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Hutchinson JR, Pringle EV. Footfall patterns and stride parameters of Common hippopotamus ( Hippopotamus amphibius) on land. PeerJ 2024; 12:e17675. [PMID: 38974416 PMCID: PMC11227274 DOI: 10.7717/peerj.17675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Accepted: 06/12/2024] [Indexed: 07/09/2024] Open
Abstract
Common hippopotamuses (hippos) are among the largest extant land mammals. They thus offer potential further insight into how giant body size on land influences locomotor patterns and abilities. Furthermore, as they have semi-aquatic habits and unusual morphology, they prompt important questions about how locomotion evolved in Hippopotamidae. However, basic information about how hippos move is limited and sometimes contradictory. We aimed to test if hippos trot at all speeds and if they ever use an aerial (suspended) phase, and to quantify how their locomotor patterns (footfalls and stride parameters) change with approximate speed. We surveyed videos available online and collected new video data from two zoo hippos in order to calculate the data needed to achieve our aims; gathering a sample of 169 strides from 32 hippos. No hippos studied used other than trotting (or near-trotting) footfall patterns, but at the fastest relative speeds hippos used brief aerial phases, apparently a new discovery. Hippos exhibit relatively greater athletic capacity than elephants in several ways, but perhaps not greater than rhinoceroses. Our data help form a baseline for assessing if other hippos use normal locomotion; relevant to clinical veterinary assessments of lameness; and for reconstructing the evolutionary biomechanics of hippo lineages.
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Affiliation(s)
- John R. Hutchinson
- Comparative Biomedical Sciences, Structure and Motion Laboratory, The Royal Veterinary College, North Mymms, Hertfordshire, United Kingdom
| | - Emily V. Pringle
- Comparative Biomedical Sciences, Structure and Motion Laboratory, The Royal Veterinary College, North Mymms, Hertfordshire, United Kingdom
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2
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Labonte D, Bishop PJ, Dick TJM, Clemente CJ. Dynamic similarity and the peculiar allometry of maximum running speed. Nat Commun 2024; 15:2181. [PMID: 38467620 PMCID: PMC10928110 DOI: 10.1038/s41467-024-46269-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/20/2024] [Indexed: 03/13/2024] Open
Abstract
Animal performance fundamentally influences behaviour, ecology, and evolution. It typically varies monotonously with size. A notable exception is maximum running speed; the fastest animals are of intermediate size. Here we show that this peculiar allometry results from the competition between two musculoskeletal constraints: the kinetic energy capacity, which dominates in small animals, and the work capacity, which reigns supreme in large animals. The ratio of both capacities defines the physiological similarity index Γ, a dimensionless number akin to the Reynolds number in fluid mechanics. The scaling of Γ indicates a transition from a dominance of muscle forces to a dominance of inertial forces as animals grow in size; its magnitude defines conditions of "dynamic similarity" that enable comparison and estimates of locomotor performance across extant and extinct animals; and the physical parameters that define it highlight opportunities for adaptations in musculoskeletal "design" that depart from the eternal null hypothesis of geometric similarity. The physiological similarity index challenges the Froude number as prevailing dynamic similarity condition, reveals that the differential growth of muscle and weight forces central to classic scaling theory is of secondary importance for the majority of terrestrial animals, and suggests avenues for comparative analyses of locomotor systems.
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Affiliation(s)
- David Labonte
- Department of Bioengineering, Imperial College London, London, UK.
| | - Peter J Bishop
- Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA
- Geosciences Program, Queensland Museum, Brisbane, QLD, Australia
| | - Taylor J M Dick
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Christofer J Clemente
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia
- School of Science and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia
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3
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Turner A, Masters N, Pfau T, Hutchinson JR, Weller R. DEVELOPMENT AND EVALUATION OF A STANDARDIZED SYSTEM FOR THE ASSESSMENT OF LOCOMOTOR HEALTH IN ELEPHANTS UNDER HUMAN CARE. J Zoo Wildl Med 2023; 54:529-537. [PMID: 37817618 DOI: 10.1638/2022-0110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2023] [Indexed: 10/12/2023] Open
Abstract
Although lameness is a common problem in elephants (Asian elephant [Elephas maximus] and African elephants Loxodonta africana and Loxodonta cyclotis) under human care, there has not been a standardized lameness assessment system to date. This study developed and evaluated a standardized system for the assessment of locomotion in elephants under human care regardless of husbandry system. In total, 72 elephants out of a possible 73 in the United Kingdom and Ireland were filmed from behind, from in front, and from both sides. Using a questionnaire and a select panel of elephant specialists, a zoo veterinarian, and a locomotion expert, a numerical rating scoring (NRS) system was proposed. Locomotion was scored on a 4-point scale with numerical values 0-4 corresponding to specific criteria as follows: 0 = clinically sound, 1 = stiffness, 2 = abnormal tracking, and 4 = reluctance to bear weight. The intra- and interobserver repeatability of five veterinary surgeons using this system was determined and compared with a visual analog scale (VAS) expressed as a 100-mm line. Overall intraobserver reliability was moderate (Cohen's kappa [κ] = 0.676) and interobserver reliability was fair (κ = 0.37) for the presence of lameness. Interobserver agreement improved from the first scoring to second scoring from slight agreement to fair agreement for stiffness and reluctance to bear weight. Abnormal tracking had moderate intraobserver agreement for both scoring sessions. There were wide widths of agreement for the VAS interobserver (67 mm); however, they were narrower for the intraobserver (33 mm). The developed NRS can be used on freely moving elephants to evaluate elephant locomotion, regardless of husbandry methods, and has been shown to be more reliable than a VAS.
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Affiliation(s)
- Abigail Turner
- Royal Veterinary College, Hatfield, AL9 7TA, United Kingdom,
| | - Nic Masters
- Veterinary Department, ZSL Whipsnade Zoo, Dunstable, Bedfordshire, LU6 2LF, United Kingdom
| | - Thilo Pfau
- Royal Veterinary College, Hatfield, AL9 7TA, United Kingdom
| | | | - Renate Weller
- Royal Veterinary College, Hatfield, AL9 7TA, United Kingdom
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4
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Kurz MJ, Hutchinson JR. Visual feedback influences the consistency of the locomotor pattern in Asian elephants ( Elephas maximus). Biol Lett 2023; 19:20230260. [PMID: 37753637 PMCID: PMC10523196 DOI: 10.1098/rsbl.2023.0260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/08/2023] [Indexed: 09/28/2023] Open
Abstract
Elephants are atypical of most quadrupeds in that they maintain the same lateral sequence footfall pattern across all locomotor speeds. It has been speculated that the preservation of the footfall patterns is necessary to maintain a statically stable support polygon. This should be a particularly important constraint in large, relatively slow animals. This suggests that elephants must rely on available sensory feedback mechanisms to actively control their massive pillar-like limbs for proper foot placement and sequencing. How the nervous system of elephants integrates the available sensory information for a stable gait is unknown. Here we explored the role that visual feedback plays in the control of the locomotor pattern in Asian elephants. Four Asian elephants (Elephas maximus) walked with and without a blindfold as we measured their stride time intervals. Coefficient of variation was used to assess changes in the overall variability of the stride time intervals, while approximate entropy was used to measure the stride-to-stride consistency of the time intervals. We show that visual feedback plays a role in the stride-to-stride consistency of the locomotor pattern in Asian elephants. These results suggest that elephants use visual feedback to correct and maintain proper sequencing of the limbs during locomotion.
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Affiliation(s)
- Max J. Kurz
- Institute for Human Neuroscience, Boys Town National Research Hospital, 14090 Mother Teresa Lane, Boys Town, NE 68010, USA
| | - John R. Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Hatfield, Hertfordshire AL9 7TA, UK
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Belyaev RI, Kuznetsov AN, Prilepskaya NE. Truly dorsostable runners: Vertebral mobility in rhinoceroses, tapirs, and horses. J Anat 2023; 242:568-591. [PMID: 36519561 PMCID: PMC10008283 DOI: 10.1111/joa.13799] [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: 05/30/2022] [Revised: 11/16/2022] [Accepted: 11/20/2022] [Indexed: 12/23/2022] Open
Abstract
The vertebral column is a hallmark of vertebrates; it is the structural basis of their body and the locomotor apparatus in particular. Locomotion of any vertebrate animal in its typical habitat is directly associated with functional adaptations of its vertebrae. This study is the first large-scale analysis of mobility throughout the presacral region of the vertebral column covering a majority of extant odd-toed ungulates from 6 genera and 15 species. In this study, we used a previously developed osteometry-based method to calculate available range of motion. We quantified all three directions of intervertebral mobility: sagittal bending (SB), lateral bending (LB), and axial rotation (AR). The cervical region in perissodactyls was found to be the most mobile region of the presacral vertebral column in LB and SB. Rhinoceroses and tapirs are characterized by the least mobile necks in SB among odd-toed and even-toed ungulates. Equidae are characterized by very mobile necks, especially in LB. The first intrathoracic joint (T1-T2) in Equidae and Tapiridae is characterized by significantly increased mobility in the sagittal plane compared to the typical thoracic joints and is only slightly less mobile than typical cervical joints. The thoracolumbar part of the vertebral column in odd-toed ungulates is very stiff. Perissodactyls are characterized by frequent fusions of vertebrae with each other with complete loss of mobility. The posterior half of the thoracic region in perissodactyls is characterized by especially stiff intervertebral joints in the SB direction. This is probably associated with hindgut fermentation in perissodactyls: the sagittal stiffness of the posterior thoracic region of the vertebral column is able to passively support the hindgut heavily loaded with roughage. Horses are known as a prime example of a dorsostable galloper among mammals. However, based on SB in the lumbosacral part of the backbone, equids appear to be the least dorsostable among extant perissodactyls; the cumulative SB in equids and tapirs is as low as in the largest representatives of artiodactyls, while in Rhinocerotidae it is even lower representing the minimum across all odd-toed and even-toed ungulates. Morphological features of small Paleogene ancestors of rhinoceroses and equids indicate that dorsostability is a derived feature of perissodactyls and evolved convergently in the three extant families.
