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Journal of Athletic Training Nov 2023Shoulder muscles are active during front crawl swimming to provide propulsion and stabilize the glenohumeral and scapulothoracic joints. It has been proposed that...
CONTEXT.
Shoulder muscles are active during front crawl swimming to provide propulsion and stabilize the glenohumeral and scapulothoracic joints. It has been proposed that fatigue might contribute to altered activation of these muscles and represent a risk factor for injuries. Tensiomyography (TMG) might represent a non-invasive tool to detect exercise-induced neuromuscular fatigue changes in contractile parameters of the skeletal muscles, and it has never been used in the shoulder muscles in swimmers.
OBJECTIVE.
The aim of this study was to assess the effects of a fatiguing swimming protocol on shoulder muscles TMG parameters and isometric strength in competitive swimmers.
DESIGN.
A cross-sectional study.
SETTING.
A swimming pool facility.
PATIENTS OR OTHER PARTICIPANTS.
Sixteen young front crawl competitive swimmers were invited to participate in the study, and 14 of them (21 y, range 17-26, 11 males 3 females) completed all the assessments before and after a 30-min high-intensity swimming training.
MAIN OUTCOME MEASURE(S).
The main outcome included the TMG assessment which was performed on seven muscles of the shoulder according to front crawl biomechanics and applicability of the technique, in order to obtain data such as time to contraction and muscle belly radial displacement (Dm), whereas isometric strength was assessed with a digital dynamometer during shoulder flexion, extension, external rotation and internal rotation.
RESULTS.
Fatigue induced a smaller Dm (-0.5 mm, 95% CI: -0.7 - -0.3, p< 0.001, pη2= 0.692), mostly observable in latissimus dorsi and pectoralis major muscles. Only shoulder extension showed a significant isometric strength reduction after the fatiguing protocol (-0.03 N/kg, 95% CI: -0.05 - -0.01, p= 0.045, pη2= 0.275).
CONCLUSIONS.
This study provides preliminary evidence for the usefulness of TMG to detect fatigue-induced changes in contractile properties of the shoulder muscles in swimmers, in particular the latissimus dorsi, pectoralis major and lower trapezius.
PubMed: 38014804
DOI: 10.4085/1062-6050-0265.23 -
Cureus Oct 2023The pathology of the shoulder is among the most widespread medical presentations and may be a result of existing anatomical variations. Therefore, the knowledge of the... (Review)
Review
The pathology of the shoulder is among the most widespread medical presentations and may be a result of existing anatomical variations. Therefore, the knowledge of the variations is vital for physicians and clinicians, tasked with treating patients presenting similar complaints to minimize misdiagnosis and prevent iatrogenic injuries. Therefore, the main objective of the present systematic review the variations in pectoralis minor muscle origin and insertion/attachment point. The study also seeks to better inform physicians and clinicians of the task of treating patients with various pathology problems and to ascertain that, upon identification, the pectoralis minor muscle variants are aptly appreciated. The search method used in this systematic review entails the use of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, and the searching of several online databases, for studies focusing on variations in pectoralis minor muscles. The author reviewer evaluated the studies for eligibility, and the selection criteria for the studies used are described below. This systematic review has disclosed that, in some individuals, the pectoralis minor muscles have their origins in the second, third, and fourth ribs, even as others have their origin in the third and fourth ribs. Still, the systematic review has disclosed that, in certain individuals, the insertion of the pectoralis minor muscle occurs at the supraspinatus tendon, even as there are anomalies in the pectoralis minor insertion points linked to subacromial impingement, possible compression of the brachial plexus anteromedial and the axillary artery, and the subcoracoid impingement.
