Multibody dynamic simulation of knee contact mechanics

Area of Science:

• Biomechanics
• Musculoskeletal Modeling
• Computational Mechanics

Background:

• Current multibody knee models are limited to either quasi-static simulations with deformable contact or dynamic simulations with rigid contact.
• Simultaneous prediction of muscle forces and joint contact pressures is crucial for clinical applications in knee joint degeneration and restoration.

Purpose of the Study:

• To develop a computationally efficient methodology for integrating multibody dynamic simulation with deformable contact knee models.
• To enable accurate prediction of muscle forces and joint contact pressures in knee models.

Main Methods:

• Developed a methodology combining multibody dynamic simulation with deformable contact.
• Prepared articular surface geometry and implemented efficient contact distance calculation and solvers.
• Created an application programming interface for integration with multibody dynamic simulation environments.

Main Results:

• Static analysis of a natural knee model (1 min CPU) showed peak pressure differences between small and large strain models.
• Dynamic simulation of an artificial knee model (10 min CPU) revealed differences in contact pressure due to material nonlinearity.
• Methodology demonstrated computational efficiency for both static and dynamic knee simulations.

Conclusions:

• The proposed methodology successfully combines dynamic simulation with deformable knee contact.
• This approach is a significant step towards creating dynamic musculoskeletal models for in vivo knee motion and loading prediction.
• The methodology supports various knee models and material properties, offering flexibility for research and clinical applications.