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Affiliation(s)
- Ruslan I Belyaev
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russian Federation
| | - Alexander N Kuznetsov
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russian Federation.,Borissiak Paleontological Institute, Russian Academy of Sciences, Moscow, Russian Federation
| | - Natalya E Prilepskaya
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russian Federation
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Birgfellner CMV, Soley JT, Polsterer E, Forstenpointner G, Weissengruber GE. The graviportal spine: Epaxial muscles of the African savanna elephant (Loxodonta africana). Anat Histol Embryol 2023; 52:135-147. [PMID: 35988023 DOI: 10.1111/ahe.12849] [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: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/01/2022]
Abstract
In this study, we present not only a new and detailed anatomical description of the epaxial muscles and adjacent ligamentous and fascial structures in the African savanna elephant but also a structural and functional comparison with other Afrotherian mammals and some domestic quadrupeds. All structures were examined by means of standard anatomical techniques. The back of the largest land mammal is a crucial part of trunk construction according to the bow and string concept, which is applied also in other quadrupedal animals. The epaxial muscles of the African savanna elephant play an important role in the biomechanical properties of the entire back and in supporting and moving the heavy head. Situated in the short cervical region of the African savanna elephant is a large mass comprised of numerous muscle individuals together with a well-developed ligamentum nuchae. Parts of the mm. interansversarii ventralis cervicis form a strong muscle belly, which was named the m. intertransversarius longus. Whereas the head is held in a high or extended position most of the time during locomotion, the head and neck are highly mobile while the animal is foraging or socially interacting. Movements between the elements of the thoracic and lumbar spine are likely to be very limited due to the obvious rigidity of the bony vertebral column. Aponeuroses surrounding long epaxial muscles could contribute to an energy-saving mechanism, which is active during both stance and locomotion. The well-developed m. serratus dorsalis cranialis helps in facilitating effective breathing in an animal, which is equipped with an unusual pleural structure.
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Affiliation(s)
| | - John Thomson Soley
- Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Eva Polsterer
- Institute of Morphology, University of Veterinary Medicine, Vienna, Austria
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Bader C, Delapré A, Houssaye A. Shape variation in the limb long bones of modern elephants reveals adaptations to body mass and habitat. J Anat 2023; 242:806-830. [PMID: 36824051 PMCID: PMC10093169 DOI: 10.1111/joa.13827] [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: 08/29/2022] [Revised: 01/06/2023] [Accepted: 01/06/2023] [Indexed: 02/25/2023] Open
Abstract
During evolution, several vertebrate lineages have shown trends towards an increase in mass. Such a trend is associated with physiological and musculoskeletal changes necessary to carry and move an increasingly heavy body. Due to their prominent role in the support and movement of the body, limb long bones are highly affected by these shifts in body mass. Elephants are the heaviest living terrestrial mammals, displaying unique features allowing them to withstand their massive weight, such as the columnarity of their limbs, and as such are crucial to understand the evolution towards high body mass in land mammals. In this study, we investigate the shape variation of the six limb long bones among the modern elephants, Elephas maximus and Loxodonta africana, to understand the effect of body mass and habitat on the external anatomy of the bones. To do so, we use three-dimensional geometric morphometrics (GMMs) and qualitative comparisons to describe the shape variation, at both the intraspecific and interspecific levels. Our results reveal that the two species share similar negative ontogenetic allometric patterns (i.e. becoming stouter with increased length) in their humerus and femur, but not in the other bones: the proximal epiphyses of the stylopod bones develop considerably during growth, while the distal epiphyses, which are involved in load distribution in the elbow and knee joints, are already massive in juveniles. We attribute this pattern to a weight-bearing adaptation already present in young specimens. Among adults of the same species, bone robustness increases with body mass, so that heavier specimens display stouter bones allowing for a better mechanical load distribution. While this robustness variation is significant for the humerus only, all the other bones appear to follow the same pattern. This is particularly visible in the ulna and tibia, but less so in the femur, which suggests that the forelimb and hindlimb adapted differently to high body mass support. Robustness analyses, while significant for the humerus only, suggest more robust long bones in Asian elephants than in African savanna elephants. More specifically, GMMs and qualitative comparisons indicate that three bones are clearly distinct when comparing the two species: in E. maximus the humerus, the ulna and the tibia display enlarged areas of muscular insertions for muscles involved in joint and limb stabilization, as well as in limb rotation. These results suggest a higher limb compliance in Asian elephants, associated with a higher dexterity, which could be linked to their habitat and foraging habits.
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Affiliation(s)
- Camille Bader
- Département Adaptations du Vivant, UMR 7179, Mécanismes adaptatifs et Évolution (MECADEV) CNRS/Muséum national d'Histoire naturelle, Paris, France
| | - Arnaud Delapré
- UMR 7205, Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, SU, EPHE, UA, Paris, France
| | - Alexandra Houssaye
- Département Adaptations du Vivant, UMR 7179, Mécanismes adaptatifs et Évolution (MECADEV) CNRS/Muséum national d'Histoire naturelle, Paris, France
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8
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Clark CJ, Hutchinson JR, Garland T. The Inverse Krogh Principle: All Organisms Are Worthy of Study. Physiol Biochem Zool 2023; 96:1-16. [PMID: 36626844 DOI: 10.1086/721620] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
AbstractKrogh's principle states, "For such a large number of problems there will be some animal of choice, or a few such animals, on which it can be most conveniently studied." The downside of picking a question first and then finding an ideal organism on which to study it is that it will inevitably leave many organisms neglected. Here, we promote the inverse Krogh principle: all organisms are worthy of study. The inverse Krogh principle and the Krogh principle are not opposites. Rather, the inverse Krogh principle emphasizes a different starting point for research: start with a biological unit, such as an organism, clade, or specific organism trait, then seek or create tractable research questions. Even the hardest-to-study species have research questions that can be asked of them: Where does it fall within the tree of life? What resources does it need to survive and reproduce? How does it differ from close relatives? Does it have unique adaptations? The Krogh and inverse Krogh approaches are complementary, and many research programs naturally include both. Other considerations for picking a study species include extreme species, species informative for phylogenetic analyses, and the creation of models when a suitable species does not exist. The inverse Krogh principle also has pitfalls. A scientist that picks the organism first might choose a research question not really suited to the organism, and funding agencies rarely fund organism-centered grant proposals. The inverse Krogh principle does not call for all organisms to receive the same amount of research attention. As knowledge continues to accumulate, some organisms-models-will inevitably have more known about them than others. Rather, it urges a broader search across organismal diversity to find sources of inspiration for research questions and the motivation needed to pursue them.
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Development of a Protocol for Biomechanical Gait Analysis in Asian Elephants Using the Triaxial Inertial Measurement Unit (IMU). Vet Sci 2022; 9:vetsci9080432. [PMID: 36006347 PMCID: PMC9413814 DOI: 10.3390/vetsci9080432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 07/21/2022] [Accepted: 08/10/2022] [Indexed: 12/04/2022] Open
Abstract
Simple Summary In general practice, the veterinarian and caregiver usually detect lameness in elephants from observation of any discomforting characteristics when walking. Currently, motion analysis can offer an objective method to evaluate normal and abnormal gait accurately, thus identifying changes in some characteristics when walking. This report aimed to introduce a recent technology utilizing wireless sensors for quantitative analysis of joint angles during the gait cycle in Asian elephants. To enable three-dimensional limb segment motion, a triaxial inertial measurement unit (IMU) is equipped with three sensor types: an accelerometer, a gyroscope, and a magnetometer. Therefore, we hope that this portable sensor-based system can help clinicians in diagnosis, especially in the early stages of lameness. Moreover, with wireless signal transmission, the system is clinically applicable for use in all areas where electricity is available. Abstract Gait analysis is a method of gathering quantitative information to assist in determining the cause of abnormal gait for the purpose of making treatment decisions in veterinary medicine. Recent technology has offered the wearable wireless sensor of an inertial measurement unit (IMU) for determining gait parameters. This study proposed the use of a triaxial IMU, comprising an accelerometer, a gyroscope, and a magnetometer, for detecting three-dimensional limb segment motion (XYZ axis) during the gait cycle in Asian elephants. A new algorithm was developed to estimate the kinematic parameter that represents each limb segment of the forelimbs and hindlimbs while walking at a comfortable speed. For future use, this study aimed to create a new prototype of the IMU with a configuration that is tailored to the elephant and apply machine learning in an effort to achieve greater precision.
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Struble MK, Gibb AC. Do we all walk the walk? A comparison of walking behaviors across tetrapods. Integr Comp Biol 2022; 62:icac125. [PMID: 35945645 DOI: 10.1093/icb/icac125] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A walking gait has been identified in a range of vertebrate species with different body plans, habitats, and life histories. With increased application of this broad umbrella term, it has become necessary to assess the physical characteristics, analytical approaches, definitions, and diction used to describe walks. To do this, we reviewed studies of slow speed locomotion across a range of vertebrates to refine the parameters used to define walking, evaluate analytical techniques, and propose approaches to maximize consistency across subdisciplines. We summarize nine key parameters used to characterize walking behaviors in mammals, birds, reptiles, amphibians, and fishes. After identifying consistent patterns across groups, we propose a comprehensive definition for a walking gait. A walk is a form of locomotion where the majority of the forward propulsion of the animal comes from forces generated by the appendages interacting with the ground. During a walk, an appendage must be out of phase with the opposing limb in the same girdle and there is always at least one limb acting as ground-support (no suspension phase). Additionally, walking occurs at dimensionless speeds <1 v* and the duty factor of the limbs is always >0.5. Relative to other gaits used by the same species, the stance duration of a walk is long, the cycle frequency is low, and the cycle distance is small. Unfortunately, some of these biomechanical parameters, while effectively describing walks, may also characterize other, non-walking gaits. Inconsistent methodology likely contributes to difficulties in comparing data across many groups of animals; consistent application of data collection and analytical techniques in research methodology can improve these comparisons. Finally, we note that the kinetics of quadrupedal movements are still poorly understood and much work remains to be done to understand the movements of small, exothermic tetrapods.
