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1.
PeerJ ; 12: e17678, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39119105

RESUMO

Take-off is a vital part of powered flight which likely constrains the size of birds, yet extinct pterosaurs are known to have reached far larger sizes. Three different hypothesised take-off motions (bipedal burst launching, bipedal countermotion launching, and quadrupedal launching) have been proposed as explanations for how pterosaurs became airborne and circumvented this proposed morphological limit. We have constructed a computational musculoskeletal model of a 5 m wingspan ornithocheiraean pterosaur, reconstructing thirty-four key muscles to estimate the muscle moment arms throughout the three hypothesised take-off motions. Range of motion constrained hypothetical kinematic sequences for bipedal and quadrupedal take-off motions were modelled after extant flying vertebrates. Across our simulations we did not find higher hindlimb moment arms for bipedal take-off motions or noticeably higher forelimb moment arms in the forelimb for quadrupedal take-off motions. Despite this, in all our models we found the muscles utilised in the quadrupedal take-off have the largest total launch applicable moment arms throughout the entire take-off sequences and for the take-off pose. This indicates the potential availability of higher leverage for a quadrupedal take-off than hypothesised bipedal motions in pterosaurs pending further examination of muscle forces.


Assuntos
Dinossauros , Voo Animal , Animais , Fenômenos Biomecânicos , Voo Animal/fisiologia , Dinossauros/fisiologia , Dinossauros/anatomia & histologia , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Fósseis , Modelos Biológicos , Membro Anterior/fisiologia , Membro Anterior/anatomia & histologia , Simulação por Computador
2.
J Sports Sci ; 42(12): 1157-1163, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39087807

RESUMO

Minimalist walking shoes have been shown to improve foot muscle size and strength in active adults, but not in our previous study involving children, which could relate to the more structured footwear used in our study. Hence, this study examined the effects of true minimalists on intrinsic foot muscle size and strength, foot arch integrity, and physical function among primary school children. After a baseline assessment, 30 primary school students aged between 9 and 12 were given a pair of minimalist shoes (minimalist index = 92%) as their regular school shoes for two school terms, followed by a re-assessment. Seventeen of the 30 participants in the minimalist group completed the study. Compared to the control group, the minimalist group showed significantly increased cross-sectional area of abductor hallucis (p = 0.047, Cohen's d = 0.57) and flexor digitorum brevis (p = 0.037, Cohen's d = 0.80), increased strength of the hallux (p = 0.015, Cohen's d = 0.76) and lesser toes (p = 0.014, Cohen's d = 0.66), greater arch height (p = 0.020, Cohen's d = 0.52) and standing long jump distance (p = 0.001, Cohen's d = 9.79). The control group exhibited improved standing long jump performance only (p = 0.020, Cohen's d = 10.70). Minimalist shoes worn daily to school promote intrinsic foot muscle size and strength, and improve foot arch integrity among primary school students.


Assuntos
, Força Muscular , Músculo Esquelético , Sapatos , Humanos , Criança , Força Muscular/fisiologia , Pé/fisiologia , Pé/anatomia & histologia , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Masculino , Feminino , Caminhada/fisiologia , Desenho de Equipamento , Instituições Acadêmicas
3.
PLoS Comput Biol ; 20(7): e1012243, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38968305

RESUMO

Computational models of musculoskeletal systems are essential tools for understanding how muscles, tendons, bones, and actuation signals generate motion. In particular, the OpenSim family of models has facilitated a wide range of studies on diverse human motions, clinical studies of gait, and even non-human locomotion. However, biological structures with many joints, such as fingers, necks, tails, and spines, have been a longstanding challenge to the OpenSim modeling community, especially because these structures comprise numerous bones and are frequently actuated by extrinsic muscles that span multiple joints-often more than three-and act through a complex network of branching tendons. Existing model building software, typically optimized for limb structures, makes it difficult to build OpenSim models that accurately reflect these intricacies. Here, we introduce ArborSim, customized software that efficiently creates musculoskeletal models of highly jointed structures and can build branched muscle-tendon architectures. We used ArborSim to construct toy models of articulated structures to determine which morphological features make a structure most sensitive to branching. By comparing the joint kinematics of models constructed with branched and parallel muscle-tendon units, we found that among various parameters-the number of tendon branches, the number of joints between branches, and the ratio of muscle fiber length to muscle tendon unit length-the number of tendon branches and the number of joints between branches are most sensitive to branching modeling method. Notably, the differences between these models showed no predictable pattern with increased complexity. As the proportion of muscle increased, the kinematic differences between branched and parallel models units also increased. Our findings suggest that stress and strain interactions between distal tendon branches and proximal tendon and muscle greatly affect the overall kinematics of a musculoskeletal system. By incorporating complex muscle-tendon branching into OpenSim models using ArborSim, we can gain deeper insight into the interactions between the axial and appendicular skeleton, model the evolution and function of diverse animal tails, and understand the mechanics of more complex motions and tasks.


