Muscle Attachment Research Articles

Efficacy of Fu's Subcutaneous Needling in Treating Soft Tissue Pain of Knee Osteoarthritis: A Randomized Clinical Trial.

Fu's subcutaneous needling (FSN) is a new acupuncture technique that produces a long-lasting effect in soft-tissue injuries. In patients with degenerative knee osteoarthritis (OA), myofascial trigger points (MTrPs) are common in the lower-limb muscles. In this randomized clinical trial, we evaluated the immediate, 1-week and 2-week effectiveness of FSN therapy in the treatment of degenerative knee OA. We randomly divided 32 patients with knee OA into the FSN group (mean age: 65.73 ± 6.79 years) or the transcutaneous electrical nerve stimulation (TENS) group (mean age: 62.81 ± 5.72 years). The pressure pain threshold (PPT) and tissue hardness (TH) of the muscle and tendon attachment sites, knee range of motion, and physical ability (average walking speed) were measured. The subjective pain intensity index, Western Ontario and McMaster Universities OA Index (WOMAC), and Lequesne index were used to determine the efficacy of FSN on MTrP-induced soft-tissue pain compared with that of TENS. A significantly greater improvement in pain qualities in the VAS (p < 0.05) was found in the FSN group. Moreover, in muscle and tendon qualities (including PPT and TH), a significant difference in the PPT of the quadriceps muscle (p < 0.05) was also observed among the immediate treatments in the FSN group. As for the functional index questionnaire assessment, the FSN group exhibited significant improvements among the immediate, 1-week and 2-week efficacies in terms of WOMAC (p < 0.05) and Lequesne index scores (p < 0.05). FSN was effective in treating soft-tissue pain in degenerative knee OA in terms of alleviating pain, strengthening walking ability, and improving overall functional performance. Pain relief was the primary benefit of FSN and a significant correlation between pain relief and knee joint mobility improvement was found. ClinicalTrials.gov Protocol Registration and Results System (registration number: NCT04356651).

Complications Patients Faces while Fixation, in Terms of Pain Relief, Walking, Sitting

Background: The fracture of the trochanteric area of the femur is one of the most frequent and challenging complications orthopedic surgeons deal daily. In virtually all instances, fractures develop through the highly vascular cancellous bone and heal within 8 to 12 weeks, independent of therapy. Malunion and varus angulations are prevalent. Due to the demands placed on the patient, nursing staff, and length of hospitalization, conservative therapy is no longer acceptable. Seventy percent of intertrochanteric fractures are considered unstable. During regular exercises, the proximal femoral loading has been calculated to reach up to three times the body weight. Muscle attachments apply force vectors in several directions, hence contributing to a trend for fracture displacement. This fracture is typically accompanied by severe comminution and osteopenia. Objective: The main objective of this study is to find thecomplications patients faces while fixation, in terms of pain relief, walking, witting. Materials and Methods: Descriptive study conducted at Department of Orthopedic Surgery, Chittagong Medical College Hospital, Chittagong, with the sample size of 36 patients aged above 50 years admitted to the Chittagong Medical College Hospital with closed trochanteric fracture. The aim of the study is to find out the Effectiveness of dynamic hip screw in fixation of trochanteric fractures of femur in elderly patients. Results: The patients' ages ranged from 52 to 95 years. The majority of patients were 70-79 years old (36.1 percent), followed by 80-89 years (25 percent), 60-69 years (22.2 percent), 50-59 years (11.1 percent), and 90-99 years (5.6 percent). The mean (±SD) age of the total study patients (n=36) was 72.± 1.20 years, male (n=21) was 75.05±12.62 years and female (n=15) were 68.07±7.46 years. There are considerable disparities between the age groups of 70-79 and 90-99.Males made up the majority of patients (58.3 percent), while females made up 41.7 percent. ....

Role of cardiac magnetic resonance (CMR) in planning ventricular septal myomectomy in patients with hypertrophic obstructive cardiomyopathy (HOCM).

