Computational methods for the kinematic analysis of diarthrodial joints
Allmendinger, Felix; Corves, Burkhard (Thesis advisor); Parenti-Castelli, Vincenzo (Thesis advisor)
Aachen : Publikationsserver der RWTH Aachen University (2015)
Dissertation / PhD Thesis
Aachen, Techn. Hochsch., Diss., 2015
A diarthrodial joint occurs where two or more cartilaginous bone surfaces adjoin and articulate: the surfaces move with respect to one another and forces are transmitted across them. In diarthrodial joint kinematics, the shapes of the articulating surfaces are essential because they constrain their possible relative motion and determine the characteristics of the force transmission.This property of diarthrodial joints is not reflected in ideal joints that are widely used in simulation models of the musculoskeletal system. Imaging-assisted biomechanic studies do measure the bone surface geometry, but are otherwise limited: the subsequent analysis procedures found in the literature operate either on static postures or on the bone motion without taking the surface geometry further into account. For the kinematic analysis of two articulating surfaces in a diarthrodial joint, however, both measured geometry and motion must concurrently be considered. To this end, this thesis proposes computational methods to analyze how and where complex-shaped articulating surfaces interact during their relative motion. These methods are inspired by mechanical engineering approaches to such issues: the articulating surfaces are treated like mechanical components forming a joint in a moving machine. Data measured in a living body cannot directly be fed to algorithms originally derived for the kinematic analysis of machinery. This is because the description of the surface geometry and the relative motion in a diarthrodial joint is more complex than in a man-made technical joint. Hence, the approach in this thesis is two fold: on the one hand, methods are presented that process measured anatomical data such that kinematic analyses become feasible. On the other hand, mechanical engineering methods are generalized in a way that they can operate on a more complex form of surface and motion data.One important novel aspect of the resulting methodology is that the motion and surface geometry measured in a diarthrodial joint are analyzed together. The developed methods are applied to in-vivo measured data of human wrist bones.The result of the proposed methodology are key figures quantifying the surface-surface interaction. These key figures can be computed for healthy joints as well as for joints with a disorder or an implant. Thereby, this thesis contributes both to the understanding of human joint kinematics and to future improvement of medical care.
- Chair and Institute of Mechanism Theory, Machine Dynamics and Robotics