Assuntos
Articulações , Músculo Esquelético , Software , Tendões , Tendões/fisiologia , Tendões/anatomia & histologia , Humanos , Fenômenos Biomecânicos , Articulações/fisiologia , Articulações/anatomia & histologia , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Modelos Biológicos , Biologia Computacional , Simulação por Computador , Animais
4.
Sensors (Basel) ; 24(13)2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-39000851

RESUMO

This study investigates gender differences in core muscle morphology among elite alpine skiers using ultrasonography, highlighting significant disparities that could influence training and injury prevention strategies. METHODS: A cross-sectional design was employed, examining ultrasound imaging (USI) in 22 elite skiers (11 male, 11 female) to assess the thickness of the external oblique (EO), internal oblique (IO), transversus abdominis (TrAb), and rectus abdominis (RA) muscles. RESULTS: Significant differences were noted, with male skiers displaying greater muscle thickness, particularly in the right IO and RA and left IO, EO, TrAb, and RA. CONCLUSIONS: These findings suggest that male and female skiers may require different training approaches to optimize performance and reduce injury risks. This research contributes to a deeper understanding of the physical demands on elite skiers and underscores the need for gender-specific training regimens to enhance athletic outcomes and prevent injuries.


Assuntos
Esqui , Ultrassonografia , Humanos , Esqui/fisiologia , Feminino , Masculino , Ultrassonografia/métodos , Estudos Transversais , Adulto , Adulto Jovem , Fatores Sexuais , Músculo Esquelético/fisiologia , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/anatomia & histologia , Atletas , Músculos Abdominais/diagnóstico por imagem , Músculos Abdominais/fisiologia , Músculos Abdominais/anatomia & histologia
5.
PeerJ ; 12: e17606, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952989

RESUMO

Objective: To investigate the effects of 12-week weight-bearing dance aerobics (WBDA) on muscle morphology, strength and functional fitness in older women. Methods: This controlled study recruited 37 female participants (66.31y ± 3.83) and divided them into intervention and control groups according to willingness. The intervention group received 90-min WBDA thrice a week for 12 weeks, while the control group maintained normal activities. The groups were then compared by measuring muscle thickness, fiber length and pennation angle by ultrasound, muscle strength using an isokinetic multi-joint module and functional fitness, such as 2-min step test, 30-s chair stand, chair sit-and-reach, TUG and single-legged closed-eyed standing test. The morphology, strength, and functional fitness were compared using ANCOVA or Mann-Whitney U test to study the effects of 12 weeks WBDA. Results: Among all recruited participants, 33 completed all tests. After 12 weeks, the thickness of the vastus intermedius (F = 17.85, P < 0.01) and quadriceps (F = 15.62, P < 0.01) was significantly increased in the intervention group compared to the control group, along with a significant increase in the torque/weight of the knee flexor muscles (F = 4.47, P = 0.04). Similarly, the intervention group revealed a significant improvement in the single-legged closed-eyed standing test (z = -2.16, P = 0.03) compared to the control group. Conclusion: The study concluded that compared to the non-exercising control group, 12-week WBDA was shown to thicken vastus intermedius, increase muscle strength, and improve physical function in older women. In addition, this study provides a reference exercise program for older women.


Assuntos
Dança , Força Muscular , Suporte de Carga , Humanos , Feminino , Força Muscular/fisiologia , Idoso , Dança/fisiologia , Suporte de Carga/fisiologia , Aptidão Física/fisiologia , Extremidade Inferior/fisiologia , Extremidade Inferior/diagnóstico por imagem , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/diagnóstico por imagem , Exercício Físico/fisiologia , Músculo Quadríceps/fisiologia , Músculo Quadríceps/diagnóstico por imagem , Músculo Quadríceps/anatomia & histologia
6.
J Biomech Eng ; 146(10)2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39082779

RESUMO

Skeletal muscle architecture is a strong predictor of in vivo functional capacity and is evaluated in fixed tissues, accommodating the study of human muscles from cadaveric donors. Previous studies evaluating the pelvic floor muscles (PFMs) demonstrated that the rat is the most appropriate small animal model for the study of female PFM architecture, but the rat's suitability for the study of male PFMs is undetermined. We aimed to determine (1) whether PFM architecture exhibits sexual dimorphism in rats or humans, and (2) if the rat is also a suitable animal model for the study of male human PFMs. PFMs were fixed in situ and harvested en bloc from male and female cadaveric donors and 3-month-old male and female Sprague-Dawley rats. Three architectural parameters influenced by species size were used to compare male versus female PFMs within species, while four size-independent measures compared species within sex. All comparisons were made with two-way analysis of variances and Tukey's multiple comparisons tests post hoc. Sarcomere length (rats and humans, p = 0.016 and = 0.002) and normalized fiber length (rats, p < 0.001) were significantly larger in male PFMs. Three of the size-independent measures exhibited similar species trends in both sexes, while the size-independent sarcomere length measure (Ls/Lso) differed between male rats and humans (p < 0.001). Thus, sexual dimorphism is present in rat and human PFM architecture, and the male rat is suitable for studies of human male PFMs.


