Thomas K Uchida

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Muscle-driven simulations of human and animal motion are widely used to complement physical experiments for studying movement dynamics. Musculotendon models are an essential component of muscle-driven simulations, yet neither the computational speed nor the biological accuracy of the simulated forces has been adequately evaluated. Here we compare the speed(More)
Computational modeling and simulation of neuromusculoskeletal (NMS) systems enables researchers and clinicians to study the complex dynamics underlying human and animal movement. NMS models use equations derived from physical laws and biology to help solve challenging real-world problems, from designing prosthetics that maximize running speed to developing(More)
Muscles attach to bones via tendons that stretch and recoil, affecting muscle force generation and metabolic energy consumption. In this study, we investigated the effect of tendon compliance on the metabolic cost of running using a full-body musculoskeletal model with a detailed model of muscle energetics. We performed muscle-driven simulations of running(More)
Tools have been used for millions of years to augment the capabilities of the human body, allowing us to accomplish tasks that would otherwise be difficult or impossible. Powered exoskeletons and other assistive devices are sophisticated modern tools that have restored bipedal locomotion in individuals with paraplegia and have endowed unimpaired individuals(More)
Impacts are instantaneous, computationally efficient approximations of collisions. Current impact models sacrifice important physical principles to achieve that efficiency, yielding qualitative and quantitative errors when applied to simultaneous impacts in spatial multibody systems. We present a new impact model that produces behaviour similar to that of a(More)
An online library of computational multibody benchmark problems was presented by Masoudi et al. [3], along with its potential applications in the field and anticipated benefits to the multibody community. The web-based library was initially developed as a collaboration between themark library has since been refined and improved, applying feedback from(More)
a r t i c l e i n f o a b s t r a c t Many mechanical systems of practical interest contain closed kinematic chains, and are most conveniently modeled using a set of redundant generalized coordinates. The governing dynamic equations for systems with more coordinates than degrees-of-freedom are differential-algebraic, and can be difficult to solve(More)
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