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Kis J, Rózsa L, Husvéth F, Mezőszentgyörgyi D, Kovács S, Bakos Z, Zsolnai A, Anton I. Association of myostatin gene polymorphism with echocardiographic and muscular ultrasonographic measurements in Hungarian thoroughbreds horses. Res Vet Sci 2023; 160:45-49. [PMID: 37267767 DOI: 10.1016/j.rvsc.2023.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 06/04/2023]
Abstract
The g.66493737C/T polymorphism of the myostatin gene (MSTN) majorly influences muscle fiber composition and best race distance of Thoroughbreds. Thus, a better understanding of this process may lead to superior genetic exploitation for maximizing Thoroughbred athletic potential. Our objective is to investigate whether myostatin genotypes are associated with muscular development and cardiac variables of Thoroughbreds. Echocardiography and muscular ultrasonography were performed on three groups having C/C, C/T, and T/T genotypes, respectively. Each group consisted of 22 animals. Homogeneity of variance between the groups was checked by Levene's test. Multivariate analysis of variance was applied to determine differences in measured variables vs. MSTN genotypes. Fascicle length of anconeus and thickness of triceps brachii muscles showed significant differences between C/C and T/T genotypes (pFascicle-length-of-anconeus = 0.004, pthickness-of-triceps-brachii < 0.001). According to the primary outcome, there are associations between myostatin genotypes and cardiac variables. Aortic diameter at the sinus of Valsalva (end-diastole and end-systole) and aortic diameter at the valve (end-systole) indicated significant differences between C/C and T/T genotypes (paortic-diameter-at-the-sinus-of-Valsalva-end-diastole = 0.015, paortic-diameter-at-the-sinus-of-Valsalva-end-systole = 0.011, paortic-diameter-at-the-valve-end-systole = 0.014). Pearson correlation effect sizes were rFascicle-length-of-anconeus = 0.460, rthickness-of-triceps-brachii = 0.590, raortic-diameter-at-the-sinus-of-Valsalva-end-diastole = 0.423, raortic-diameter-at-the-sinus-of-Valsalva-end-systole = 0.450, and raortic-diameter-at-the-valve-end-systole = 0.462. C/C genotypes gave 22.1, 12.2, 6.3, 6.0, and 6.7% higher values compared to T/T genotypes, respectively. Differences regarding aortic diameter between genotype groups support the hypothesis that C/C animals have consequently increased cardiac output and aerobic capacity.
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Affiliation(s)
- Judit Kis
- Hungarian University of Agriculture and Life Sciences, Herceghalom, Hungary
| | - László Rózsa
- Hungarian University of Agriculture and Life Sciences, Keszthely, Hungary
| | - Ferenc Husvéth
- Hungarian University of Agriculture and Life Sciences, Keszthely, Hungary
| | | | - Szilvia Kovács
- University of Veterinary Medicine Budapest, Üllő, Hungary
| | - Zoltán Bakos
- University of Veterinary Medicine Budapest, Üllő, Hungary
| | - Attila Zsolnai
- Hungarian University of Agriculture and Life Sciences, Herceghalom, Hungary.
| | - István Anton
- Hungarian University of Agriculture and Life Sciences, Herceghalom, Hungary
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2
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Sahd L, Doubell N, Bennett NC, Kotzé SH. Muscle architecture and muscle fibre type composition in the forelimb of two African mole-rat species, Bathyergus suillus and Heterocephalus glaber. J Morphol 2023; 284:e21557. [PMID: 36630620 DOI: 10.1002/jmor.21557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 01/04/2023] [Accepted: 01/06/2023] [Indexed: 01/13/2023]
Abstract
The scratch-digging Cape dune mole-rat (Bathyergus suillus), and the chisel-toothed digging naked mole-rat (Heterocephalus glaber) are African mole-rats that differ in their digging strategy. The aim of this study was to determine if these behavioural differences are reflected in the muscle architecture and fibre-type composition of the forelimb muscles. Muscle architecture parameters of 39 forelimb muscles in both species were compared. Furthermore, muscle fibre type composition of 21 forelimb muscles were analysed using multiple staining protocols. In B. suillus, muscles involved with the power stroke of digging (limb retractors and scapula elevators), showed higher muscle mass percentage, force output and shortening capacity compared to those in H. glaber. Additionally, significantly higher percentages of glycolytic fibres were observed in the scapular elevators and digital flexors of B. suillus compared to H. glaber, suggesting that the forelimb muscles involved in digging in B. suillus provide fast, powerful motions for effective burrowing. In contrast, the m. sternohyoideus a head and neck flexor, had significantly more oxidative fibres in H. glaber compared to B. suillus. In addition, significantly greater physiological cross-sectional area and fascicle length values were seen in the neck flexor, m. sternocleidomastoideus, in H. glaber compared to B. suillus, which indicates a possible adaptation for chisel-tooth digging. While functional demands may play a significant role in muscle morphology, the phylogenetic differences between the two species may play an additional role which needs further study.
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Affiliation(s)
- Lauren Sahd
- Division of Clinical Anatomy, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.,Evolutionary Developmental Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
| | - Narusa Doubell
- Division of Clinical Anatomy, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Nigel C Bennett
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Sanet H Kotzé
- Division of Clinical Anatomy, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.,Division of Anatomy, Department of Biomedical Sciences, Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis
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3
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Charles J, Kissane R, Hoehfurtner T, Bates KT. From fibre to function: are we accurately representing muscle architecture and performance? Biol Rev Camb Philos Soc 2022; 97:1640-1676. [PMID: 35388613 PMCID: PMC9540431 DOI: 10.1111/brv.12856] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 03/22/2022] [Accepted: 03/25/2022] [Indexed: 12/11/2022]
Abstract
The size and arrangement of fibres play a determinate role in the kinetic and energetic performance of muscles. Extrapolations between fibre architecture and performance underpin our understanding of how muscles function and how they are adapted to power specific motions within and across species. Here we provide a synopsis of how this 'fibre to function' paradigm has been applied to understand muscle design, performance and adaptation in animals. Our review highlights the widespread application of the fibre to function paradigm across a diverse breadth of biological disciplines but also reveals a potential and highly prevalent limitation running through past studies. Specifically, we find that quantification of muscle architectural properties is almost universally based on an extremely small number of fibre measurements. Despite the volume of research into muscle properties, across a diverse breadth of research disciplines, the fundamental assumption that a small proportion of fibre measurements can accurately represent the architectural properties of a muscle has never been quantitatively tested. Subsequently, we use a combination of medical imaging, statistical analysis, and physics-based computer simulation to address this issue for the first time. By combining diffusion tensor imaging (DTI) and deterministic fibre tractography we generated a large number of fibre measurements (>3000) rapidly for individual human lower limb muscles. Through statistical subsampling simulations of these measurements, we demonstrate that analysing a small number of fibres (n < 25) typically used in previous studies may lead to extremely large errors in the characterisation of overall muscle architectural properties such as mean fibre length and physiological cross-sectional area. Through dynamic musculoskeletal simulations of human walking and jumping, we demonstrate that recovered errors in fibre architecture characterisation have significant implications for quantitative predictions of in-vivo dynamics and muscle fibre function within a species. Furthermore, by applying data-subsampling simulations to comparisons of muscle function in humans and chimpanzees, we demonstrate that error magnitudes significantly impact both qualitative and quantitative assessment of muscle specialisation, potentially generating highly erroneous conclusions about the absolute and relative adaption of muscles across species and evolutionary transitions. Our findings have profound implications for how a broad diversity of research fields quantify muscle architecture and interpret muscle function.
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Affiliation(s)
- James Charles
- Structure and Motion Lab, Comparative Biomedical Sciences, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, U.K.,Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, U.K
| | - Roger Kissane
- Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, U.K
| | - Tatjana Hoehfurtner
- School of Life Sciences, University of Lincoln, Joseph Banks Laboratories, Green Lane, Lincoln, LN6 7DL, U.K
| | - Karl T Bates
- Department of Musculoskeletal & Ageing Science, Institute of Life Course & Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, U.K
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4
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Bardin AL, Taylor NC, Robert Colborne G. Response of the Thoroughbred forelimb to perturbations caused by a change in ground surface. J Equine Vet Sci 2022; 112:103897. [PMID: 35150852 DOI: 10.1016/j.jevs.2022.103897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/04/2022] [Accepted: 02/07/2022] [Indexed: 11/15/2022]
Abstract
Thoroughbred racehorses are often affected by musculoskeletal injuries, leading to involuntary rest, early retirement or death. Hardness and consistency of the track surface have been implicated as major risk factors for limb injury. The purpose was to test the utility of a preliminary AnyBody musculoskeletal model of the equine forelimb for its responses on two perturbing surfaces. A musculoskeletal model was developed using CT, muscle, tendon and ligament properties, and kinematic data were applied from ridden trials using five Thoroughbred horses. Horses were ridden at trot and canter on a baseline sand surface, and through two perturbation pits containing a harder and a softer surface for one stance phase. In response to the hard perturbation, the proximal limb was more compliant at trot and canter, as measured by increased shoulder flexion in the perturbed stance phase and increased elbow and carpal flexion in the subsequent swing phase. The suspensory ligaments and muscle-tendon units were less strained while lacertus fibrosus was more strained. In response to the soft perturbation, the coffin joint was more flexed and the elbow was more extended in the acute stance phase at trot, resulting in increased strain to the DDF, extensor branches and lacertus fibrosus. At canter, the coffin was more flexed, the fetlock less hyperextended and so the suspensory structures were less strained in the perturbed stance phase, but more strained in the second stance phase. Changes in ground surface affect both the perturbed stance phase, and the following stance phase.