Septal myectomy is currently the gold standard treatment for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM). The procedure needs to be tailored and performed in a personalized fashion, taking into consideration the anatomic and physiologic heterogeneity of this disease. The extent and location of surgical myectomy will depend on the location of the hypertrophy, with the goal of widening the outflow tract and improve the function of the mitral valve. CMR helps to identify hypertrophy not well visualized by TTE, providing more accurate wall thickness measurements and differentiating HOCM from other causes of LV hypertrophy. CMR also helps identify an abnormal attachment of papillary muscle to the MV or to the septal myocardium and mitral valve pathology. A collaborative approach with cardiac surgeons, radiologists and cardiologists will optimize preoperative planning to improve the success for surgical myectomy.

Homoplasy in shells discombobulated the taxonomy: revision of the larger helicarionid land snails of northern Queensland, Australia (Stylommatophora: Helicarionidae)

ABSTRACT Helicarionid land snails with large shells have been placed in three genera: Malandena, Pravonitor and Elatonitor. These taxa are revised herein using comparative morpho-anatomy and mitochondrial phylogenetics. We demonstrate that these species represent three independent radiations, but this is not reflected in the current generic arrangement. Phylogenetic reconstruction revealed that these genera do not form a monophyletic group, and we conclude that large shells have evolved multiple times among helicarionids in Queensland, Australia, presumably as an adaptation to moist environments. Species belonging to Pravonitor have a medium-sized to large, glossy shell, often with a peripheral band. Among other traits, they always have a single-chambered, internally pustulose or ridged penis, an epiphallus with a slender flagellum, and a long epiphallic caecum with medial penial retractor muscle attachment. This genus comprises eight species: Pravonitor kreffti, P. ferrugineus, P. insularum, P. annulus, P. aquilonia comb. nov., P. monteithi comb. nov., P. septentrionalis sp. nov. and P. stuarti sp. nov. We describe Geminitor gen. nov. for Geminitor laura comb. nov., G. villaris comb. nov., G. kullaensis sp. nov., G. macveae sp. nov. and G. wenlockensis sp. nov. Geminitor has a small to medium-sized shell, a long, two-chambered penis, an epiphallus with a slender flagellum, and an epiphallic caecum with basal penial retractor muscle attachment. The unavailable genus name Malandena is subsumed under Elatonitor, which now contains Elatonitor montanus and E. suturalis comb. nov. Elatonitor has a large glossy shell with an angulate periphery, a long, narrow, single-chambered penis with longitudinal pilasters, an epiphallus with a broad flagellum, and no epiphallic caecum. While this study has nearly doubled the number of known large helicarionid species in Far North Queensland, there are still knowledge gaps and we recommend further surveys to search for undocumented species, improve our understanding of species distribution and undertake vital conservation assessments. http://www.zoobank.org/urn:lsid:zoobank.org:pub:83362BEC-6E6B-4B65-AC1E-F49762C744B8

Ocruranus-Eohalobia Sclerites from the Cambrian Stage 2 Yanjiahe Formation in South China: Scleritome Reconstruction and Zoological Affinity.

The isolated sclerites of the Ocruranus and Eohalobia group are abundant among the early Cambrian small shelly fossil assemblages, which were recently assigned to the same scleritome as an early member of the polyplacophoran (chiton) stem lineage. However, the scleritome reconstruction and zoological affinities of these sclerites are still controversial due to the lack of exceptionally preserved articulated specimens with in-situ sclerites. Herein, we report new specimens of Ocruranus and Eohalobia sclerites from Member 5 of the Yanjiahe Formation, which provide new insights into the reconstruction of the original scleritome. The Eohalobia sclerites from the Yanjiahe Formation have an extended and upfolded proximal field with dense wrinkles, which seems to be a weakly mineralized structure and acted as a joint with another sclerite, Ocruranus. Comparing the butterfly-shaped proximal field on a unique sclerite of Eohalobia with the sub-apical field on Ocruranus sclerites suggests that the original scleritome of this group may consist of only two types of sclerites: the Ocruranus-type and the Eohalobia-type. The polygonal structure on the internal mold of Eohalobia sclerites is interpreted herein as the muscle attachment zone; their distribution corresponds well with that of the modern chitons, which provides strong evidence to support the close relationship between the Ocruranus-Eohalobia group and the Polyplacophora.