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Affiliation(s)
- M K Struble
- Northern Arizona University S San Francisco St, Flagstaff, AZ 86011
- Department of Biological Sciences 617 S Beaver St, Flagstaff, AZ 86011
| | - A C Gibb
- Northern Arizona University S San Francisco St, Flagstaff, AZ 86011
- Department of Biological Sciences 617 S Beaver St, Flagstaff, AZ 86011
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Abstract
Giant land vertebrates have evolved more than 30 times, notably in dinosaurs and mammals. The evolutionary and biomechanical perspectives considered here unify data from extant and extinct species, assessing current theory regarding how the locomotor biomechanics of giants has evolved. In terrestrial tetrapods, isometric and allometric scaling patterns of bones are evident throughout evolutionary history, reflecting general trends and lineage-specific divergences as animals evolve giant size. Added to data on the scaling of other supportive tissues and neuromuscular control, these patterns illuminate how lineages of giant tetrapods each evolved into robust forms adapted to the constraints of gigantism, but with some morphological variation. Insights from scaling of the leverage of limbs and trends in maximal speed reinforce the idea that, beyond 100-300 kg of body mass, tetrapods reduce their locomotor abilities, and eventually may lose entire behaviours such as galloping or even running. Compared with prehistory, extant megafaunas are depauperate in diversity and morphological disparity; therefore, turning to the fossil record can tell us more about the evolutionary biomechanics of giant tetrapods. Interspecific variation and uncertainty about unknown aspects of form and function in living and extinct taxa still render it impossible to use first principles of theoretical biomechanics to tightly bound the limits of gigantism. Yet sauropod dinosaurs demonstrate that >50 tonne masses repeatedly evolved, with body plans quite different from those of mammalian giants. Considering the largest bipedal dinosaurs, and the disparity in locomotor function of modern megafauna, this shows that even in terrestrial giants there is flexibility allowing divergent locomotor specialisations.
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Affiliation(s)
- John R. Hutchinson
- Structure & Motion Lab, Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA,UK
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12
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Dececchi TA, Mloszewska AM, Holtz TR, Habib MB, Larsson HCE. The fast and the frugal: Divergent locomotory strategies drive limb lengthening in theropod dinosaurs. PLoS One 2020; 15:e0223698. [PMID: 32401793 PMCID: PMC7220109 DOI: 10.1371/journal.pone.0223698] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 04/14/2020] [Indexed: 12/15/2022] Open
Abstract
Limb length, cursoriality and speed have long been areas of significant interest in theropod paleobiology, since locomotory capacity, especially running ability, is critical in the pursuit of prey and to avoid becoming prey. The impact of allometry on running ability, and the limiting effect of large body size, are aspects that are traditionally overlooked. Since several different non-avian theropod lineages have each independently evolved body sizes greater than any known terrestrial carnivorous mammal, ~1000kg or more, the effect that such large mass has on movement ability and energetics is an area with significant implications for Mesozoic paleoecology. Here, using expansive datasets that incorporate several different metrics to estimate body size, limb length and running speed, we calculate the effects of allometry on running ability. We test traditional metrics used to evaluate cursoriality in non-avian theropods such as distal limb length, relative hindlimb length, and compare the energetic cost savings of relative hindlimb elongation between members of the Tyrannosauridae and more basal megacarnivores such as Allosauroidea or Ceratosauridae. We find that once the limiting effects of body size increase is incorporated there is no significant correlation to top speed between any of the commonly used metrics, including the newly suggested distal limb index (Tibia + Metatarsus/ Femur length). The data also shows a significant split between large and small bodied theropods in terms of maximizing running potential suggesting two distinct strategies for promoting limb elongation based on the organisms’ size. For small and medium sized theropods increased leg length seems to correlate with a desire to increase top speed while amongst larger taxa it corresponds more closely to energetic efficiency and reducing foraging costs. We also find, using 3D volumetric mass estimates, that the Tyrannosauridae show significant cost of transport savings compared to more basal clades, indicating reduced energy expenditures during foraging and likely reduced need for hunting forays. This suggests that amongst theropods, hindlimb evolution was not dictated by one particular strategy. Amongst smaller bodied taxa the competing pressures of being both a predator and a prey item dominant while larger ones, freed from predation pressure, seek to maximize foraging ability. We also discuss the implications both for interactions amongst specific clades and Mesozoic paleobiology and paleoecological reconstructions as a whole.
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Affiliation(s)
- T. Alexander Dececchi
- Division of Natural Sciences, Department of Biology, Mount Marty College, Yankton, South Dakota, United States of America
- * E-mail:
| | | | - Thomas R. Holtz
- Department of Geology, University of Maryland, College Park, Maryland, United States of America
- Department of Paleobiology, National Museum of Natural History, Washington, DC, United States of America
| | - Michael B. Habib
- Integrative Anatomical Sciences, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States of America
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Patoz A, Gindre C, Thouvenot A, Mourot L, Hébert-Losier K, Lussiana T. Duty Factor Is a Viable Measure to Classify Spontaneous Running Forms. Sports (Basel) 2019; 7:E233. [PMID: 31717680 PMCID: PMC6915645 DOI: 10.3390/sports7110233] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/07/2019] [Accepted: 11/08/2019] [Indexed: 11/24/2022] Open
Abstract
Runners were classified using two different methods based on their spontaneous running form: (1) subjectively using the V®score from the Volodalen® scale, leading to terrestrial and aerial groups; and (2) objectively using the duty factor (DF), leading to high (DFhigh) and low (DFlow) DF groups. This study aimed to compare these two classification schemes. Eighty-nine runners were divided in two groups using the V®score (VOL groups) and were also ranked according to their DF. They ran on a treadmill at 12 km·h-1 with simultaneous recording of running kinematics, using a three-dimensional motion capture system. DF was computed from data as the ratio of ground contact time to stride time. The agreement (95% confidence interval) between VOL and DF groups was 79.8% (69.9%, 87.6%), with relatively high sensitivity (81.6% (68.0%, 91.2%)) and specificity (77.5% (61.6%, 89.2%)). Our results suggest that the DF and V®score reflect similar constructs and lead to similar subgroupings of spontaneous running form (aerial runners if DF < 27.6% and terrestrial runners if DF > 28.8% at 12 km·h-1). These results suggest that DF could be a useful objective measure to monitor real-time changes in spontaneous running form using wearable technology. As a forward-looking statement, spontaneous changes in running form during racing or training could assist in identifying fatigue or changes in environmental conditions, allowing for a better understanding of runners.
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Affiliation(s)
- Aurélien Patoz
- Research and Development Department, Volodalen Swiss SportLab, 1860 Aigle, Switzerland;
| | - Cyrille Gindre
- Research and Development Department, Volodalen Swiss SportLab, 1860 Aigle, Switzerland;
| | - Adrien Thouvenot
- Research and Development Department, Volodalen, 39134 Chavéria, France; (A.T.); (T.L.)
- Research Unit EA3920 Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation platform, University of Fanche-Comté, 25000 Besançon, France;
| | - Laurent Mourot
- Research Unit EA3920 Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation platform, University of Fanche-Comté, 25000 Besançon, France;
- Division for Physical Education, Tomsk Polytechnic University, 634050 Tomsk, Russia
| | - Kim Hébert-Losier
- Adams Centre for High Performance, Division of Health, Engineering, Computing and Science, Te Huataki Waiora School of Health, University of Waikato, Tauranga 3116, New Zealand;
| | - Thibault Lussiana
- Research and Development Department, Volodalen, 39134 Chavéria, France; (A.T.); (T.L.)
- Research Unit EA3920 Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation platform, University of Fanche-Comté, 25000 Besançon, France;
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14
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Thomson TJ. Three-Legged Locomotion and the Constraints on Limb Number: Why Tripeds Don't Have a Leg to Stand On. Bioessays 2019; 41:e1900061. [PMID: 31531902 DOI: 10.1002/bies.201900061] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/06/2019] [Indexed: 11/09/2022]
Abstract
Three-legged animals do not exist today and such an animal is not found in the fossil record. Which constraints operate to result in the lack of a triped phenotype? Consideration of animal locomotion and robotic studies suggests that physical constraints would not prevent a triped from being functional or advantageous. As is reviewed here, the strongest constraint on the evolution of a triped is phylogenetic: namely, the early genetic adoption of a bilaterally symmetrical body plan occurring before the advent of limbs. Presumably, this would greatly constrain any three-legged animal from ever evolving. Tripedalism is employed only by a few animals, but many use a tripod stance while engaged in a variety of activities. Because terms are often used interchangeably in the literature, a standardization of locomotion terminology is proposed. Understanding the constraints behind "forbidden" phenotypes forces us to confront gaps in our evolutionary understanding of which we may be unaware.
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Affiliation(s)
- Tracy J Thomson
- 2119 Earth and Planetary Sciences, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
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15
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Ihwagi FW, Skidmore AK, Wang T, Bastille‐Rousseau G, Toxopeus AG, Douglas‐Hamilton I. Poaching lowers elephant path tortuosity: implications for conservation. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21688] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Festus W. Ihwagi
- Department of Natural ResourcesFaculty of Geo‐Information Science and Earth Observation (ITC), University of TwenteP.O. Box 217 7500 AE Enschede The Netherlands
| | - Andrew K. Skidmore
- Department of Natural ResourcesFaculty of Geo‐Information Science and Earth Observation (ITC), University of TwenteP.O. Box 217 7500 AE Enschede The Netherlands
| | - Tiejun Wang
- Department of Natural ResourcesFaculty of Geo‐Information Science and Earth Observation (ITC), University of TwenteP.O. Box 217 7500 AE Enschede The Netherlands
| | | | - Albertus G. Toxopeus
- Department of Natural ResourcesFaculty of Geo‐Information Science and Earth Observation (ITC), University of TwenteP.O. Box 217 7500 AE Enschede The Netherlands
| | - Iain Douglas‐Hamilton
- Save the ElephantsP.O. Box 54667 ‐ 00200 Nairobi Kenya USA
- Department of ZoologyUniversity of Oxford Oxford OX1 3PS United Kingdom
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16
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Escalante I, Badger MA, Elias DO. Variation in movement: multiple locomotor gaits in Neotropical harvestmen. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Ignacio Escalante
- Department of Environmental Sciences, Policy, & Management, University of California, Berkeley, Berkeley, CA, USA
| | - Marc A Badger
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Damian O Elias
- Department of Environmental Sciences, Policy, & Management, University of California, Berkeley, Berkeley, CA, USA
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17
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Sumida SS, Jefcoat B. Anatomy, Animation, and Visual Effects: The Reciprocal Tools of Biology and Film-Making. Integr Comp Biol 2018; 58:1269-1278. [PMID: 30137369 DOI: 10.1093/icb/icy092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Locomotion studies, biomechanics, and particularly vertebrate paleontology have had a deep influence on the development of motion pictures, animation, and computer generated visual effects. Biologically straightforward concepts such as morphological correlates of diet, sexual dimorphism, and ontogenetic change are powerful tools for animators and visual effects artists. Despite this deep debt to the ever-increasing role of science and technology in film making, scientists often forget to mine the communication strategies of their science-savvy entertainment industry kin. Further, many of the tools of the film industry are making a direct impact on basic research or have the potential to do so. It is becoming increasingly clear as part of the overall outreach for science, technology, engineering, and mathematics ("STEM"), scientists must inform and engage with the public. Significantly, many of the concepts and stories we offer as useful to film makers are compelling stories to offer to our own students. And these can be as compelling to the public as the entertainment they often facilitate. Whereas STEM is critically important, adding "A"-art-as in the artistic strategies from the fields of animation and visual effects to produce "STEAM" helps to build a potentially unstoppable tool for science communication and the public good.