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Affiliation(s)
- Alienor L Bardin
- School of Veterinary Science, Massey University, Palmerston North 4410, New Zealand
| | - Nila C Taylor
- School of Veterinary Science, Massey University, Palmerston North 4410, New Zealand
| | - G Robert Colborne
- School of Veterinary Science, Massey University, Palmerston North 4410, New Zealand.
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5
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Mansuit R, Herrel A. The Evolution of Appendicular Muscles During the Fin-to-Limb Transition: Possible Insights Through Studies of Soft Tissues, a Perspective. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.702576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The evolution of the appendages during the fin-to-limb transition has been extensively studied, yet the majority of studies focused on the skeleton and the fossil record. Whereas the evolution of the anatomy of the appendicular musculature has been studied, the changes in the muscular architecture during the fin-to-limb transition remain largely unstudied, yet may provide important new insights. The fin-to-limb transition is associated with the appearance of a new mode of locomotion and the associated shift from pectoral to pelvic dominance. Here, we propose ways to investigate this question and review data on muscle mass and muscle architecture of the pectoral and pelvic muscles in extant vertebrates. We explore whether changes in appendage type are associated with changes in the muscular architecture and the relative investment in different muscle groups. These preliminary data show a general increase in the muscle mass of the appendages relative to the body mass during the fin-to-limb transition. The locomotor shift suggested to occur during the fin-to-limb transition appears supported by our preliminary data since in “fish” the pectoral fins are heavier than the pelvic fins, whereas in tetrapods, the forelimb muscles are less developed than the hind limb muscles. Finally, a shift in the investment in different muscle groups with an increase of the contribution of the superficial groups in tetrapods compared to “fish” appears to take place. Our study highlights the potential of investigating quantitative features of the locomotor muscles, yet also demonstrates the lack of quantitative data allowing to test these ideas.
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6
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Bardin AL, Tang L, Panizzi L, Rogers CW, Colborne GR. Development of An Anybody Musculoskeletal Model of The Thoroughbred Forelimb. J Equine Vet Sci 2021; 103:103666. [PMID: 34281648 DOI: 10.1016/j.jevs.2021.103666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/01/2021] [Accepted: 05/04/2021] [Indexed: 11/19/2022]
Abstract
Musculoskeletal injuries in horses are the main cause of retirement, rest, and death. To understand these injuries, it is necessary to study loads in muscles, tendons and ligaments. A musculoskeletal model makes it possible to consider all structures simultaneously and avoids invasive measurements. At present, most computational models of the equine limb described in the literature have been limited to the distal limb. The aim of this study was to create a preliminary musculoskeletal model of the whole equine forelimb and to run it with kinematic data collected during gait. The model was developed with the AnyBody Modelling System. It includes six limb segments, 11 muscle groups and 17 ligaments. Kinematic data were collected from the right forelimb of four Thoroughbreds at trot, right and left lead canter, and were then used in the model to compute sagittal plane joint excursions and ligament and tendon strains. The modelled joint excursions were in reasonable agreement with previous reports in the literature despite breed, gait and surface differences. Strain patterns of the tendons of the suspensory apparatus agreed with the literature, with maxima in mid-stance or at the end of stance. Strains in the distal palmar ligaments peaked in mid-stance, while strain in lacertus fibrosus peaked at the stance-swing transition. Tendon and ligament strains at canter were greatest when the measured forelimb was the trailing limb. Strain amplitudes varied against earlier models and these differences are discussed in relation to variations in methods, and especially in relation to attachment points of tendons and ligaments.
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Affiliation(s)
- Alienor L Bardin
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Liqiong Tang
- School of Engineering and Advanced Technology, Massey University, Palmerston North, New Zealand
| | - Luca Panizzi
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Chris W Rogers
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - G Robert Colborne
- School of Veterinary Science, Massey University, Palmerston North, New Zealand.
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7
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Etienne C, Houssaye A, Hutchinson JR. Limb myology and muscle architecture of the Indian rhinoceros Rhinoceros unicornis and the white rhinoceros Ceratotherium simum (Mammalia: Rhinocerotidae). PeerJ 2021; 9:e11314. [PMID: 34026351 PMCID: PMC8121076 DOI: 10.7717/peerj.11314] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/30/2021] [Indexed: 12/17/2022] Open
Abstract
Land mammals support and move their body using their musculoskeletal system. Their musculature usually presents varying adaptations with body mass or mode of locomotion. Rhinocerotidae is an interesting clade in this regard, as they are heavy animals potentially reaching three tons but are still capable of adopting a galloping gait. However, their musculature has been poorly studied. Here we report the dissection of both forelimb and hindlimb of one neonate and one adult each for two species of rhinoceroses, the Indian rhinoceros (Rhinoceros unicornis) and the white rhinoceros (Ceratotherium simum). We show that their muscular organisation is similar to that of their relatives, equids and tapirs, and that few evolutionary convergences with other heavy mammals (e.g. elephants and hippopotamuses) are present. Nevertheless, they show clear adaptations to their large body mass, such as more distal insertions for the protractor and adductor muscles of the limbs, giving them longer lever arms. The quantitative architecture of rhino muscles is again reminiscent of that of horses and tapirs, although contrary to horses, the forelimb is much stronger than the hindlimb, which is likely due to its great role in body mass support. Muscles involved mainly in counteracting gravity (e.g. serratus ventralis thoracis, infraspinatus, gastrocnemius, flexores digitorum) are usually highly pennate with short fascicles facilitating strong joint extension. Muscles involved in propulsion (e.g. gluteal muscles, gluteobiceps, quadriceps femoris) seem to represent a compromise between a high maximal isometric force and long fascicles, allowing a reasonably fast and wide working range. Neonates present higher normalized maximal isometric force than the adults for almost every muscle, except sometimes for the extensor and propulsor muscles, which presumably acquire their great force-generating capacity during the growth of the animal. Our study clarifies the way the muscles of animals of cursorial ancestry can adapt to support a greater body mass and calls for further investigations in other clades of large body mass.
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Affiliation(s)
- Cyril Etienne
- UMR 7179 Mécanismes adaptatifs et évolution (MECADEV), Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Paris, France
| | - Alexandra Houssaye
- UMR 7179 Mécanismes adaptatifs et évolution (MECADEV), Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Paris, France
| | - John R Hutchinson
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, United Kingdom
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8
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MacLaren JA. Biogeography a key influence on distal forelimb variation in horses through the Cenozoic. Proc Biol Sci 2021; 288:20202465. [PMID: 33434465 DOI: 10.1098/rspb.2020.2465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Locomotion in terrestrial tetrapods is reliant on interactions between distal limb bones (e.g. metapodials and phalanges). The metapodial-phalangeal joint in horse (Equidae) limbs is highly specialized, facilitating vital functions (shock absorption; elastic recoil). While joint shape has changed throughout horse evolution, potential drivers of these modifications have not been quantitatively assessed. Here, I examine the morphology of the forelimb metacarpophalangeal (MCP) joint of horses and their extinct kin (palaeotheres) using geometric morphometrics and disparity analyses, within a phylogenetic context. I also develop a novel alignment protocol that explores the magnitude of shape change through time, correlated against body mass and diet. MCP shape was poorly correlated with mass or diet proxies, although significant temporal correlations were detected at 0-1 Myr intervals. A clear division was recovered between New and Old World hipparionin MCP morphologies. Significant changes in MCP disparity and high rates of shape divergence were observed during the Great American Biotic Interchange, with the MCP joint becoming broad and robust in two separate monodactyl lineages, possibly exhibiting novel locomotor behaviour. This large-scale study of MCP joint shape demonstrates the apparent capacity for horses to rapidly change their distal limb morphology to overcome discrete locomotor challenges in new habitats.
