3D reconstruction of shoulder muscles in hominoid primates: Correlating scapular attachment areas with muscle volume

Journal of Anatomy, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 4, 2025

Abstract Digital muscle reconstructions have gained attraction in recent years, serving as powerful tools both educational and research contexts. These can be derived from various 2D 3D data sources, enabling detailed anatomical analyses. In this study, we evaluate the efficacy of surface scans accurately reconstructing volumes rotator cuff teres major muscles across a diverse sample hominoids. Additionally, investigate whether origin area, dissection‐based observation, reliably predict volume. Our findings reveal that provide sufficient coverage to reproduce situ muscles. However, volume was estimated less reliably, suggesting with distinct skeletal boundaries may present challenges for accurate reconstruction. Future studies will explore such reconstructed greater precision. Furthermore, identify significant correlation between area supraspinatus, infraspinatus, subscapularis results suggest serve reliable predictor volume, offering indicator estimating size extant extinct insights are particularly valuable paleontological reconstructions, where direct soft tissue evidence is often lacking. By establishing relationship traits our study provides framework evaluating accuracy hominoid species. This approach not only enhances understanding anatomy but also offers new avenues exploring functional morphology taxa.

Language: Английский

---

Reconstructing dinosaur locomotion

Biology Letters, Journal Year: 2025, Volume and Issue: 21(1)

Published: Jan. 1, 2025

Dinosaur locomotor biomechanics are of major interest. Locomotion an animal affects many, if not most, aspects life reconstruction, including behaviour, performance, ecology and appearance. Yet locomotion is one aspect non-avian dinosaurs that we cannot directly observe. To shed light on how moved, must draw from multiple sources evidence. Extant taxa provide the basic principles locomotion, bracket soft-tissue reconstructions validation data for methods hypotheses applied to dinosaurs. The skeletal evidence itself can be used reconstruct posture, range motion mass (segment whole-body). Building reconstructions, musculoskeletal models inform muscle function form basis simulations test performance. Finally, fossilized footprints our only direct record important snapshots extinct animals, shedding speed, gait posture. confident dinosaur requires all four information. This review explores recent work in these areas, with a methodological focus.

Language: Английский

---

Human evolution: Run Lucy, run!

Current Biology, Journal Year: 2025, Volume and Issue: 35(1), P. R9 - R11

Published: Jan. 1, 2025

Language: Английский

---

Passive responses in mouse hind leg locomotion

Current Biology, Journal Year: 2025, Volume and Issue: unknown

Published: March 1, 2025

Language: Английский

---

Quantitative biomechanical assessment of locomotor capabilities of the stem archosaur Euparkeria capensis

Royal Society Open Science, Journal Year: 2023, Volume and Issue: 10(1)

Published: Jan. 1, 2023

Birds and crocodylians are the only remaining members of Archosauria (ruling reptiles) they exhibit major differences in posture gait, which polar opposites terms locomotor strategies. Their broader lineages (Avemetatarsalia Pseudosuchia) evolved a multitude modes Triassic Jurassic periods, including several occurrences bipedalism. The exact timings frequencies bipedal origins within archosaurs, thus their ancestral capabilities, contentious. It is often suggested that archosaurs ancestrally exhibited some form Euparkeria capensis central taxon for investigation locomotion due to its phylogenetic position intermediate skeletal morphology, argued be representative facultative bipedalism this group. However, no studies date have biomechanically tested if bipedality was feasible Eupakeria. Here, we use musculoskeletal models static simulations hindlimb test influences body muscle parameter estimation methods on potential. Our analyses show resulting negative pitching moments around centre mass were prohibitive sustainable bipedality. We conclude it unlikely facultatively bipedal, probably quadrupedal, rendering inference abilities unlikely.

Language: Английский

---

Static versus dynamic muscle modelling in extinct species: a biomechanical case study of the Australopithecus afarensis pelvis and lower extremity

PeerJ, Journal Year: 2024, Volume and Issue: 12, P. e16821 - e16821

Published: Jan. 31, 2024

The force a muscle generates is dependent on structure, in which fibre length, pennation angle and tendon slack length all influence production. Muscles are not preserved the fossil record these parameters must be estimated when constructing musculoskeletal model. Here, we test capability of digitally reconstructed muscles Australopithecus afarensis model (specimen AL 288-1) to maintain an upright, single-support limb posture. Our aim was ascertain that different architectural estimation methods have specialisation subsequent inferences can extrapolated about function. Parameters were for 36 pelvis lower seven models 288-1 produced. These represented either ‘static’ Hill-type ( n = 4 variants) only incorporated force, or instead ‘dynamic’ with elastic fibres could vary force-length-velocity properties 3 variants). Each muscle’s angle, maximal isometric calculated based upon input variables. Static (inverse) simulations computed vertical mediolateral ground reaction forces (GRF) incrementally increased until collapse (simulation failure). All variants produced somewhat similar simulated activation patterns, but maximum GRF exerted single consistent between models. Three four static-muscle unable support >1.8 times body weight under-performed. dynamic-muscle stronger. Comparative results human imply group activations species needed sustain single-limb at maximally applied GRFs terms simplified static e.g. , same walking pose) used here. This approach demonstrated range outputs generated extinct individual. Despite mostly comparable outputs, diverged strength.

