, contact force catheters, ICE + CARTO Sound and use of cryoablation catheters. Limited data and efforts have focused around more precise activation mapping. Propose a more precise invasive mapping technique for papillary muscle PVCs. We utilized the Abbott HD Grid mapping catheter in 5 consecutive patients with papillary muscle PVCs that met clinical criteria for catheter ablation. ICE was utilized to place the mapping catheter on both the superior and inferior aspect of the papillary muscle for each patient. We then annotated the site of earliest exit and site of the best pace-map to the clinical PVC. The HD Grid mapping catheter was easily visualized in all 5 patients with ICE. Excellent catheter stability and motion with the papillary muscle was noted, allowing for accurate activation and pace mapping. Radiofrequency ablation was successful in acutely suppressing PVCs in all 5 patients. Use of the Abbott HD Grid mapping catheter may provide more accurate activation and pace-mapping for papillary muscle PVCs.

Interactive modelling of volumetric musculoskeletal anatomy

We present a new approach for modelling musculoskeletal anatomy. Unlike previous methods, we do not model individual muscle shapes as geometric primitives (polygonal meshes, NURBS etc.). Instead, we adopt a volumetric segmentation approach where every point in our volume is assigned to a muscle, fat, or bone tissue. We provide an interactive modelling tool where the user controls the segmentation via muscle curves and we visualize the muscle shapes using volumetric rendering. Muscle curves enable intuitive yet powerful control over the muscle shapes. This representation allows us to automatically handle intersections between different tissues (muscle-muscle, muscle-bone, and muscle-skin) during the modelling and automates computation of muscle fiber fields. We further introduce a novel algorithm for converting the volumetric muscle representation into tetrahedral or surface geometry for use in downstream tasks. Additionally, we introduce an interactive skeleton authoring tool that allows the users to create skeletal anatomy starting from only a skin mesh using a library of bone parts.

Quantitative Evaluation of the Movement Distance of Deep Fascia and Change of Muscle Shape Related to Chain Response in Fascia Tissue of Lower Limb.

By using ultrasonography, we measured the longitudinal movement distance of the deep fascia (LMDDF), change of the pennation angle (PA) and muscle thickness (MT) in both the tensor fasciae latae muscle (TFL) and the gluteus medius muscle (G-Med) during passive movement of the toes/ankle joints. 21 right lower limbs of 21 healthy males were evaluated in this study. We measured the LMDDF of the TFL and G-Med by measuring distance between the designated landmark on skin and the intersection of the major deep-fascia (D-fascia) and the fascial bundle. We also measured change of the PA and MT of both muscles. Additionally, we also measured the reliability of the measurement and the measurement error. The measurement was performed during three manual positions on the toes/ankle; manual holding of the toes and ankle joint in neutral, toes flexion and ankle plantar flexion/inversion position, toes extension and ankle extension/valgus position. The existence of muscle contraction of both the muscles during passive motion was monitored by active surface electrodes. This study confirmed mobility of the D-fascia in which the TFL’s D-fascia moves and change of muscle shape in the distal direction during no muscle contraction due to passive movement. This fact suggests the possibility that passive tension on fascia tissue of the ankle extends to the proximal part of the limb, i.e., to the D-fascia of the TFL.

Segmentation of pectoral muscle from digital mammograms with depth-first search algorithm towards breast density classification

Digital mammography acts as a unique screening technology to protect the lives of females against breast cancer for the past few decades. Mammographic breast density is a well-known biomarker and plays a substantial role in breast cancer prediction and treatments. Breast density is calculated based on the opacity of fibro-glandular tissue reflected on digital mammograms concerning the whole area of the breast. The opacity of pectoral muscle and fibro-glandular tissue is similar to each other; hence, the small presence of the pectoral muscle in the breast area can hamper the accuracy of breast density classification. Successful removal of pectoral muscle is challenging due to changes in shape, size, and texture of pectoral muscle in every MLO and LMO views of mammogram. In this article, the depth-first search (DFS) algorithm is proposed to remove artifacts and pectoral muscle from digital mammograms. In the proposed algorithm, image enhancement is performed to improve the pixel quality of the input image. The whole breast as a single connected component is identified from the background region to remove the artifacts and tags. The depth-first search method with and without the heuristic approach is used to delineate the pectoral muscle, and then final suppression is performed on it. This algorithm is tested on 2675 images of the DDSM dataset, which is further divided into four density classes as per BIRADs classification. Segmentation results are calculated individually on each BIRADs density class of the DDSM dataset. Results are validated subjectively by the expert's Radiologist's ground truth with segmentation accuracy and objectively by the Jaccard coefficient and a dice similarity coefficient. This algorithm is found robust on each density class and provides overall segmentation accuracy of 86.18%, a mean value of Jaccard index, and a Dice similarity coefficient of 0.9315 and 0.9548, respectively. The experimental results show that the proposed algorithms applied for pectoral muscle removal follow the ground truth marked by an expert radiologist. The proposed algorithm can be part of the pre-processing unit of breast density measurement and breast cancer detection system used during clinical practice.