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Affiliation(s)
- Jamie A MacLaren
- Evolution and Diversity Dynamics Laboratory, Department of Geology, Université de Liege, Building B18, Allée du Six Août 14, Sart-Tillman Campus, Liege 4000, Belgium.,Functional Morphology Laboratory, Department of Biology, Universiteit Antwerpen, Antwerpen 2610, Belgium
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9
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Takahashi Y, Mukai K, Ohmura H, Takahashi T. Do Muscle Activities of M. Splenius and M. Brachiocephalicus Decrease Because of Exercise-Induced Fatigue in Thoroughbred Horses? J Equine Vet Sci 2019; 86:102901. [PMID: 32067667 DOI: 10.1016/j.jevs.2019.102901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/21/2019] [Accepted: 12/21/2019] [Indexed: 11/30/2022]
Abstract
Muscle activities of the major hindlimb muscles have been reported to decrease with fatigue in horses. However, those in other muscles have been scarcely reported. We aimed to quantify fatigue-induced electromyographic changes in head and neck muscles and muscles around the shoulder joints in horses. Surface electromyographic recording of the splenius, brachiocephalicus, infraspinatus, and deltoid muscles was performed on a total of nine healthy Thoroughbred horses. Horses galloped on a treadmill inclined to 3% at a constant speed (12.7-14.6 m/second) to make them fatigued after approximately 5 minutes. They trotted at 3.5 m/second before and after this exercise. Stride frequency, integrated electromyographic values for a stride, and median frequency of the muscle discharge were calculated every 30 seconds. These parameters were compared at the start and end of the gallop exercise for the lead and trailing limbs and while trotting before and after the exercise using a paired t-test. The stride frequency significantly decreased at the end of the gallop (P < .001), whereas it did not change while trotting. Integrated electromyographic values of the splenius and brachiocephalicus muscles in both lead and trailing limbs at the gallop and those of both left and right sides at the trot significantly decreased with fatigue (P < .05), whereas those of infraspinatus and deltoid muscles did not change at either gallop or trot. No changes were observed in median frequency in any muscles with fatigue. These results suggest that splenius and brachiocephalicus muscle activities can be associated with stride frequency and speed.
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Affiliation(s)
- Yuji Takahashi
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Tochigi, Japan.
| | - Kazutaka Mukai
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Tochigi, Japan
| | - Hajime Ohmura
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Tochigi, Japan
| | - Toshiyuki Takahashi
- Sports Science Division, Equine Research Institute, Japan Racing Association, Shimotsuke, Tochigi, Japan
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10
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MacLaren JA, McHorse BK. Comparative forelimb myology and muscular architecture of a juvenile Malayan tapir (Tapirus indicus). J Anat 2019; 236:85-97. [PMID: 31515803 DOI: 10.1111/joa.13087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2019] [Indexed: 12/21/2022] Open
Abstract
The absence of preserved soft tissues in the fossil record is frequently a hindrance for palaeontologists wishing to investigate morphological shifts in key skeletal systems, such as the limbs. Understanding the soft tissue composition of modern species can aid in understanding changes in musculoskeletal features through evolution, including those pertaining to locomotion. Establishing anatomical differences in soft tissues utilising an extant phylogenetic bracket can, in turn, assist in interpreting morphological changes in hard tissues and modelling musculoskeletal movements during evolutionary transitions (e.g. digit reduction in perissodactyls). Perissodactyls (horses, rhinoceroses, tapirs and their relatives) are known to have originated with a four-toed (tetradactyl) forelimb condition. Equids proceeded to reduce all but their central digit, resulting in monodactyly, whereas tapirs retained the ancestral tetradactyl state. The modern Malayan tapir (Tapirus indicus) has been shown to exhibit fully functional tetradactyly in its forelimb, more so than any other tapir, and represents an ideal case-study for muscular arrangement and architectural comparison with the highly derived monodactyl Equus. Here, we present the first quantification of muscular architecture of a tetradactyl perissodactyl (T. indicus), and compare it to measurements from modern monodactyl caballine horse (Equus ferus caballus). Each muscle of the tapir forelimb was dissected out from a cadaver and measured for architectural properties: muscle-tendon unit (MTU) length, MTU mass, muscle mass, pennation angle, and resting fibre length. Comparative parameters [physiological cross-sectional area (PCSA), muscle volume, and % muscle mass] were then calculated from the raw measurements. In the shoulder region, the infraspinatus of T. indicus exhibits dual origination sites on either side of the deflected scapular spine. Within ungulates, this condition has only been previously reported in suids. Differences in relative contribution to limb muscle mass between T. indicus and Equus highlight forelimb muscles that affect mobility in the lateral and medial digits (e.g. extensor digitorum lateralis). These muscles were likely reduced in equids during their evolutionary transition from tetradactyl forest-dwellers to monodactyl, open-habitat specialists. Patterns of PCSA across the forelimb were similar between T. indicus and Equus, with the notable exceptions of the biceps brachii and flexor carpi ulnaris, which were much larger in Equus. The differences observed in PCSA between the tapir and horse forelimb muscles highlight muscles that are essential for maintaining stability in the monodactyl limb while moving at high speeds. This quantitative dataset of muscle architecture in a functionally tetradactyl perissodactyl is a pivotal first step towards reconstructing the locomotor capabilities of extinct, four-toed ancestors of modern perissodactyls, and providing further insights into the equid locomotor transition.
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Affiliation(s)
- Jamie A MacLaren
- Functional Morphology Lab, Department of Biology, Universiteit Antwerpen, Antwerp, Belgium.,Evolution and Diversity Dynamics Lab, Department of Geology, Université Liège, Liège, Belgium
| | - Brianna K McHorse
- Museum of Comparative Zoology, Cambridge, MA, USA.,Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.,Concord Field Station, Department of Organismic and Evolutionary Biology, Harvard University, Bedford, MA, USA
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11
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Bribiesca‐Contreras F, Parslew B, Sellers WI. A Quantitative and Comparative Analysis of the Muscle Architecture of the Forelimb Myology of Diurnal Birds of Prey (Order Accipitriformes and Falconiformes). Anat Rec (Hoboken) 2019; 302:1808-1823. [DOI: 10.1002/ar.24195] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 11/03/2018] [Accepted: 12/31/2018] [Indexed: 11/06/2022]
Affiliation(s)
| | - Ben Parslew
- School of Mechanical, Aerospace and Civil EngineeringThe University of Manchester Manchester UK
| | - William I. Sellers
- School of Earth and Environmental SciencesThe University of Manchester Manchester UK
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12
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Tsang AS, Dart AJ, Biasutti SA, Jeffcott LB, Smith MM, Little CB. Effects of tendon injury on uninjured regional tendons in the distal limb: An in-vivo study using an ovine tendinopathy model. PLoS One 2019; 14:e0215830. [PMID: 31013317 PMCID: PMC6478347 DOI: 10.1371/journal.pone.0215830] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 04/09/2019] [Indexed: 12/11/2022] Open
Abstract
Following injury to a tendon little is known about potential for pathology to develop in other regional tendons from overloading or altered function. The aim of this study was to investigate the gene expression and histopathological changes that occur 1) within the deep digital flexor tendon (DDFT) after injury to the superficial digital flexor tendon (SDFT) and 2) within the flexor tendons (SDFT and DDFT) after injury to the extensor tendons. Merino wethers [Ovis aries] (n = 18) were divided into three equal groups and underwent either partial transection of the SDFT, complete transection of the extensor tendons or were left as non-operated controls. Tendons were harvested and sampled regionally for gene expression (real time PCR) and histologic analysis eight weeks after surgery. Transection of the SDFT resulted in increased expression of collagen III, versican, biglycan, lumican and MMP1 (P<0.026 for all genes) within the DDFT. There was no effect of transecting the extensor tendons on the expression of any gene tested in either the SDFT or the DDFT. The DDFT had elevated histopathology scores induced by transection of the SDFT, eight weeks previously. There were minimal histological differences in either the SDFT or DDFT after transection of the extensor tendons. Transection of the SDFT results in a mild, subclinical tendinopathy within the DDFT with potential implications on treatment and rehabilitation of SDFT injuries. Injury to the extensor tendons has minimal measured effect on the SDFT or DDFT.
