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Muscle Architecture (muscle + architecture)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

Comparative Analysis of Muscle Architecture in Primate Arm and Forearm

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2010
Yasuhiro Kikuchi
With 7 figures and 3 tables Summary A comparative study of myological morphology, i.e. muscle mass (MM), muscle fascicle length and muscle physiological cross-sectional area (an indicator of the force capacity of muscles), was conducted in nine primate species: human (Homo sapiens), chimpanzee (Pan troglodytes), gibbon (Hylobates spp.), papio (Papio hamadryas), lutong (Trachypithecus francoisi), green monkey (Chlorocebus aethiops), macaque monkey (Macaca spp.), capuchin monkey (Cebus albifrons) and squirrel monkey (Saimiri sciureus). The MM distributions and the percentages in terms of functional categories were calculated as the ratios of the muscle masses. Moreover, individual normalized data were compared directly amongst species, independent of size differences. The results show that the different ratios of forearm-rotation muscles between chimpanzee and gibbons may be related to the differences in their main positional behaviour, i.e. knuckle-walking in chimpanzees and brachiation in gibbons, and the different frequencies of arm-raising locomotion between these two species. Moreover, monkeys have larger normalized MM values for the elbow extensor muscles than apes, which may be attributed to the fact that almost all monkeys engage in quadrupedal locomotion. The characteristics of the muscle internal parameters of ape and human are discussed in comparison with those of monkey. [source]

In vivo muscle architecture and size of the rectus femoris and vastus lateralis in children and adolescents with cerebral palsy

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 10 2009
NOELLE G MOREAU PHD PT
Aim, Our aim was to investigate muscle architecture and size of the rectus femoris (RF) and vastus lateralis (VL) in children and adolescents with cerebral palsy (CP) compared with age-matched typically developing participants. Method, Muscle architecture and size were measured with ultrasound imaging in 18 participants with spastic CP (9 females, 9 males; age range 7.5,19y; mean age 12y [SD 3y 2mo]) within Gross Motor Function Classification System levels I (n=4), II (n=2), III (n=9), and IV (n=3) and 12 typically developing participants (10 females, 2 males; age range 7,20y; mean age 12y 4mo [SD 3y 11mo]). Exclusion criteria were orthopedic surgery or neurosurgery within 6 months before testing or botulinum toxin injections to the quadriceps within 3 months before testing. Results, RF cross-sectional area was significantly lower (48%), RF and VL muscle thickness 30% lower, RF fascicle length 27% lower, and VL fascicle angle 3° less in participants with CP compared to the typically developing participants (p<0.05). Intraclass correlation coefficients were ,0.93 (CP) and , 0.88 (typical development), indicating excellent reliability. Interpretation, These results provide the first evidence of altered muscle architecture and size of the RF and VL in CP, similar to patterns observed with disuse and aging. These alterations may play a significant role in the decreased capacity for force generation as well as decreased shortening velocity and range of motion over which the quadriceps can act. [source]

Architectural properties of the first dorsal interosseous muscle

JOURNAL OF ANATOMY, Issue 4 2010
Benjamin W. Infantolino
Abstract Muscle architecture is considered to reflect the function of muscle in vivo, and is important for example to clinicians in designing tendon-transfer and tendon-lengthening surgeries. The purpose of this study was to quantify the architectural properties of the FDI muscle. It is hypothesized that there will be consistency, that is low variability, in the architectural parameters used to describe the first dorsal interosseous muscle because of its clear functional role in index finger motion. The important architectural parameters identified were those required to characterize a muscle adequately by modeling. Specifically the mass, cross-sectional area, and length of the tendon and muscle were measured in cadavers along with the muscle fiber optimum length and pennation angle, and the moment arm of the first dorsal interosseous at the metacarpophalangeal joint. These parameters provide a characterization of the architecture of the first dorsal interosseous, and were used to indicate the inherent variability between samples. The results demonstrated a large amount of variability for all architectural parameters measured; leading to a rejection of the hypothesis. Ratios designed to describe the functioning of the muscles in vivo, for example the ratio of tendon to fiber optimum lengths, also demonstrated a large variability. The results suggest that function cannot be deduced from form for the first dorsal interosseous, and that subject-specific architectural parameters may be necessary for the formulation of accurate musculoskeletal models or making clinical decisions. [source]