Transcriptome analysis of embryonic muscle development in Chengkou Mountain Chicken

BackgroundMuscle is the predominant portion of any meat product, and growth performance and product quality are the core of modern breeding. The embryonic period is highly critical for muscle development, the number, shape and structure of muscle fibers are determined at the embryonic stage. Herein, we performed transcriptome analysis to reveal the law of muscle development in the embryonic stage of Chengkou Mountain Chicken at embryonic days (E) 12, 16, 19, 21.ResultsDiameter and area of muscle fibers exhibited significant difference at different embryonic times(P < 0.01). A total of 16,330 mRNAs transcripts were detected, including 109 novel mRNAs transcripts. By comparing different embryonic muscle development time points, 2,262 in E12vsE16, 5,058 in E12vsE19, 6139 in E12vsE21, 1,282 in E16vsE19, 2,920 in E16vsE21, and 646 in E19vsE21differentially expressed mRNAs were identified. It is worth noting that 7,572 mRNAs were differentially expressed. The time-series expression profile of differentially expressed genes (DEGs) showed that the rising and falling expression trends were significantly enriched. The significant enrichment trends included 3,150 DEGs. GO enrichment analysis provided three significantly enriched categories of significantly enriched differential genes, including 65 cellular components, 88 molecular functions, and 453 biological processes. Through KEGG analysis, we explored the biological metabolic pathways involved in differentially expressed genes. A total of 177 KEGG pathways were enriched, including 19 significant pathways, such as extracellular matrix-receptor interactions. Similarly, numerous pathways related to muscle development were found, including the Wnt signaling pathway (P < 0.05), MAPK signalingpathway, TGF-beta signaling pathway, PI3K-Akt signaling pathway and mTOR signaling pathway. Among the differentially expressed genes, we selected those involved in developing 4-time points; notably, up-regulated genes included MYH1F, SLC25A12, and HADHB, whereas the down-regulated genes included STMN1, VASH2, and TUBAL3.ConclusionsOur study explored the embryonic muscle development of the Chengkou Mountain Chicken. A large number of DEGs related to muscle development have been identified ,and validation of key genes for embryonic development and preliminary explanation of their role in muscle development. Overall, this study broadened our current understanding of the phenotypic mechanism for myofiber formation and provides valuable information for improving chicken quality.

A genetic screen for regulators of muscle morphogenesis in Drosophila.

The mechanisms that determine the final topology of skeletal muscles remain largely unknown. We have been developing Drosophila body wall musculature as a model to identify and characterize the pathways that control muscle size, shape, and orientation during embryogenesis. Our working model argues muscle morphogenesis is regulated by (1) extracellular guidance cues that direct muscle cells toward muscle attachment sites, and (2) contact-dependent interactions between muscles and tendon cells. While we have identified several pathways that regulate muscle morphogenesis, our understanding is far from complete. Here, we report the results of a recent EMS-based forward genetic screen that identified a myriad of loci not previously associated with muscle morphogenesis. We recovered new alleles of known muscle morphogenesis genes, including back seat driver, kon-tiki, thisbe, and tumbleweed, arguing our screen had the depth and precision to uncover myogenic genes. We also identified new alleles of spalt-major, barren, and patched that presumably disrupt independent muscle morphogenesis pathways. Equally as important, our screen shows that at least 11 morphogenetic loci remain to be mapped and characterized. Our screen has developed exciting new tools to study muscle morphogenesis, which may provide future insights into the mechanisms that regulate skeletal muscle topology.

IFSS-Net: Interactive Few-Shot Siamese Network for Faster Muscle Segmentation and Propagation in Volumetric Ultrasound.