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Affiliation(s)
- Stuart S Sumida
- Department of Biology, California State University San Bernardino, 5500 University Parkway, San Bernardino, CA 92407, USA
| | - Brian Jefcoat
- DreamWorks Feature Animation, 1000 Flower Street, Glendale, CA 91201, USA
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18
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Cole WG, Vereijken B, Young JW, Robinson SR, Adolph KE. Use it or lose it? Effects of age, experience, and disuse on crawling. Dev Psychobiol 2018; 61:29-42. [PMID: 30447002 DOI: 10.1002/dev.21802] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 09/23/2018] [Accepted: 09/29/2018] [Indexed: 11/09/2022]
Abstract
What happens to early acquired but later abandoned motor skills? To investigate effects of disuse on early-developing motor skills, we examined crawling in two groups of habitual crawlers (34 6-12-month-old infants and five adults with Uner Tan Syndrome) and two groups of rusty crawlers (27 11-12-year-old children and 13 college-aged adults). Habitual crawlers showed striking similarities in gait patterns, limbs supporting the body, and crawling speed, despite dramatic differences in crawling practice, posture, and body size. Habitual crawlers trotted predominantly, whereas rusty crawlers showed a variety of gait patterns. Within sequences, habitual crawlers and children showed more switches in gait patterns than young adults. Children crawled faster and kept fewer limbs on the grounds than the other groups. Old crawling patterns were retained despite disuse, but new ones were also added. Surprisingly, results indicate that nothing was lost with disuse, but some features of crawling were gained or altered.
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Affiliation(s)
- Whitney G Cole
- Department of Psychology, New York University, New York City, New York
| | - Beatrix Vereijken
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jesse W Young
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio
| | | | - Karen E Adolph
- Department of Psychology, New York University, New York City, New York
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19
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Lee DV, Harris SL. Linking Gait Dynamics to Mechanical Cost of Legged Locomotion. Front Robot AI 2018; 5:111. [PMID: 33500990 PMCID: PMC7805771 DOI: 10.3389/frobt.2018.00111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 09/05/2018] [Indexed: 11/23/2022] Open
Abstract
For millenia, legged locomotion has been of central importance to humans for hunting, agriculture, transportation, sport, and warfare. Today, the same principal considerations of locomotor performance and economy apply to legged systems designed to serve, assist, or be worn by humans in urban and natural environments. Energy comes at a premium not only for animals, wherein suitably fast and economical gaits are selected through organic evolution, but also for legged robots that must carry sufficient energy in their batteries. Although a robot's energy is spent at many levels, from control systems to actuators, we suggest that the mechanical cost of transport is an integral energy expenditure for any legged system—and measuring this cost permits the most direct comparison between gaits of legged animals and robots. Although legged robots have matched or even improved upon total cost of transport of animals, this is typically achieved by choosing extremely slow speeds or by using regenerative mechanisms. Legged robots have not yet reached the low mechanical cost of transport achieved at speeds used by bipedal and quadrupedal animals. Here we consider approaches used to analyze gaits and discuss a framework, termed mechanical cost analysis, that can be used to evaluate the economy of legged systems. This method uses a point mass perspective to evaluate the entire stride as well as to identify individual events that accrue mechanical cost. The analysis of gait began at the turn of the last century with spatiotemporal analysis facilitated by the advent of cine film. These advances gave rise to the “gait diagram,” which plots duty factors and phase separations between footfalls. This approach was supplanted in the following decades by methods using force platforms to determine forces and motions of the center of mass (CoM)—and analytical models that characterize gait according to fluctuations in potential and kinetic energy. Mechanical cost analysis draws from these approaches and provides a unified framework that interprets the spatiotemporal sequencing of leg contacts within the context of CoM dynamics to determine mechanical cost in every instance of the stride. Diverse gaits can be evaluated and compared in biological and engineered systems using mechanical cost analysis.
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Affiliation(s)
- David V Lee
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV, United States
| | - Sarah L Harris
- Department of Electrical and Computer Engineering, University of Nevada Las Vegas, Las Vegas, NV, United States
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20
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Tennett KA, Costa DP, Nicastro AJ, Fish FE. Terrestrial locomotion of the northern elephant seal ( Mirounga angustirostris): limitation of large aquatically adapted seals on land? ACTA ACUST UNITED AC 2018; 221:jeb.180117. [PMID: 30127084 DOI: 10.1242/jeb.180117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/25/2018] [Indexed: 11/20/2022]
Abstract
The aquatic specializations of phocid seals have restricted their ability to locomote on land. The amphibious northern elephant seal, Mirounga angustirostris, is the second largest phocid seal in the world, with males reaching 2700 kg. Although elephant seals are proficient swimmers and deep divers, their extreme size and aquatic specializations limit terrestrial movement. The kinematics of terrestrial locomotion in northern elephant seals were analyzed from video recordings of animals observed on the beach of Año Nuevo State Reserve, CA, USA. The seals moved using a series of rhythmic undulations produced by dorsoventral spinal flexion. The traveling spinal wave moved anteriorly along the dorsal margin of the body with the chest, pelvic region and foreflippers serving as the main points of contact with the ground. The hindflippers were not used. The spinal wave and foreflippers were used to lift the chest off the ground as the body was pushed forward from the pelvis as the foreflippers were retracted to pull the body forward. Seals moved over land at 0.41-2.56 m s-1 (0.12-0.71 body lengths s-1). The frequency and amplitude of spinal flexions both displayed a direct increase with increasing speed. The duty factor for the pelvic region decreased with increasing velocity while the duty factor of the foreflipper remained constant. Kinematic data for elephant seals and other phocids were used in a biomechanical model to calculate the mechanical energy expended during terrestrial locomotion. The elephant seals were found to expend more energy when traveling over land for their size than smaller phocids. The unique method of terrestrial movement also exhibited greater energy expenditure on land than values for large quadrupeds. The trade-off for the northern elephant seal is that its massive size and morphology have well adapted it to an aquatic existence but limited its locomotor performance (i.e. speed, endurance) on land.
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Affiliation(s)
- Kelsey A Tennett
- Department of Biology, West Chester University, West Chester, PA 19383, USA
| | - Daniel P Costa
- Department of Ecology & Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Anthony J Nicastro
- Department of Physics, West Chester University, West Chester, PA 19383, USA
| | - Frank E Fish
- Department of Biology, West Chester University, West Chester, PA 19383, USA
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21
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Bishop PJ, Clemente CJ, Weems RE, Graham DF, Lamas LP, Hutchinson JR, Rubenson J, Wilson RS, Hocknull SA, Barrett RS, Lloyd DG. Using step width to compare locomotor biomechanics between extinct, non-avian theropod dinosaurs and modern obligate bipeds. J R Soc Interface 2018; 14:rsif.2017.0276. [PMID: 28724627 DOI: 10.1098/rsif.2017.0276] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/22/2017] [Indexed: 12/13/2022] Open
Abstract
How extinct, non-avian theropod dinosaurs locomoted is a subject of considerable interest, as is the manner in which it evolved on the line leading to birds. Fossil footprints provide the most direct evidence for answering these questions. In this study, step width-the mediolateral (transverse) distance between successive footfalls-was investigated with respect to speed (stride length) in non-avian theropod trackways of Late Triassic age. Comparable kinematic data were also collected for humans and 11 species of ground-dwelling birds. Permutation tests of the slope on a plot of step width against stride length showed that step width decreased continuously with increasing speed in the extinct theropods (p < 0.001), as well as the five tallest bird species studied (p < 0.01). Humans, by contrast, showed an abrupt decrease in step width at the walk-run transition. In the modern bipeds, these patterns reflect the use of either a discontinuous locomotor repertoire, characterized by distinct gaits (humans), or a continuous locomotor repertoire, where walking smoothly transitions into running (birds). The non-avian theropods are consequently inferred to have had a continuous locomotor repertoire, possibly including grounded running. Thus, features that characterize avian terrestrial locomotion had begun to evolve early in theropod history.