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Affiliation(s)
- Albert S. Tsang
- Research and Clinical Training Unit, University Veterinary Teaching Hospital, Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Camden, Australia
- * E-mail:
| | - Andrew J. Dart
- Research and Clinical Training Unit, University Veterinary Teaching Hospital, Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Camden, Australia
| | - Sara A. Biasutti
- Research and Clinical Training Unit, University Veterinary Teaching Hospital, Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Camden, Australia
| | - Leo B. Jeffcott
- Research and Clinical Training Unit, University Veterinary Teaching Hospital, Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Camden, Australia
| | - Margaret M. Smith
- Raymond Purves Bone and Joint Research Laboratories, The Kolling Institute, Sydney Medical School, University of Sydney, Sydney, Australia
- The Institute of Bone and Joint Research, Royal North Shore Hospital, Sydney, Australia
| | - Christopher B. Little
- Raymond Purves Bone and Joint Research Laboratories, The Kolling Institute, Sydney Medical School, University of Sydney, Sydney, Australia
- The Institute of Bone and Joint Research, Royal North Shore Hospital, Sydney, Australia
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King MR, Haussler KK, Kawcak CE, McIlwraith CW, Reiser RF, Frisbie DD, Werpy NM. Biomechanical and histologic evaluation of the effects of underwater treadmill exercise on horses with experimentally induced osteoarthritis of the middle carpal joint. Am J Vet Res 2017; 78:558-569. [PMID: 28441054 DOI: 10.2460/ajvr.78.5.558] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the effects of exercise in an underwater treadmill (UWT) on forelimb biomechanics and articular histologic outcomes in horses with experimentally induced osteoarthritis of the middle carpal joint. ANIMALS 16 horses. PROCEDURES An osteochondral fragment was induced arthroscopically (day 0) in 1 middle carpal joint of each horse. Beginning on day 15, horses were assigned to exercise in a UWT or in the UWT without water (simulating controlled hand walking) at the same speed, frequency, and duration. Thoracic and pelvic limb ground reaction forces, thoracic limb kinematics, and electromyographic results for select thoracic limb muscles acting on the carpi were collected on days -7 (baseline), 14, 42, and 70. Weekly evaluations included clinical assessments of lameness, response to carpal joint flexion, and goniometric measurements of thoracic limb articulations. At study conclusion, articular cartilage and synovial membrane from the middle carpal joints was histologically examined. RESULTS Exercise in a UWT significantly reduced synovial membrane inflammation and resulted in significant clinical improvements with regard to symmetric thoracic limb loading, uniform activation patterns of select thoracic limb muscles, and return to baseline values for carpal joint flexion, compared with results for horses with simulated hand walking. CONCLUSIONS AND CLINICAL RELEVANCE Overall improvements in thoracic limb function, joint range of motion, and synovial membrane integrity indicated that exercise in a UWT was a potentially viable therapeutic option for the management of carpal joint osteoarthritis in horses.
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Clayton HM. HORSE SPECIES SYMPOSIUM: Biomechanics of the exercising horse1. J Anim Sci 2016; 94:4076-4086. [DOI: 10.2527/jas.2015-9990] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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15
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Mayfield DL, Launikonis BS, Cresswell AG, Lichtwark GA. Additional in-series compliance reduces muscle force summation and alters the time course of force relaxation during fixed-end contractions. ACTA ACUST UNITED AC 2016; 219:3587-3596. [PMID: 27609762 DOI: 10.1242/jeb.143123] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/31/2016] [Indexed: 02/06/2023]
Abstract
There are high mechanical demands placed on skeletal muscles in movements requiring rapid acceleration of the body or its limbs. Tendons are responsible for transmitting muscle forces, but, because of their elasticity, can manipulate the mechanics of the internal contractile apparatus. Shortening of the contractile apparatus against the stretch of tendon affects force generation according to known mechanical properties; however, the extent to which differences in tendon compliance alter force development in response to a burst of electrical impulses is unclear. To establish the influence of series compliance on force summation, we studied electrically evoked doublet contractions in the cane toad peroneus muscle in the presence and absence of a compliant artificial tendon. Additional series compliance reduced tetanic force by two-thirds, a finding predicted based on the force-length property of skeletal muscle. Doublet force and force-time integral expressed relative to the twitch were also reduced by additional series compliance. Active shortening over a larger range of the ascending limb of the force-length curve and at a higher velocity, leading to a progressive reduction in force-generating potential, could be responsible. Muscle-tendon interaction may also explain the accelerated time course of force relaxation in the presence of additional compliance. Our findings suggest that a compliant tendon limits force summation under constant-length conditions. However, high series compliance can be mechanically advantageous when a muscle-tendon unit is actively stretched, permitting muscle fibres to generate force almost isometrically, as shown during stretch-shorten cycles in locomotor activities. Restricting active shortening would likely favour rapid force development.
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Affiliation(s)
- Dean L Mayfield
- Centre for Sensorimotor Performance, School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | | | - Andrew G Cresswell
- Centre for Sensorimotor Performance, School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Glen A Lichtwark
- Centre for Sensorimotor Performance, School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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Hardeman LC, van der Meij BR, Lamers AAH, van der Kolk JH, Back W, Wijnberg ID. Determination of equine deep digital flexor muscle volume based on distances between anatomical landmarks. Res Vet Sci 2014; 97:397-9. [PMID: 25264361 DOI: 10.1016/j.rvsc.2014.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 07/01/2014] [Accepted: 08/21/2014] [Indexed: 11/26/2022]
Abstract
In equine medicine the use of Botox® is experimental. Dosages are determined from human treatment-protocols and limited numbers of equine studies. Determination of target-muscle volume can be helpful to extrapolate human dosages. The aim of the study was to calculate a formula enabling the estimation of the deep digital flexor muscle (DDFM) volume based on distances between anatomical landmarks. Nineteen cadaveric limbs were collected and distance A (top of olecranon to Os carpi accessorium) and B (circumference of limb) were measured. Converting mathematical formulas, C was calculated: π × (((0.5B)/π)(2)) × A. DDFM volume was determined by water displacement. Linear Regression Analysis was used to analyse data. The line best fitting the observed points was: Ln(volume[ml]) = -1.89 + 0.98 × Ln(value C[cm(3)]). Correlation was highest when natural logarithm was applied to both variables and was 0.97. The calculated formula enables estimating DDFM volume of a living horse. This estimated volume can be useful to apply human Botox® treatment-protocols.
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Affiliation(s)
- L C Hardeman
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - B R van der Meij
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - A A H Lamers
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - J H van der Kolk
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - W Back
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands; Department of Surgery and Anaesthesiology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - I D Wijnberg
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
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Kikuchi Y, Kuraoka A. Differences in Muscle Dimensional Parameters Between Non-Formalin-Fixed (Freeze-Thawed) and Formalin-Fixed Specimen in Gorilla (Gorilla gorilla). MAMMAL STUDY 2014. [DOI: 10.3106/041.039.0101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Maniakas I, Youlatos D. Myological adaptations to fast enduring flight in European free-tailed bats,Tadarida teniotis(Molossidae, Chiroptera). ACTA ACUST UNITED AC 2012. [DOI: 10.1080/11250003.2012.718374] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Moore AL, Budny JE, Russell AP, Butcher MT. Architectural specialization of the intrinsic thoracic limb musculature of the American badger (Taxidea taxus). J Morphol 2012; 274:35-48. [DOI: 10.1002/jmor.20074] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 06/26/2012] [Accepted: 07/30/2012] [Indexed: 11/08/2022]
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Harrison SM, Whitton RC, King M, Haussler KK, Kawcak CE, Stover SM, Pandy MG. Forelimb muscle activity during equine locomotion. J Exp Biol 2012; 215:2980-91. [DOI: 10.1242/jeb.065441] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Few quantitative data exist to describe the activity of the distal muscles of the equine forelimb during locomotion, and there is an incomplete understanding of the functional roles of the majority of the forelimb muscles. Based on morphology alone it would appear that the larger proximal muscles perform the majority of work in the forelimb, whereas the smaller distal muscles fulfil supplementary roles such as stabilizing the joints and positioning the limb for impact with the ground. We measured the timing and amplitude of the electromyographic activity of the intrinsic muscles of the forelimb in relation to the phase of gait (stance versus swing) and the torque demand placed on each joint during walking, trotting and cantering. We found that all forelimb muscles, except the extensor carpi radialis (ECR), were activated just prior to hoof-strike and deactivated during stance. Only the ECR was activated during swing. The amplitudes of muscle activation typically increased as gait speed increased. However, the amplitudes of muscle activation were not proportional to the net joint torques, indicating that passive structures may also contribute significantly to torque generation. Our results suggest that the smaller distal muscles help to stabilize the forelimb in early stance, in preparation for the passive structures (tendons and ligaments) to be stretched. The distal forelimb muscles remain active throughout stance only during canter, when the net torques acting about the distal forelimb joints are highest. The larger proximal muscles activate in a complex coordination to position and stabilize the shoulder and elbow joints during ground contact.