In vivo muscle architecture and size of the rectus femoris and vastus lateralis in children and adolescents with cerebral palsy

Superficial digital flexor tendon lesions in racehorses as a sequela to muscle fatigue: A preliminary study

EQUINE VETERINARY JOURNAL, Issue 6 2007
M. T. Butcher
Summary Reasons for performing study: Racing and training related lesions of the forelimb superficial digital flexor tendon are a common career ending injury to racehorses but aetiology and/or predisposing causes of the injury are not completely understood. Objectives: Although the injury takes place within the tendon, the lesion must be considered within the context of the function of the complete suspensory system of the distal limb, including the associated muscles. Methods: Both muscle and tendon function were investigated in vivo using implanted strain gauges in 3 Thoroughbred horses walking, trotting and cantering on a motorised treadmill. These data were combined with assessments of muscle architecture and fibre composition to arrive at an overview of the contribution of each muscle-tendon unit during locomotion. Results: The superficial digital flexor muscle has fatigue-resistant and high force production properties that allow its tendon to store and return elastic energy, predominantly at the trot. As running speed increases, deep digital flexor tendon force increases and it stabilises hyperextension of the fetlock, thus reinforcing the superficial digital flexor in limb load support. The deep digital flexor muscle has fast contracting properties that render it susceptible to fatigue. Conclusion: Based on these measurements and supporting evidence from the literature, it is proposed that overloading of the superficial digital flexor tendon results from fatigue of the synergistic, faster contracting deep digital flexor muscle. Potential relevance: Future research investigating distal limb system function as a whole should help refine clinical diagnostic procedures and exercise training approaches that will lead to more effective prevention and treatment of digital flexor tendon injuries in equine athletes. [source]

Human jaw muscle strength and size in relation to limb muscle strength and size

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2004
M. C. Raadsheer
The aim of the present study was to investigate to what extent general factors (e.g. genotype, hormones) and factors at the craniofacial level (e.g. craniofacial size, jaw muscle architecture) contribute to the size and strength of the jaw muscles. A strong relationship of jaw muscle size and strength with that of other muscles would argue for general influences, whereas a weak relationship would argue for craniofacial influences. In 121 adult individuals, moments of maximal bite force, arm flexion force and leg extension force were measured. In addition, thicknesses of jaw muscles, arm flexor muscles and leg extensor muscles were measured using ultrasound. Relationships were assessed by using a principal component analysis. In females, one component was found in which all force moments were represented. Bite force moment, however, loaded very low. In males, two components were found. One component loaded for arm flexion and leg extension moments, the other loaded for bite force moments. In both females and males, only one component was found for the muscle thicknesses in which all muscle groups loaded similarly. It was concluded that the size of the jaw muscles was significantly related to the size of the limb muscles, suggesting that they were both subject to the same general influences. Maximal voluntary bite force moments were not significantly related to the moments of the arm flexion and leg extension forces, suggesting that besides the general influence on the muscle size, variation in bite force moment was also influenced by local variables, such as craniofacial morphology. [source]

Myotendinous plasticity to ageing and resistance exercise in humans

EXPERIMENTAL PHYSIOLOGY, Issue 3 2006
N. D. Reeves
The age-related loss of muscle mass known as senile sarcopenia is one of the main determinants of frailty in old age. Molecular, cellular, nutritional and hormonal mechanisms are at the basis of sarcopenia and are responsible for a progressive deterioration in skeletal muscle size and function. Both at single-fibre and at whole-muscle level, the loss of force exceeds that predicted by the decrease in muscle size. For single fibres, the loss of intrinsic force is mostly due to a loss in myofibrillar protein content. For whole muscle, in addition to changes in neural drive, alterations in muscle architecture and in tendon mechanical properties, exemplified by a reduction in tendon stiffness, have recently been shown to contribute to this phenomenon. Resistance training can, however, cause substantial gains in muscle mass and strength and provides a protective effect against several of the cellular and molecular changes associated with muscle wasting and weakness. In old age, not only muscles but also tendons are highly responsive to training, since an increase in tendon stiffness has been observed after a period of increased loading. Many of the myotendinous factors characterizing ageing can be at least partly reversed by resistance training. [source]

Masticatory muscle architecture in the Laotian rock rat Laonastes aenigmamus (Mammalia, Rodentia): new insights into the evolution of hystricognathy

