Strand-based musculotendon simulation of the hand

• Main Author: Sueda, Shinjiro
• Language: English
• Published: University of British Columbia 2010
• Online Access: http://hdl.handle.net/2429/30506

This dissertation develops a framework for modelling biomechanical systems, with special focus on the muscles, tendons, and bones of the human hand. Two complementary approaches for understanding the functions of the hand are developed: the strand simulator for computer modelling, and an imaging apparatus for acquiring a rich data set from cadaver hands. Previous biomechanical simulation approaches, based on either lines-of-force or solid mechanics models, are not well-suited for the hand, where multiple contact constraints make it difficult to route muscles and tendons effectively. In lines-of-force models, wrapping surfaces are used to approximate the curved paths of tendons and muscles near joints. These surfaces affect only the kinematics, and not the dynamics, of musculotendons. In solid mechanics models, the 3D deformation of muscles can be fully accounted for, but these models are difficult to create and expensive to simulate; moreover, the fibre-like properties of muscles are not directly represented and must be added on as auxiliary functions. Neither of these approaches properly handles both the dynamics of the musculotendons and the complex routing constraints. We present a new, strand-based approach, capable of handling the coupled dynamics of muscles, tendons, and bones through various types of routing constraints. The functions of the hand can also be studied from the analysis of data obtained from a cadaver hand. We present a hardware and software setup for scanning a cadaver hand that is capable of simultaneously obtaining the skeletal trajectory, tendon tension and excursion, and tendon marker motion. We finish with a preliminary qualitative comparison of a simulation model of the index finger with real world data acquired from ex vivo specimen, using the strands framework.