We present an accurate, fast and efficient method for segmentation and muscle mask propagation in 3D freehand ultrasound data, towards accurate volume quantification. A deep Siamese 3D Encoder-Decoder network that captures the evolution of the muscle appearance and shape for contiguous slices is deployed. We use it to propagate a reference mask annotated by a clinical expert. To handle longer changes of the muscle shape over the entire volume and to provide an accurate propagation, we devise a Bidirectional Long Short Term Memory module. Also, to train our model with a minimal amount of training samples, we propose a strategy combining learning from few annotated 2D ultrasound slices with sequential pseudo-labeling of the unannotated slices. We introduce a decremental update of the objective function to guide the model convergence in the absence of large amounts of annotated data. After training with a few volumes, the decremental update strategy switches from a weak supervised training to a few-shot setting. Finally, to handle the class-imbalance between foreground and background muscle pixels, we propose a parametric Tversky loss function that learns to penalize adaptively the false positives and the false negatives. We validate our approach for the segmentation, label propagation, and volume computation of the three low-limb muscles on a dataset of 61600 images from 44 subjects. We achieve a Dice score coefficient of over 95% and a volumetric error of 1.6035 ± 0.587%.

The Visible Korean: movable surface models of the hip joint.

In this study, we presented movable surface models to help medical students understand the multiaxial movements of the hip joint. The secondary objective was to demonstrate a simple method to make movable surface models for other researchers. We used 166 surface models of the virtual human, and the commercial software was used for all the processes described in this study. Virtual joints were created for the hip joint of the surface models to simulate realistic movements of the joints. Bone surface models were processed to maintain the original shape of the bones during movement. Muscle surface models were processed to express deformation of the muscle shapes during movement. Next, the muscle and bone surface models were moved over six movements of the hip joint (flexion, extension, abduction, adduction, lateral rotation, and medial rotation). The surface models of these six movements were saved and packaged in a PDF file. The PDF file enabled users to see the stereoscopic shapes of the bones and muscles of the hip joint and to scrutinize the six movements on the X, Y, and Z axes of the joint. The movable surface models of the hip joint of this study will be helpful for medical students to learn the multiaxial movements of the hip joint. We expect to develop simulations of other joints that can be used in the education of medical students using the materials and methods described in this study.

The action of ciliary muscle contraction on accommodation of the lens explored with a 3D model

The eye's accommodative mechanism changes optical power for near vision. In accommodation, ciliary muscle excursion relieves lens tension, allowing it to return to its more convex shape. Lens deformation alters its refractive properties, but the mechanics of ciliary muscle actions are difficult to intuit due to the complex architecture of the tissues involved. The muscle itself comprises three sections of dissimilarly oriented cells. These cells contract, transmitting forces through the zonule fibers and extralenticular structures. This study aims to create a finite element model (FEM) to predict how the action of the ciliary muscle sections leads to lens displacement. The FEM incorporates initialization of the disaccommodated lens state and ciliary muscle contraction, with three muscle sections capable of independent activation, to drive accommodative movement. Model inputs were calibrated to replicate experimentally measured disaccommodated lens and accommodated ciliary muscle shape changes. Additional imaging studies were used to validate model predictions of accommodative lens deformation. Models were analyzed to quantify mechanical actions of ciliary muscle sections in lens deformation and position modulation. Analyses revealed that ciliary muscle sections act synergistically: the circular section contributes most to increasing lens thickness, while longitudinal and radial sections can oppose this action. Conversely, longitudinal and radial sections act to translate the lens anteriorly with opposition from the circular section. This FEM demonstrates the complex interplay of the three sections of ciliary muscle in deforming and translating the lens during accommodation, providing a useful framework for future investigations of accommodative dysfunction that occurs with age in presbyopia.

Comparison of Facial Muscle Activation Patterns Between Healthy and Bell's Palsy Subjects Using High-Density Surface Electromyography.