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Affiliation(s)
- Simon M. Harrison
- Department of Mechanical Engineering, University of Melbourne, Parkville, VIC 3010, Australia
| | - R. Chris Whitton
- Equine Centre, Faculty of Veterinary Science, University of Melbourne, Werribee, VIC 3030, Australia
| | - Melissa King
- Gail Holmes Equine Orthopaedic Research Center, Colorado State University, CO 80523, USA
| | - Kevin K. Haussler
- Gail Holmes Equine Orthopaedic Research Center, Colorado State University, CO 80523, USA
| | - Chris E. Kawcak
- Gail Holmes Equine Orthopaedic Research Center, Colorado State University, CO 80523, USA
| | - Susan M. Stover
- JD Wheat Veterinary Orthopedic Research Lab, University of California at Davis, CA 95616, USA
| | - Marcus G. Pandy
- Department of Mechanical Engineering, University of Melbourne, Parkville, VIC 3010, Australia
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Borgia LA, Valberg SJ, Essen-Gustavsson B. Differences in the metabolic properties of gluteus medius and superficial digital flexor muscles and the effect of water treadmill training in the horse. Equine Vet J 2011:665-70. [PMID: 21059078 DOI: 10.1111/j.2042-3306.2010.00229.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
REASONS FOR PERFORMING STUDY Flexor tendon injury may be due to flexor muscle fatigue, contributing to fetlock joint hyperextension and tendon damage. A water treadmill provides resistance training on flexor tendon muscles, which might reduce the risk of tendon injury. OBJECTIVE To determine the effect of water treadmill training on the properties of the gluteal and superficial digital flexor (SDF) muscles and on cardiocirculatory response to a standardised exercise test. METHODS Five healthy unfit horses were trained on a water treadmill for 5 days/week for 4 weeks, starting with 5 min/day increasing to 20 min/day. Before and after the water treadmill training, an incremental SET was performed on a land treadmill to determine velocity at a heart rate 200 beats/min (V(200)) and resting gluteal and SDF muscle biopsies were obtained for biochemical analyses. RESULTS There was no measurable difference in resting concentrations of gluteal or SDF muscle glycogen, lactate, ATP or glucose-6-phosphate (G6P), or activities of citrate synthase (CS), 3-hydroxyacyl CoA dehydrogenase (HAD) and lactate dehydrogenase (LDH) after training and no change in V(200), Lactate, glycogen, G6P and ATP concentrations were 50% lower and type 1 fibres 30% higher in SDF compared to gluteal muscles. CS and HAD activities were similar between SDF and gluteal, while LDH was lower in the SDF muscle. CONCLUSIONS A more strenuous water treadmill conditioning protocol may be needed to induce a training effect in gluteal and SDF muscle and heart rate response. The low substrate concentrations and oxidative capacity of SDF may predispose this muscle to catastrophic fatigue during maximal exercise.
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Affiliation(s)
- L A Borgia
- College of Veterinary Medicine, University of Minnesota, USA.
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Wareing K, Tickle PG, Stokkan KA, Codd JR, Sellers WI. The musculoskeletal anatomy of the reindeer (Rangifer tarandus): fore- and hindlimb. Polar Biol 2011. [DOI: 10.1007/s00300-011-1017-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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23
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Harrison SM, Whitton RC, Kawcak CE, Stover SM, Pandy MG. Relationship between muscle forces, joint loading and utilization of elastic strain energy in equine locomotion. J Exp Biol 2010; 213:3998-4009. [DOI: 10.1242/jeb.044545] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Storage and utilization of strain energy in the elastic tissues of the distal forelimb of the horse is thought to contribute to the excellent locomotory efficiency of the animal. However, the structures that facilitate elastic energy storage may also be exposed to dangerously high forces, especially at the fastest galloping speeds. In the present study, experimental gait data were combined with a musculoskeletal model of the distal forelimb of the horse to determine muscle and joint contact loading and muscle–tendon work during the stance phase of walking, trotting and galloping. The flexor tendons spanning the metacarpophalangeal (MCP) joint – specifically, the superficial digital flexor (SDF), interosseus muscle (IM) and deep digital flexor (DDF) – experienced the highest forces. Peak forces normalized to body mass for the SDF were 7.3±2.1, 14.0±2.5 and 16.7±1.1 N kg–1 in walking, trotting and galloping, respectively. The contact forces transmitted by the MCP joint were higher than those acting at any other joint in the distal forelimb, reaching 20.6±2.8, 40.6±5.6 and 45.9±0.9 N kg–1 in walking, trotting and galloping, respectively. The tendons of the distal forelimb (primarily SDF and IM) contributed between 69 and 90% of the total work done by the muscles and tendons, depending on the type of gait. The tendons and joints that facilitate storage of elastic strain energy in the distal forelimb also experienced the highest loads, which may explain the high frequency of injuries observed at these sites.
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Affiliation(s)
- Simon M. Harrison
- Department of Mechanical Engineering, University of Melbourne, Parkville, VIC 3010, Australia
| | - R. Chris Whitton
- Equine Centre, Faculty of Veterinary Science, University of Melbourne, Werribee, VIC 3030, Australia
| | - Chris E. Kawcak
- Gail Holmes Equine Orthopaedic Research Center, Colorado State University, CO 80523USA
| | - Susan M. Stover
- JD Wheat Veterinary Orthopedic Research Lab, University of California at Davis, CA 95616, USA
| | - Marcus G. Pandy
- Department of Mechanical Engineering, University of Melbourne, Parkville, VIC 3010, Australia
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Butcher MT, Chase PB, Hermanson JW, Clark AN, Brunet NM, Bertram JEA. Contractile properties of muscle fibers from the deep and superficial digital flexors of horses. Am J Physiol Regul Integr Comp Physiol 2010; 299:R996-R1005. [PMID: 20702801 DOI: 10.1152/ajpregu.00510.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Equine digital flexor muscles have independent tendons but a nearly identical mechanical relationship to the main joint they act upon. Yet these muscles have remarkable diversity in architecture, ranging from long, unipennate fibers ("short" compartment of DDF) to very short, multipennate fibers (SDF). To investigate the functional relevance of the form of the digital flexor muscles, fiber contractile properties were analyzed in the context of architecture differences and in vivo function during locomotion. Myosin heavy chain (MHC) isoform fiber type was studied, and in vitro motility assays were used to measure actin filament sliding velocity (V(f)). Skinned fiber contractile properties [isometric tension (P(0)/CSA), velocity of unloaded shortening (V(US)), and force-Ca(2+) relationships] at both 10 and 30°C were characterized. Contractile properties were correlated with MHC isoform and their respective V(f). The DDF contained a higher percentage of MHC-2A fibers with myosin (heavy meromyosin) and V(f) that was twofold faster than SDF. At 30°C, P(0)/CSA was higher for DDF (103.5 ± 8.75 mN/mm(2)) than SDF fibers (81.8 ± 7.71 mN/mm(2)). Similarly, V(US) (pCa 5, 30°C) was faster for DDF (2.43 ± 0.53 FL/s) than SDF fibers (1.20 ± 0.22 FL/s). Active isometric tension increased with increasing Ca(2+) concentration, with maximal Ca(2+) activation at pCa 5 at each temperature in fibers from each muscle. In general, the collective properties of DDF and SDF were consistent with fiber MHC isoform composition, muscle architecture, and the respective functional roles of the two muscles in locomotion.
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Affiliation(s)
- M T Butcher
- Dept. of Biological Sciences, Youngstown State University, OH 44555, USA.
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Superficial digital flexor tendon lesions in racehorses as a sequela to muscle fatigue: A preliminary study. Equine Vet J 2010; 39:540-5. [DOI: 10.2746/042516407x212475] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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26
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Contractile behavior of the forelimb digital flexors during steady-state locomotion in horses (Equus caballus): An initial test of muscle architectural hypotheses about in vivo function. Comp Biochem Physiol A Mol Integr Physiol 2009; 152:100-14. [DOI: 10.1016/j.cbpa.2008.09.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 09/04/2008] [Accepted: 09/05/2008] [Indexed: 11/23/2022]
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Williams SB, Wilson AM, Daynes J, Peckham K, Payne RC. Functional anatomy and muscle moment arms of the thoracic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris). J Anat 2008; 213:373-82. [PMID: 19034998 DOI: 10.1111/j.1469-7580.2008.00962.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We provide quantitative muscle-tendon architecture and geometry data for the racing greyhound thoracic limb. Muscle mass, belly length, fascicle lengths, pennation angles and moment arms were measured, as were tendon masses and lengths. Maximum isometric force and maximum power were estimated for muscles, and maximum stress and strain were estimated for tendons. Results are compared with other fast quadrupedal runners, and to previously published data in mixed-breed dogs. The implications of the functional adaptations of the greyhound thoracic limb for sprinting performance are discussed. The thoracic limb was found to benefit from a similar proportion of locomotor muscle mass to the pelvic limb, suggesting that it may be used to some extent in propulsion, or alternatively that stabilisation is very important in this animal. Extrinsic muscles, especially latissimus dorsi and pectoralis profundus, were predicted to be powerful and important for generating net positive work during accelerations. Proximal biarticular muscles show specialisation toward preventing collapse of the shoulder and elbow joints to enable strut-like limb function, or some form of dynamic control. Distal muscles did not appear specialised for elastic energy storage, a functional difference to pelvic limb muscles, and the equivalents in horse thoracic limbs. The greyhound thoracic limb appears to possess substantial differences from both that of more 'sub-maximal specialist' quadrupeds, and from the greyhound pelvic limb.