Investigation of pelvic symmetry: A systematic analysis using computer aided design software

AbstractObjectivesThis study aimed to investigate the symmetry of the Chinese pelvis.MethodsComputed tomography scan images of each of 50 Chinese pelvises were converted to 3D models and the left sides of the pelvises were reflected on Mimics software. Then, the reflected left side model was aligned with the right side using the closest point algorithm function of Geomagic software to perform symmetry analysis. The volume and surface area of either side of the pelvises were also calculated. The mean standard deviation (SD), the mean percentage of permissible deviations within the ±2 mm range, the percentage differences in volume and surface area were measured to compare pelvic symmetry. In addition, the distribution of pelvic bilateral symmetry associated with both age and sex were compared.ResultsThe mean SD was 1.15 ± 0.16 mm and the mean percentage of permissible deviations was 90.82% ± 4.67%. The deviation color maps showed that the specific areas of asymmetry were primarily localized to major muscle or ligament attachment sites and the sacroiliac joint surfaces. There was no significant difference between the bilateral sides of the pelvis in either volume or surface area. Additionally, no difference in any indexes was exhibited in relation to sex and age distribution.ConclusionOur results demonstrated that the pelvis has high bilateral symmetry, which confirmed the potential of using contralateral pelvic models to create fully patient‐specific and custom‐made pelvic implants applicable for the treatment of fracture and bony destruction.

Abstract 9841: Outcomes Following Biventricular Repair of Atrioventricular Septal Defect With a Single Left Ventricular Papillary Muscle

Introduction: In patients with atrioventricular septal defect (AVSD) with single papillary muscle attachments in the left ventricle (LV), the left AV valve (LAVV) is at risk for suboptimal repair. This study aimed to evaluate outcomes following repair of AVSD with single LV papillary muscle attachments and to identify preoperative predictors of postoperative LAVV outcomes. Methods: All patients with AVSD and anatomically or functionally single LV papillary muscle who underwent biventricular repair at our institution from 07/01/2000 - 07/01/2020 were retrospectively reviewed. Univariate analysis was used to identify associations between patient demographics, preoperative echocardiographic measures, and surgical characteristics with the degree of LAVV stenosis or regurgitation postoperatively and the need for reintervention on the LAVV. Results: Of 38 patients included, nearly all (97%) were repaired with no or partial closure of the LAVV cleft. Freedom from LAVV reintervention was 91% and 84% at 1 and 3 years. Five patients (13%) required reintervention on the LAVV with a median time to reintervention of 3.3 months post-AVSD repair; indication was LAVV regurgitation for four of the five patients. Preoperative LAVV regurgitation > mild was associated with an increased risk for LAVV reintervention (p= 0.02). At discharge, 63% of patients had > mild LAVV regurgitation and 5% had > mild LAVV stenosis. At most recent follow-up, 32% had > mild LAVV regurgitation and 12% had > mild LAVV stenosis. Patients with younger age at repair and preoperative AV valve index <0.67 had significantly increased risk of > mild LAVV regurgitation at discharge (p=0.01 and p=0.04, respectively), however this did not persist at most recent follow-up. More pronounced unbalance of the AVSD was not associated with postoperative LAVV stenosis. Conclusions: Despite concern for repair in patients with AVSD and single papillary muscle attachments, surgical outcomes are favorable with low risk for reintervention. Risk of LAVV stenosis is low when repair of LAVV cleft is modified. Preoperative LAVV regurgitation, younger age at repair, and more pronounced unbalance of the AVSD predicted early postoperative LAVV regurgitation, with improvement over time.

