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bioRxiv · 10.64898/2026.05.11.723556

Muscle-driven hand simulations emphasize the critical role of the extensor mechanism

Carvajal, M.·Murray, W. M.·Miller, L. E.·Firouzabadi, P.·Rizzoglio, F.·Darbhe, V.·Cotton, J.
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Abstract

Biomechanical simulations of complex hand motions remain scarce, due to challenges that span computation and data acquisition. Using a computer vision-based motion capture approach, a 23-degree of freedom musculoskeletal model, and direct collocation optimization, we performed muscle-driven simulations to track hand kinematics from 7 participants performing American Sign Language gestures. While proximal joints were tracked accurately, interphalangeal joint tracking was significantly worse, with a consistent flexion bias. Modifications to finger extensor muscle paths that incorporated the dual-inserting nature of the extensors improved accuracy, suggesting better representation of extensor force distribution across distal joints may be necessary for accurate hand simulations.

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Carvajal, M., Murray, W. M., Miller, L. E., Firouzabadi, P., Rizzoglio, F., Darbhe, V., Cotton, J.. 2026-05-14. Muscle-driven hand simulations emphasize the critical role of the extensor mechanism. https://doi.org/10.64898/2026.05.11.723556

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