Facial muscle activities are essential for the appearance and communication of human beings. Therefore, exploring the activation patterns of facial muscles can help understand facial neuromuscular disorders such as Bell’s palsy. Given the irregular shape of the facial muscles as well as their different locations, it should be difficult to detect the activities of whole facial muscles with a few electrodes. In this study, a high-density surface electromyogram (HD sEMG) system with 90 electrodes was used to record EMG signals of facial muscles in both healthy and Bell’s palsy subjects when they did different facial movements. The electrodes were arranged in rectangular arrays covering the forehead and cheek regions of the face. The muscle activation patterns were shown on maps, which were constructed from the Root Mean Square (RMS) values of all the 90-channel EMG recordings. The experimental results showed that the activation patterns of facial muscles were distinct during doing different facial movements and the activated muscle regions could be clearly observed. Moreover, two features of the activation patterns, 2D correlation coefficient (corr2) and Centre of Gravity (CG) were extracted to quantify the spatial symmetry and the location of activated muscle regions respectively. Furthermore, the deviation of activated muscle regions on the paralyzed side of a face compared to the healthy side was quantified by calculating the distance between two sides of CGs. The results revealed that corr2 of the activated facial muscle region (classified into forehead region and cheek region) in Bell’s palsy subjects was significantly (p < 0.05) lower than that in healthy subjects, while CG distance of activated facial region in Bell’s palsy subjects was significantly (p < 0.05) higher than that in healthy subjects. The correlation between corr2 of these regions and Bell’s palsy [assessed by the Facial Nerve Grading Scale (FNGS) 2.0] was also significant (p < 0.05) in Bell’s palsy subjects. The spatial information on activated muscle regions may be useful in the diagnosis and treatment of Bell’s palsy in the future.

Accessory Head of the Flexor Pollicis Longus: A Cadaveric Study on the Gantzer’s Muscle

Introduction: The anterior interosseus nerve syndrome is a compression neuropathy affecting the anterior interosseus nerve, resulting in motor weakness of the long tendons to the index finger and thumb. Of the many conditions leading to this syndrome, one of the more common yet most overlooked aetiologies is the presence of accessory head of the flexor pollicis longus muscle, also called the Gantzer’s muscle. Even though numerous studies have been done in both Indian and international populations regarding the frequency of the Gantzer’s muscle, there are hardly any studies involving the South Indian population. Aim: To analyse the frequency and morphology of the Gantzer’s muscle in the sub-population of Malabar region, Kerala. Materials and Methods: This descriptive observational study was performed in Department of Anatomy at Malabar Medical College, Atholi, Kerala, India, from July 2021 to August 2021. Study included 60 upper limbs from the cadavers provided for undergraduate medical education. In the limbs where the muscle was identified, parameters such as proximal and distal attachments, shape and length of muscle and tendon, relation to adjacent median and anterior interosseus nerves were studied. Frequencies of each of these parameters were analysed using Statistical Package for the Social Sciences (SPSS) software version 21.0. Percentages obtained were compared with existing studies. Results: The Gantzer’s muscle was found in 28 of the 60 limbs dissected. It was more common on the right side (17 limbs), and the most common origin was the medial epicondyle (53.6%). All the cases identified were inserted onto the ulnar aspect of the Flexor Pollicis Longus tendon, mostly in the upper third. In all cases, the Median Nerve was superficial and the Anterior Interosseus Nerve was deep to the accessory head. In majority of the cases, the Anterior Interosseus Nerve was related to the posterior aspect of the belly of the Gantzer’s muscle (82.1%). Conclusion: Clinicians and surgeons should be conscious of the possibility of the Gantzer’s muscle being the aetiology, in cases of isolated Anterior Interosseus nerve palsies.

Shape analysis of rectus extraocular muscles with age and axial length using anterior segment optical coherence tomography

PurposeThis study aimed to evaluate the shape of the extraocular muscles (EOMs) in normal subjects using the en-face images of anterior segment optical coherence tomography (AS-OCT). The EOM insertion and the direction of the muscle fibers were investigated.Subjects and methodsA total of 97 healthy normal subjects (194 eyes) at Okayama University Hospital (age, 47.1±21.5 years; range, 8–79 years) participated in the study. A series of 256 tomographic images of the rectus EOMs were captured using the C-scan function of the AS-OCT (CASIA2, TOMEY Co., Japan), and the images were converted to en-face images in multi-TIFF format. The anterior chamber angle to EOM insertion distance (AID) and the angle of the muscle fibers from the insertion site (angle of muscles) were measured from the images. The correlations of AID and angle of muscles with age and axial length were investigated and evaluated.ResultsAID and angle of muscles were significantly correlated with age or axial length in some EOMs. The AIDs of medial rectus (MR) (P = 0.000) and superior rectus (SR) (P = 0.005) shortened with age. The AIDs of MR (P = 0.001) and inferior rectus (IR) (P = 0.035) elongated with axial length, whereas lateral rectus (LR) (P = 0.013) shortened. The angles of MR (P = 0.001) and LR (P = 0.000) were found to have a more downward direction toward the posterior in older subjects.ConclusionEn-face images can be created by AS-OCT, and the shape of the EOMs in normal subjects using these image measurements was available. With the ability to assess the EOMs, AID and angle of muscles are expected give useful information for treating and diagnosing strabismus-related diseases.