Paleopathology, Entheseal Changes, and Cross-Sectional Geometry: The Zooarchaeology of Working Animals

Morphological changes in the skeletons of working animals such as reindeer, horse, and cattle have long been observed and documented in the archaeological record. Activities such as riding, carrying cargo on their backs, and pulling vehicles like sleds and ploughs throughout an animal’s life history cause alterations and variations to skeletal tissue. Such alterations include paleopatho­logical lesions, entheseal changes (EC)—alterations in muscle, tendon, and ligament attachment sites on bone—and variations in cross-sectional bone geometry (CSBG). These clues are helpful for reconstructing human-animal relationships in faunal remains of our archaeological past. However, other factors influence the morphological appearance of skeletal tissue besides working activities, such as age, sex, body size, nutrition, genetics, environmental factors, and management by human caretakers. This article explores how paleopathological lesions, EC, and CSBG in faunal skeletal remains are examined to reconstruct working activity and changes to human-animal rela­tionships in the archaeological record. In particular, we discuss two primary topics of inquiry: (1) a review of paleopathological identifiers in working animals such as cattle, horse, camel, and rein­deer; and (2) how EC and CSBG are understood in terms of bone functional adaptation, and their application in working and non-working animals such as reindeer and horse. Next, we analyze each topic highlighting their benefits and limitations, including how they contribute to archeolog­ical understandings of human-animal relationships in the past, as well as their implications for future research.

Microfluidics-integrated spaceflight hardware for measuring muscle strength of Caenorhabditis elegans on the International Space Station

Caenorhabditis elegans is a low-cost genetic model that has been flown to the International Space Station to investigate the influence of microgravity on changes in the expression of genes involved in muscle maintenance. These studies showed that genes that encode muscle attachment complexes have decreased expression under microgravity. However, it remains to be answered whether the decreased expression leads to concomitant changes in animal muscle strength, specifically across multiple generations. We recently reported the NemaFlex microfluidic device for the measurement of muscle strength of C. elegans (Rahman et al., Lab Chip, 2018). In this study, we redesign our original NemaFlex device and integrate it with flow control hardware for spaceflight investigations considering mixed animal culture, constraints on astronaut time, crew safety, and on-orbit operations. The technical advances we have made include (i) a microfluidic device design that allows animals of a given size to be sorted from unsynchronized cultures and housed in individual chambers, (ii) a fluid handling protocol for injecting the suspension of animals into the microfluidic device that prevents channel clogging, introduction of bubbles, and crowding of animals in the chambers, and (iii) a custom-built worm-loading apparatus interfaced with the microfluidic device that allows easy manipulation of the worm suspension and prevents fluid leakage into the surrounding environment. Collectively, these technical advances enabled the development of new microfluidics-integrated hardware for spaceflight studies in C. elegans. Finally, we report Earth-based validation studies to test this new hardware, which has led to it being flown to the International Space Station.

A new proterochampsid (Archosauriformes: Proterochampsia) from the Late Triassic of southern Brazil and the emergence of archosaurian hind limb traits

Characterized by an elongated snout, proterochampsids are carnivorous non-archosaur archosauriforms. The clade is endemic to South America and its fossil record extends from the early Carnian to the late Carnian/early Norian. Nesting close to Archosauria, it is a key clade for understanding the origin and evolution of archosaurian traits. Unfortunately, hind limb elements are usually poorly preserved for the group. Therefore, the hind limb anatomy of proterochampsids still lacks detailed descriptions. In the present study, we partially fill this gap with the description of a new proterochampsid represented by a complete and well-preserved hind limb. Stenoscelida aurantiacus gen. et sp. nov. was excavated from the late Carnian/early Norian (Late Triassic) beds of southern Brazil. A phylogenetic investigation recovers the new taxon as a non-rhadinosuchine proterochampsid. The species bears an unusual set of traits for the group, which provides clues on the evolutionary origins of some muscle attachment structures. For instance, the femur of Stenoscelida aurantiacus gen. et sp. nov. possesses an anterior trochanter and an anterolateral scar. So far, these features have not been reported in other non-archosaurian archosauriforms. Therefore, the new specimen indicates that some typical archosaurian features evolved earlier than previously thought. The taxon also carries additional uncommon features for proterochampsids, such as an iliofibularis tubercle on the anterior margin of the fibula and a vestigial phalanx in digit V. In sum, Stenoscelida aurantiacus has one of the best-preserved hind limbs within Proterochampsidae and sheds light on the polarization of important traits regarding the evolutionary context of Archosauria. http://zoobank.org/urn:lsid:zoobank.org:pub:C78B7CE3-AB9B-4543-833E-B2A3FEA957D9