JOURNAL OF ANATOMY, Issue 4 2009
Lionel Hautier
Abstract We present the first descriptive comparison of the skull, mandible and jaw muscles of the recently recovered Laotian rock rat Laonastes aenigmamus. The gross anatomy of five specimens captured in Laos and internal architecture of the jaw musculature were studied using dissections. The following muscles are described: temporal, masseter, pterygoids, digastric, mylohyoid, geniohyoid and transverse mandibular. The description of the masticatory apparatus of L. aenigmamus offers a rare opportunity to assess the order of establishment of the morphological characters during the evolution of Ctenohystrica. Striking convergences have occurred during the evolution of Diatomyidae and L. aenigmamus presents a unique combination of myological features that corresponds to a mixture of sciurognathous and hystricognathous characters. If L. aenigmamus is a sciurognathous rodent, we have to assume that it independently acquired a pars reflexa of the superficial masseter. We show for the first time that the development of this pars reflexa has occurred several times during the evolution of Ctenohystrica and can no longer be considered a synapomorphic feature of ,Hystricognathi'. These results bring new insights into the evolution of hystricognathy and have profound implications for the interpretation of the fossil record of early hystricognath rodents. [source]

Intra- and intermuscular variation in human quadriceps femoris architecture assessed in vivo

JOURNAL OF ANATOMY, Issue 3 2006
Anthony J. Blazevich
Abstract Despite the functional importance of the human quadriceps femoris in movements such as running, jumping, lifting and climbing, and the known effects of muscle architecture on muscle function, no research has fully described the complex architecture of this muscle group. We used ultrasound imaging techniques to measure muscle thickness, fascicle angle and fascicle length at multiple regions of the four quadriceps muscles in vivo in 31 recreationally active, but non-strength-trained adult men and women. Our analyses revealed a reasonable similarity in the superficial quadriceps muscles, which is suggestive of functional similarity (at least during the uni-joint knee extension task) given that they act via a common tendon. The deep vastus intermedius (VI) is architecturally dissimilar and therefore probably serves a different function(s). Architecture varies significantly along the length of the superficial muscles, which has implications for the accuracy of models that assume a constant intramuscular architecture. It might also have consequences for the efficiency of intra- and intermuscular force transmission. Our results provide some evidence that subjects with a given architecture of one superficial muscle, relative to the rest of the subject sample, also have a similar architecture in other superficial muscles. However, this is not necessarily true for vastus lateralis (VL), and was not the case for VI. Therefore, the relative architecture of one muscle cannot confidently be used to estimate the relative architecture of another. To confirm this, we calculated a value of whole quadriceps architecture by four different methods. Regardless of the method used, we found that the absolute or relative architecture of one muscle could not be used as an indicator of whole quadriceps architecture, although vastus medialis, possibly in concert with VL and the anterior portion of VI, could be used to provide a useful snapshot. Importantly, our estimates of whole quadriceps architecture show a gender difference in whole quadriceps muscle thickness, and that muscle thickness is positively correlated with fascicle angle whereas fascicle length is negatively, although weakly, correlated with fascicle angle. These results are supportive of the validity of estimates of whole quadriceps architecture. These data are interpreted with respect to their implications for neural control strategies, region-specific adaptations in muscle size in response to training, and gender-dependent differences in the response to exercise training. [source]

Comparative analysis of masseter fiber architecture in tree-gouging (Callithrix jacchus) and nongouging (Saguinus oedipus) callitrichids