Assuntos
Diafragma da Pelve , Ratos Sprague-Dawley , Caracteres Sexuais , Animais , Diafragma da Pelve/anatomia & histologia , Diafragma da Pelve/fisiologia , Feminino , Masculino , Humanos , Ratos , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia
7.
Surg Radiol Anat ; 46(9): 1447-1454, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39043949

RESUMO

PURPOSE: Depending on its axis, pronation varies from the radius rotation around the steady ulna to the reciprocal adduction of the radius and abduction of the ulna. While there is no question that pronator teres is a central pronation agonist, anconeus's role is not settled. The current investigation comparing palpation and ultrasonography in these two muscles during pronation along the axis capitulum-second digit evolved from a serendipitous finding in a clinical anatomy seminar. METHODS: Single-hand palpation and two-transducer ultrasonography over anconeus and pronator teres were used on ten normal subjects to investigate their contraction during pronation around the capitulum-second digit axis. These studies were done independently and blind to the results of the other. The statistical analysis between palpation and ultrasonography was performed with Cohen's kappa coefficient and the χ2 test. RESULTS: On palpation, on resisted full pronation, anconeus contracted in 8/10 subjects and pronator teres in 10/10 subjects. Without resistance, the corresponding ratios were 5/10 and 9/10. On two-transducer ultrasonography, the comparable ratios were 7/10 and 10/10, and 3/10 and 10/10. A fair concordance (Cohen's kappa = 0.21) between palpation and ultrasonography in detecting the simultaneous status of anconeus and pronator teres during resisted full pronation. Anatomic dissection illustrated the elements involved. CONCLUSIONS: Plain palpation confirmed by ultrasonography showed the simultaneous contraction of anconeus and pronator teres during resisted pronation in most of the studied subjects. The study suggests that palpation can be helpful in directly studying muscle activity during movement.


Assuntos
Voluntários Saudáveis , Músculo Esquelético , Palpação , Pronação , Ultrassonografia , Humanos , Pronação/fisiologia , Ultrassonografia/métodos , Masculino , Adulto , Feminino , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Palpação/métodos , Adulto Jovem , Contração Muscular/fisiologia
8.
J Strength Cond Res ; 38(9): 1640-1650, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39016320

RESUMO

ABSTRACT: Moeskops, S, Oliver, JL, Radnor, JM, Haff, GG, Myer, GD, Ramachandran, AK, Kember, LS, Pedley, JS, and Lloyd, RS. Effects of neuromuscular training on muscle architecture, isometric force production, and stretch-shortening cycle function in trained young female gymnasts. J Strength Cond Res 38(9): 1640-1650, 2024-This study evaluated the effects of a 10-month neuromuscular training (NMT) intervention on muscle architecture, isometric force production, and stretch-shortening cycle (SSC) function. Thirty-seven girls aged 6-12 years were placed into gymnastics + NMT (gNMT; n = 15), gymnastics only (GYM; n = 10), or maturity-matched control (CON; n = 12) groups. The gNMT group followed a 10-month NMT program in addition to gymnastics training, whereas the GYM group only participated in gymnastics training. Isometric midthigh pull (IMTP) and drop jump (DJ) kinetics were measured, in addition to muscle thickness, fascicle length, and pennation angle of the gastrocnemius medialis at baseline and at 4, 7, and 10 months. A 3 × 4 (group × time) repeated-measures ANCOVA (covariate, % predicted adult height) was used to evaluate within-group changes. Significance level was set at p < 0.05. Significant interaction effects were observed in muscle thickness, absolute (PF abs ) and relative peak force (PF rel ) in the IMTP and various DJ variables. The gNMT group demonstrated improvements in muscle thickness, IMTP PF abs and PF rel , and DJ kinetics, most commonly evidenced from 7 months onward. The GYM group's muscle thickness also significantly improved, accompanied by improvements in some DJ kinetics. The CON group did not experience any desirable changes. Overall, NMT elicited positive changes in muscle thickness, PF abs and PF rel , and SSC function to a greater extent than gymnastics training alone or growth and maturation. As most adaptations took 7 months, longer-term NMT programs should be implemented with youth female gymnasts.