Variant pectoralis minor muscle: a case study with clinical relevance.

The pectoralis minor (PMn) muscle originates from the third, fourth, and fifth ribs near the costochondral junctionusually and gets inserted on the medial margin and upper surface of the coracoid process of the scapula. To look at the morphological insertion patterns and sites of attachment of the PMn muscle in the donated cadavers. Over all 19 limbs were included in the study (9 right and 10 left). Out of 19 limbs, 10 belonged to female and 9 belonged to male cadavers. The cadavers were meticulously dissected to determine the morphological insertion types and location of the attachment of the muscle. Unusual pattern of insertion was observed in 6 limbs (31.6%) out of total 19 limbs included in the study. The variations we observed does not fall completely in the classification by Le Double, hence variations we observed can be considered as new and rare variant which to our knowledge is not reported in literature. We propose this new variant to be type 4 of Le Double classification. The potential of ectopic PMn tendon should be taken into consideration and tested out, especially in patients with shoulder discomfort and stiffening who have ruled out the more frequent diseases. For proper surgical planning, a preoperative magnetic resonance imaging or USG examination of the shoulder joint is required considering the prevalence of variation in the insertion pattern of PMn muscle. Preoperative identification of any abnormal PMn insertion can help to reduce the risk of iatrogenic tendon injury and post-operative problems.

Craniomandibular osteology of Manidens condorensis (Ornithischia: Heterodontosauridae) from the upper Lower Jurassic of Argentina

ABSTRACT Heterodontosauridae is a clade that appears early in the ornithischian fossil record, and includes small-bodied, highly specialized species characterized by an unusual heterodont dentition. Although known from relatively few taxa, the early representation of the clade and unsolved phylogenetic relationships within heterodontosaurids and among early ornithischians implies that novel information has a marked effect on broader phylogenetic hypotheses and our understanding of early diversification patterns within Ornithischia. This paper describes the cranial osteology of the heterodontosaurid Manidens condorensis based on computed micro-tomographic scans of MPEF-PV 3211 and MPEF-PV 3809. This enabled more detailed descriptions of previously recognized bones, corrections to the literature, and the identification of undescribed elements. We present a new skull reconstruction and propose an emended diagnosis in light of novel anatomical information. Areas of jaw muscle attachment were identified and compared with Heterodontosaurus and Lesothosaurus, and mandibular function among heterodontosaurids is discussed. Our results indicate that diverse skull morphologies and functions existed among Early Jurassic ornithischians, with Manidens being intermediate between the plesiomorphic cranial shape and function associated with a generalist diet in ornithischians such as Tianyulong and Lesothosaurus, and the more derived cranial construction specialized for herbivory identified in heterodontosaurids from South Africa such as Heterodontosaurus.

A new chelid turtle, Prochelidella palomoi sp. nov., from campanian Anacleto Formation, Neuquén Basin, North-Western Patagonia, Argentina.