PubMed: 37916251
DOI: 10.7759/cureus.46329 -
Journal of Hand Surgery Global Online Jul 2023Thoracic outlet syndrome (TOS) is caused by entrapment of the neurovascular bundle in the interscalene, costoclavicular, or subpectoral minor space. Compression in the... (Review)
Review
Thoracic outlet syndrome (TOS) is caused by entrapment of the neurovascular bundle in the interscalene, costoclavicular, or subpectoral minor space. Compression in the interscalene or costoclavicular space with the first rib and scalene muscle leads to vascular and neurogenic TOS, whereas compression in the subpectoral minor space leads to pectoralis minor syndrome. Various surgical approaches exist for the treatment of TOS. The introduction and development of surgical approaches have minimized surgical invasiveness and complications. The reported approaches include transaxillary, supraclavicular, infraclavicular, posterior, combined transaxillary and supraclavicular, combined supraclavicular and infraclavicular (paraclavicular), endoscopic-assisted transaxillary, and video-assisted thoracoscopic approaches. In this review, we summarize the reported surgical approaches for TOS treatment, in terms of the history of the approach, surgical procedure, advantages and disadvantages, clinical outcomes, and complications. An adequate excision of compression structures, including the first rib and scalene muscles, provides satisfactory outcomes regardless of the approach selected, whereas an inadequate release of compression structures leads to failed or recurrent outcomes. Reducing the risk of complications is the most important aspect of TOS management. Surgery should be performed safely, with sufficient resection of compression structures. Additionally, the approach should be selected based on the surgeon's skill, surgeon's preferences, surgical invasiveness, cosmetic appearance, and the presence of special equipment, as well as other advantages and disadvantages of each approach.
PubMed: 37521542
DOI: 10.1016/j.jhsg.2022.04.007 -
Neurological Sciences : Official... Nov 2023Muscle ultrasound is a fast, non-invasive and cost-effective examination that can identify structural muscular changes by assessing muscle thickness and echointensity...
INTRODUCTION
Muscle ultrasound is a fast, non-invasive and cost-effective examination that can identify structural muscular changes by assessing muscle thickness and echointensity (EI) with a quantitative analysis (QMUS). To assess applicability and repeatability of QMUS, we evaluated patients with genetically confirmed facioscapulohumeral muscular dystrophy type 1 (FSHD1), comparing their muscle ultrasound characteristics with healthy controls and with those detected by MRI. We also evaluated relationships between QMUS and demographic and clinical characteristics.
MATERIALS AND METHODS
Thirteen patients were included in the study. Clinical assessment included MRC sum score, FSHD score and The Comprehensive Clinical Evaluation Form (CCEF). QMUS was performed with a linear transducer scanning bilaterally pectoralis major, deltoid, rectus femoris, tibialis anterior and semimembranosus muscles in patients and healthy subjects. For each muscle, we acquired three images, which were analysed calculating muscle EI by computer-assisted grey-scale analysis. QMUS analysis was compared with semiquantitative 1.5 T muscle MRI scale.
RESULTS
All muscles in FSHD patients showed a significant increased echogenicity compared to the homologous muscles in healthy subjects. Older subjects and patients with higher FSHD score presented increased muscle EI. Tibialis anterior MRC showed a significant inverse correlation with EI. Higher median EI was found in muscles with more severe MRI fat replacement.
CONCLUSIONS
QMUS allows quantitative evaluation of muscle echogenicity, displaying a tight correlation with muscular alterations, clinical and MRI data. Although a confirmation on larger sample is needed, our research suggests a possible future application of QMUS in diagnosis and management of muscular disorders.
PubMed: 37311950
DOI: 10.1007/s10072-023-06842-5 -
Medicina (Kaunas, Lithuania) Mar 2024Implant-based breast reconstruction (IBBR) is the most frequently performed procedure for breast reconstruction following mastectomy, which involves the surgical... (Review)
Review
Implant-based breast reconstruction (IBBR) is the most frequently performed procedure for breast reconstruction following mastectomy, which involves the surgical placement of breast implants. The approach to breast reconstruction can be divided into two main categories, namely prepectoral breast reconstruction (PPBR) and subpectoral breast reconstruction (SPBR), based on the implant plan and placement technique. In recent years, there has been a significant surge in the popularity of prepectoral implant-based breast reconstruction, where the implants are positioned above the chest muscle, as opposed to beneath it in the subpectoral approach. However, despite this growing preference, there is a lack of comprehensive data regarding the national trends in the utilization of this technique, thus necessitating further investigation. This narrative review aims to ascertain the current global patterns linked to prepectoral breast reconstruction and elucidate the considerations surrounding patient and implant selection, reconstructive techniques, the utilization of meshes in prepectoral reconstruction, the ensuing outcomes and complications, the ramifications of radiotherapy, and the potential advantages of integrating fat infiltration into the implementation of this technique in breast reconstruction with a focus on published papers in last five years. Conclusion: Prepectoral breast reconstruction has emerged as an appropriate surgical option for individuals seeking breast reconstruction. This development can be attributed to the recent progress made in implant technology, which has significantly enhanced the outcomes of this procedure. Additionally, advancements in mastectomy techniques, autologous fat grafting, and the use of acellular dermal matrices (ADMs) have also played a vital role in improving the aesthetic results of prepectoral breast reconstruction. As a result, the significance and effectiveness of this technique in the field of breast reconstruction have been firmly established, making it an essential component of the overall armamentarium available to plastic surgeons for breast reconstruction purposes.
