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Ogihara, N.

Publications and source records attributed to Ogihara, N..

2 recordsLinked to original sources

Simulating human foot mechanics during walking based on an anatomically detailed forward dynamic finite element model

PurposeForward dynamic musculoskeletal simulation is a powerful computational approach for investigating the biomechanics of human locomotion. However, existing models often oversimplify foot anatomy, thereby limiting our understanding of the role of detailed foot morphology in gait mechanics. In this study, we developed an anatomically accurate three-dimensional finite element (FE) model of the human foot to simulate its dynamic behavior during the stance phase of walking using an explicit forward dynamics approach. MethodsThe model incorporated detailed representations of bones, soft tissues, ligaments, and the plantar aponeurosis, and was driven by experimentally measured tibial kinematics and estimated muscle forces. ResultsSimulation results reasonably matched experimental data on ground reaction forces, plantar pressure distributions, and bone movements, confirming the models ability to replicate key aspects of foot-ground interactions during walking. Moreover, the model enabled the estimation of internal forces, stresses, and strains in foot structures that are not directly measurable in vivo, offering new insights into the biomechanics underlying foot pathologies. ConclusionsThis study potentially provides a robust framework for exploring the form-function relationship of the human foot, with applications in evolutionary biology, clinical interventions, and the study of locomotor disorders.

bioengineering↗

Skipping without and with hurdles in bipedal macaque: Global mechanics

Macaques trained to perform bipedally used running gaits across a wide range of speed. At higher speeds they preferred unilateral skipping (galloping). The same asymmetric stepping pattern was used while hurdling across two low obstacles placed at the distance of a stride within our experimental track. In bipedal macaques during skipping, we expected a differential use of the trailing and leading legs. The present study investigated global properties of the effective and virtual leg, the location of the virtual pivot point (VPP), and the energetics of the center of mass (CoM), with the aim of clarifying the differential leg operation during skipping in bipedal macaques. Macaques skipping displayed minor double support and aerial phases during one stride. Asymmetric leg use indicated by differences in leg kinematics. Axial damping and tangential leg work did not influence the indifferent peak ground reaction forces and impulses, but resulted in a lift of the CoM during contact of the leading leg. The aerial phase was largely due to the use of the double support. Hurdling amplified the differences. Here, higher ground reaction forces combined with increased double support provided the vertical impulse to overcome the hurdles. Following CoM dynamics during a stride skipping and hurdling represented bouncing gaits. The elevation of the VPP of bipedal macaques resembled that of human walking and running in the trailing and leading phases, respectively. Due to anatomical restrictions, macaque unilateral skipping differs from that of humans, and may represent an intermediate gait between grounded and aerial running.

zoology↗