The new turtle remains were found in the Anacleto Formation (Campanian) exposed in the Aguada Grande site. This area is located 10 km from the south of the city of Rincón de Los Sauces, in the north of the province of Neuquén, Patagonia, Argentina. The specimen (MAU-Pv-AG-452) consists of a partially preserved skull, carapace remains, an almost complete plastron, and a left ilium. The skull shows some features (a developed retropterygoid foramen, and a big muscle attachment area over the basisphenoid) that allow us to refer this specimen to the genus Prochelidella. The visceral view of the first costal bone exhibits deeper axillary buttresses that extend 2/3 of the costal width. This condition is also observed in the costal bone of Prochelidella buitreraensis from the Candeleros Formation (Cenomanian). The scute pattern observed in the anterior lobe of the plastron shows a large gular that extends along the entoplastra length, and small extragulars over the epiplastra. In contrast with the scute scheme observed in Prochelidella cerrobarcinae and Prochelidella portezuelae where the gular does not extend beyond the first 1/3 of the entoplastron. The phylogenetic analyses performed recovered this new species as a member of Prochelidella. The material recovered from the Anacleto Formation represents the first undoubtedly finding of Prochelidella in the late Cretaceous (Campanian) and the second skull recognized for the genus.

Comparative morpho-functional analysis of the humerus and ulna in three Western European moles species of the genus Talpa, including the newly described T. aquitania.

The forelimb is involved in many behaviours including locomotion. Notably, the humero-ulnar articulation, implicated in the elbow joint, is of particular importance for both mobility and stability. Functional constraints, induced in part by environmental plasticity, are thought to drive an important part of the bone shape as bone directly responds and remodels in response to both muscle and external forces. In this context, the study of subterranean moles is of particular interest. These moles occupy a hard and heavy medium in comparison with air or water, requiring a powerful body structure to shear and shift the soil. Their general morphology is therefore adapted to digging and to their subterranean lifestyle. The various morpho-functional patterns, which drive diverse abilities according to the environment, are likely targets of natural selection and it is, therefore, useful to understand the relationships between the bone shape and their function. Here, we quantify, through 3D geometric morphometric methods, the interspecific variability in the morphology of the ulna and humerus of three Talpa species, including the new species Talpa aquitania, to infer their potential consequence in species digging performance. We also quantify shape covariation and morphological integration between the humerus and the ulna to test whether these bones evolve as a uniform functional unit or as more or less independent modules. Our results show that interspecific anatomical differences in the humerus and ulna exist among the three species. Shape changes are mostly located at the level of joints and muscle attachments. As the species tend to live in allopatry and the fossorial lifestyle induces strong ecological constraints, interspecific variations could be explained by the properties of the environment in which they live, such as the compactness of the soil. Our results also show that the humerus and ulna are highly integrated. The covariation between the humerus and ulna in moles is dominated by variation in the attachment areas and particularly of the attachment areas of shoulder muscles concerning the humerus, which affect the mechanical force deployed during locomotion and digging. This study also highlights that in the new species, T. aquitania, variations in anatomical structure (general shape and joints) exist and are related to the locality of collect of the individuals.

Gross anatomy of the gluteal and posterior thigh muscles in koalas based on their innervations.

Morphological and functional comparison of convergently-evolved traits in marsupials and eutherians is an important aspect of studying adaptive divergence in mammals. However, the anatomy of marsupials has been particularly difficult to evaluate for multiple reasons. First, previous studies on marsupial anatomy are often uniformly old and non-exhaustive. Second, muscle identification was historically based on muscle attachment sites, but attachment sites have since been declared insufficient for muscle identification due to extensive interspecific variation. For example, different names have been used for muscles that are now thought to be equivalent among several different species, which causes confusion. Therefore, descriptions of marsupial muscles have been inconsistent among previous studies, and their anatomical knowledge itself needs updating. In this study, the koala was selected as the representative marsupial, in part because koala locomotion may comprise primate (eutherian)-like and marsupial-like mechanics, making it an interesting phylogenetic group for studying adaptive divergence in mammals. Gross dissection of the lower limb muscles (the gluteal and the posterior thigh regions) was performed to permit precise muscle identification. We first resolved discrepancies among previous studies by identifying muscles according to their innervation; this recent, more reliable technique is based on the ontogenetic origin of the muscle, and it allows for comparison with other taxa (i.e., eutherians). We compared our findings with those of other marsupials and arboreal primates and identified traits common to both arboreal primates and marsupials as well as muscle morphological features unique to koalas.