Topics: Humans; Female; Mastectomy; Breast Neoplasms; Pectoralis Muscles; Mammaplasty; Breast Implantation; Retrospective Studies
PubMed: 38541157
DOI: 10.3390/medicina60030431 -
PeerJ 2023This study aimed to observe the effect of different finger rest positions on the muscular activity of the hand, forearm, arm, shoulder, thorax, and neck, as well as on...
OBJECTIVES
This study aimed to observe the effect of different finger rest positions on the muscular activity of the hand, forearm, arm, shoulder, thorax, and neck, as well as on the angular deviation from the neutral position of the neck, trunk, upper arm, and forearm on the working side during pre-clinical procedures.
METHODS
An experimental laboratory study was performed. Response variables were muscle activation of the abductor pollicis, brachioradialis, biceps brachii, deltoid, pectoralis major, and right sternocleidomastoid muscles and angular deviation from the neutral position of the neck, trunk, arm, and forearm during simulated clinical procedures. Independent variable was finger-rest position during cavity preparation (no finger rest, usual rest, and ergonomic rest). Class I cavity preparations (N = 120) were performed on artificial first molars (16, 26, 36, and 46) (N = 120). Muscular activation was assessed by surface electromyography and angular deviations using Software for Postural Assessment (SAPO) version 0.69. One-way analysis of variance and Tukey's or Games-Howell's tests were performed (α = 0.05).
RESULTS
For the sternocleidomastoid muscle, there was no statistically significant difference between the different rest positions. For the deltoid muscle, work with no finger rest resulted in greater muscle activation ( < 0.001) during work on tooth 36. Regarding the pectoralis major and right brachioradialis muscles, we observed that for both teeth 16 and 26, working with ergonomic rest showed less muscle activation. Muscle activation of the right biceps brachii was higher for work with no rest in both the upper and lower arches, differing significantly only from the usual rest in tooth 16 ( < 0.001), usual rest and ergonomic rest in teeth 26 and 46 ( < 0.001), and only ergonomic rest in tooth 36 ( = 0.044). In the right abductor pollicis muscle, work with ergonomic rest resulted in less muscle activation for cavity preparation in teeth 16, 26, and 36, which was significantly different from work with no rest ( = 0.029, < 0.001, and = 0.013, respectively). Regarding angular deviation, it was observed that for tooth 16, there was a greater angular deviation of the arm when performing cavity preparations with no finger rest. For teeth 26 and 46, the ergonomic finger rest provided lower angular deviation from the neutral position of the right arm. For tooth 36, ergonomic rest provided less angular deviation from the neutral neck position.
CONCLUSION
In general, the use of non-active finger rest during simulated cavity preparations, regardless of the type of rest, provided less muscle activation and angular deviation from the neutral position of the body's upper extremity when performing pre-clinical procedures.
PubMed: 37520265
DOI: 10.7717/peerj.15663 -
Clinics in Shoulder and Elbow Sep 2023Rupture of the pectoralis major muscle typically occurs in the young, active male. Acute management of these injuries is recommended; however, what if the patient...
Rupture of the pectoralis major muscle typically occurs in the young, active male. Acute management of these injuries is recommended; however, what if the patient presents with a chronic tear of the pectoralis major? Physical exams and magnetic resonance imaging can help identify the injury and guide the physician with a plan for management. Nonoperative management is feasible, but is recommended for elderly, low-demand patients whose functional goals are minimal. Repair of chronic tears should be reserved for younger, healthier patients with high functional demands. Although operative management provides better functional outcomes, operative treatment of chronic pectoralis tears can be challenging. Tendon retraction, poor tendinous substance and quality of tissue, muscle atrophy, scar formation, and altered anatomy make direct repairs complicated, often necessitating auto- or allograft use. We review the various graft options and fixation methods that can be used when treating patients with chronic pectoralis major tears.