Assuntos
Ginástica , Contração Isométrica , Músculo Esquelético , Humanos , Ginástica/fisiologia , Feminino , Criança , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Contração Isométrica/fisiologia , Força Muscular/fisiologia , Condicionamento Físico Humano/métodos , Condicionamento Físico Humano/fisiologia
9.
J R Soc Interface ; 21(216): 20230593, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38981517

RESUMO

Birds, bats and insects have evolved unique wing structures to achieve a wide range of flight capabilities. Insects have relatively stiff and passive wings, birds have a complex and hierarchical feathered structure and bats have an articulated skeletal system integrated with a highly stretchable skin. The compliant skin of the wing distinguishes bats from all other flying animals and contributes to bats' remarkable, highly manoeuvrable flight performance and high energetic efficiency. The structural and functional complexity of the bat wing skin is one of the least understood although important elements of the bat flight anatomy. The wing skin has two unusual features: a discrete array of very soft elastin fibres and a discrete array of skeletal muscle fibres. The latter is intriguing because skeletal muscle is typically attached to bone, so the arrangement of intramembranous muscle in soft skin raises questions about its role in flight. In this paper, we develop a multi-scale chemo-mechanical constitutive model for bat wing skin. The chemo-mechanical model links cross-bridge cycling to a structure-based continuum model that describes the active viscoelastic behaviour of the soft anisotropic skin tissue. Continuum models at the tissue length-scale are valuable as they are easily implemented in commercial finite element codes to solve problems involving complex geometries, loading and boundary conditions. The constitutive model presented in this paper will be used in detailed finite element simulations to improve our understanding of the mechanics of bat flight in the context of wing kinematics and aerodynamic performance.


Assuntos
Quirópteros , Voo Animal , Modelos Biológicos , Músculo Esquelético , Asas de Animais , Animais , Quirópteros/fisiologia , Quirópteros/anatomia & histologia , Asas de Animais/fisiologia , Asas de Animais/anatomia & histologia , Voo Animal/fisiologia , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Fenômenos Biomecânicos , Fenômenos Fisiológicos da Pele
10.
Surg Radiol Anat ; 46(9): 1465-1468, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38963432

RESUMO

PURPOSE: A deep knowledge of the variations of the posterior forearm musculature is crucial for assessing and diagnosing conditions in this region. Extensor indicis (EI) is one of the muscles in this region, which exhibits diverse anatomical variations. This report documents an extremely unusual form of the EI with an accessory head on the dorsum of the hand. METHODS: During routine dissection, an extremely rare presentation of the EI was found in the left forearm of a 94-year-old female cadaver. RESULTS: This unusual EI consisted of two muscle bellies. The traditional belly originated from the distal two-thirds of the ulna. The muscle became tendinous around the carpal area, distal to the extensor retinaculum. The tendon was subsequently joined by an accessory muscle belly originating from the distal radioulnar ligament. The EI tendon inserted onto the dorsal expansion of the index finger, ulnar to that of the extensor digitorum. The posterior interosseous nerve innervated the muscle. CONCLUSION: Herein, we report an extremely rare form of the EI. To our knowledge, EI with an accessory head has only been reported rarely over the past 200 years. Moreover, our report appears to be the first case with photographic details of this anatomical variation. Clinicians should be aware of this variation for proper diagnosis and treatment.


Assuntos
Variação Anatômica , Cadáver , Antebraço , Músculo Esquelético , Humanos , Feminino , Idoso de 80 Anos ou mais , Músculo Esquelético/anormalidades , Músculo Esquelético/anatomia & histologia , Antebraço/anormalidades , Antebraço/inervação , Tendões/anormalidades , Tendões/anatomia & histologia , Dissecação
11.
Ann Anat ; 255: 152284, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38830558

RESUMO

INTRODUCTION: The purpose of this study was to characterize the morphological variations in the quadratus femoris muscle (QF) and to create an anatomical classification that could be used in the planning of surgical procedures in this area, radiological imaging, and rehabilitation. MATERIALS AND METHODS: Ninety-two lower limbs from 46 cadavers, fixed in 10 % formalin solution, were examined. RESULTS: The QF muscle was present in all specimens. According to morphology, the QF muscle was classified into three types. The most common type was Type I, characterized by one muscular belly (78.3 %), while the second most common type was Type II, characterized by two bellies, was observed in 17.4 % of cases. The rarest type was Type III. It was characterized by three bellies and was found in 4.3 % of the cases. CONCLUSIONS: The current classification system on quadratus femoris morphological variability is novel. Morphological variants may contribute to clinical issues, such as the ischiofemoral impingement syndrome, that could arise from type I quadratus femoris. Hence, the current study may be applicated to planning surgical procedures, imaging, and rehabilitation.