Improved Muscle Regeneration into a Joint Prosthesis with Mechano-Growth Factor Loaded within Mesoporous Silica Combined with Carbon Nanotubes on a Porous Titanium Alloy.

Total joint replacement (TJR) is widely applied as a promising treatment for the reconstruction of serious joint diseases but is usually characterized by critical loss of skeletal muscle attachment to metal joint prostheses, resulting in fibrous scar tissue formation and subsequent motor dysfunction. Tissue engineering technology may provide a potential strategy for skeletal muscle regeneration into metal joint prostheses. Here, a porous titanium (Ti) alloy scaffold coated with carbon nanotubes (CNTs) and mesoporous silica nanoparticles (MSNs) through electrophoretic deposition (EPD) was designed as a mechano-growth factor (MGF) carrier. This two-layered coating exhibits a nanostructured topology, excellent MGF loading, and prolonged release performance via covalent bonding to improve myoblast adhesion, proliferation and myogenic differentiation in porous Ti alloy scaffolds without cytotoxicity. The Akt/mTOR signaling pathway plays a key role in this process. Furthermore, in vivo studies show that the scaffold promotes the growth of muscle, rather than fibrotic tissue, into the porous Ti alloy structure and improves muscle-derived mechanical properties, the migration of satellite cells, and possibly immunomodulation. In summary, this nanomaterial-coated scaffold provides a practical biomaterial platform to regenerate periprosthetic muscle tissue and restore comparable motor function to that of the natural joint.

The Surgical Anatomy of the Jowl and the Mandibular Ligament Reassessed

IntroductionA visible jowl is a reason patients consider lower facial rejuvenation surgery. The anatomical changes that lead to formation of the jowl remain unclear. The aim of this study was to elucidate the anatomy of the jowl, the mandibular ligament and the labiomandibular crease, and their relationship with the marginal mandibular branch of the facial nerve.Materials and MethodsForty-nine cadaver heads were studied (16 embalmed, 33 fresh, mean age 75 years). Following preliminary dissections and macro-sectioning, a series of standardized layered dissections were performed, complemented by histology, sheet plastination and micro-CT.ResultsThe jowl forms in the subcutaneous layer where it overlies the posterior part of the mandibular ligament. The mandibular ligament proper exists only in the deep, sub-platysma plane, formed by the combined muscular attachment to the mandible of the specific lower lip depressor muscles and the platysma. The mandibular ligament does not have a definitive subcutaneous component. The labiomandibular crease inferior to the oral commissure marks the posterior extent of the fixed dermal attachment of depressor anguli oris.ConclusionJowls develop as a consequence of aging changes on the functional adaptions of the mouth in humans. To accommodate wide jaw opening with a narrowed commissure requires hypermobility of the tissues overlying the mandible immediately lateral to the level of the oral commissure. This hypermobility over the mandibular attachment of the lower lip depressor muscles occurs entirely in the subcutaneous layer to allow the mandible to move largely independent from the skin. The short, elastic subcutaneous connective tissue, which allows this exceptional mobility without laxity in youth, lengthens with aging, resulting in laxity. The development of subcutaneous and dermal redundancy constitutes the jowl in this location.Level of Evidence IV"This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266."Graphical

Features of the flexor retinaculum and its individual variation in carpal tunnel syndrome predisposition - a systematic review

Abstract The flexor retinaculum is a structure located in the wrist, which spreads between the bones forming the carpal tunnel. Its task is to maintain the relative stabilization and protection of incorporated structures. It is also an attachment for the thenar muscles, causing biomechanical interactions in the wrist. Pathologies occurring in the carpal tunnel structures often cause pressure increase, leading to compression of the median nerve, causing carpal tunnel syndrome (CTS). This work aims to review literature knowledge and compile research outcomes in the PubMED and Google scholar databases. The results indicate the variability in size and aspects of flexor retinaculum due to gender, and the relationship between gender and the incidence of CTS. The data also show the flexor retinaculum’s molecular variability and environmental factors’ potential impact on these changes. This article demonstrates how anatomical conditions and physical features influence CTS development.