PubMed: 37607861
DOI: 10.5397/cise.2023.00129 -
Frontiers in Physiology 2023Meat-type (broiler) and egg-type (layer) chickens were bred by intensive selection over the years, resulting in more numbers and larger sizes of myofibers. Although the...
Meat-type (broiler) and egg-type (layer) chickens were bred by intensive selection over the years, resulting in more numbers and larger sizes of myofibers. Although the characteristics are important parameters in muscle growth and meat quality, muscle bundle characteristics have not been studied in poultry. Therefore, this study aimed to compare the histological characteristics of myofibers and muscle bundles in muscles between male broiler (Ross broiler breed) chickens and layer (Hy-Line) chickens. Chicken muscles, (PM) and (GM), were sampled at the age of 49 days and stained to analyze histological characteristics. Expectedly, body weights (BWs) and weights of PM and GM muscles in 49-day-old broilers were significantly heavier than those in layers. Within PM, broilers exhibited greater number and cross-sectional area (CSA) of myofibers than layers (3.3- and 3.3-fold, respectively). The total number and CSA of PM muscle bundles were approximately 1.5 and 6.6 times greater, respectively, in broilers than layers. Moreover, broilers exhibited 2 times greater number of myofibers per bundle of PM muscle than layers. Within GM, myofiber number and CSA were 2.3- and 2.4-fold greater, respectively, in broilers than layers. In addition, the total number of muscle bundles and bundle CSA were 2.5- and 2.1-fold greater, respectively, in broilers than in the layers. The novel findings of the current study provide evidence that greater muscle mass of broilers occurs by both hyperplasia and hypertrophy of muscle bundles and myofibers.
PubMed: 37877096
DOI: 10.3389/fphys.2023.1285938 -
BMC Veterinary Research Aug 2023The purpose of this study was to explore whether domestication could lead to evolutionary changes towards flightlessness in the domestic duck (Anas platyrhynchos...
Morphological, radiographic, three-dimensional computed tomographic, and histological features of the primary upstroke and downstroke muscles and bones in the domestic duck (Anas platyrhynchos domesticus) and the cattle egret (Bubulcus ibis, Linnaeus, 1758), reflecting the evolutionary transition...
BACKGROUND
The purpose of this study was to explore whether domestication could lead to evolutionary changes towards flightlessness in the domestic duck (Anas platyrhynchos domesticus) compared to the cattle egret (Bubulcus ibis) as a nonflying and flying biological model, respectively. Bones of the pectoral girdle (scapula, clavicle, and coracoid) and the foramen triosseum were comparatively assessed using anatomical, radiographic, and 3D computed tomographic (CT) studies. Additionally, the muscles pectoralis and the supracoracoideus were histologically and immunohistochemically assessed.
RESULTS
Among the differences observed, radiographically, the distance between the paired clavicles was significantly wider (p < 0.05) in the domestic duck (mean ± SD 1.43 ± 0.23 cm) compared with the cattle egret (0.96 ± 0.13 cm). Unlike cattle egrets, there was no connection between the sternum and the hypocladium of furcula in domestic ducks. The scapula, clavicle, coracoid, sternum, and humerus were considerably longer in domestic ducks than in cattle egrets. The foramen triosseum appeared significantly (p < 0.01) wider in domestic ducks (0.7 ± 1.17 cm) compared to cattle egrets (0.49 ± 0.03 cm). Histologically, compared to cattle egrets, the muscle fibers in domestic ducks were loosely connected and contained fewer nuclei and perimysial/endomysial spaces. A higher myoglobin expression was evident in cattle egrets compared with domestic ducks.
CONCLUSIONS
Results of this study indicate that the bones and muscles of the pectoral girdle generally show specific morphological and structural changes reflective of the loss of prerequisites associated with flight behavior in domestic ducks due to domestication effects compared to cattle egrets.
Topics: Animals; Cattle; Ducks; Birds; Humerus; Scapula; Myocardium
PubMed: 37626319
DOI: 10.1186/s12917-023-03649-6