In vivo manipulation of muscle shape and tendinous stiffness affects the human ability to generate torque rapidly.

What is the central question of this study? What are the determinants of muscle belly gearing, and how does it affect the torque rise? What is the main finding and its importance? Change in muscle thickness of the gastrocnemius medialis is related to variations in belly gearing. Belly gearing has a key role in the rise of muscle torque and rate of torque development (RTD). Besides, the increase of tendinous tissue stiffness could increase the torque rise as well, and in turn, the RTD. However, changes in the tendinous tissue stiffness showed no effects on muscle fascicle behaviour, suggesting a possible uncoupling between muscle and tendon mechanical properties. During fixed-end contractions, muscles bulge in thickness and/or width to maintain a constant volume, whereas tendons lengthen over the entire contraction period. These dynamic changes play a key functional role in modulating the generated torque. However, the literature has revealed a limited understanding of in vivo dynamic muscle-tendon changes during rapid contractions. Therefore, this study aimed to investigate the determinants of belly gearing (belly velocity/fascicle velocity) and its effects on rapid torque production during in vivo fixed-end contractions. Twenty healthy males were recruited for the study. Muscle shape and tendon stiffness were manipulated by applying a transverse load (2-10kg) and an ankle rotation manoeuvre, respectively. Ultrafast-ultrasound was employed to quantify medial gastrocnemius architecture during evoked contraction and a dynamometer was used to measure the muscle torque and quantify the rate of torque development (RTD). Torque and RTD diminished by transverse load application, whereas they increased during the ankle rotation manoeuvre. Belly gearing declined with increasing transverse load but was unaffected by tendinous stiffness variations. Alterations in belly gearing were strongly related to variations in muscle thickness throughout any load applied and affected the torque rise rapidly. In contrast, changes in tendinous tissue stiffness affected the torque rise only but did not modify the muscle shape. These data may suggest that concurrent manipulation of the tendinous tissue stiffness and muscle shape does not affect the explosive rise in torque capacity, suggesting a possible uncoupling between mechanical properties of muscle and tendon.

Fully automated 3D segmentation of MR-imaged calf muscle compartments: Neighborhood relationship enhanced fully convolutional network

Automated segmentation of individual calf muscle compartments from 3D magnetic resonance (MR) images is essential for developing quantitative biomarkers for muscular disease progression and its prediction. Achieving clinically acceptable results is a challenging task due to large variations in muscle shape and MR appearance. In this paper, we present a novel fully convolutional network (FCN) that utilizes contextual information in a large neighborhood and embeds edge-aware constraints for individual calf muscle compartment segmentations. An encoder–decoder architecture is used to systematically enlarge convolution receptive field and preserve information at all resolutions. Edge positions derived from the FCN output muscle probability maps are explicitly regularized using kernel-based edge detection in an end-to-end optimization framework. Our method was evaluated on 40 T1-weighted MR images of 10 healthy and 30 diseased subjects by fourfold cross-validation. Mean DICE coefficients of 88.00–91.29% and mean absolute surface positioning errors of 1.04–1.66 mm were achieved for the five 3D muscle compartments.

Local retinoic acid signaling directs emergence of the extraocular muscle functional unit.

Coordinated development of muscles, tendons, and their attachment sites ensures emergence of functional musculoskeletal units that are adapted to diverse anatomical demands among different species. How these different tissues are patterned and functionally assembled during embryogenesis is poorly understood. Here, we investigated the morphogenesis of extraocular muscles (EOMs), an evolutionary conserved cranial muscle group that is crucial for the coordinated movement of the eyeballs and for visual acuity. By means of lineage analysis, we redefined the cellular origins of periocular connective tissues interacting with the EOMs, which do not arise exclusively from neural crest mesenchyme as previously thought. Using 3D imaging approaches, we established an integrative blueprint for the EOM functional unit. By doing so, we identified a developmental time window in which individual EOMs emerge from a unique muscle anlage and establish insertions in the sclera, which sets these muscles apart from classical muscle-to-bone type of insertions. Further, we demonstrate that the eyeballs are a source of diffusible all-trans retinoic acid (ATRA) that allow their targeting by the EOMs in a temporal and dose-dependent manner. Using genetically modified mice and inhibitor treatments, we find that endogenous local variations in the concentration of retinoids contribute to the establishment of tendon condensations and attachment sites that precede the initiation of muscle patterning. Collectively, our results highlight how global and site-specific programs are deployed for the assembly of muscle functional units with precise definition of muscle shapes and topographical wiring of their tendon attachments.