Qualitative and Quantitative Anatomy of the Humeral Attachment of the Pectoralis Major Muscle and Structures at Risk: A Cadaveric Study.

Background:Surgical pectoralis major (PM) repair can offer improved functional outcomes over nonoperative treatment. However, there is a lack of literature on consensus of the anatomical site of the humeral attachment.Purpose:To provide qualitative and quantitative anatomic analysis of the PM by focusing on humeral insertion and relevant structures at risk.Study Design:Descriptive laboratory study.Methods:Eight fresh-frozen male cadavers were dissected. The relevant landmarks that were collected and measured included (1) PM footprint length at the humeral insertion (total, sternal head, and clavicular head insertions); (2) PM tendon length from the humeral insertion to the musculotendinous junction; (3) distance from the PM humeral insertion to the lateral (LPN) and medial (MPN) pectoral nerves; and (4) distance from the coracoid process to the musculocutaneous nerve (MCN) in anatomical position.Results:The total PM footprint length was 81.4 mm (95% CI, 71.4-91.3). The sternal and clavicular heads that make up the PM had footprint lengths of 42.1 mm (95% CI, 32.9-51.4) and 56.6 mm (95% CI, 46.5-66.7), respectively. The PM tendon was wider at the clavicular head (74.7 mm; 95% CI, 67.5-81.7) than the sternal head insertions (43.0 mm; 95% CI, 40.1-45.9). The distances from the PM humeral insertion to LPN and MPN were 93.2 mm (95% CI, 83.1-103.3) and 103.8 mm (95% CI, 98.3-109.4), respectively. The coracoid process to MCN distance was 68.5 mm (95% CI, 60.2-76.8).Conclusion:This study successfully quantifies anatomic dimensions of the PM tendon, its sternal and clavicular head insertions, and its location relative to nearby vital structures. Such knowledge can provide surgeons with a better understanding of the PM in relation to nearby neurovascular structures during anatomic PM repair and reconstruction to avoid debilitating complications.Clinical Relevance:Knowledge of the quantitative anatomy of the PM at the humeral footprint along structures at risk may aid surgeons with identifying the injured part of the PM and improve outcomes for anatomic repair and reconstruction.

Virtual skeletons and digital muscles: an experimental bioarchaeological approach to the pre-Hispanic production of millstones (Tenerife, Canary Islands)

Highlights: The combination of biomechanical analysis and open-access Kinovea software enables the study of musculoskeletal and articular wear of experimentally reproduced tasks. The repeated use of the right arm during indirect percussion and abrasion in lithic production could increase the changes in bone robusticity of specific muscle attachments observed in the osteoarchaeological record. Motion ranges and postural angles analysis can generate more accurate representations of "virtual humans" in their archaeological context. Abstract: Understanding the physical impact of ancient labours has become an important experimental bioarchaeology area. Complex motion capture systems and digital tools have been used in biomechanical analysis during the reproduction of manual tasks. However, these systems are costly, so the researchers have explored alternative digital solutions. Therefore, the open-access Kinovea software was checked to confirm its reliability in characterizing the physical loads associated with particular works of ancient times. In this case study, the authors have analyzed the central postural angles and muscle chains involved in the indigenous manufacturing process of rotary stone mills, in the high mountains of Tenerife. The study included a virtual motion capture analysis carried out during the different phases of the experimental reproduction of this process; it was defined from the archaeological record of the quarries-workshops of Las Cañadas del Teide National Park (Canary Islands, Spain) volcanic millstones. The results of this study have demonstrated the software's effectiveness to virtually analyze the significant differences in posture between work techniques, observing a predominance of the use of m. biceps brachii, the m. brachioradialis, and the elbow joint during the manufacture of stone mills. On the other hand, Kinovea also has excellent potential in virtual archaeology, giving users tools to generate the average postural angles. As a result, building "virtual skeletons" in more precise work postures has been possible. This may serve as the base element to create complete body representations in virtual environments.