| We
have used rigid body contact modeling to predict the motions of
knee implants during a stepup activity. A three-dimensional, dynamic
simulation of the tibiofemoral and patellofemoral articulations
was created.
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 |
Patterns of muscle activity, initial joint
angles and velocities, and kinematics of the hip and ankle were measured
experimentally and used as inputs to the simulation. Prosthetic knee
kinematics were determined by integration of dynamic equations of
motion subject to forces generated by muscles, ligaments, and contact
at both the tibiofemoral and patellofemoral articulations. The modeling
of contacts between implants did not rely upon explicit constraint
equations; thus, changes in the number of contact points were allowed
without modification to the model formulation. Our simulation has
reproduced experimentally-measured extension of the knee.
We are also developing and using compliant contact
models and finite element analysis to represent articular contacts.
|
Piazza and Delp. Three-dimensional Dynamic Simulation
of Total Knee Replacement Motion During a Stepup Task. Journal of Biomechanical
Engineering, 2001. (Download
PDF) |