Histopathological effects and biomarker response of earthworms, Eisenia fetida, after exposure to crude oil contaminated soils.

Earthworms are the most abundant invertebrates in the soils and are permanently in close contact with soil particles. Therefore, they are significantly affected by the pollutants that reach the soil system. The study was aimed at evaluating the effect of exposure to crude oil contaminated soil on Eisenia fetida using cellular antioxidant enzymes and tissue organization as biomarkers. E. fetida were exposed to different concentrations of crude oil contamination of 1 mL, 2 mL. and 3 mL (0.25, 0.50 and 0.75%) for 14 days. The antioxidant/oxidant parameters were analysed in the muscle and liver tissues. The results showed that only the reduced glutathione (GSH) of earthworms exposed to 1 mL were not significant (p>0.05) from the control, while the other concentrations (2 mL – 0.50% and 3 mL – 0.75%) were significantly different (p<0.05) from the control. The activity of catalase (CAT) with respect to the total protein content was highest in the liver of earthworms exposed to 1 mL (0.25% conc.) on day 7 (51.84 μmol/mg pro) while the least CAT activity with respect to the total protein content was reported in the liver of control earthworms after 14 days (19.51 μmol/mL/min). A significant increase in the activity of superoxide dismutase at all the concentrations (0.25, 0.50 and 0.75%) after 14 days were also observed. Significant histopathological alterations were observed in E. fetida from the three concentrations. Severe disruptions in the arrangement of their body wall muscle layers, distorted internal viscera, as well as cellular degeneration, pigments, moderate to severe areas of lesion, and distortion of the shape of circular and longitudinal muscles, eroding of internal and external tissues leading to total destruction of body wall were observed. In conclusion, the study revealed that crude oil even at lower concentration induced biomarker responses in E. fetida such as higher levels of Malondialdehyde in E. fetida after exposure crude oil due its toxicity. Histopathological alterations such as cellular degeneration, moderate to severe areas of necrosis, areas of inflammation, inclusion bodies, pigments, and distortion of the shapes of circular and longitudinal muscles also showed the adverse impacts of crude oil pollution in the soils.

Anatomy of the thoracic limb muscles of wild boars (Sus scrofa, Artiodactyla: Suidae).

The study of the muscular anatomy of wild boar(Sus scrofa) is important, because it allows the understanding of the locomotor and evolutionary aspects, besides the improvement of surgical techniques used by veterinarians in swine. Thus, the objective of this study was to describe the morphology and disposition of the shoulder and arm muscles of S. scrofa. Twelve young specimens of hybrid S. scrofa, six males and six females were fixed and dissected following usual anatomy techniques. The bones of two specimens were prepared to analyze the fixation points of the muscles. The shoulder muscles presented fixation at the scapula and humerus, in distinct bone accidents, and were divided on lateral and medial faces. On the lateral face, the deltoid (divided in acromial and scapular parts), supraspinatus, infraspinatus (divided in cranial and caudal parts) and teres minor (deep to the caudal part of the infraspinatus) muscleswere found. In the medial face, the subscapular, coracobrachialis and teres majormuscles were observed. The arm muscles were arranged essentially around the humerus and were seen largely on its medial face, namely biceps brachii (originated by a single tendon), brachialis, tensor fasciae antebrachii (fused with the long head of the triceps brachii), triceps brachii (divided in lateral, long and medial heads) and anconeus (located mostly on the lateral side) muscles. Thus, it can be concluded that the S. scrofa presented seven muscles in the shoulder region and six muscles in the arm region, all with morphological similarities to domestic and some wild animals. Some differences werefound, for the most part, in the shape, division and fixation points of certain muscles.