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Affiliation(s)
- P J Bishop
- Geosciences Program, Queensland Museum, Brisbane, Australia .,School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia
| | - C J Clemente
- School of Science and Engineering, University of the Sunshine Coast, Maroochydore, Australia.,School of Biological Sciences, University of Queensland, Brisbane, Australia
| | - R E Weems
- Calvert Marine Museum, Solomons, USA.,Paleo Quest, Gainesville, FL, USA
| | - D F Graham
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia
| | - L P Lamas
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, UK.,Faculdade de Medicina Veterinária, Universidade de Lisboa, Lisbon, Portugal
| | - J R Hutchinson
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, UK
| | - J Rubenson
- College of Health and Human Development, Pennsylvania State University, University Park, PA, USA.,School of Human Sciences, University of Western Australia, Crawley, Australia
| | - R S Wilson
- School of Biological Sciences, University of Queensland, Brisbane, Australia
| | - S A Hocknull
- Geosciences Program, Queensland Museum, Brisbane, Australia.,School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia
| | - R S Barrett
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia
| | - D G Lloyd
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia.,School of Human Sciences, University of Western Australia, Crawley, Australia
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22
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Nagel RM, Forstenpointner G, Soley JT, Weissengruber GE. Muscles and fascial elements of the antebrachium and manus of the African elephant (Loxodonta africana, Blumenbach 1797): starring comparative and functional considerations. Anat Histol Embryol 2018; 47:195-205. [PMID: 29460451 DOI: 10.1111/ahe.12340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 12/27/2017] [Indexed: 11/30/2022]
Abstract
The structure of the limbs of elephants is unusual among mammals. In African elephants (Loxodonta africana, Blumenbach 1797), the front limbs serve to support the greatest part of the body mass of the largest land animal. In this study, we present new and detailed anatomical data regarding muscular and specific fascial structures of the lower front limb which were examined by means of standard anatomical and histological techniques. The muscles and tendons of the forearm (antebrachium) and hand (manus) are tightly surrounded by thick, highly elastic fascial layers which fuse with the lacertus (lac.) fibrosus and the so-called ligamentum (lig.) humeroulnare. A well-developed musculus (m.) brachioradialis occupies the proximolateral aspect of the forearm and its tendon inserts together with the lac. fibrosus on the os carpi intermedium. The lac. fibrosus, the lig. humeroulnare and the m. flexor carpi radialis reveal a large proportion of elastic fibres. These three structures may play an important role in storing strain energy thus promoting energy-saving locomotion. On the palmar aspect of the carpus, metacarpus and digits, short flexor, abductor, adductor, lumbricales and interossei muscles are present, whereas supinator muscles are absent in all specimens. The short muscles of the hand together with specific dorsal tendons enable precise movements of specific toes.
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Affiliation(s)
- R M Nagel
- Institute of Topographic Anatomy, University of Veterinary Medicine, Vienna, Austria
| | - G Forstenpointner
- Institute of Topographic Anatomy, University of Veterinary Medicine, Vienna, Austria
| | - J T Soley
- Department of Anatomy and Physiology, University of Pretoria, Faculty of Veterinary Science, Onderstepoort, South Africa
| | - G E Weissengruber
- Institute of Topographic Anatomy, University of Veterinary Medicine, Vienna, Austria
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23
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Affiliation(s)
- Advait M Jukar
- Environmental Science and Policy, George Mason University, Fairfax, VA, USA
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - S Kathleen Lyons
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Mark D Uhen
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- Atmospheric, Oceanic and Earth Sciences, George Mason University, Fairfax, VA, USA
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24
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Shahriyari L, Mahdipour-Shirayeh A. Modeling dynamics of mutants in heterogeneous stem cell niche. Phys Biol 2017; 14:016004. [PMID: 28102174 DOI: 10.1088/1478-3975/aa5a61] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Studying the stem cell (SC) niche architecture is a crucial step for investigating the process of oncogenesis and obtaining an effective stem cell therapy for various cancers. Recently, it has been observed that there are two groups of SCs in the SC niche collaborating with each other to maintain tissue homeostasis: border stem cells (BSCs), which are responsible in controlling the number of non-stem cells as well as stem cells, and central stem cells (CeSCs), which regulate the SC niche. Here, we develop a bi-compartmental stochastic model for the SC niche to study the spread of mutants within the niche. The analytic calculations and numeric simulations, which are in perfect agreement, reveal that in order to delay the spread of mutants in the SC niche, a small but non-zero number of SC proliferations must occur in the CeSC compartment. Moreover, the migration of BSCs to CeSCs delays the spread of mutants. Furthermore, the fixation probability of mutants in the SC niche is independent of types of SC division as long as all SCs do not divide fully asymmetrically. Additionally, the progeny of CeSCs have a much higher chance than the progeny of BSCs to take over the entire niche.
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Affiliation(s)
- L Shahriyari
- Mathematical Biosciences Institute, The Ohio State University, OH, United States of America
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25
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Young JW, Stricklen BM, Chadwell BA. Effects of support diameter and compliance on common marmoset (Callithrix jacchus) gait kinematics. J Exp Biol 2016; 219:2659-72. [DOI: 10.1242/jeb.140939] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 06/21/2016] [Indexed: 11/20/2022]
Abstract
ABSTRACT
Locomotion is precarious in an arboreal habitat, where supports can vary in both diameter and level of compliance. Several previous studies have evaluated the influence of substrate diameter on the locomotor performance of arboreal quadrupeds. The influence of substrate compliance, however, has been mostly unexamined. Here, we used a multifactorial experimental design to investigate how perturbations in both diameter and compliance affect the gait kinematics of marmosets (Callithrix jacchus; N=2) moving over simulated arboreal substrates. We used 3D-calibrated video to quantify marmoset locomotion over a horizontal trackway consisting of variably sized poles (5, 2.5 and 1.25 cm in diameter), analyzing a total of 120 strides. The central portion of the trackway was either immobile or mounted on compliant foam blocks, depending on condition. We found that narrowing diameter and increasing compliance were both associated with relatively longer substrate contact durations, though adjustments to diameter were often inconsistent relative to compliance-related adjustments. Marmosets also responded to narrowing diameter by reducing speed, flattening center of mass (CoM) movements and dampening support displacement on the compliant substrate. For the subset of strides on the compliant support, we found that speed, contact duration and CoM amplitude explained >60% of the variation in substrate displacement over a stride, suggesting a direct performance advantage to these kinematic adjustments. Overall, our results show that compliant substrates can exert a significant influence on gait kinematics. Substrate compliance, and not just support diameter, should be considered a critical environmental variable when evaluating locomotor performance in arboreal quadrupeds.
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Affiliation(s)
- Jesse W. Young
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University (NEOMED), Rootstown, OH 44272, USA
- Musculoskeletal Biology Research Focus Area, NEOMED, Rootstown, OH 44272, USA
- School of Biomedical Sciences, Kent State University, Kent, OH 44240, USA
| | - Bethany M. Stricklen
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University (NEOMED), Rootstown, OH 44272, USA
| | - Brad A. Chadwell
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University (NEOMED), Rootstown, OH 44272, USA
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26
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Kim S, Clark JE, Cutkosky MR. iSprawl: Design and Tuning for High-speed Autonomous Open-loop Running. Int J Rob Res 2016. [DOI: 10.1177/0278364906069150] [Citation(s) in RCA: 207] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We describe the design features that underlie the operation of iSprawl, a small (0.3 kg) autonomous, bio-inspired hexapod that runs at 15 body-lengths/second (2.3 m/s). These features include a tuned set of leg compliances for efficient running and a light and flexible power transmission system. This transmission system permits high speed rotary power to be converted to periodic thrusting and distributed to the tips of the rapidly swinging legs. The specific resistance of iSprawl is approximately constant at 1.75 for speeds between 1.25 m/s and 2.5 m/s. Examination of the trajectory of the center of mass and the ground reaction forces for iSprawl show that it achieves a stable, bouncing locomotion similar to that seen in insects and in previous (slower) bio-inspired robots, but with an unusually high stride frequency for its size.
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Affiliation(s)
- Sangbae Kim
- Center for Design Research Stanford University Stanford, CA 94305-2232, USA,
| | - Jonathan E. Clark
- GRASP Laboratory University of Pennsylvania Philadelphia, PA 19104, USA,
| | - Mark R. Cutkosky
- Center for Design Research Stanford University Stanford, CA 94305-2232, USA,
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27
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Nichol JG, Singh SP, Waldron KJ, Palmer LR, Orin DE. System Design of a Quadrupedal Galloping Machine. Int J Rob Res 2016. [DOI: 10.1177/0278364904047391] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this paper we present the system design of a machine that we have constructed to study a quadrupedal gallop gait. The gallop gait is the preferred high-speed gait of most cursorial quadrupeds. To gallop, an animal must generate ballistic trajectories with characteristic strong impacts, coordinate leg movements with asymmetric footfall phasing, and effectively use compliant members, all the while maintaining dynamic stability. In this paper we seek to further understand the primary biological features necessary for galloping by building and testing a robotic quadruped similar in size to a large goat or antelope. These features include high-speed actuation, energy storage, on-line learning control, and high-performance attitude sensing. Because body dynamics are primarily influenced by the impulses delivered by the legs, the successful design and control of single leg energetics is a major focus of this work. The leg stores energy during flight by adding tension to a spring acting across an articulated knee. During stance, the spring energy is quickly released using a novel capstan design. As a precursor to quadruped control, two intelligent strategies have been developed for verification on a one-legged system. The Levenberg-Marquardt on-line learning method is applied to a simple heuristic controller and provides good control over height and forward velocity. Direct adaptive fuzzy control, which requires no system modeling but is more computationally expensive, exhibits better response. Using these techniques we have been successful in operating one leg at speeds necessary for a dynamic gallop of a machine of this scale. Another necessary component of quadruped locomotion is high-resolution and high-bandwidth attitude sensing. The large ground impact accelerations, which cause problems for any single traditional sensor, are overcome through the use of an inertial sensing approach using updates from optical sensors and vehicle kinematics.
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Affiliation(s)
- J. Gordon Nichol
- Stanford University, 424 Panama Mall, Bldg 560, Stanford, CA 94305, USA,
| | - Surya P.N. Singh
- Stanford University, 424 Panama Mall, Bldg 560, Stanford, CA 94305, USA
| | | | - Luther R. Palmer
- Ohio State University, Department of Electrical and Computer Engineering, 2015 Neil Avenue, Columbus, OH 43210, USA
| | - David E. Orin
- Ohio State University, Department of Electrical and Computer Engineering, 2015 Neil Avenue, Columbus, OH 43210, USA
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28
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Shine CL, Penberthy S, Robbins CT, Nelson OL, McGowan CP. Grizzly bear (Ursus arctos horribilis) locomotion: gaits and ground reaction forces. ACTA ACUST UNITED AC 2015; 218:3102-9. [PMID: 26254319 DOI: 10.1242/jeb.121806] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 07/29/2015] [Indexed: 11/20/2022]
Abstract
Locomotion of plantigrade generalists has been relatively little studied compared with more specialised postures even though plantigrady is ancestral among quadrupeds. Bears (Ursidae) are a representative family for plantigrade carnivorans, they have the majority of the morphological characteristics identified for plantigrade species, and they have the full range of generalist behaviours. This study compared the locomotion of adult grizzly bears (Ursus arctos horribilis Linnaeus 1758), including stride parameters, gaits and analysis of three-dimensional ground reaction forces, with that of previously studied quadrupeds. At slow to moderate speeds, grizzly bears use walks, running walks and canters. Vertical ground reaction forces demonstrated the typical M-shaped curve for walks; however, this was significantly more pronounced in the hindlimb. The rate of force development was also significantly higher for the hindlimbs than for the forelimbs at all speeds. Mediolateral forces were significantly higher than would be expected for a large erect mammal, almost to the extent of a sprawling crocodilian. There may be morphological or energetic explanations for the use of the running walk rather than the trot. The high medial forces (produced from a lateral push by the animal) could be caused by frontal plane movement of the carpus and elbow by bears. Overall, while grizzly bears share some similarities with large cursorial species, their locomotor kinetics have unique characteristics. Additional studies are needed to determine whether these characters are a feature of all bears or plantigrade species.