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Affiliation(s)
- S B Williams
- Department of Veterinary Preclinical Sciences, University of Liverpool, Liverpool, UK
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Higham TE, Biewener AA. Integration within and between muscles during terrestrial locomotion: effects of incline and speed. ACTA ACUST UNITED AC 2008; 211:2303-16. [PMID: 18587125 DOI: 10.1242/jeb.016139] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Animals must continually adapt to varying locomotor demands when moving in their natural habitat. Despite the dynamic nature of locomotion, little is known about how multiple muscles, and different parts of a muscle, are functionally integrated as demand changes. In order to determine the extent to which synergist muscles are functionally heterogeneous, and whether this heterogeneity is altered with changes in demand, we examined the in vivo function of the lateral (LG) and medial (MG) gastrocnemius muscles of helmeted guinea fowl (Numida meleagris) during locomotion on different inclines (level and uphill at 14 degrees ) and at different speeds (0.5 and 2.0 m s(-1)). We also quantified function in the proximal (pMG) and distal (dMG) regions of the MG to examine the extent to which a single muscle is heterogeneous. We used electromyography, sonomicrometry and tendon force buckles to quantify activation, length change and force patterns of both muscles, respectively. We show that the LG and MG exhibited an increase in force and stress with a change in gait and an increase in locomotor speed, but not with changes in incline. While the LG and MG exhibited similar levels of stress when walking at 0.5 m s(-1), stress in the LG was 1.8 times greater than in the MG when running at 2.0 m s(-1). Fascicle shortening increased with an increase in speed on both inclines for the LG, but only on the level for the pMG. Positive work performed by the LG exceeded that of the pMG and dMG for all conditions, and this difference was magnified when locomotor speed increased. Within the MG, the pMG shortened more, and at a faster rate than the dMG, resulting in a greater amount of positive work performed by the pMG. Mean spike amplitude of the electromyogram (EMG) bursts increased for all muscle locations with an increase in speed, but changes with incline were more variable. The functional differences between the LG and MG are likely due to the different moments each exerts at the knee, as well as differences in motor unit recruitment. The differences within the MG are likely due to motor unit recruitment differences, but also differences in architecture. Fascicles within the dMG insert into an extensive aponeurosis, which results in a higher apparent dynamic stiffness relative to fascicles operating within the pMG. On the level surface, the greater compliance of the pMG leads to increased stretch of its fascicles at the onset of force, further enhancing force production. Our results demonstrate the capacity for functional diversity between and within muscle synergists, which occur with changes in gait, speed and grade.
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Affiliation(s)
- Timothy E Higham
- Department of Organismic and Evolutionary Biology, Concord Field Station, Harvard University, 100 Old Causeway Road, Bedford, MA 01730, USA.
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Crook TC, Cruickshank SE, McGowan CM, Stubbs N, Wakeling JM, Wilson AM, Payne RC. Comparative anatomy and muscle architecture of selected hind limb muscles in the Quarter Horse and Arab. J Anat 2008; 212:144-52. [PMID: 18194205 DOI: 10.1111/j.1469-7580.2007.00848.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The Quarter Horse (bred for acceleration) and the Arab (bred for endurance) are situated at either end of the equine athletic spectrum. Studies into the form and function of the leg muscles in human sprint and endurance runners have demonstrated that differences exist in their muscle architecture. It is not known whether similar differences exist in the horse. Six Quarter Horse and six Arab fresh hind limb cadavers were dissected to gain information on the muscle mass and architecture of the following muscles: gluteus medius; biceps femoris; semitendinosus; vastus lateralis; gastrocnemius; tibialis cranialis and extensor digitorum longus. Specifically, muscle mass, fascicle length and pennation angle were quantified and physiological cross-sectional area (PCSA) and maximum isometric force were estimated. The hind limb muscles of the Quarter Horse were of a significantly greater mass, but had similar fascicle lengths and pennation angles when compared with those of the Arab; this resulted in the Quarter Horse hind limb muscles having greater PCSAs and hence greater isometric force potential. This study suggests that Quarter Horses as a breed inherently possess large strong hind limb muscles, with the potential to accelerate their body mass more rapidly than those of the Arab.
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Affiliation(s)
- T C Crook
- Structure and Motion Lab, Royal Veterinary College, London, UK.
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Williams SB, Wilson AM, Payne RC. Functional specialisation of the thoracic limb of the hare (Lepus europeus). J Anat 2007; 210:491-505. [PMID: 17428206 PMCID: PMC2100293 DOI: 10.1111/j.1469-7580.2007.00703.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
We provide quantitative anatomical data on the muscle-tendon architecture of the hare thoracic limb (specifically muscle mass, fascicle length, pennation angle, tendon mass and length). In addition, moment arms of major thoracic limb muscles were measured. Maximum isometric force and power of muscles, the moment of force about a joint, and tendon stress and strain were estimated. Data are compared with those from other cursorial mammals. The thoracic limb of the hare consists predominantly of extrinsic musculature with long parallel fascicles, specialised for generating force over a large range. A large shoulder flexor/elbow extensor muscle mass is present, in particular Triceps brachii. The pennate nature of the long head of this muscle suggests it has an important role in stabilising the elbow joint during stance, whilst moment arm curves suggest that it may also play a role in initiating shoulder flexion. In addition, Supraspinatus and Infraspinatus are capable of generating high forces, potentially to stabilise the shoulder joint during the stance phase of locomotion. Supraspinatus may in addition play an important role in forelimb protraction. The Subscapularis muscle was capable of generating surprisingly high forces, suggesting that the hare must be able to withstand/produce high forces during activities that need medio-lateral stability, such as turning. Distally, tendons were relatively short, showing little potential for elastic energy storage when compared with both their pelvic limb counterparts and their equivalents in the horse thoracic limb. Thus, a 'stiffer' thoracic limb may be beneficial in terms of behaving like a strut, simply supporting and deflecting the body during high-speed running. This more distal/less proximal distribution of limb mass is also likely to be important in retaining the manipulative/adaptive/non-locomotor capabilities of the limb.
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Affiliation(s)
- S B Williams
- Structure and Motion Laboratory, The Royal Veterinary College, London, UK.
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Abstract
Tendons are dense regular connective tissue structures that are defined based on their anatomical position of connecting muscle to bone. Despite these obvious commons features tendons from different locations within the body show remarkable variation in terms of their morphological, molecular and mechanical properties which relates to their specialized function. An appreciation of these differences is necessary to understand all aspects of tendon biology in health and disease. In our work, we have used a combination of mechanical assessment, histological measurements and molecular analysis of matrix in functionally distinct tendons to determine relationships between function and structure. We have found significant differences in material and molecular properties between spring-like tendons that are subjected to high strains during locomotion and positional tendons which are subjected to much lower strains. Furthermore, we have data to suggest that not only is the matrix composition different but also the ability of cells to synthesize and degrade the matrix (matrix turnover) varies between tendon types. We propose that these differences relate to the magnitude of strain that the tendon experiences during normal activities in life. Tendon cells may be preprogrammed during embryological development for the strain they will encounter in life or may simply respond to the particular strain environment they are subjected to. The elucidation of controlling mechanisms resulting in tendon cell specialization will have important consequences for cell based therapies and engineering strategies to repair damaged tendons.
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Affiliation(s)
- Helen L Birch
- Institute of Orthopaedics and Musculoskeletal Science, University College London, Stanmore, UK.
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Abstract
We provide quantitative anatomical data on the muscle-tendon architecture of the hare pelvic limb (specifically muscle mass, fascicle length, pennation angle, tendon mass and length). In addition, moment arms of major pelvic limb muscles were measured. Maximum isometric force and power of muscles, the moment of force about a joint, and tendon stress and strain were estimated. Data are compared with published data for other cursorial mammals such as the horse and dog, and a non-specialised Lagamorph, the rabbit. The pelvic limb of the hare was found to contain substantial amounts of hip extensor and adductor/abductor muscle volume, which is likely to be required for power production and stability during rapid turning. A proximal to distal reduction in muscle volume and fascicle length was also observed, as is the case in other cursorial quadrupeds, along with a reduction in distal limb mass via the replacement of muscle volume by long distal limb tendons, capable of storing large amounts of elastic energy. The majority of hare pelvic limb muscle moment arms varied with joint position, giving the hare the capacity to vary muscle function with limb posture and presumably different locomotor activities.
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Affiliation(s)
- S B Williams
- Structure and Motion Laboratory, The Royal Veterinary College, London, UK.
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Santschi EM, Leibsle SR, Morehead JP, Prichard MA, Clayton MK, Keuler NS. Carpal and fetlock conformation of the juvenile Thoroughbred from birth to yearling auction age. Equine Vet J 2007; 38:604-9. [PMID: 17228573 DOI: 10.2746/042516406x159025] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY There is little information available about conformational changes in the forelimbs of growing foals. OBJECTIVES To describe the conformation of the carpus and fetlock of Thoroughbred foals from birth to yearling sale age. METHODS Subjective assessments of the fetlock and carpal conformation of 119 Thoroughbred foals were made within the first month of life and then at 30 day intervals until at least age 120 days. At least 70 subjects were examined further at 60 day intervals until September of their second year. Conformation grades are reported for 5 age groups: first 7 days and at a mean of 46, 176, 362 and 525 days. The conformation of all available sires and dams of subjects was also graded. RESULTS All subjects demonstrated carpal deviations, such as valgus, outward rotation and offset, and approximately 30% had fetlock deviations. Heavier birth weights were associated with carpal offset and fetlock inward conformation at most ages, and heavier yearlings were more likely to be carpal valgus. The carpal conformation of the sire (offset and outward rotation) was associated with similar yearling carpal conformation. During the study period, the carpal conformation of Thoroughbred foals became less valgus and more offset. Fetlock conformation became more inwardly deviated during the first 6 months of the study. CONCLUSIONS Carpal and fetlock conformation change greatly in Thoroughbred foals up to age 18 months. The phenotype of the sire can be associated with yearling carpal conformation and bodyweight, particularly at birth and as yearlings, is associated with yearling fetlock and carpal conformation. POTENTIAL RELEVANCE New factors associated with forelimb conformational deviations have been identified that may help breeders better to manage young racing stock.