Shoulder pain and scapular dyskinesis associated with lower trapezius dysplasia – A case report

BackgroundScapular dyskinesis (SD) has been associated with shoulder soft-tissue tightness as well scapular muscle strength and/or activation deficits. Inadequate development of the trapezius muscle (trapezius dysplasia) is a relatively rare condition inconsistently associated with shoulder dysfunction. Case descriptiona 24-year old male complaining of left scapular area pain associated with SD and scapular muscle weakness was noted to present with a smaller ipsilateral lower trapezius (LT). Further inquiry including electromyography, rehabilitative ultrasound imaging (RUSI) and magnetic resonance imaging ruled out nerve palsy and demonstrated a hypoplastic left LT. This led to a greater emphasis on serratus anterior (SA) training along with the addition of neuromuscular electrical stimulation of the LT. OutcomesFollowing 12 sessions over a 5-month period the patient reported no pain or functional deficits, and was able to resume all recreational activities. The patient’s subjective shoulder value increased from 55% to 80%, and LT strength was markedly improved. DiscussionScapular muscle dysplasia may represent a less recognized cause of SD. A more thorough inspection of scapular muscle shape and orientation, possibly augmented by RUSI may be indicated in patients presenting with SD. Neuromuscular electrical stimulation is a potentially useful modality for addressing scapular muscle activation and strength deficits and future research into its efficacy under these circumstances may be warranted.

Artists With Anatomical Knowledge After Anathomia (1316) and Before Fabrica (1543).

In the Renaissance, anatomical science was a major source of inspiration for artists. By the 15th century, interest had emerged in anatomy, and the artists of the period dissected cadavers. The aim of this paper was to analyze the works of 15th century artists who had a good knowledge of human anatomy.In PubMed and Google, "Renaissance" and "artist" and ("anatomy" or "cadaver" or "corpse") were searched. In the book Lives of the Painters, Sculptors, and Architects by Vasari, the terms "cadaver" or "dissect" or "corps" or "anatomy" were searched. Fourteen artists (Donato di Niccolò di Betto Bardi, Piero della Francesca Andrea del Castagno, Antonio del Pollaiuolo, Andrea del Verrocchio, Leonardo da Vinci, Michelangelo di Lodovico Buonarroti Simoni, Domenico di Pace Beccafumi, Baccio Bandinelli, Giovanni Antonio Lappoli, Rosso Fiorentino, Silvio Cosini of Fiesole, Jan van Calcar, and Taddeo Zucchero) who learned anatomy or performed dissections were identified, and artworks representing their knowledge of human anatomical structures were analyzed.In this review, we identified artists who had a good knowledge of anatomy and applied anatomical knowledge of features such as muscle shape and volume in their works.The artists sought to accurately portray facial expressions, positions, reflexive motions, and draped clothing. Observation of living subjects is the primary source of artists' expertise. Dissection provides fixed model without flowing blood, which cannot be used as an animated model. It is thought that these artists learned about the origins of vivid expressions from the anatomy of the muscles lying beneath the skin.

Blood Flow Restriction Exercise: Effects of Sex, Cuff Width, and Cuff Pressure on Perceived Lower Body Discomfort.

Narrow cuffs cause less discomfort than wide cuffs immediately following elbow flexion exercise in combination with blood flow restriction, possibly due to a balling up effect of the bicep underneath the cuff. In this study, we sought to examine the impact of cuff width, sex, and pressure on perceived discomfort in the quadriceps, following knee extensions. One hundred participants completed three separate experiments. In Experiment 1, we compared participants' discomfort at rest after using a 5 and a 12 cm cuff. In Experiment 2, we compared the discomfort from these two cuffs after four sets of exercise. In Experiment 3, we used the same exercise protocol as in Experiment 2, but we compared the discomfort between a 12 cm cuff inflated to an inappropriate pressure and a 12 cm cuff inflated to the recommended pressure. We found no sex differences in Experiments 1 and 3. In Experiment 1, the narrow cuff had higher discomfort (16 vs 12 AU). In Experiment 2, men reported higher discomfort than women, with no discomfort differences related to cuff width, though narrow cuffs were most preferred. In Experiment 3, cuffs inflated to a pressure intended for narrow cuffs were associated with higher discomfort, and participants preferred to use it less. In summary, we found no strong evidence for discomfort differences due to cuff width. There was some indication that participants preferred narrow cuffs with pressures inflated to the recommended relative pressure. Muscle shape may influence how cuff width affects discomfort.