Assuntos
Cadáver , Músculo Esquelético , Humanos , Masculino , Feminino , Idoso , Músculo Esquelético/anatomia & histologia , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade
12.
Sci Rep ; 14(1): 14847, 2024 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937524

RESUMO

Muscle morphological architecture, a crucial determinant of muscle function, has fascinated researchers since the Renaissance. Imaging techniques enable the assessment of parameters such as muscle thickness (MT), pennation angle (PA), and fascicle length (FL), which may vary with growth, sex, and physical activity. Despite known interrelationships, robust mathematical models like causal mediation analysis have not been extensively applied to large population samples. We recruited 109 males and females, measuring knee flexor and extensor, and plantar flexor MT, PA, and FL using real-time ultrasound imaging at rest. A mixed-effects model explored sex, leg (dominant vs. non-dominant), and muscle region differences. Males exhibited greater MT in all muscles (0.1 to 2.1 cm, p < 0.01), with no sex differences in FL. Dominant legs showed greater rectus femoris (RF) MT (0.1 cm, p = 0.01) and PA (1.5°, p = 0.01), while vastus lateralis (VL) had greater FL (1.2 cm, p < 0.001) and PA (0.6°, p = 0.02). Regional differences were observed in VL, RF, and biceps femoris long head (BFlh). Causal mediation analyses highlighted MT's influence on PA, mediated by FL. Moderated mediation occurred in BFlh, with FL differences. Gastrocnemius medialis and lateralis exhibited FL-mediated MT and PA relationships. This study unveils the intricate interplay of MT, FL, and PA in muscle architecture.


Assuntos
Extremidade Inferior , Músculo Esquelético , Ultrassonografia , Humanos , Masculino , Feminino , Adulto , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Ultrassonografia/métodos , Extremidade Inferior/diagnóstico por imagem , Extremidade Inferior/fisiologia , Extremidade Inferior/anatomia & histologia , Adulto Jovem , Músculo Quadríceps/diagnóstico por imagem , Músculo Quadríceps/anatomia & histologia , Músculo Quadríceps/fisiologia
13.
Medicine (Baltimore) ; 103(25): e38598, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38905373

RESUMO

Accurate detection of the levator scapulae muscle is critical for effective diagnostic and therapeutic interventions. The commonly used surface anatomy approach has not been validated and is less accurate than ultrasound-guided techniques. Therefore, we determined the needle insertion point for the levator scapulae using a new technique based on the anatomy of the scapula. This investigation used 15 fresh-frozen cadavers to explore the relationship between the acromial angle and medial tip of the scapular spine (O) of the scapular spine. Based on the x-axis (the distance [L] from Point O to point acromial angle) and the y-axis perpendicular to the x-axis passing through Point O, the barycentric coordinates were determined through the intersections of each axis and the superior angle of the scapula with the levator scapulae. Various ratios involving the established distance L) were ascertained, we compared the measurements and ratios between the male and female groups, and the accuracy of the new technique was compared with the conventional technique. The optimal site of the new technique was within 6 to 7% of distance L on the x-axis and 42 to 44% of distance L on the y-axis. This technique was significantly more accurate than the conventional technique (P = .006). Although ultrasound allows for accurate injections via real-time visualization, its unavailability in some cases highlights the importance of understanding surface anatomy landmarks. Our new technique, based on the anatomy of the scapula and relative measurements, is more accurate than the conventional technique. This should enable more precise detection of the levator scapulae for accurate and efficient diagnostic and therapeutic procedures.


Assuntos
Cadáver , Escápula , Humanos , Masculino , Feminino , Escápula/anatomia & histologia , Escápula/diagnóstico por imagem , Injeções Intramusculares/métodos , Idoso , Idoso de 80 Anos ou mais , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/diagnóstico por imagem , Pessoa de Meia-Idade
14.
Nature ; 630(8017): 671-676, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38867039

RESUMO

The subpectoral diverticulum (SPD) is an extension of the respiratory system in birds that is located between the primary muscles responsible for flapping the wing1,2. Here we survey the pulmonary apparatus in 68 avian species, and show that the SPD was present in virtually all of the soaring taxa investigated but absent in non-soarers. We find that this structure evolved independently with soaring flight at least seven times, which indicates that the diverticulum might have a functional and adaptive relationship with this flight style. Using the soaring hawks Buteo jamaicensis and Buteo swainsoni as models, we show that the SPD is not integral for ventilation, that an inflated SPD can increase the moment arm of cranial parts of the pectoralis, and that pectoralis muscle fascicles are significantly shorter in soaring hawks than in non-soaring birds. This coupling of an SPD-mediated increase in pectoralis leverage with force-specialized muscle architecture produces a pneumatic system that is adapted for the isometric contractile conditions expected in soaring flight. The discovery of a mechanical role for the respiratory system in avian locomotion underscores the functional complexity and heterogeneity of this organ system, and suggests that pulmonary diverticula are likely to have other undiscovered secondary functions. These data provide a mechanistic explanation for the repeated appearance of the SPD in soaring lineages and show that the respiratory system can be co-opted to provide biomechanical solutions to the challenges of flight and thereby influence the evolution of avian volancy.