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Affiliation(s)
- E M Santschi
- Department of Surgical Sciences, School of Veterinary Medicine, 2015 Linden Drive, Madison, Wisconsin 53706, USA
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Dutto DJ, Hoyt DF, Clayton HM, Cogger EA, Wickler SJ. Joint work and power for both the forelimb and hindlimb during trotting in the horse. ACTA ACUST UNITED AC 2007; 209:3990-9. [PMID: 17023593 DOI: 10.1242/jeb.02471] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The net work of the limbs during constant speed over level ground should be zero. However, the partitioning of negative and positive work between the fore- and hindlimbs of a quadruped is not likely to be equal because the forelimb produces a net braking force while the hindlimb produces a net propulsive force. It was hypothesized that the forelimb would do net negative work while the hindlimb did net positive work during trotting in the horse. Because vertical and horizontal impulses remain unchanged across speeds it was hypothesized that net work of both limbs would be independent of speed. Additionally because the major mass of limb musculature is located proximally, it was hypothesized that proximal joints would do more work than distal joints. Kinetic and kinematic analysis were combined using inverse dynamics to calculate work and power for each joint of horses trotting at between 2.5 and 5.0 m s(-1). Work done by the hindlimb was indeed positive (consistently 0.34 J kg(-1) across all speeds), but, contrary to our hypothesis, net work by the forelimb was essentially zero (but also independent of trotting speed). The zero net work of the forelimb may be the consequence of our not being able to account, experimentally, for the negative work done by the extrinsic muscles connecting the scapula and the thorax. The distal three joints of both limbs behaved elastically with a period of energy absorption followed by energy return. Proximal forelimb joints (elbow and shoulder) did no net work, because there was very little movement of the elbow and shoulder during the portion of stance when an extensor moment was greatest. Of the two proximal hindlimb joints, the hip did positive work during the stride, generating energy almost throughout stance. The knee did some work, but like the forelimb proximal joints, had little movement during the middle of stance when the flexion moment was the greatest, probably serving to allow the efficient transmission of energy from the hip musculature to the ground.
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Affiliation(s)
- Darren J Dutto
- School of Physical Education and Health, Eastern Oregon University, La Grande, OR 97850, USA.
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35
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Lagaria A, Youlatos D. ANATOMICAL CORRELATES TO SCRATCH DIGGING IN THE FORELIMB OF EUROPEAN GROUND SQUIRRELS (SPERMOPHILUS CITELLUS). J Mammal 2006. [DOI: 10.1644/05-mamm-a-251r1.1] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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36
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Payne RC, Hutchinson JR, Robilliard JJ, Smith NC, Wilson AM. Functional specialisation of pelvic limb anatomy in horses (Equus caballus). J Anat 2005; 206:557-74. [PMID: 15960766 PMCID: PMC1571521 DOI: 10.1111/j.1469-7580.2005.00420.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We provide quantitative anatomical data on the muscle-tendon units of the equine pelvic limb. Specifically, we recorded muscle mass, fascicle length, pennation angle, tendon mass and tendon rest length. Physiological cross sectional area was then determined and maximum isometric force estimated. There was proximal-to-distal reduction in muscle volume and fascicle length. Proximal limb tendons were few and, where present, were relatively short. By contrast, distal limb tendons were numerous and long in comparison to mean muscle fascicle length, increasing potential for elastic energy storage. When compared with published data on thoracic limb muscles, proximal pelvic limb muscles were larger in volume and had shorter fascicles. Distal limb muscle architecture was similar in thoracic and pelvic limbs with the exception of flexor digitorum lateralis (lateral head of the deep digital flexor), the architecture of which was similar to that of the pelvic and thoracic limb superficial digital flexors, suggesting a functional similarity.
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Affiliation(s)
- R C Payne
- Structure and Motion Laboratory, The Royal Veterinary College, London , UK.
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37
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Lichtwark GA, Wilson AM. Effects of series elasticity and activation conditions on muscle power output and efficiency. J Exp Biol 2005; 208:2845-53. [PMID: 16043589 DOI: 10.1242/jeb.01710] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe activation of a muscle depends on the function that it is performing and on the architectural properties of that muscle; the two are inextricably linked. Activation conditions such as activation timing, duration and amplitude can be varied throughout a cyclical movement (such as locomotion)and the length change of the whole muscle tendon unit (MTU) can also be varied. Architecturally, muscles have a range of fibre lengths, maximum force-producing capabilities and stiffness of the series elastic element(SEE). In the present work we use a model to explore the relationship between power output and efficiency of a muscle across a range of contraction conditions. We have also examined the mechanical and energetic effects of changing muscle architecture within the model. Our results indicate that whilst there are clear optimal conditions for achieving maximum power output and maximum efficiency, the design of the muscle allows high levels of both to be achieved over a range of activation conditions. This range changes with both SEE compliance and the amplitude of the cyclical length change. The results suggest that a compliant SEE allows a muscle to function closer to the maximum of both power output and efficiency. In addition, by varying the amplitude of the activation level, the efficiency can theoretically remain unchanged, whilst the power output can be modulated.
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Affiliation(s)
- G A Lichtwark
- Structure and Motion Laboratory, Institute of Orthopaedics and Musculoskeletal Sciences, University College London, Royal National Orthopedic Hospital, Brockley Hill, Stanmore, Middlesex, HA7 4LP, UK
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38
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Abstract
Muscles have two major roles in locomotion: to generate force and to absorb/generate power (do work). Economical force generation is achieved by short-fibred pennate muscle while the maximum power output of a muscle is architecture independent. In this study we tested the hypothesis that there is an anatomical and structural separation between the force-generating anti-gravity muscles and the propulsive (limb/trunk moving) muscles of the equine forelimb. Muscle mass and fascicle length measurements were made on the thoracic limb extrinsic muscles of six fresh horse cadavers. Physiological cross-sectional area and maximum isometric force were then estimated. Maximum power was estimated from muscle volume and published contraction velocity data. The majority of extrinsic forelimb muscles were large with long fascicles arranged in parallel to the long axis of the muscle. Muscles arranged in this way are optimised for doing work. The architecture of serratus ventralis thoracis (SVT) was unique. It had short (48 +/- 17 mm) fascicles, arranged at about 45 degrees to the long axis of the muscle, which would suggest a force-generating, anti-gravity role. The muscle belly of SVT was sandwiched between two broad, thick sheets of aponeurosis. Hence, SVT could make a significant contribution to the overall elastic properties of the thoracic limb.
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Affiliation(s)
- R C Payne
- Structure and Motion Laboratory, The Royal Veterinary College, London, UK.
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39
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Eizema K, van den Burg MMM, de Jonge HW, Dingboom EG, Weijs WA, Everts ME. Myosin Heavy Chain Isoforms in Equine Gluteus Medius Muscle: Comparison of mRNA and Protein Expression Profiles. J Histochem Cytochem 2005; 53:1383-90. [PMID: 15983121 DOI: 10.1369/jhc.4a6609.2005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The major structural protein in skeletal muscle, myosin heavy chain (MyHC), is primarily transcriptionally controlled. We compared the expression of MyHC isoforms on the mRNA and protein level in biopsies from the m. gluteus medius from adult untrained horses. In transverse sections, the majority of fibers showed qualitatively identical mRNA and protein expression patterns. However, coexpression of 2a and 2d/x MyHCs was substantially more common at the protein than at the mRNA level, suggesting a fine-tuning of these two genes in normal muscle not subjected to any training protocol. Because transverse sections give a limited sampling of mRNA expression in the case of uneven distribution of transcripts in a muscle fiber, we also analyzed longitudinal sections. We present, for the first time, evidence that expression of MyHC mRNA and protein was equal along the length of the fiber. Hence, mRNA expression is not regulated by differential expression of isoforms by separate myonuclei. It is concluded that the number of protein hybrid fibers in equine gluteus medius muscle is controlled by alteration of the transcription pattern uniformly along the fiber, rather than by simultaneous transcription of genes. The differences with the results in muscle of small animals and humans are discussed.
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Affiliation(s)
- Karin Eizema
- Utrecht University, Faculty of Veterinary Medicine, Division of Anatomy and Physiology, PO Box 80.158, NL-3508 TD Utrecht, The Netherlands.