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Affiliation(s)
- Catherine L Shine
- University of Idaho, Department of Biological Sciences, Life Sciences Building, University Avenue, Moscow, ID 83844, USA
| | - Skylar Penberthy
- University of Idaho, Department of Biological Sciences, Life Sciences Building, University Avenue, Moscow, ID 83844, USA
| | - Charles T Robbins
- Washington State University, School of the Environment and School of Biological Sciences, Pullman, WA 99164, USA
| | - O Lynne Nelson
- Washington State University, Department of Veterinary and Clinical Sciences, Pullman, WA 99164, USA
| | - Craig P McGowan
- University of Idaho, Department of Biological Sciences, Life Sciences Building, University Avenue, Moscow, ID 83844, USA WWAMI Regional Medical Education Program, University of Idaho, Moscow, ID 83844, USA
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Shahriyari L, Komarova NL. The role of the bi-compartmental stem cell niche in delaying cancer. Phys Biol 2015; 12:055001. [PMID: 26228740 DOI: 10.1088/1478-3975/12/5/055001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In recent years, by using modern imaging techniques, scientists have found evidence of collaboration between different types of stem cells (SCs), and proposed a bi-compartmental organization of the SC niche. Here we create a class of stochastic models to simulate the dynamics of such a heterogeneous SC niche. We consider two SC groups: the border compartment, S1, is in direct contact with transit-amplifying (TA) cells, and the central compartment, S2, is hierarchically upstream from S1. The S1 SCs differentiate or divide asymmetrically when the tissue needs TA cells. Both groups proliferate when the tissue requires SCs (thus maintaining homeostasis). There is an influx of S2 cells into the border compartment, either by migration, or by proliferation. We examine this model in the context of double-hit mutant generation, which is a rate-limiting step in the development of many cancers. We discover that this type of a cooperative pattern in the stem niche with two compartments leads to a significantly smaller rate of double-hit mutant production compared with a homogeneous, one-compartmental SC niche. Furthermore, the minimum probability of double-hit mutant generation corresponds to purely symmetric division of SCs, consistent with the literature. Finally, the optimal architecture (which minimizes the rate of double-hit mutant production) requires a large proliferation rate of S1 cells along with a small, but non-zero, proliferation rate of S2 cells. This result is remarkably similar to the niche structure described recently by several authors, where one of the two SC compartments was found more actively engaged in tissue homeostasis and turnover, while the other was characterized by higher levels of quiescence (but contributed strongly to injury recovery). Both numerical and analytical results are presented.
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Affiliation(s)
- Leili Shahriyari
- Mathematical Biosciences Institute, Ohio State University, Columbus, OH, USA
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Pellegrini B, Zoppirolli C, Bortolan L, Zamparo P, Schena F. Gait models and mechanical energy in three cross-country skiing techniques. ACTA ACUST UNITED AC 2015; 217:3910-8. [PMID: 25355851 DOI: 10.1242/jeb.106740] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Fluctuations in mechanical energy of the body center of mass (COM) have been widely analyzed when investigating different gaits in human and animal locomotion. We applied this approach to estimate the mechanical work in cross-country skiing and to identify the fundamental mechanisms of this particular form of locomotion. We acquired movements of body segments, skis, poles and plantar pressures for eight skiers while they roller skied on a treadmill at 14 km h(-1) and a 2 deg slope using three different techniques (diagonal stride, DS; double poling, DP; double poling with kick, DK). The work associated with kinetic energy (KE) changes of COM was not different between techniques; the work against gravity associated with potential energy (PE) changes was higher for DP than for DK and was lowest for DS. Mechanical work against the external environment was 0.87 J m(-1) kg(-1) for DS, 0.70 J m(-1) kg(-1) for DP and 0.79 J m(-1) kg(-1) for DK. The work done to overcome frictional forces, which is negligible in walking and running, was 17.8%, 32.3% and 24.8% of external mechanical work for DS, DP and DK, respectively. The pendulum-like recovery (R%) between PE and KE was ~45%, ~26% and ~9% for DP, DK and DS, respectively, but energy losses by friction are not accounted for in this computation. The pattern of fluctuations of PE and KE indicates that DS can be described as a 'grounded running', where aerial phases are substituted by ski gliding phases, DP can be described as a pendular gait, whereas DK is a combination of both.
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Affiliation(s)
- Barbara Pellegrini
- CeRiSM, Center of Research in Mountain Sport and Health, University of Verona, 38068 Rovereto, Italy Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
| | - Chiara Zoppirolli
- CeRiSM, Center of Research in Mountain Sport and Health, University of Verona, 38068 Rovereto, Italy Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
| | - Lorenzo Bortolan
- CeRiSM, Center of Research in Mountain Sport and Health, University of Verona, 38068 Rovereto, Italy Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
| | - Paola Zamparo
- Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
| | - Federico Schena
- CeRiSM, Center of Research in Mountain Sport and Health, University of Verona, 38068 Rovereto, Italy Department of Neurological and Movement Sciences, University of Verona, Verona 37129, Italy
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Fast running restricts evolutionary change of the vertebral column in mammals. Proc Natl Acad Sci U S A 2014; 111:11401-6. [PMID: 25024205 DOI: 10.1073/pnas.1401392111] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The mammalian vertebral column is highly variable, reflecting adaptations to a wide range of lifestyles, from burrowing in moles to flying in bats. However, in many taxa, the number of trunk vertebrae is surprisingly constant. We argue that this constancy results from strong selection against initial changes of these numbers in fast running and agile mammals, whereas such selection is weak in slower-running, sturdier mammals. The rationale is that changes of the number of trunk vertebrae require homeotic transformations from trunk into sacral vertebrae, or vice versa, and mutations toward such transformations generally produce transitional lumbosacral vertebrae that are incompletely fused to the sacrum. We hypothesize that such incomplete homeotic transformations impair flexibility of the lumbosacral joint and thereby threaten survival in species that depend on axial mobility for speed and agility. Such transformations will only marginally affect performance in slow, sturdy species, so that sufficient individuals with transitional vertebrae survive to allow eventual evolutionary changes of trunk vertebral numbers. We present data on fast and slow carnivores and artiodactyls and on slow afrotherians and monotremes that strongly support this hypothesis. The conclusion is that the selective constraints on the count of trunk vertebrae stem from a combination of developmental and biomechanical constraints.
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32
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Reinhardt L, Blickhan R. Level locomotion in wood ants: evidence for grounded running. ACTA ACUST UNITED AC 2014; 217:2358-70. [PMID: 24744414 DOI: 10.1242/jeb.098426] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In order to better understand the strategies of locomotion in small insects, we have studied continuous level locomotion of the wood ant species Formica polyctena. We determined the three-dimensional centre of mass kinematics during the gait cycle and recorded the ground reaction forces of single legs utilising a self-developed test site. Our findings show that the animals used the same gait dynamics across a wide speed range without dissolving the tripodal stride pattern. To achieve higher velocities, the ants proportionally increased stride length and stepping frequency. The centre of mass energetics indicated a bouncing gait, in which horizontal kinetic and gravitational potential energy fluctuated in close phase. We determined a high degree of compliance especially in the front legs, as the effective leg length was nearly halved during the contact phase. This leads to only small vertical oscillations of the body, which are important in maintaining ground contact. Bouncing gaits without aerial phases seem to be a common strategy in small runners and can be sufficiently described by the bipedal spring-loaded inverted pendulum model. Thus, with our results, we provide evidence that wood ants perform 'grounded running'.
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Affiliation(s)
- Lars Reinhardt
- Science of Motion, Friedrich-Schiller-University Jena, Seidelstr. 20, 07749 Jena, Germany
| | - Reinhard Blickhan
- Science of Motion, Friedrich-Schiller-University Jena, Seidelstr. 20, 07749 Jena, Germany
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Birn-Jeffery AV, Higham TE. The Scaling of Uphill and Downhill Locomotion in Legged Animals. Integr Comp Biol 2014; 54:1159-72. [DOI: 10.1093/icb/icu015] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Bohrer G, Beck PSA, Ngene SM, Skidmore AK, Douglas-Hamilton I. Elephant movement closely tracks precipitation-driven vegetation dynamics in a Kenyan forest-savanna landscape. MOVEMENT ECOLOGY 2014; 2:2. [PMID: 25520813 PMCID: PMC4267703 DOI: 10.1186/2051-3933-2-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 12/23/2013] [Indexed: 05/27/2023]
Abstract
BACKGROUND This study investigates the ranging behavior of elephants in relation to precipitation-driven dynamics of vegetation. Movement data were acquired for five bachelors and five female family herds during three years in the Marsabit protected area in Kenya and changes in vegetation were mapped using MODIS normalized difference vegetation index time series (NDVI). In the study area, elevations of 650 to 1100 m.a.s.l experience two growth periods per year, while above 1100 m.a.s.l. growth periods last a year or longer. RESULTS We find that elephants respond quickly to changes in forage and water availability, making migrations in response to both large and small rainfall events. The elevational migration of individual elephants closely matched the patterns of greening and senescing of vegetation in their home range. Elephants occupied lower elevations when vegetation activity was high, whereas they retreated to the evergreen forest at higher elevations while vegetation senesced. Elephant home ranges decreased in size, and overlapped less with increasing elevation. CONCLUSIONS A recent hypothesis that ungulate migrations in savannas result from countervailing seasonally driven rainfall and fertility gradients is demonstrated, and extended to shorter-distance migrations. In other words, the trade-off between the poor forage quality and accessibility in the forest with its year-round water sources on the one hand and the higher quality forage in the low-elevation scrubland with its seasonal availability of water on the other hand, drives the relatively short migrations (the two main corridors are 20 and 90 km) of the elephants. In addition, increased intra-specific competition appears to influence the animals' habitat use during the dry season indicating that the human encroachment on the forest is affecting the elephant population.