Assuntos
Voo Animal , Falcões , Respiração , Sistema Respiratório , Asas de Animais , Animais , Evolução Biológica , Fenômenos Biomecânicos/fisiologia , Voo Animal/fisiologia , Falcões/anatomia & histologia , Falcões/classificação , Falcões/fisiologia , Pulmão/anatomia & histologia , Pulmão/fisiologia , Modelos Biológicos , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Sistema Respiratório/anatomia & histologia , Asas de Animais/fisiologia , Asas de Animais/anatomia & histologia , Masculino , Feminino
15.
PeerJ ; 12: e17506, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38860209

RESUMO

Introduction: The interest in estimating muscle mass (MM) and bone mass (BM) has grown in the sporting arena, and more specifically in recreational strength trainees, leading to the creation of different strategies to assess them. The aims were: 1) to investigate the agreement between different MM and BM formulas, and the muscle-bone index (MBI), and to establish the differences between them, in a healthy young adult population; and 2) to analyze if there are differences between males and females in the comparison of MM, BM and MBI formulas. Methods: This study followed a descriptive cross-sectional design. A total of 130 adult active recreational strength trainees were evaluated according to the procedures described by the International Society for the Advancement in Kinanthropometry (ISAK). Estimations were made in kilograms of MM and BM by following the equations by different authors. Results: The results showed significant differences between the values obtained by all the MM and BM formulas in the general sample (p < 0.001), and by the majority of formulas for male and female samples. In the general sample, Lin's coefficient indicated a strong agreement between Kerr, Lee, and Poortmans' MM estimation equations (concordance correlation coefficient (CCC) = 0.96-0.97). However, when stratifying by sex, this agreement persisted only in males (CCC = 0.90-0.94), in contrast with a lack of agreement observed in females (CCC < 0.90). Discrepancies in bone mass agreement were noted both in the general sample (CCC < 0.15) and when stratified by sex (CCC < 0.12). Conclusions: In general, differences were found between the values reported by the MM and BM formulas in recreational strength trainees, without an agreement between them. Sex was shown to significantly influence the differences found. The practical implications are that when comparing an individual with reference tables, other studies, or if analyzing an individual's evolution, the same estimation equation should be used, as they are not interchangeable.


Assuntos
Antropometria , Músculo Esquelético , Humanos , Masculino , Feminino , Estudos Transversais , Adulto , Antropometria/métodos , Adulto Jovem , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Densidade Óssea/fisiologia , Força Muscular/fisiologia , Composição Corporal/fisiologia , Fatores Sexuais
16.
J Musculoskelet Neuronal Interact ; 24(2): 127-138, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38825995

RESUMO

OBJECTIVES: The aim of this study was to compare torque-velocity profiles, muscle architecture, tendon dimensions, and bilateral-symmetry between competitive cyclists (CY), competitive runners (RN), ice-hockey players (IH), basketball players (BP), and physically-active individuals (CN) (n=10 for each group). METHODS: Vastus lateralis (VL) muscle and patellar tendon (PT) structures were determined with B-mode ultrasonography, and maximal knee extensor isokinetic torque was assessed at three different velocities. RESULTS: Optimal torque and velocity were lower in runners than CY, BP and IH (p<0.05). Maximal power was similar between the athlete groups but greater than CN (p<0.05). Furthermore, RN and BP reached their peak-torque at longer muscle lengths compared to IH and CY (p<0.05). RN had the lowest VL muscle thickness and the greatest fascicle length, while CY had the greatest pennation angle (p<0.05). CY had the greatest PT thickness, particularly at the proximal and medial sites, while BP at the distal point (p<0.05), with similar trends observed for PT cross-sectional-area. CONCLUSIONS: Our findings show that even if power generating capacity is similar between athletic disciplines, there are discipline-specific muscle adaptations, where particularly runners appear to have muscles adapted for speed rather than torque development, while in cyclists, velocity is sacrificed for torque development.