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40
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Bobbert MF, Santamaría S. Contribution of the forelimbs and hindlimbs of the horse to mechanical energy changes in jumping. ACTA ACUST UNITED AC 2005; 208:249-60. [PMID: 15634844 DOI: 10.1242/jeb.01373] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The purpose of the present study was to gain more insight into the contribution of the forelimbs and hindlimbs of the horse to energy changes during the push-off for a jump. For this purpose, we collected kinematic data at 240 Hz from 23 5-year-old Warmbloods (average mass: 595 kg) performing free jumps over a 1.15 m high fence. From these data, we calculated the changes in mechanical energy and the changes in limb length and joint angles. The force carried by the forelimbs and the amount of energy stored was estimated from the distance between elbow and hoof, assuming that this part of the leg behaved as a linear spring. During the forelimb push, the total energy first decreased by 3.2 J kg(-1) and then increased again by 4.2 J kg(-1) to the end of the forelimb push. At the end of the forelimb push, the kinetic energy due to horizontal velocity of the centre of mass was 1.6 J kg(-1) less than at the start, while the effective energy (energy contributing to jump height) was 2.3 J kg(-1) greater. It was investigated to what extent these changes could involve passive spring-like behaviour of the forelimbs. The amount of energy stored and re-utilized in the distal tendons during the forelimb push was estimated to be on average 0.4 J kg(-1) in the trailing forelimb and 0.23 J kg(-1) in the leading forelimb. This means that a considerable amount of energy was first dissipated and subsequently regenerated by muscles, with triceps brachii probably being the most important contributor. During the hindlimb push, the muscles of the leg were primarily producing energy. The total increase in energy was 2.5 J kg(-1) and the peak power output amounted to 71 W kg(-1).
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Affiliation(s)
- Maarten F Bobbert
- Institute for Fundamental and Clinical Human Movement Sciences, Vrije Universiteit, van der Boechorstraat 9, NL-1081 BT Amsterdam, The Netherlands.
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41
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Abstract
Muscles have two major roles in locomotion: to generate force and to absorb/generate power (do work). Economical force generation is achieved by short-fibred pennate muscle while the maximum power output of a muscle is architecture independent. In this study we tested the hypothesis that there is an anatomical and structural separation between the force-generating anti-gravity muscles and the propulsive (limb/trunk moving) muscles of the equine forelimb. Muscle mass and fascicle length measurements were made on the thoracic limb extrinsic muscles of six fresh horse cadavers. Physiological cross-sectional area and maximum isometric force were then estimated. Maximum power was estimated from muscle volume and published contraction velocity data. The majority of extrinsic forelimb muscles were large with long fascicles arranged in parallel to the long axis of the muscle. Muscles arranged in this way are optimised for doing work. The architecture of serratus ventralis thoracis (SVT) was unique. It had short (48 +/- 17 mm) fascicles, arranged at about 45 degrees to the long axis of the muscle, which would suggest a force-generating, anti-gravity role. The muscle belly of SVT was sandwiched between two broad, thick sheets of aponeurosis. Hence, SVT could make a significant contribution to the overall elastic properties of the thoracic limb.
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Affiliation(s)
- R C Payne
- Structure and Motion Laboratory, The Royal Veterinary College, London, UK.
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42
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Zarucco L, Taylor KT, Stover SM. Determination of muscle architecture and fiber characteristics of the superficial and deep digital flexor muscles in the forelimbs of adult horses. Am J Vet Res 2004; 65:819-28. [PMID: 15198223 DOI: 10.2460/ajvr.2004.65.819] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To provide a quantitative description of the architecture of superficial digital flexor (SDF) and deep digital flexor (DDF) muscles in adult horses to predict muscle-tendon behavior and estimate muscle forces. SAMPLE POPULATION 7 forelimb specimens from 7 adult Thoroughbreds. PROCEDURE Muscle and tendon lengths and volumes were measured from 6 fixed forelimbs. After processing, fiber bundle and sarcomere lengths were measured. Optimal fascicle lengths and muscle length-to-fascicle length, muscle length-to-free tendon length, and fascicle length-to-tendon length ratios were calculated, as were tendon and muscle physiologic cross-sectional areas (PCSAs). Pennation angles were measured in 1 embalmed specimen. RESULTS The SDF optimal fascicle lengths were uniformly short (mean +/- SD, 0.8 +/- 0.1 cm), whereas DDF lengths ranged from 0.9 +/- 0.2 cm to 10.8 +/- 1.6 cm. The DDF humeral head had 3 architectural subunits, each receiving a separate median nerve branch, suggestive of neuromuscular compartmentalization. Pennation angles were small (10 degrees to 25 degrees). The PCSAs of the SDF and DDF muscle were 234 +/- 51 cm2 and 259 +/- 30 cm2, with estimated forces of 4,982 +/- 1148 N and 5,520 +/- 544 N, respectively. CONCLUSIONS AND CLINICAL RELEVANCE The SDF muscle appears to provide strong tendinous support with little muscle fascicular shortening and fatigue-resistance properties. The DDF muscle combines passive and dynamic functions with larger tension development and higher shortening velocities during digital motion. Architectural parameters are useful for estimation of forces and have implications for analysis of muscle-tendon function, surgical procedures involving muscle-tendon lengthening, and biomechanical modeling.
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Affiliation(s)
- Laura Zarucco
- J. D. Wheat Veterinary Orthopedic Research Laboratory, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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43
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Abstract
The object of this study was to obtain the anatomic and morphometric data required for biomechanical analyses of the forelimb in dogs. Following the euthanasia of four healthy, adult, crossbred dogs, 44 muscles of the right forelimb were identified and meticulously removed. Morphometric data for all muscles were collected and physiologic cross-sectional areas (PCSA) and architectural indices (AI) were calculated. The coordinates of the origin and insertion of each muscle were determined using orthogonal, right-handed coordinate systems embedded in the scapula, humerus, and radius-ulna. The PCSA and AI were calculated for all the muscles and coordinates for the origins and insertions of these muscles were determined. Results provide the morphometric and anatomic data necessary for three-dimensional biomechanical studies of the forelimb in dogs.
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Affiliation(s)
- Ron Shahar
- Section of Surgery, Veterinary Teaching Hospital, Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot 76100, Israel.
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44
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Taylor AB, Vinyard CJ. Comparative analysis of masseter fiber architecture in tree-gouging (Callithrix jacchus) and nongouging (Saguinus oedipus) callitrichids. J Morphol 2004; 261:276-85. [PMID: 15281057 DOI: 10.1002/jmor.10249] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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.
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Affiliation(s)
- Andrea B Taylor
- Department of Community and Family Medicine, Duke University School of Medicine, Durham, North Carolina 27710, USA.
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45
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Brown NAT, Pandy MG, Kawcak CE, McIlwraith CW. Force- and moment-generating capacities of muscles in the distal forelimb of the horse. J Anat 2003; 203:101-13. [PMID: 12892409 PMCID: PMC1571149 DOI: 10.1046/j.1469-7580.2003.00206.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2003] [Indexed: 11/20/2022] Open
Abstract
A detailed musculoskeletal model of the distal equine forelimb was developed to study the influence of musculoskeletal geometry (i.e. muscle paths) and muscle physiology (i.e. force-length properties) on the force- and moment-generating capacities of muscles crossing the carpal and metacarpophalangeal joints. The distal forelimb skeleton was represented as a five degree-of-freedom kinematic linkage comprised of eight bones (humerus, radius and ulna combined, proximal carpus, distal carpus, metacarpus, proximal phalanx, intermediate phalanx and distal phalanx) and seven joints (elbow, radiocarpal, intercarpal, carpometacarpal, metacarpophalangeal (MCP), proximal interphalangeal (pastern) and distal interphalangeal (coffin)). Bone surfaces were reconstructed from computed tomography scans obtained from the left forelimb of a Thoroughbred horse. The model was actuated by nine muscle-tendon units. Each unit was represented as a three-element Hill-type muscle in series with an elastic tendon. Architectural parameters specifying the force-producing properties of each muscle-tendon unit were found by dissecting seven forelimbs from five Thoroughbred horses. Maximum isometric moments were calculated for a wide range of joint angles by fully activating the extensor and flexor muscles crossing the carpus and MCP joint. Peak isometric moments generated by the flexor muscles were an order of magnitude greater than those generated by the extensor muscles at both the carpus and the MCP joint. For each flexor muscle in the model, the shape of the maximum isometric joint moment-angle curve was dominated by the variation in muscle force. By contrast, the moment-angle curves for the muscles that extend the MCP joint were determined mainly by the variation in muscle moment arms. The suspensory and check ligaments contributed more than half of the total support moment developed about the MCP joint in the model. When combined with appropriate in vivo measurements of joint kinematics and ground-reaction forces, the model may be used to determine muscle-tendon and joint-reaction forces generated during gait.
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Affiliation(s)
- Nicholas A T Brown
- Department of Biomedical Engineering, The University of Texas, Austin, USA.
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