JOURNAL OF MORPHOLOGY, Issue 3 2004
Andrea B. Taylor
Abstract Common marmosets (Callithrix jacchus) and cotton-top tamarins (Saguinus oedipus) (Callitrichidae, Primates) share a broadly similar diet of fruits, insects, and tree exudates. Common marmosets, however, differ from tamarins by actively gouging trees with their anterior teeth to elicit tree exudate flow. During tree gouging, marmosets produce relatively large jaw gapes, but do not necessarily produce relatively large bite forces at the anterior teeth. We compared the fiber architecture of the masseter muscle in tree-gouging Callithrix jacchus (n = 10) to nongouging Saguinus oedipus (n = 8) to determine whether the marmoset masseter facilitates producing these large gapes during tree gouging. We predict that the marmoset masseter has relatively longer fibers and, hence, greater potential muscle excursion (i.e., a greater range of motion through increased muscle stretch). Conversely, because of the expected trade-off between excursion and force production in muscle architecture, we predict that the cotton-top tamarin masseter has more pinnate fibers and increased physiological cross-sectional area (PCSA) as compared to common marmosets. Likewise, the S. oedipus masseter is predicted to have a greater proportion of tendon relative to muscle fiber as compared to the common marmoset masseter. Common marmosets have absolutely and relatively longer masseter fibers than cotton-top tamarins. Given that fiber length is directly proportional to muscle excursion and by extension contraction velocity, this result suggests that marmosets have masseters designed for relatively greater stretching and, hence, larger gapes. Conversely, the cotton-top tamarin masseter has a greater angle of pinnation (but not significantly so), larger PCSA, and higher proportion of tendon. The significantly larger PCSA in the tamarin masseter suggests that their masseter has relatively greater force production capabilities as compared to marmosets. Collectively, these results suggest that the fiber architecture of the common marmoset masseter is part of a suite of features of the masticatory apparatus that facilitates the production of relatively large gapes during tree gouging. J. Morphol. 261:276,285, 2004. © 2004 Wiley-Liss, Inc. [source]

Postcontraction changes of muscle architecture in human quadriceps muscle

MUSCLE AND NERVE, Issue 4 2004
Konrad Mahlfeld MD
Abstract Maximal voluntary contraction changes the mechanical properties of skeletal muscle. Using ultrasound, we investigated whether these changes are reflected by changes in muscle architecture in the vastus lateralis muscle of 8 healthy volunteers. The mean pennation angle during the time interval from 3 to 6 min after maximal voluntary contraction (late postcontraction state) was 14.4 ± 1.11° (mean ± SEM) and differed significantly from the precontraction state (16.2 ± 1.39°), but the pennation angle in the early postcontraction state did not change statistically from the precontraction angle. Thus, postcontraction changes of the muscle,tendon interface appeared for 6 min after a maximal contraction, which may be important for biomechanical optimization of force transmission in vivo. Muscle Nerve 29: 597,600, 2004 [source]

Gross morphology of the vastus lateralis muscle: An anatomical review

CLINICAL ANATOMY, Issue 4 2009
Ines Becker
Abstract To understand the role of the vastus lateralis (VL) muscle in the pathogenesis of common knee disorders such as patellofemoral joint syndrome, knowledge of its anatomical structure is essential. The aim of this study was to review currently available information on the gross morphology of VL. A structured literature review was undertaken and 36 references, comprising 22 scientific papers and 14 anatomical textbooks, were included. Results of this literature review show that most of the included studies exhibited methodological limitations, and focused on different parameters of the VL muscle. Hence, reproducibility of these studies and comparison of results was difficult. This review also demonstrates a dearth of information on the muscle architecture, compartmentalization, nerve supply and fusion of VL, and that there has been no investigation of the muscle as a whole unit. Further research is required of the architecture and innervation of the VL muscle to better understand its function. Clin. Anat. 22:436,450, 2009. © 2009 Wiley-Liss, Inc. [source]

Documentation and three-dimensional modelling of human soleus muscle architecture

CLINICAL ANATOMY, Issue 4 2003
Anne M. Agur
Abstract The purpose of this study was to visualize and document the architecture of the human soleus muscle throughout its entire volume. The architecture was visualized by creating a three-dimensional (3D) manipulatable computer model of an entire cadaveric soleus, in situ, using B-spline solid to display muscle fiber bundles that had been serially dissected, pinned, and digitized. A database of fiber bundle length and angle of pennation throughout the marginal, posterior, and anterior soleus was compiled. The computer model allowed documentation of the architectural parameters in 3D space, with the angle of pennation being measured relative to the tangent plane of the point of attachment of a fiber bundle. Before this study, the only architectural parameters that have been recorded have been 2D. Three-dimensional reconstruction is an exciting innovation because it makes feasible the creation of an architectural database and allows visualization of each fiber bundle in situ from any perspective. It was concluded that the architecture is non-uniform throughout the volume of soleus. Detailed architectural studies may lead to the development of muscle models that can more accurately predict interaction between muscle parts, force generation, and the effect of pathologic states on muscle function. Clin. Anat. 16:285,293, 2003. © 2003 Wiley-Liss, Inc. [source]