Assuntos
Atletas , Torque , Humanos , Masculino , Adulto , Adulto Jovem , Músculo Esquelético/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/diagnóstico por imagem , Ultrassonografia/métodos , Ligamento Patelar/fisiologia , Ligamento Patelar/diagnóstico por imagem , Ligamento Patelar/anatomia & histologia , Corrida/fisiologia
17.
Int. j. morphol ; 42(3): 773-778, jun. 2024. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-1564626

RESUMO

SUMMARY: The dorsal interosseous muscles (DIM) are intrinsic muscles of the hand located dorsally between metacarpal bones, which play a role in finger abduction. Anatomical variations of these muscles in terms of form and length have been well documented, but variations regarding sex and laterality are underexplored. The aim of this study was to investigate the morphology and morphometry of the DIM of the hand regarding sexual dimorphism and laterality. Twenty human cadavers belonging to the white individuals (n = 40 hands) with known sex and laterality were used for this study. DIMs were dissected and observed for morphology. Also, a digital calliper was used to measure the midpoint length of the DIM. The origin and insertion of all the DIM were normal with the left hand having no additional, supernumerary, and absent muscles in each compartment. The variations were only found on the right side and predominant in females: 2 out of 11 (18.18%) hands containing a space with a supernumerary muscle; 1 out of 11 (9.09%) hands having a space with a double muscle; and 1 out of 11 (9.09%) hands having a compartment with a unipennate muscle. In males, 1 out of 9 (11.11%) hands had a compartment with a supernumerary muscle. The mean midpoint length of each muscle in females and males in both hands from the first to the fourth muscle, respectively, was documented. In females on the left: 46.79 ± 3.56; 42.62 ± 3.57; 49.02 ± 4.21; 41.66 ± 2.15 and right: 47.30 ± 2.49; 39.27 ± 4.14; 45.69 ± 4.64; 38.12 ± 4.08. In males, it was on the left: 50.01 ± 3.95; 41.98 ± 3.79; 47.90 ± 4.83; 41.79 ± 4.25, and on the right: 46.65 ± 2.09; 39.01 ± 4.25; 47.47 ± 3.41; 38.31 ± 4.40. The mean midpoint length of the DIM was relatively higher on the left hand compared to the right hand in both females and males. In this study, variations regarding the supernumerary muscle, double interosseous space, and unipennate muscles were only observed on the right-hand side and predominantly in females, an insight that may guide in the treatment of fractures, stiffness of the hand, and compartment syndromes.


Los músculos interóseos dorsales (DIM) son músculos intrínsecos de la mano ubicados dorsalmente entre los huesos metacarpianos, que desempeñan un papel en la abducción de los dedos. Las variaciones anatómicas de estos músculos en términos de forma y longitud están bien documentadas, pero las variaciones con respecto al sexo y la lateralidad están poco exploradas. El objetivo de este estudio fue investigar la morfología y morfometría de los DIM de la mano con respecto al dimorfismo sexual y la lateralidad. Para este estudio se utilizaron veinte cadáveres humanos pertenecientes a individuos blancos (n = 40 manos) con sexo y lateralidad conocidos. Los DIM se diseccionaron y observaron para determinar su morfología. Además, se utilizó un calibrador digital para medir la longitud del punto medio del DIM. El origen y la inserción de todos los DIM fueron normales y la mano izquierda no tenía músculos adicionales, supernumerarios y ausentes en cada compartimento. Las variaciones se encontraron sólo en el lado derecho y predominaron en el sexo femenino: 2 de 11 (18,18%) manos contenían un espacio con un músculo supernumerario; 1 de cada 11 (9,09%) manos presentando un espacio con doble músculo; y 1 de cada 11 (9,09%) manos presentaba un compartimento con músculo unipenate. En los hombres, 1 de cada 9 (11.11%) manos tenía un compartimento con un músculo supernumerario. Se documentó la longitud media del punto medio de cada músculo en mujeres y hombres en ambas manos desde el primer al cuarto músculo, respectivamente. En mujeres de izquierda: 46,79 ± 3,56; 42,62 ± 3,57; 49,02 ± 4,21; 41,66 ± 2,15 y derecha: 47,30 ± 2,49; 39,27 ± 4,14; 45,69 ± 4,64; 38,12 ± 4,08. En los varones fue hacia la izquierda: 50,01 ± 3,95; 41,98 ± 3,79; 47,90 ± 4,83; 41,79 ± 4,25, y a la derecha: 46,65 ± 2,09; 39,01 ± 4,25; 47,47 ± 3,41; 38,31 ± 4,40. La longitud media del punto medio del DIM fue relativamente mayor en la mano izquierda en comparación con la derecha tanto en mujeres como en hombres. En este estudio, las variaciones con respecto al músculo supernumerario, el doble espacio interóseo y los músculos unipennados sólo se observaron en el lado derecho y predominantemente en el sexo femenino, un conocimiento que puede guiar en el tratamiento de fracturas, rigidez de la mano y síndromes compartimentales.