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Affiliation(s)
- Gil Bohrer
- />The Ohio State University, Department of Civil, Environmental and Geodetic Engineering, 2070 Neil Ave., Columbus, OH 43210 USA
| | - Pieter SA Beck
- />Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540-1644 USA
| | - Shadrack M Ngene
- />Kenya Wildlife Service, Meru National Park, P.O. Box 11, Maua, Kenya
| | - Andrew K Skidmore
- />International Institute of Geo-information Science and Earth Observation, Hengelosestraat 99, P.O. Box 6, 7500 AA Enschede, The Netherlands
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Pontzer H, Raichlen DA, Rodman PS. Bipedal and quadrupedal locomotion in chimpanzees. J Hum Evol 2014; 66:64-82. [PMID: 24315239 DOI: 10.1016/j.jhevol.2013.10.002] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 09/17/2013] [Accepted: 10/18/2013] [Indexed: 10/25/2022]
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Schanz T, Lins Y, Viefhaus H, Barciaga T, Läbe S, Preuschoft H, Witzel U, Sander PM. Quantitative interpretation of tracks for determination of body mass. PLoS One 2013; 8:e77606. [PMID: 24204890 PMCID: PMC3812993 DOI: 10.1371/journal.pone.0077606] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 09/06/2013] [Indexed: 11/18/2022] Open
Abstract
To better understand the biology of extinct animals, experimentation with extant animals and innovative numerical approaches have grown in recent years. This research project uses principles of soil mechanics and a neoichnological field experiment with an African elephant to derive a novel concept for calculating the mass (i.e., the weight) of an animal from its footprints. We used the elephant's footprint geometry (i.e., vertical displacements, diameter) in combination with soil mechanical analyses (i.e., soil classification, soil parameter determination in the laboratory, Finite Element Analysis (FEA) and gait analysis) for the back analysis of the elephant's weight from a single footprint. In doing so we validated the first component of a methodology for calculating the weight of extinct dinosaurs. The field experiment was conducted under known boundary conditions at the Zoological Gardens Wuppertal with a female African elephant. The weight of the elephant was measured and the walking area was prepared with sediment in advance. Then the elephant was walked across the test area, leaving a trackway behind. Footprint geometry was obtained by laser scanning. To estimate the dynamic component involved in footprint formation, the velocity the foot reaches when touching the subsoil was determined by the Digital Image Correlation (DIC) technique. Soil parameters were identified by performing experiments on the soil in the laboratory. FEA was then used for the backcalculation of the elephant's weight. With this study, we demonstrate the adaptability of using footprint geometry in combination with theoretical considerations of loading of the subsoil during a walk and soil mechanical methods for prediction of trackmakers weight.
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Affiliation(s)
- Tom Schanz
- Lehrstuhl für Grundbau, Boden- und Felsmechanik, Ruhr-Universität Bochum, Bochum, Germany
- * E-mail:
| | - Yvonne Lins
- Lehrstuhl für Grundbau, Boden- und Felsmechanik, Ruhr-Universität Bochum, Bochum, Germany
| | - Hanna Viefhaus
- Lehrstuhl für Grundbau, Boden- und Felsmechanik, Ruhr-Universität Bochum, Bochum, Germany
| | - Thomas Barciaga
- Lehrstuhl für Grundbau, Boden- und Felsmechanik, Ruhr-Universität Bochum, Bochum, Germany
| | - Sashima Läbe
- Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Universität Bonn, Bonn, Germany
| | - Holger Preuschoft
- Abteilung für Funktionelle Morphologie, Institut für Anatomie, Ruhr-Universität Bochum, Bochum, Germany
| | - Ulrich Witzel
- Forschungsgruppe Biomechanik, Lehrstuhl für Maschinenelemente und Konstruktionslehre, Ruhr-Universität Bochum, Bochum, Germany
| | - P. Martin Sander
- Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Universität Bonn, Bonn, Germany
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Rowe MF, Bakken GS, Ratliff JJ, Langman VA. Heat storage in Asian elephants during submaximal exercise: behavioral regulation of thermoregulatory constraints on activity in endothermic gigantotherms. J Exp Biol 2013; 216:1774-85. [DOI: 10.1242/jeb.076521] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Gigantic size presents both opportunities and challenges in thermoregulation. Allometric scaling relationships suggest that gigantic animals have difficulty dissipating metabolic heat. Large body size permits the maintenance of fairly constant core body temperatures in ectothermic animals by means of gigantothermy. Conversely, gigantothermy combined with endothermic metabolic rate and activity likely results in heat production rates that exceed heat loss rates. In tropical environments, it has been suggested that a substantial rate of heat storage might result in a potentially lethal rise in core body temperature in both elephants and endothermic dinosaurs. However, the behavioral choice of nocturnal activity might reduce heat storage. We sought to test the hypothesis that there is a functionally significant relationship between heat storage and locomotion in Asian elephants (Elephas maximus), and model the thermoregulatory constraints on activity in elephants and a similarly sized migratory dinosaur, Edmontosaurus. Pre- and post-exercise (N=37 trials) measurements of core body temperature and skin temperature, using thermography were made in two adult female Asian elephants at the Audubon Zoo in New Orleans, LA, USA. Over ambient air temperatures ranging from 8 to 34.5°C, when elephants exercised in full sun, ~56 to 100% of active metabolic heat production was stored in core body tissues. We estimate that during nocturnal activity, in the absence of solar radiation, between 5 and 64% of metabolic heat production would be stored in core tissues. Potentially lethal rates of heat storage in active elephants and Edmontosaurus could be behaviorally regulated by nocturnal activity.
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Affiliation(s)
- M. F. Rowe
- Biology Department, Indiana State University, Terre Haute, IN 47809, USA
| | - G. S. Bakken
- Biology Department, Indiana State University, Terre Haute, IN 47809, USA
| | - J. J. Ratliff
- Audubon Nature Institute, New Orleans, LA 70118, USA
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Brassey CA, Kitchener AC, Withers PJ, Manning PL, Sellers WI. The Role of Cross-Sectional Geometry, Curvature, and Limb Posture in Maintaining Equal Safety Factors: A Computed Tomography Study. Anat Rec (Hoboken) 2013; 296:395-413. [DOI: 10.1002/ar.22658] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 12/16/2012] [Indexed: 11/09/2022]
Affiliation(s)
| | - Andrew C. Kitchener
- Department of Natural Sciences; National Museum of Scotland; Edinburgh United Kingdom
- Institute of Geography; School of Geosciences; University of Edinburgh; Drummond Street Edinburgh United Kingdom
| | - Philip J. Withers
- Henry Moseley X-Ray Imaging Facility; School of Materials; University of Manchester; Manchester United Kingdom
| | - Phillip L. Manning
- School of Earth; Atmospheric and Environmental Sciences; University of Manchester; Manchester United Kingdom
| | - William I. Sellers
- Faculty of Life Sciences; University of Manchester; Manchester United Kingdom
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Horvath G, Farkas E, Boncz I, Blaho M, Kriska G. Cavemen were better at depicting quadruped walking than modern artists: erroneous walking illustrations in the fine arts from prehistory to today. PLoS One 2012; 7:e49786. [PMID: 23227149 PMCID: PMC3515592 DOI: 10.1371/journal.pone.0049786] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 10/17/2012] [Indexed: 12/03/2022] Open
Abstract
The experts of animal locomotion well know the characteristics of quadruped walking since the pioneering work of Eadweard Muybridge in the 1880s. Most of the quadrupeds advance their legs in the same lateral sequence when walking, and only the timing of their supporting feet differ more or less. How did this scientific knowledge influence the correctness of quadruped walking depictions in the fine arts? Did the proportion of erroneous quadruped walking illustrations relative to their total number (i.e. error rate) decrease after Muybridge? How correctly have cavemen (upper palaeolithic Homo sapiens) illustrated the walking of their quadruped prey in prehistoric times? The aim of this work is to answer these questions. We have analyzed 1000 prehistoric and modern artistic quadruped walking depictions and determined whether they are correct or not in respect of the limb attitudes presented, assuming that the other aspects of depictions used to determine the animals gait are illustrated correctly. The error rate of modern pre-Muybridgean quadruped walking illustrations was 83.5%, much more than the error rate of 73.3% of mere chance. It decreased to 57.9% after 1887, that is in the post-Muybridgean period. Most surprisingly, the prehistoric quadruped walking depictions had the lowest error rate of 46.2%. All these differences were statistically significant. Thus, cavemen were more keenly aware of the slower motion of their prey animals and illustrated quadruped walking more precisely than later artists.
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Affiliation(s)
- Gabor Horvath
- Department of Biological Physics, Physical Institute, Eotvos University, Budapest, Hungary.
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Abstract
Widely accepted relationships between gaits (footfall patterns) and center of mass mechanics have been formulated from observations for cursorial mammals. However, sparse data on smaller or more generalized forms suggest a fundamentally different relationship. This study explores locomotor dynamics in one eutherian and five metatherian (marsupials) mammals-all small-bodied (<2 kg) with generalized body plans that utilize symmetrical gaits. Across our sample, trials conforming to vaulting mechanics occurred least frequently (<10% of all trials) while bouncing mechanics was obtained most commonly (60%); the remaining trials represented mixed mechanics. Contrary to the common situation in large mammals, there was no evidence for discrete gait switching within symmetrical gaits as speed increased. This was in part due to the common practice of grounded running. The adaptive advantage of different patterns of center-of-mass motion and their putative energy savings remain questionable in small-bodied mammals.