Language: Английский

---

Estimation of the forces exerted on the limb long bones of a white rhinoceros (Ceratotherium simum) using musculoskeletal modelling and simulation

Journal of Anatomy, Journal Year: 2024, Volume and Issue: 245(2), P. 240 - 257

Published: April 1, 2024

Abstract Heavy animals incur large forces on their limb bones, due to the transmission of body weight and ground reaction forces, contractions various muscles limbs. This is particularly true for rhinoceroses, heaviest extant capable galloping. Several studies have examined musculoskeletal system bones incur, but no detailed quantification has ever been attempted. Such could help understand better link between form function in giant land animals. Here we constructed three‐dimensional models forelimb hindlimb Ceratotherium simum , rhino species, used static optimisation (inverse) simulations estimate applied when standing at rest, including magnitudes directions. Overall, unsurprisingly, most active were antigravity muscles, which generate moments opposing (thereby incurring force), thus keep joints extended, avoiding joint collapse via flexion. Some an action around several joints, found be highly active, likely specialised support ( ulnaris lateralis ; digital flexors). The humerus was subjected greatest amount terms total magnitude; furthermore came from a great variety radius mainly subject high‐magnitude compressive little muscular tension, whereas opposite pattern observed ulna. femur had similar that humerus, tibia's intermediate, being compression its caudal side tension cranial (i.e. bending). fibula by far lowest force magnitude. estimated consistent with documented morphofunctional adaptations C. simum's long larger insertion areas greater robusticity overall than those lighter rhinos, reflecting intense here. Our estimates muscle bone (joint) loading regimes this tetrapod improve understanding links supportive tissues extended other aspects morphology, such as microanatomy.

Language: Английский

---

A comparative approach for characterizing the relationship among morphology, range-of-motion and locomotor behaviour in the primate shoulder

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 290(2009)

Published: Oct. 17, 2023

Shoulder shape directly impacts forelimb function by contributing to glenohumeral (GH) range-of-motion (ROM). However, identifying traits that contribute most ROM and visualizing how they do so remains challenging, ultimately limiting our ability reconstruct behaviour in fossil species. To address these limitations, we developed an silico proximity-driven model simulate visualize three-dimensional (3D) GH rotations living primate species with diverse locomotor profiles, identify those shapes are predictive of using geometric morphometrics, apply subsequent insights interpret the hominin Australopithecus sediba. We found metrics incorporated 3D best discriminated groups, magnitude (mobility) was decoupled from anatomical location (e.g. high abduction versus low abduction). Morphological enhanced mobility were enabled overhead positions, all non-human apes possessed latter but not necessarily former. Model simulation A. sediba predicted a centred at lower levels than higher modern humans. Together results novel form-to-function relationships shoulder enhance visualization tools past behaviour.

Language: Английский

---

Biomechanical modeling of musculoskeletal function related to the terrestrial locomotion of Riojasuchus tenuisceps (Archosauria: Ornithosuchidae)

The Anatomical Record, Journal Year: 2024, Volume and Issue: 308(2), P. 369 - 393

Published: June 29, 2024

Abstract Riojasuchus tenuisceps was a pseudosuchian archosaur from the Late Triassic period in Argentina. Like other ornithosuchids, it had unusual morphology such as unique “crocodile‐reversed” ankle joint, lesser trochanter dinosaurs and few archosaurs, robust vertebrae, somewhat shortened, gracile forelimbs. Such traits have fuelled controversies about its locomotor function—were limbs erect or “semi‐erect”? Was quadrupedal bipedal, mixture thereof? These seem to persist because analyses been qualitative (functional morphology) correlative (morphometrics) rather than explicitly, quantitatively testing mechanistic hypotheses function. Here, we develop 3D whole‐body model of R. with musculoskeletal apparatus hindlimbs represented detail using new muscle reconstruction. We use this quantify body dimensions hindlimb leverages enigmatic taxon, estimate joint ranges motion functions. Our supports prior arguments that used an posture, parasagittal gait plantigrade pes. However, some our inferences illuminate contradictory nature evidence system —different features support (or are ambiguous regarding) quadrupedalism bipedalism. Deeper biomechanical could move toward consensus regarding ornithosuchid locomotion. Answering these questions would not only help understand palaeobiology bizarre clade, but also more broadly if how) abilities played role survival versus extinction various lineages during end‐Triassic mass event.

Language: Английский

---

Applying 3D Models of Giant Salamanders to Explore Form-function Relationships in Early Digit-bearing Tetrapods

Integrative and Comparative Biology, Journal Year: 2024, Volume and Issue: 64(3), P. 715 - 728

Published: Aug. 2, 2024

Synopsis Extant salamanders are used as modern analogs of early digit-bearing tetrapods due to general similarities in morphology and ecology, but the study species have been primarily terrestrial relatively smaller when earliest were aquatic an order magnitude larger. Thus, we created a 3D computational model underwater walking extant Japanese giant (Andrias japonicus) using photogrammetry open-access graphics software (Blender) broaden range testable hypotheses about incipient stages locomotion. Our protocol represent initial pipeline that could serve “one-stop-shop” for studying locomotor function, from creating models analyzing mechanics gaits. While other pipelines generally require multiple programs accomplish different steps locomotion, our is built entirely within Blender fully customizable with its Python scripting so users can devote more time instead navigating learning curves several programs. The main value approach key kinematic variables (e.g. speed, stride length, elbow flexion) be easily altered on model, allowing scientists test function conduct manipulative experiments lengthening bones) difficult perform vivo. accurate meshes (and animations) generated through also provide exciting opportunities expand abundance diversity digital animals available researchers, educators, artists, conservation biologists, etc. maximize societal impacts.

Language: Английский

---