Assuntos
Humanos , Masculino , Feminino , Músculo Esquelético/anatomia & histologia , Mãos/anatomia & histologia , Cadáver , Caracteres Sexuais , Variação Anatômica , Lateralidade Funcional
18.
J Ultrasound Med ; 43(9): 1757-1762, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38733350

RESUMO

The adductor magnus ischiocondylar origin (AM-IO) tendon has often been described as a third proximal hamstring tendon due to its common origin on the ischial tuberosity as well as similar function. Prior studies have described the magnetic resonance imaging characteristics of the AM-IO; however, its appearance on ultrasound has not been well-detailed. The purpose of our study is to describe the sonographic appearance of the AM-IO and provide a structured scanning protocol for complete evaluation of the tendon.


Assuntos
Ultrassonografia , Humanos , Ultrassonografia/métodos , Masculino , Feminino , Adulto , Tendões/diagnóstico por imagem , Tendões/anatomia & histologia , Ísquio/diagnóstico por imagem , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/anatomia & histologia , Pessoa de Meia-Idade
19.
J Anat ; 245(2): 258-270, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38690607

RESUMO

The human rotator cuff consists of four muscles, each with a complex, multipennate architecture. Despite the functional and clinical importance, the architecture of the human rotator cuff has yet to be clearly described in humans in vivo. The purpose of this study was to investigate the intramuscular, intermuscular, and interindividual variations in architecture and moment arms of the human rotator cuff. Muscle volumes, fascicle lengths, physiological cross-sectional areas (PCSAs), pennation angles, and moment arms of all four rotator cuff muscles were measured from mDixon and diffusion tensor imaging (DTI) scans of the right shoulders of 20 young adults. In accordance with the most detailed dissections available to date, we found substantial intramuscular variation in fascicle length (coefficients of variation (CVs) ranged from 26% to 40%) and pennation angles (CVs ranged from 56% to 62%) in all rotator cuff muscles. We also found substantial intermuscular and interindividual variations in muscle volumes, but relatively consistent mean fascicle lengths, pennation angles, and moment arms (CVs for all ≤17%). Moreover, when expressed as a proportion of total rotator cuff muscle volume, the volumes of individual rotator cuff muscles were highly consistent between individuals and sexes (CVs ≤16%), suggesting that rotator cuff muscle volumes scale uniformly, at least in a younger population without musculoskeletal problems. Together, these data indicate limited interindividual and intermuscular variability in architecture, which may simplify scaling routines for musculoskeletal models. However, the substantial intramuscular variation in architecture questions the validity of previously reported mean architectural parameters to adequately describe rotator cuff function.


Assuntos
Manguito Rotador , Humanos , Masculino , Manguito Rotador/anatomia & histologia , Manguito Rotador/diagnóstico por imagem , Manguito Rotador/fisiologia , Feminino , Adulto , Adulto Jovem , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Músculo Esquelético/diagnóstico por imagem , Imageamento Tridimensional
20.
Poult Sci ; 103(7): 103763, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38697005

RESUMO

The purpose of the study was to compare young (6-wk-old) and spent (52-wk-old) Japanese quail in terms of body weight, carcass characteristics, and some meat quality traits. Whole carcasses were dissected, pectoral muscles and leg muscles were sampled for determination of basic chemical composition and L*a*b* color parameters, while m. pectoralis major was sampled for texture and microstructure traits. Age of quails had a significant effect on body weight, carcass weight, carcass yield, pectoral muscle, abdominal fat and skin with subcutaneous fat, and carcass remainders contents in eviscerated carcass. Spent quails had significantly higher intramuscular fat content in pectoral and leg muscles and protein content in breast muscle, and also lower content of water in breast and leg muscles than young quails. Slaughter age significantly affected lightness (L*) and redness (a*) of pectoral muscles, as well as texture traits (except for cohesiveness) and microstructure of m. pectoralis major, except for thickness of perimysium and endomysium. Regardless of age, quail sex had an effect on the carcass traits studied (except for leg muscle content), intramuscular fat content of pectoral and leg muscles, water content of leg muscles and yellowness of pectoral muscle. In addition, a significant effect of quail sex was found on cutting work, springiness, chewiness and marked microstructural characteristics, except for vertical fiber diameter. The interaction between age and sex was significant for most slaughter and microstructural characteristics and also WB-shear force of m. pectoralis major, and L*, b* pectoral muscles. Higher fatness of carcasses, higher intramuscular fat in meat, and poorer textural and microstructural characteristics of m. pectoralis major spent Japanese quail indicate poorer fulfillment of most consumers' requirements compared to carcasses and meat of young quails.


Assuntos
Coturnix , Carne , Animais , Carne/análise , Coturnix/anatomia & histologia , Coturnix/fisiologia , Masculino , Feminino , Fatores Etários , Músculo Esquelético/química , Músculo Esquelético/anatomia & histologia , Músculos Peitorais/química , Músculos Peitorais/fisiologia , Músculos Peitorais/anatomia & histologia , Composição Corporal
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