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Demes B, O'Neill MC. Ground reaction forces and center of mass mechanics of bipedal capuchin monkeys: Implications for the evolution of human bipedalism. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2012; 150:76-86. [DOI: 10.1002/ajpa.22176] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 09/06/2012] [Indexed: 11/07/2022]
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O'Neill MC, Schmitt D. The gaits of primates: center of mass mechanics in walking, cantering and galloping ring-tailed lemurs, Lemur catta. ACTA ACUST UNITED AC 2012; 215:1728-39. [PMID: 22539740 DOI: 10.1242/jeb.052340] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Most primates, including lemurs, have a broad range of locomotor capabilities, yet much of the time, they walk at slow speeds and amble, canter or gallop at intermediate and fast speeds. Although numerous studies have investigated limb function during primate quadrupedalism, how the center of mass (COM) moves is not well understood. Here, we examined COM energy, work and power during walking, cantering and galloping in ring-tailed lemurs, Lemur catta (N=5), over a broad speed range (0.43-2.91 m s(-1)). COM energy recoveries were substantial during walking (35-71%) but lower during canters and gallops (10-51%). COM work, power and collisional losses increased with speed. The positive COM works were 0.625 J kg(-1) m(-1) for walks and 1.661 J kg(-1) m(-1) for canters and gallops, which are in the middle range of published values for terrestrial animals. Although some discontinuities in COM mechanics were evident between walking and cantering, there was no apparent analog to the trot-gallop transition across the intermediate and fast speed range (dimensionless v>0.75, Fr>0.5). A phenomenological model of a lemur cantering and trotting at the same speed shows that canters ensure continuous contact of the body with the substrate while reducing peak vertical COM forces, COM stiffness and COM collisions. We suggest that cantering, rather than trotting, at intermediate speeds may be tied to the arboreal origins of the Order Primates. These data allow us to better understand the mechanics of primate gaits and shed new light on primate locomotor evolution.
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Affiliation(s)
- Matthew C O'Neill
- Department of Anatomical Sciences, Stony Brook University School of Medicine, Stony Brook, NY 11794, USA.
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Langman VA, Rowe MF, Roberts TJ, Langman NV, Taylor CR. Minimum cost of transport in Asian elephants: do we really need a bigger elephant? J Exp Biol 2012; 215:1509-14. [DOI: 10.1242/jeb.063032] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Body mass is the primary determinant of an animal’s energy requirements. At their optimum walking speed, large animals have lower mass-specific energy requirements for locomotion than small ones. In animals ranging in size from 0.8 g (roach) to 260 kg (zebu steer), the minimum cost of transport (COTmin) decreases with increasing body size roughly as COTmin∝body mass (Mb)–0.316±0.023 (95% CI). Typically, the variation of COTmin with body mass is weaker at the intraspecific level as a result of physiological and geometric similarity within closely related species. The interspecific relationship estimates that an adult elephant, with twice the body mass of a mid-sized elephant, should be able to move its body approximately 23% cheaper than the smaller elephant. We sought to determine whether adult Asian and sub-adult African elephants follow a single quasi-intraspecific relationship, and extend the interspecific relationship between COTmin and body mass to 12-fold larger animals. Physiological and possibly geometric similarity between adult Asian elephants and sub-adult African elephants caused body mass to have a no effect on COTmin (COTmin∝Mb0.007±0.455). The COTmin in elephants occurred at walking speeds between 1.3 and ∼1.5 m s–1, and at Froude numbers between 0.10 and 0.24. The addition of adult Asian elephants to the interspecific relationship resulted in COTmin∝M–0.277±0.046b. The quasi-intraspecific relationship between body mass and COTmin among elephants caused the interspecific relationship to underestimate COTmin in larger elephants.
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Affiliation(s)
| | - Michael F. Rowe
- Biology Department, Indiana State University, Terre Haute, IN 47802, USA
| | - Thomas J. Roberts
- Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, USA
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HURST JONATHANW. THE ELECTRIC CABLE DIFFERENTIAL LEG: A NOVEL DESIGN APPROACH FOR WALKING AND RUNNING. INT J HUM ROBOT 2011. [DOI: 10.1142/s0219843611002459] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This paper documents the mechanical system of the electric cable differential (ECD) leg, and its incorporation into a monopod hopping robot named "Thumper" and a bipedal robot named "Mabel." The ECD leg is designed with physical springs and other passive dynamics to match a mathematically simple, bioinspired mass-spring model, which can exhibit robust and economic walking and running gaits. With this design approach, existing spring-mass theory-based controllers can be used to control the robot. The scientific goals of this work focus on finding an energetically optimal leg stiffness for running, and results from experimentation on Thumper and on a simulation of Thumper are presented.
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Affiliation(s)
- JONATHAN W. HURST
- School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, 204 Rogers Hall, Corvallis, Oregon, 97331-6001, USA
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Hurst JW, Chestnutt JE, Rizzi AA. The Actuator With Mechanically Adjustable Series Compliance. IEEE T ROBOT 2010. [DOI: 10.1109/tro.2010.2052398] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Genin JJ, Willems PA, Cavagna GA, Lair R, Heglund NC. Biomechanics of locomotion in Asian elephants. ACTA ACUST UNITED AC 2010; 213:694-706. [PMID: 20154184 DOI: 10.1242/jeb.035436] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Elephants are the biggest living terrestrial animal, weighing up to five tons and measuring up to three metres at the withers. These exceptional dimensions provide certain advantages (e.g. the mass-specific energetic cost of locomotion is decreased) but also disadvantages (e.g. forces are proportional to body volume while supportive tissue strength depends on their cross-sectional area, which makes elephants relatively more fragile than smaller animals). In order to understand better how body size affects gait mechanics the movement of the centre of mass (COM) of 34 Asian elephants (Elephas maximus) was studied over their entire speed range of 0.4-5.0 m s(-1) with force platforms. The mass-specific mechanical work required to maintain the movements of the COM per unit distance is approximately 0.2 J kg(-1) m(-1) (about 1/3 of the average of other animals ranging in size from a 35 g kangaroo rat to a 70 kg human). At low speeds this work is reduced by a pendulum-like exchange between the kinetic and potential energies of the COM, with a maximum energy exchange of approximately 60% at 1.4 m s(-1). At high speeds, elephants use a bouncing mechanism with little exchange between kinetic and potential energies of the COM, although without an aerial phase. Elephants increase speed while reducing the vertical oscillation of the COM from about 3 cm to 1 cm.
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Affiliation(s)
- J J Genin
- Unité de physiologie et de biomécanique de la locomotion, IEPR, Université catholique de Louvain, Louvain-la-Neuve, 1348, Belgium
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KOKSHENEV VALERYB, CHRISTIANSEN PER. Salient features in the locomotion of proboscideans revealed via the differential scaling of limb long bones. Biol J Linn Soc Lond 2010. [DOI: 10.1111/j.1095-8312.2010.01415.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Integration of biomechanical compliance, leverage, and power in elephant limbs. Proc Natl Acad Sci U S A 2010; 107:7078-82. [PMID: 20351297 DOI: 10.1073/pnas.0911396107] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The structure and motion of elephant limbs are unusual compared with those of other animals. Elephants stand and move with straighter limbs (at least when walking), and have limited speed and gait. We devised novel experiments to examine how the limbs of elephants support and propel their mass and to explore the factors that may constrain locomotor performance in these largest of living land animals. We demonstrate that elephant limbs are remarkably compliant even in walking, which maintains low peak forces. Dogma defines elephant limbs as extremely "columnar" for effective weight support, but we demonstrate that limb effective mechanical advantage (EMA) is roughly one-third of that predicted for their size. EMA in elephants is actually smaller than that in horses, which are only one-tenth their mass; it is comparable to human limb values. EMA drops sharply with speed in elephants, as it does in humans. Muscle forces therefore must increase as the limbs become more flexed, and we show how this flexion translates to greater volumes of muscle recruited for locomotion and hence metabolic cost. Surprisingly, elephants use their forelimbs and hindlimbs in similar braking and propulsive roles, not dividing these functions among limbs as was previously assumed or as in other quadrupeds. Thus, their limb function is analogous to four-wheel-drive vehicles. To achieve the observed limb compliance and low peak forces, elephants synchronize their limb dynamics in the vertical direction, but incur considerable mechanical costs from limbs working against each other horizontally.
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Lemelin P, Cartmill M. The effect of substrate size on the locomotion and gait patterns of the kinkajou (Potos flavus). JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL GENETICS AND PHYSIOLOGY 2010; 313:157-68. [PMID: 20095011 DOI: 10.1002/jez.591] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Diagonal-sequence (DS) gaits, which are very rare among mammals, are common and well documented in primates and some arboreal marsupials. DS walking gaits have been reported in the kinkajou (Potos flavus), which shows ecological similarities with primates and arboreal opossums but lacks prehensile specializations of the hindfoot. Nevertheless, the actual frequency of DS gaits and the functional context in which these gaits occur in this highly arboreal mammal remain unknown. We examined the effect of substrate size on the locomotion and gait patterns of kinkajous by recording gaits in two individuals walking and running on poles of two different diameters and on a runway. Diagonality and limb duty factors were calculated for 534 gait cycles. Kinkajous relied mostly on DS gaits and trots during walking, and increased the diagonality of their gait patterns on thinner substrates. The proposed functional link between locomotion on thin branches and the presence of a grasping, primate-like hindfoot is not supported by these data. However, further analysis of kinkajou gait cycles showed that DS gaits may have advantages overlooked earlier. DS gaits, during walking, minimize the distance between two ipsilateral feet during short periods of unilateral bipedality, and per corollary maximize the distance between two contralateral feet during the much longer periods of diagonal bipedality. Such foot positioning during the gait cycle could be beneficial in walking on a relatively thin substrate and could explain why kinkajous adopt DS walking gaits, especially on thinner poles, despite lacking prehensile specializations of the hindfoot.
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Affiliation(s)
- Pierre Lemelin
- Division of Anatomy, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
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Ngene SM, Van Gils H, Van Wieren SE, Rasmussen H, Skidmore AK, Prins HHT, Toxopeus AG, Omondi P, Douglas-Hamilton I. The ranging patterns of elephants in Marsabit protected area, Kenya: the use of satellite-linked GPS collars. Afr J Ecol 2009. [DOI: 10.1111/j.1365-2028.2009.01125.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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